Part 1 out of 2
Produced by by Jon Niehof, Don Kretz, Juliet Sutherland, Charles Franks
and the DP Team
SCIENTIFIC AMERICAN SUPPLEMENT NO. 601
NEW YORK, JULY 9, 1887
Scientific American Supplement. Vol. XXIV, No. 601.
Scientific American established 1845
Scientific American Supplement, $5 a year.
Scientific American and Supplement, $7 a year.
* * * * *
TABLE OF CONTENTS.
I. ASTRONOMY.--A Star Finder.--A simple apparatus that can be
constructed by any mechanic.--1 illustration.
Photographic Study of Stellar Spectra, Harvard College Observatory.
--First annual report of the Henry Draper memorial observations.
--Review of the work by Prof. EDWARD C. PICKERING.
II. BIOLOGY.--Sponges.--The growth and life history of sponges.--Report
of a recent lecture at the London Royal Institution by Dr.
R. VON LEDENFELD.
III. ELECTRICITY.--Phenomena of Alternating Currents.--By Prof.
ELIHU THOMSON.--16 illustrations.
IV. ENGINEERING.--An English Car Coupling.--Description of an
English automatic coupling.--2 illustrations.
A New Process of Casting Iron and other Metals upon Lace,
Embroideries, Fern Leaves, and other Combustible Materials.
--By A.E. OUTERBRIDGE, JR.--A new and eminently practical
process of producing ornamental castings.--4 illustrations.
Bricks and Brick Work.--By Prof. T. ROGER SMITH, F.R.I.B.A.
--The history and technical review of this subject.--A most
remarkable contribution to the engineering of architecture.
Link Belting.--By CHARLES A. SCHIEREN.--An interesting and
practical paper on leather belting made of links.
Recent Progress in Gas Engineering.--A lecture by Mr. A.
MACPHERSON, of Kirkcaldy, reviewing the last improvements
in this branch.
V. MISCELLANEOUS.--Herbet's Tepid Douche.--Apparatus in use
for bathing soldiers in the French barracks.--1 illustration.
Kent's Torsion Balance.--A new type of balance, involving
torsional suspension instead of knife edges.--5 illustrations.
Preservative Liquid.--Note on preservation of organic
The Falls of Gairsoppa.--The great Indian falls, higher than
The New British Coinage and Jubilee Medal.--Illustrations and
descriptions of the new pieces.--8 illustrations.
The Winner of the Derby.--Portrait and description of Merry
VI. NAVAL ENGINEERING.--The Falke Type Torpedo Boat.--The fastest
type of British torpedo boat, constructed by Messrs. Yarrow
& Co.--1 illustration.
The German Navy.--The New Gunboat Eber.--A description of
a late accession to the German navy.--1 illustration.
VII. ORDNANCE AND GUNNERY.--Magazine Rifles.--Continuation of
this important article, including the Chaffee-Reece,
Kropatschek, and other magazine guns.--3 illustrations.
New British Torpedo Experiments.--Experiments with torpedoes
against a ship.--The efficiency or torpedo nets.--The effects of
* * * * *
THE FALKE TYPE TORPEDO BOAT.
Among the different classes of vessels designed for special services,
constructed by Messrs. Yarrow & Co., at Poplar, for the British
government, is one which is stated to be the fastest torpedo boat in her
majesty's navy. This boat has been put through its official trials; with
a load of 15 tons, running continuously for two hours without stopping,
a speed of 23 knots, which is equal to 261/2 statute miles, an hour was
obtained. The boat is 135 ft. long by 14 ft. beam. Its design is known
as the Falke type, being in many respects similar, but very superior, to
a torpedo boat of that name which was built two years ago by the same
firm for the Austrian government. The form of the hull is of such a
character as to give exceptional steering capabilities; at the time of
trial it was found to be able to steer round in a circle of a diameter
of 100 yards, averaging 62 seconds. The forward part of the boat is
completely covered over by a large turtle back, which is the customary
form of the boats built by Messrs. Yarrow & Co. It was first introduced
in the Batoum, which they constructed eight years ago for the Russian
government. This turtle back increases the seaworthiness of the craft by
throwing the water that comes upon it freely away. It forms, also, good
and roomy accommodation for the crew, and incloses a large portion of
the torpedo apparatus. The forward torpedo gear consists of one torpedo
gun, adapted for ejecting the Whitehead torpedo by means of gunpowder,
now preferred on account of its simplicity. The boiler, one of Messrs.
Yarrow & Co.'s special construction, of a type which has undergone many
years of constant trial, is capable of developing 1,660 horse power. In
the engine room there are six engines--one for driving the boat, two for
compressing the air for the torpedoes, an engine for working the dynamo
for producing the electric light, an engine for forcing air into the
stoke-hole, and an engine working in conjunction with the distilling
apparatus for supplying drinking water for the crew and the waste
incidental to the boiler. Aft of the engine room come the officers'
quarters. The stern of the boat is fitted up as a pantry and for the
stowage of ammunition and stores. On the deck are mounted three machine
guns, and near the stern an additional conning tower for use in case of
need, around which revolve two torpedo guns for firing the torpedoes off
either side. These torpedo guns can be trained to any angle it may be
desired to fire them at. On both conning towers are machine
guns.--_Illustrated London News_.
[Illustration: THE "FALKE" TYPE TORPEDO BOAT, AND SECTION SHOWING
* * * * *
THE GERMAN NAVY--THE NEW GUNBOAT EBER.
The gunboat Eber is an improved vessel of the Wolf type, but differs
from other vessels of its class in that it has not a complete iron hull,
only the frame and deck beams being of iron, while the planking is of
wood and yellow metal. No copper is used on the bottom. The "composite
system" of building is looked upon with favor for ships of this kind,
because iron vessels which are kept permanently at stations in the
tropics soon become overgrown in spite of good care, and thus suffer a
great loss of speed. In a wooden vessel the crew's quarters are better
and more healthful than in iron vessels, for they are not as much
affected by the temperature outside of the ship.
The greatest length of the Eber is about 245 ft.; its breadth, 26 ft.;
its depth, 14 ft.; and it has a displacement of about 500 tons. The
armament will consist of three long 5 in. guns in center pivot
carriages, and a small number of revolvers. One of the former will be
placed at the stern on the quarter deck, and the two others on the
forecastle. Some of the revolvers will be on the quarter deck and some
on the forecastle, care being taken to arrange the guns so as to obtain
the widest possible range, thus enabling the ship to protect itself
[Illustration: THE NEW GERMAN GUNBOAT EBER.]
The Eber is provided with a two-cylinder, compound engine, which can
generate 650 horse power, giving the vessel a speed of 111/2 knots. The
coal bunkers are so large that the ship can travel 3,000 miles at a
speed slightly less than that just mentioned without requiring a fresh
supply of coal. The rigging is the same as in iron vessels of the Wolf
class, and the sails are sufficiently large to allow the vessel to
proceed without steam. The ship will carry about 90 men, including
officers, crew, engineers, and firemen.
A sum of $145,000 was appropriated for the construction and equipment of
the Eber, which was begun at Kiel in the latter part of 1885, and was
launched February 15, 1887.--_Illustrirte Zeitung_.
* * * * *
NEW BRITISH TORPEDO EXPERIMENTS.
The torpedo experiments against the Resistance, which have been
suspended since November last, were resumed on June 9 at Portsmouth by
the officers of the Vernon. The injuries received by the ironclad in the
previous experiments having been repaired, so as to make the vessel
watertight, the old ship was towed up the harbor, and moored in Fareham
Creek. Our readers are aware that the Resistance is an obsolete ironclad
which has finished her career as a battle ship, and that nothing could
have converted her into a modern armorclad.
Although it was intended to render the experiments final and conclusive
as a practical demonstration under service conditions of the destructive
effects of the Whitehead torpedo when directed against a modern vessel
of war, the results still leave behind them much uncertainty. The
Resistance was built of iron, whereas battle ships are now exclusively
constructed of steel, and it would be perhaps hazardous to state that
the behavior of the two metals under a sudden and violent shock would be
exactly the same. The construction of the double bottom of the old ship
is also different. Since the last experiments were carried out against
her, however, measures have been taken to make her as far as possible
the counterpart, so far as under water arrangements and coal protection
are concerned, of a modern ship of war.
At the last attack, the Whitehead was directed against the after part of
the hull on the port side in wake of the boilers. During the present
series of experiments the old ship was assailed on the same side, but
directly amidships, in the neighborhood of the engine room. As no steam
was got up in the boilers, the effect of the jar upon the steam pipes,
glands, and feed connections remains a matter of speculation. So far as
the consequences of the burst upon the structure of the hull itself is
concerned, every care was taken to make the ordeal as complete and
instructive as possible. The wing passage, which has a maximum diameter
of 3 ft. diminishing to a point, was left empty, although at the former
experiments the lower portions were filled with coal. But behind this,
and at a distance of 8 ft. from the bulkhead, a longitudinal or fore and
aft steel bulkhead 3/8 in. thick had been worked to a length of 61 ft.,
and, with the coal with which the intervening compartment was packed,
formed (as in recent armorclads) a solid rampart, 20 ft. high, for the
defense of the engine room.
The height of the double bottom between the outer and inner skin plating
is 21/2 ft. The watertight compartments were divided into stations by
means of vertical lightening plates pierced by three holes, and in order
to make them, as far as was practicable, resemble the bracket frames of
a modern armorclad, the center of the plates was cut away so as to leave
a single oval hole instead of the three circular holes. In view of the
differences of opinion which exist on the part of experts on the subject
of under water protection, the officers of the Vernon had determined to
submit the problem to the test of experiment. For this purpose steel
armor 11/2 in. thick had been worked along the outside of the upper skin
of the double bottom throughout one of the compartments, in addition to
the other protection mentioned. The Resistance had been brought down by
iron ballast to a trim of 25 feet 9 in. aft and 19 ft. 7 in. forward,
giving a mean draught of 22 feet 8 inches. She was consequently rather
further down by the stern than before, but was in other respects the
When in commission, the Resistance had a mean draught of 26 feet 10
inches. The present series of experiments was of even greater importance
than the first series. The attack was gradually developed by means of
fixed and outrigger charges of increasing power, and the _coup de grace_
was not given by means of a service Whitehead in actual contact until
various lessons had been derived.
The opening experiment on June 9 consisted of an attack directed against
a new system of torpedo defenses which are to be carried by ships in
action, or when in expectation of an attack, rather than an assault upon
the ship herself. The previous experiments had clearly demonstrated that
a Whitehead, when projected against a vessel at close range, and
consequently with a maximum of motive force, could not get through the
ordinary wire netting before expending its explosive energy in the air,
and that the spars by which the nets are boomed out from the ship's side
could be reduced to 25 ft. in length without danger to the hull. The
ordinary wooden booms employed on board ship, however, are heavy and
unwieldy, weighing, as they do, more than half a ton each. In ordinary
circumstances, the spars cannot be lowered into place and the nets made
taut in less than a couple of hours, and the work of stowing them is
equally slow and laborious.
Mr. Bullivant, who manufactures the torpedo netting and hawsers for the
navy, has devised a method of getting rid of the difficulties complained
of by substituting steel booms for the wooden booms and an arrangement
of pulleys and runners, whereby the protection can be run out and in,
topped and brailed up out of the way, with great facility. The system
was tried at Portsmouth last year with considerable success upon the
Dido, but as it was thought that some of the fittings were somewhat
frail and might collapse beneath the shock of a live torpedo, it was
resolved to submit them to a practical test under service conditions
upon the Resistance. The ship was consequently fitted with three of the
steel booms on the port side. They were 32 ft. long and spaced 45 ft.
apart, and connected by a jackstay to which the nets were attached. Each
steel boom weighed 5 cwt., or less than half the weight of the ordinary
boom, and whereas the latter is fixed to the ship's side by a hook which
is liable to be disconnected or broken by the jerk of an exploding
torpedo, Mr. Bullivant's boom works in a universal or socket joint,
which cannot get out of gear except by fracture, and which permits the
boom to be moved in any direction, whether vertically or fore and aft,
close in against the sides. Below each boom is a flange, which serves as
a line along which a traveler moves, the latter being actuated by means
of a topping line running over a pulley at the head and another near the
Upon the booms being topped to a perpendicular position, the nets are
attached to the runners at the bottom of the booms close inboard
(instead of, under the existing system, to the tops of the booms from
boats alongside or otherwise), and when this is done, the mere
depression of the booms into position will cause the nets to run out of
their own accord. In like manner, when the occasion for their use has
passed, the raising of the boom will cause the nets to come alongside,
when they can either be brailed up through the grummets or disconnected
for future use.
The action of the gear is so simple and rapid that the torpedo
protection can be always ready without arresting the way of the ship. As
a length of net 30 ft. by 20 ft. deep weighs about 3 cwt., it will also
be seen that the reduction of strains by working the crinolines from the
heel instead of the head of the booms is considerable. The attack by the
Whitehead upon the booms and nettings was made shortly before 2 p.m., at
the time of high tide.
The whole affair occupied a very few minutes. As soon as the red pennant
was struck on board to show that Mr. Bullivant was satisfied with the
arrangements, and that the target was ready, the torpedo vessel Vesuvius
got under way, and after circling round the doomed hulk discharged a
Whitehead against the netting from her under-water bow torpedo tube at
an approximate range of 50 yards. As on former occasions, the missile
was one of the old 16 inch pattern, but it was understood that the
charge of gun cotton had been reduced to 87 lb., so that the net
protection should not bear a greater strain than would be the case in
actual hostilities. The torpedo, which was set to a depth of about 10
feet, struck the net in the middle and threw up an immense spout of
water, but without getting to the ship, which was apparently uninjured.
Although it hit the net immediately below the center boom, no fracture
occurred, and the points remained intact. Although at the short range
the torpedo would spin through the water at from 30 to 40 horse power,
and would deliver a formidable blow upon the net, the thrust was
effectually resisted, though as a matter of course the net was much torn
by the explosion of the baffled projectile.
Although at the second torpedo attack made on the Resistance, the
following day, the offensive power that was brought to bear was quite
exceptional, the victory remained with the ship. The charge exploded was
an exceptionally heavy one. It consisted of 220 lb. of gun cotton. It
was consequently more destructive than any which is ever likely to be
launched against an armorclad much better prepared to resist it than the
obsolete and time-worn Resistance. An idea, however, had got abroad that
the Russians either have or intend to have a locomotive torpedo capable
of carrying the same weight of explosive in its head, and the object of
the experiment was to ascertain what would be the effect of the
detonation of such an enormous charge upon the submerged portions of a
ship of war.
But, while this was no doubt the primary purpose in view, the experiment
also served the secondary purpose of determining the result of the
explosion upon the net defenses of a ship. Mr. Bullivant's booms and
runners, which were found to be scarcely anything the worse from the
ordeal of the previous day, were again used. The damaged net was taken
away and one of the old service grummet nets slung in its place, the
cylinders containing the gun cotton being attached to the jackstay
immediately in front of the battered sides, and 30 feet from the hulk,
and sunk to a distance of 20 feet below the water line, which would
bring it about opposite the bend of the bilge. By 3 p.m. everything was
ready for the explosion of the charge--everybody had cleared out of the
ship while the surrounding small craft drew off to a distance of 300
feet. The charge was electrically fired from a pinnace. The burst was
terrific and the reverberation was heard and the shock distinctly felt
in the dockyard. But the remarkable thing was that the hulk did not
appear to jump in the least, though there was not more than six feet of
water under her keel. That she would not be seriously crippled by the
discharge seems to have been accepted as a foregone conclusion by
Captain Long and the other torpedoists, as the day for the third
experiment had been fixed in advance; but that the steel booms with
their double flange running ways, stays, travelers, and hinges should
have resisted the tremendous jar and upheaval was a genuine surprise for
all concerned, and goes far to prove that except a vessel be taken
unawares, it will be impossible for a torpedo to come into actual
contact with it. At the experiments last year the wooden booms were
unhinged and splintered under a much less violent shock. But the steel
booms employed, though somewhat bent, remained unbroken and in position,
and the joints were quite uninjured. All that is necessary for perfect
defense is that the booms should be made a little heavier.
The torpedo experiments against the Resistance were resumed on June 13,
when the old ironclad suffered some rough treatment. As the experiment
was understood to be the last of the second series, and was fully
expected to have a sensational termination, a considerable number of
interested spectators were attracted to the scene in Fareham Creek. The
torpedoists resorted to severe measures, but with a distinctly useful
purpose in view, having bound the ship hand and foot, so to speak, in
such a way that her name became a solecism. They exploded 95 lb. of gun
cotton 20 ft. below the water, and in contact with her double bottom.
This amount of explosive represents the full charge of the old pattern
16 in. Whiteheads; but as the hulk was, for prudential reasons, moored
close to a mud bank, and as the water was consequently much too shallow
to allow of a locomotive torpedo being set to run at the required depth,
a fixed charge was lashed fore and aft against the bottom plating of the
ship and electrically exploded from No. 95 torpedo boat.
In previous experiments this year the ironclad was attacked on the port
side, which had been specially strengthened for the occasion, and the
result was a victory for the defense. On June 13 the starboard side was
selected for attack, in order that a comparison might be instituted with
the effects produced under different conditions by a similar experiment.
Last year in the latter case the double bottom was filled with coal; and
after the charge, which was lashed against the ship in the same way, had
been exploded, it was found that the bilge keel had been shivered for a
length of 20 ft., while the lower plating had been much bulged above the
bilge keel. Four strakes of the skin plating extending up to the armor
shelf had also been forced inward and fractured where they crossed the
longitudinal frames. They had parted in the middle for a distance of 8
ft., while some of the butts had been opened so that gashes 2 in. or 3
in. wide appeared between them. The coal had been pulverized and
scattered in all directions, and other internal damage inflicted.
Nevertheless, the watertight bulkheads remained intact, and by confining
the influx of water to a single compartment so much buoyancy was
preserved that, though the ship heeled over to starboard and was maimed,
she remained afloat, and might have continued to fight her guns,
provided always that no injury had been sustained by her machinery, a
point which these experiments do not touch. Crippled, however, as she
was, it was thought at the time (and the probability was strengthened by
subsequent examination of the ship in dock) that the coal, instead of
being a protection to the double bottom, had in reality proved a source
of weakness by receiving the energy of the explosion from the outer
plating and communicating it to the inner plating, and so distributing
it throughout the submerged portions of the hulk.
The question was sufficiently important to demand an experimental
solution; hence the _raison d'etre_ of the present demonstration. The
double bottom, which is about 21/2 ft. deep, was consequently kept empty,
and the torpedo placed in immediate contact with it in such a manner
that, being overhung by the contour of the hull, the ship would feel the
full force of the upward as well as the lateral energy of the charge. On
other accounts the importance of the experiment was obvious, for,
although it had been ascertained that torpedo nets were capable of
protecting a battle ship from the bursts of the heaviest locomotive and
outrigger charges, it might happen, of course, that the nets would be
rent or displaced by shell fire or swept away by a grazing ram or even
attacked by a double torpedo, the second passing through the gashes made
by the explosion of the first in any case. It was, therefore, of urgent
necessity that the effect of a torpedo bursting in immediate contact
with a ship's bottom should be practically and clearly determined. The
charge on June 13 was fired just before 5 p.m. in the wake of the
boilers, and it was soon perceived that something of a fatal character
had taken place from the appearance of coal dust sweeping up through the
hold. The report had not the dull boom to which the spectators had
become accustomed. Instead of this, the gun cotton exploded with a
sharp, angry, whistling noise, while the manner in which the mud was
churned up showed that the force of the rebound was terrific. The ship
lifted bodily near the stern, after which it was seen to leisurely heel
over to starboard some eight or ten degrees, and finally repose, though
not until the tide fell, upon the mud. The old hulk had been mortally
wounded at last.
A complete knowledge of the disaster which has overtaken her (says the
correspondent of the London _Times_, to which we are indebted for the
above particulars) will not be obtained until a careful investigation
has been made of the hull in dock. But, from a hasty exploration which
was conducted on board, it was evident that the shot had not only
dislocated the inner plating of the double bottom, but had penetrated
the bunker compartment, stored as it was with coal, that the watertight
doors and compartments had ceased to operate, and that water was flowing
into the hull through a hundred crevices. To such an extent was this the
case that, though a strong working party was at hand ready for any
emergency, it was deemed useless to attempt to free the ship of water
until her gashes had been temporarily closed from outside. When this has
been done, she will be pumped out and brought into dock for careful
examination. From what has been said, it will be seen that while the
explosion of 95 lb. of gun cotton in actual contact last November simply
crippled the Resistance, the explosion of a like charge at the same
spot, and under approximately the same conditions, has in this instance
not simply disabled, but really sunk the ship.
* * * * *
AN ENGLISH CAR COUPLING.
The new automatic railway coupling illustrated below is the invention of
Mr. Richard Hill, and has been practically developed by Mr. B.H.
Thwaite, of Liverpool. It will be seen that the system is somewhat
similar to the parallel motion when in action.
The catch and peculiarly shaped hooks slide over the cross and catch
bars. These latter turn horizontally on a central pivot attached to the
jaw end of the drawbar. The cross catch bars adjust themselves to the
direction of the line of pull in the drawbar. The cranking of the
drawbar allows for the deflection of the buffer springs.
The arrangement of uncoupling, or throwing hooks out of gear, is
extremely simple and effective. The cranked part of the rod passing
across the end of the wagon, and with handles at each end workable from
the 6 ft. way, is attached to the catch hooks by means of a light chain.
On throwing the handle over, and against the end of the wagon, the crank
moves over and below the center, lifting up the catch into a position
out of range of action, and from this position it cannot fall except it
is released by the shunter. A shackle and links hang from the end of the
drawbar for attachment to ordinary wagons.
After a long and costly series of experiments the form of coupling shown
in illustration was adopted. Part of the experimental couplings used
were made by the Hadfield Steel Foundry Company, but the couplings used
at a recent trial at Gloucester were forged by the Gloucester Wagon
[Illustration: AN ENGLISH CAR COUPLING.]
The trial couplings were applied to old and worn-out coal wagons,
varying in relative heights and widths of buffers, and the tests were:
1. Coupling and uncoupling, and passing coupled round curves of less
than two chains radius. 2. Coupling under rapid transit movement and
violent shock. 3. Coupling under slow movement, the wagons being shunted
together by two shunters. 4. Wagons brought violently together while the
coupling hooks were lifted out of action, to test the rigidity of the
hooks in this position. 5. Tested in competition with the ordinary
The trial was a success. The new automatic coupling satisfactorily
underwent the various conditions, and it was proved that: 1. It can be
lifted out of action with one hand and quite easily. 2. It can be
coupled and uncoupled six times as fast as with the pole hook in the
daytime. At night this advantage would be considerably increased.
The coupling is strong as well as elastic in its parts, and adjusts
itself to the various conditions of traction.--_Engineering_.
* * * * *
[Continued from SUPPLEMENT, No. 597, page 9539.]
_Chaffee-Reece Magazine Rifle_.--We do not insert a drawing of this
arm--one of the three selected by the American board--as it belongs to
the same class and is similar in general construction to the Hotchkiss.
There is, however, an important difference in the magazine, which has no
spiral spring, but is furnished instead with an ingenious system of
ratchet bars. One of these carries forward the cartridge a distance
equal to its own length at each reciprocal motion of the bolt, while a
second bar has no longitudinal motion, but prevents the cartridges from
moving to the rear in the magazine tube after they have been moved
forward by the other bar. The magazine is loaded through an aperture in
the butt plate, the opening of the spring cover of which causes the two
ratchet bars to be depressed, so that the magazine can be filled by
passing the cartridges along a smooth middle bar. The act of closing the
spring cover again brings the two ratchet bars into play.
[Illustration: FIG. 9.--KROPATSCHEK MAGAZINE GUN]
By means of a cut-off the ratchet bars can be prevented from acting, and
the piece used as a single loader.
_Kropatschek Magazine Rifle_.--This rifle, which is the small arm of the
French navy, has a bolt-action rifle resembling the Gras (see Fig. 9).
The magazine is a brass tube underneath the barrel, as in the
Winchester, Vetterli, Mauser, and other rifles of class 1. It contains
six cartridges, while a seventh can be placed in the trough or carrier,
When the breech is opened by pulling back the bolt, a projection on the
latter strikes the carrier at N, causing its front extremity to raise
the cartridge into the position shown in the section. This movement is
accelerated by the spring, A, acting against a knife-edge projection on
the trough, T; in the upper position of the trough, the spring acts upon
one face of the angle, and upon the other face when in the lower
On closing the breech, the bolt pushes the cartridge into the chamber,
and when the handle is locked down to the right, a part of the bolt
presses against a stud, and thus depresses the trough to be ready to
receive another cartridge from the magazine.
The magazine can be cut off and the rifle used as a single loader by
pushing forward a thumb-piece on the right side of the shoe. The effect
of this is that, on turning down the handle to lock the bolt, the latter
does not act on the stud to depress the carrier, so that no fresh
cartridges are fed up from the magazine.
[Illustration: FIG. 10.--LEE MAGAZINE GUN]
There is a projection, Z, on the fore part of the carrier, which keeps
the next cartridge from leaving the magazine while the trough is in the
upper or loading position. A supplementary cartridge stop, R, pivoted at
P and having a spring, L, underneath it, acts in conjunction with Z in
retaining the cartridges in the magazine, and especially in preventing
more than one at a time from passing out into the carrier when the
latter is depressed; it also retains the cartridges in the magazine tube
while the latter is being filled.
_Lee Magazine Rifle_.--This arm (see Fig. 10), which occupied the place
of honor in the report of the American "Board on Magazine Guns,"
embodied two new principles of considerable importance, viz., the
central position of the magazine, and having it detachable with ease, so
that two or more magazines can be carried by the soldier.
The breech action of the Lee does not materially differ in design from
other bolt rifles, except that the bolt is in two pieces only--the body,
or bolt proper, and the hammer or cocking-piece. The firing pin, or
striker, is screwed into the hammer; the spiral main spring, which
surrounds the striker, is contained in a hollow in the body. The handle
is placed at the rear end of the bolt, and bent down toward the stock,
so as to allow the trigger to be reached without wholly quitting hold of
the bolt. The extractor is so connected with the bolt head as not to
share the rotation of the latter when the handle is turned down into the
locking position. When the handle is turned up to unlock the bolt, the
hammer is cammed slightly to the rear, by means of oblique bearings on
the bolt and hammer, so as to withdraw the point of the striker within
the face of the bolt. This oblique cam action also gives great power to
the extractor at first starting the empty cartridge case out of the
The magazine, M, is simply a sheet iron or steel box of a size to hold
five cartridges, but there seems no reason why it should not be of
larger dimensions. It is detachable from the rifle, and is inserted from
underneath into a slot or mortise in the stock and in the shoe, in front
of the trigger guard. A magazine catch, C, just above the trigger guard,
engages in a notch, N, in the rear of the magazine, the projection, L,
first entering a recess prepared for it in the shoe. There is a magazine
spring, D, at the bottom of the magazine box which pushes the cartridges
up into the shoe. The point of the top cartridge is pushed into the
projection, L, and this keeps the lower cartridges in their places in
the box while the latter is detached; when the magazine is inserted in
the rifle, the withdrawal of the bolt causes the top cartridge to be
slightly drawn back, so that it is now free to be fed up into the shoe
by the magazine spring, D.
There is a later pattern of magazine, which has its front face quite
plain, with no projection, L, as the magazine catch was found sufficient
to hold the box in its place. To prevent the cartridges being pressed
out of the magazine before the latter is inserted in the rifle, there is
a strong spring placed vertically in one side of this box, the curved
upper end of which bears upon the top cartridge; when the magazine is in
its place in the shoe, this side spring is so acted upon that it ceases
to hold down the cartridges in the box.
To use the rifle as a single loader, formerly the magazine had to be
detached, when a spring plate in the shoe, which is pushed aside by the
insertion of the magazine, starts back into its place and nearly fills
the magazine slot, so as to prevent cartridges falling through to the
ground when fed into the chamber by hand. The later pattern, however,
has two notches on the magazine for the catch, C, to engage in. When the
magazine is inserted in the slot only as far as the upper notch, the
rifle can be used only as a single loader, but on pressing the box home
to the second notch, the magazine immediately comes into play.
The magazine can be released from the slot by an upward pressure on the
lower projecting end of the magazine catch, C, which is covered by the
_Improved Lee_.--This rifle is precisely similar in principle to the
Lee, the chief difference being that the magazine is permanently fixed
in its slot underneath the shoe, and in front of the trigger guard. The
cartridges are inserted from above. There is a stop by means of which
the cartridges can be prevented rising up into the shoe, and which forms
a sort of false bottom to the slot in the latter, so that the arm can be
used as a single loader.
_Lee-Burton_.--The bolt action is the same as the Lee, but the box
magazine is attached to the right side of the shoe, instead of being
underneath, as in that rifle. When the magazine is raised to its higher
position, the cartridges pass successively into the shoe by the action
of gravity alone, and are thus pressed home into the chamber by the
closing of the bolt.
[Illustration: FIG. 11.]
A number of the Lee-Burton and improved Lee rifles are now being
manufactured for issue to the troops, in order to undergo experimental
trials on an extended scale.
Several other magazine rifles have the box central magazine, but placed
in different positions as regards the shoe and the axis of the bore. In
the original pattern of the Jarman (Sweden and Norway), the magazine is
affixed to the upper part of the shoe, inclined at a considerable angle
to the right hand (see vertical cross section, Fig. 11). Here the
operation of gravity obviates the necessity of a magazine spring, but
the magazine was found to be very much in the way and liable to be
injured. It has therefore been replaced by a magazine underneath the
barrel, as in the Kropatschek and other rifles.--_Engineering_.
(_To be continued_.)
* * * * *
For a few weeks' preservation of organic objects in their original form,
dimensions, and color, Prof. Grawitz recommends a mixture composed of 21/2
ounces of chloride of sodium, 23/4 drachms of saltpeter, and 1 pint of
water, to which is to be added 3 per cent. of boric acid.--_Annales des
* * * * *
KENT'S TORSION BALANCE.
The United States Torsion Balance Company, of New York, has recently
brought before the public a new form of balance which presents so many
ingenious and excellent features that we illustrate it below, on the
present page. The instrument in its simplest form is shown in Fig. 1. It
consists of a beam, A, which is firmly attached to a wire or band, B, at
right angles to it, and which wire is tightly stretched by any
convenient means. Then, since the wire and beam are both horizontal in
their normal position, and since the center of gravity of the beam is
immediately above or below the middle line of the wire, the torsional
resistance of the latter tends to keep the beam horizontal and to limit
its sensitiveness. When the beam is deflected out of its horizontal
position and the wire thereby twisted, the resistance to twisting
increases with the arc of rotation. To counteract this resistance and to
render the beam sensitive to a very slight excess of load at either end,
a poise, D, is attached to the beam by a standard, C, which poise
carries the center of gravity of the structure above the axis of
rotation. This high center of gravity tends to make the beam "top
heavy," or in unstable equilibrium. By properly proportioning the poise
and its distance above the wire to the resistance of the wire, the
top-heaviness may be made to exactly neutralize the torsional
resistance, and when this is done the beam is infinitely sensitive.
[Illustration: KENT'S TORSION BALANCE. Fig 1.]
The moment of the weight or its tendency to fall increases directly as
the sine of the arc of rotation, while the torsional resistance
increases as the arc, and for small angles the sine and the arc are
When arranged as in Fig. 1, the scale is balanced only when the center
of gravity of the structure is vertically above the middle line of the
wire, and the support of the scale must be leveled in the direction of
the beam, so as to cause the center of gravity to take this normal
position. After the scale is thus leveled, if from any cause whatever,
such as shifting the scale on a table, or shifting the table itself, the
scale support is thrown out of level, the center of gravity of the poise
and beam is shifted from the vertical line above the support, and its
moment immediately becomes greater than the torsional resistance, and
the beam tips out of balance, and cannot be used as a correct scale
until the support is again leveled.
[Illustration: KENT'S TORSION BALANCE. Fig 2.]
In spite of all the foregoing facts, it was reserved for the
"Encyclopedia Britannica," in its ninth edition, to use the following as
the result of its condensed wisdom:
"In the torsion balance proper, the wire is stretched out horizontally,
and supports a beam so fixed that the wire passes through the center of
gravity. Hence the elasticity of the wire plays the same part as the
weight of the beam does in the common balance. An instrument of this
sort was invented by Ritchie, for the measurement of very small weights,
and for this purpose it may offer certain advantages; but clearly if it
were ever to be used for measuring larger weights, the beam would have
to be supported by knife edges and bearing, and in regard to such
applications therefore (as in serious gravimetric work), it has no
[Illustration: KENT'S TORSION BALANCE. Fig 3.]
This would seem to settle the whole case, for if the encyclopedia says
it has no reason to be, then, like the edict of the Mikado, it is as
good as dead, and if that is the case, "Why not say so?" On the
contrary, the torsion balance seems very much alive. But as it is not
very generally known, perhaps the early history of this form of balance,
briefly sketched, may prove of interest.
One of the first forms of the torsion balance which met the disapproval
of the "Encyclopedia Britannica" was attended with the difficulty that
the pivoted wires were attached directly to the bifurcated ends of the
beam, and could not be tensioned without bending these ends unless the
beam was made so heavy as to interfere with its employment in delicate
[Illustration: KENT'S TORSION BALANCE. Fig 4.]
The next step was the substitution of light forms stiffened by the wires
being tensioned over them. This was the invention of Professor Roeder,
recently deceased. The next step was the common counter scale, and then
that form of letter scale in which one of the bands acts as a fulcrum
and the other as a pivot.
After Professor Roeder's death, Dr. Alfred Springer, of Cincinnati,
continued perfecting this invention, and with marked success--scales not
intended for anything but the weighing of the ordinary articles of a
grocery store working so accurately that up to 50 lb. two grains would
turn the balance.
As will be noted, this balance dispenses entirely with knife edges, and
this statement carries with it the gist of its entire merit. There is no
friction, and the elegance of the work and the nice adjustments of the
parts struck the writer at once.
[Illustration: KENT'S TORSION BALANCE. Fig 5.]
The prescription scale and the proportional scale (see Fig. 4) are
particularly interesting. The former is sensitive to 1/64 of a grain,
and the latter, invented by Mr. Kent, is a most ingenious method for
weighing, by which, in a small compass (101/2 in. by 41/4 in. by 33/4 in.), we
have a balance capable of weighing 3 lb. avoirdupois by thirty-seconds
of an ounce.
For ordinary balances on the torsion system, in which extreme
sensitiveness is not needed, the trouble caused by change of level of
the scale is insignificant; but it becomes a matter of importance in
more sensitive scales, such as fine analytical balances in places where
it is impossible to keep the table or support of the scale level, for
instance on shipboard.
To counteract this effect of the change of level, Dr. Alfred Springer
devised the system which is shown in its most elementary form in Fig. 2.
An additional beam, E, with wire, F, and poise, H, on support, C, were
added to the balance, and connected to it by a jointed connecting piece,
J. The moment of the structure, E C H, about its center of rotation was
made equal to the moment of A C D about the center. The wires, B and F,
are attached at their ends to supports which are both rigidly connected
to the same base or foundation. If this base, the normal position of
which is horizontal, is tipped slightly, the weights, C and H, will both
tend to fall in the same direction. But suppose the right hand end of
the base is raised, causing both of the weights to tip to the left of
the vertical, D, tending to fall over, the left tends to raise the right
hand end of the beam, and the connecting piece, J H, also tending to
fall to the left, tends to lower the left hand end of E and the piece,
J. The moments of the structure, E C H, and A B D being equal, and one
tending to raise J and the other to lower it, the effect will be zero,
and J will remain in its normal position.
It is not at all necessary, however, to have the weights and dimensions
of the structure, E C H, equal to those of A B D. All that is necessary
is that the components of the weight of each part of the structure which
act vertically on J shall be equal and opposite. For, if the left end of
the beam, E, is made shorter than the right end of the beam, A, a given
angle of rotation of the beam, A, will cause a greater-angle of rotation
of E, consequently will tip the weight, H, further from the vertical
than the weight, D, is tipped, and in that case the weight, D, must be
made smaller than H, to produce an equal and opposite effect upon J. In
practice it is convenient to make the beam, E, only one-fifth to
one-twentieth as long as A, and to correspondingly reduce the weight, H,
relatively to D. In this case, on account of the angle of rotation of
the beam, E, being greater than the angle of rotation of A, the beam, E,
becomes a multiplier of the indications of the primary beam, A.
Mr. Kent has devised a modification of Dr. Springer's system, which is
shown in Fig. 3. It is applied in those varieties of the torsion balance
in which there are two parallel beams, connected by either four or six
wires. The wire, F, carrying the secondary beam, E, and poise, H,
instead of being carried on an independent support, rigidly attached to
the base, as above described, is attached directly to a moving part of
the balance itself, and preferably to the two beams. In Fig. 3, T T T
are trusses over which are tightly stretched the wires, B B B. A A' are
two beams rigidly clamped to the wires; _t_ is another truss with
stretched wire, F F. The upper wire, F', is attached by means of a
flexible spring and standard, S, to the upper beam, and the lower wire
is attached either directly or through a standard to the lower beam. The
secondary poise, H, is rigidly attached to the truss, _t_. The secondary
beam, E, is also rigidly attached to the truss, and acts as a
multiplying beam. The secondary structure thus completely fills two
functions: First, that of multiplying the angle of rotation and thereby
increasing the apparent sensitiveness of the scale, and, second, that of
overcoming the effect of change of level. The secondary beam may be
dispensed with if a multiplier is not needed, and the secondary truss,
_t_, with its standard and counterpoise, H, used alone to counteract the
effect of change of level. Fig. 5 shows a modification of this extremely
* * * * *
[Footnote: From a paper read before the "Technischen Verein" of New
York, May 28, 1887.]
By CHAS. A. SCHIEREN.
The old saying that "there is nothing new under the sun" may well be
applied to leather link belting. It is generally believed that these
belts are of recent invention, but that is an error. They are over
thirty years old.
Mr. C.M. Roullier, of Paris, experimented that long ago with small
leather links one and one-half inches long by three-quarters of an inch
wide. These links had two small holes at equal distances apart, and were
joined with iron bolts, which were riveted at the ends, thus making a
perfectly flat surface, and in that way forming a belt entirely of
Mr. Roullier's idea was to economize; he therefore utilized the material
left over from the manufacture of flat belting. He perfected his belt
and came to this country in 1862, when he patented the article here and
tried to introduce it. At first it produced quite a sensation, and many
tests were made, but it was soon found that Roullier's belts were not
suited to running our swift motion machinery, and they were therefore
abandoned as impracticable.
Mr. Roullier then introduced his invention into England, where he met
with some success, as his belt was better suited to English slow motion
These belts are now largely used in England, many good improvements have
been made in them, and almost every belt maker in Great Britain
Mr. Jabez Oldfield, of Glasgow, has the reputation of making the best
and most reliable link belt in Great Britain. He has also the reputation
of being the originator of these belts. This is, however, an error, the
credit of the invention belonging, as we have said, to Mr. Roullier.
Mr. Oldfield, nevertheless, has invented many useful machines for
cutting and assorting the links. He has also introduced improved methods
for putting the links together.
For more than twenty years after Mr. Roullier's visit, nothing was done
with leather link belting in this country.
In 1882, however, Mr. N.W. Hall, of Newark, N.J., patented a link belt,
composed of leather and steel links. His method was to place a steel
link after every third or fourth leather one, in order to strengthen the
belt. In practical use this belt was found to be very defective, because
the leather links soon stretched, and thus all the work had to be done
by the steel links. The whole strain coming thus upon the steel links,
they in course of time cut through the bolts and thus broke the belt to
pieces. So this invention proved worthless.
In 1884 a Chicago belt company obtained a patent on another style of
link belt. In this belt all the little holes in the links were lined
with metal, similar to the holes in laced shoes. This produced an effect
similar to that produced by Hall's patent. The metal lining of the holes
cut the bolts into pieces by friction and thus ruined the belt.
Therefore this patent proved a failure also.
After all these failures it fell to our lot to improve these belts so
that they may now be worked successfully on our American fast running
machinery. During the past two years we have made and sold over five
hundred leather link belts, which are all in actual use and doing
excellent service, as is proved by many testimonials which we have
Our success with these belts has been so surprising that we think we
have found, at last, the long looked for "missing link," not in
"Darwinism," however, but in the belting line. We prophesy a great
future for these belts in this country.
How have we attained such success? First: We found that Roullier made a
mistake in using leather offal, as, in the links of an _iron chain_, if
one link is weak or defective, the whole chain is worthless, so in link
belts, if one or two links are weak or made of poor material, the whole
belt is affected by them. It is therefore of vital importance that only
the best and most solid leather be used in making the links; second, the
leather must be made very pliable, but at the same time its toughness
and tenacity must not be injured, or it will stretch and break.
[Illustration: FIG 1.]
These things are of great importance, and are the principal reasons for
the failures of all former efforts. The leather which Roullier used was
stiff, hard, and husky. He believed that the harder the link the greater
its tensile strength, but upon actual test this was found to be a fatal
Our leather links are saturated with a mixture of tallow, neatsfoot oil,
etc. This makes them very pliable and increases their toughness, so that
they will stand a strain three times as great as a piece of hard rolled
In manufacturing this belt, the joining together is important. The links
must be accurately assorted as to thickness, and the outer links
countersunk, to admit the bolt. Then the most valuable improvement of
all is our "American joint" (see Fig. 1).
By close inspection you will observe that it is absolutely necessary to
use half length bolts for the width of wide leather link belts.
Examine Figs. 2 and 3. In the latter you will notice one length of bolt
placed on a round faced pulley. That belt must either bend or break, and
in any case it will not give satisfaction; but, on the other hand,
examine Fig. 2; here two half length bolts are used, and ingeniously
joined in the center. It gives just pliability enough to lay the belt
flat upon the pulley. We experimented for some time before perfecting
this important improvement.
We also took out four patents for different methods of joining, but
abandoned them all and adopted the "American joint" system (Fig. 1) as
the most efficient, simple, and reliable. It gives the belt an unbroken
flat surface and is far superior to anything so far introduced for that
We have not stopped at _flat_ link belting, but have turned our
attention to manufacturing round solid leather link belting, and believe
that we have almost attained perfection in that line. As the
illustrations clearly show, there is quite a demand for inch and upward
solid round belting, and the difficulty always has been to join such a
belt together. All steel hooks, etc., do not seem to satisfy. This, our
new invention, is so simple that it hardly needs explanation. A belt of
this kind can be taken apart in a short time, and shortened or
lengthened at pleasure.
Now, Mr. President and gentlemen, I shall be glad to answer any
questions in reference to these link belts, or give any further
explanation you may desire.
Question.--Can these link belts be used on dynamos for electric lights?
Answer.--Yes. In England they are used almost exclusively on dynamos.
However, they run only 700 revolutions per minute there, whereas our
slowest dynamo runs 1,100.
[Illustration: Fig. 2.]
Quest.--Would you advise link belts for high rate of speed?
Ans.--No; they give better results on slow running machinery.
Quest.--Have these belts any special advantage over flat leather
Ans.--Yes, decidedly. When belts are run half crossed, or what is termed
quarter turn, it is very hard to make flat belts lie perfectly even on
the pulleys. These link belts, however, cover the entire face of the
pulley (see illustration), and therefore are superior for that purpose.
[Illustration: Fig. 3.]
Quest.--Why do they give better results when run slow?
Ans.--Partly because of their great weight over ordinary belting, also
their grip power is stronger when run slow. No belt is superior to them
for slow, hard working machinery.
Quest.--Are they more expensive than ordinary flat belting?
Ans.--Not when compared to the work they can accomplish.
Quest.--Can they be run in wet places, such as mines, etc.?
Ans.--Yes; by waterproofing the leather, no cement being used as in flat
belts. The links can be made positively waterproof. We have furnished
paper mills, tanneries and bleacheries, and other exposed places with
waterproof link belts, and all have been entirely satisfactory so far.
Quest.--Can they be run on ordinary flat pulleys?
Ans.--Yes; our "American joint" link belt can be run on any straight or
rounded pulley, whether made of iron, paper, or wood, and being all
endless they run much smoother than other belting.
[Illustration: ENGLISH HINGE JOINT:]
Quest.--How are they made endless?
Ans.--By a very simple process (see illustration), and takes almost less
time than lacing a flat belt. All that is necessary is to take both ends
and interlock the links, then pass the bolt through and rivet it, and
when you wish to shorten the belt proceed likewise: File off the end of
the bolt and take out, or add rows of links at pleasure and rejoin it
[Illustration: Fig. 4 is a complete round link belt.]
Quest.--What is the relative strength of a link belt compared to flat
Ans.--Nothing definite has yet been ascertained. We are preparing a
table showing results, and so far we can report that they can stand
about twice the strain of double flat belts. A four inch link belt one
inch thick is able to do the work of an eight inch flat double belt.
[Illustration: Fig. 5 is a side view.]
Quest.--Explain the advantage of your American joint over the English
Ans.--The American joint gives a perfect unbroken surface of entire
width of belt, whereas the English hinge joint makes two half widths,
and whenever a sudden change of power occurs and the belt runs half way
off the pulley, it will catch at the edge and tear everything to pieces.
[Illustration: Fig. 6 is an end view.]
Quest.--Have you a table or schedule of their weight per square foot?
Ans.--Yes. The following is as near as we can estimate the weight of
leather link belting per square foot:
1 inch thick, about 5 lb. per sq. ft.
7/8 " " " 41/2 " " "
3/4 " " " 4 " " "
5/8 " " " 31/2 " " "
Upon motion a vote of thanks was passed, and the paper read ordered to
[Illustration: Fig. 7 is a single link.]
* * * * *
A NEW PROCESS OF CASTING IRON AND OTHER METALS UPON LACE, EMBROIDERIES,
FERN LEAVES, AND OTHER COMBUSTIBLE MATERIALS.
[Footnote: Abstract of a paper read before the Franklin Institute,
By A.E. OUTERBRIDGE, JR.
The art of making charcoal--if, indeed, so crude a process is worthy of
being dignified by the name of an art--dates back to a remote antiquity,
and has been practiced with but little change for hundreds of years. It
is true that some improvements have been recently made, but these relate
to the recovery of certain volatile by-products which were formerly
Every one is familiar with the appearance and characteristics of
ordinary charcoal, yet I hope to show you this evening that we still
have something new to learn about its qualities and the unexpected
practical uses to which it may be applied.
We commonly regard charcoal as a brittle, readily combustible substance,
but we have before us specimens in which these qualities are
conspicuously absent. Here is a piece of carbonized cotton sheeting,
which may be rolled or folded over without breaking, and, as you see,
when placed in the flame of a Bunsen burner, the fibers may be heated
white hot in the air, and when removed from the flame, the material
shows no tendency to consume. Here, again, we have a piece of very fine
lace, which has been similarly carbonized, and displays the same
qualities of ductility and incombustibility.
These carbonized fabrics may be subjected to much more severe tests with
impunity; and when I tell you that they have been exposed to a bath of
molten iron without injury, you will readily admit that they possess
some qualities not ordinarily associated with charcoal. When removed
from the mould in which they were placed after the iron casting had
cooled, not a single fiber was consumed, but _upon the face of the
casting there was found a sharp and accurate reproduction of the design,
thus forming a die_. This die may be used for a variety of purposes,
such as embossing leather, stamping paper, sheet metal, etc., or for
producing ornamental surfaces upon such castings.
Some of the carbonized fabrics displayed upon the table are almost as
delicate as cobwebs, and one would naturally suppose that when a great
body of molten metal is poured into a mould in which they are placed,
they would be torn to fragments and float to the surface even though
they were unconsumed, yet such is not the case. I have found in practice
that the most delicate fabrics may be subjected to this treatment
without danger of destruction, and that no special care is needed either
in preparing the mould or in pouring the metal.
By the aid of the megascope, the enlarged images of some of these
castings, showing the delicate tracery of the patterns, will now be
projected upon the screen, and you can all see how perfectly the design
In these experiments, the mould was made in "green sand" in the ordinary
manner, and the fabric laid smoothly upon one face, being cut slightly
larger than the mould, in order that it might project over the edge, so
that when the moulding flask was closed, the fabric was held in its
proper position. As the molten metal flowed into the mould, it forced
the fabric firmly against the sand wall, and when the casting was
removed, the carbonized fabric was stripped off from its face without
injury. In this way several castings have been made from one carbonized
These castings are as sharp as electrotypes, whether made of soft fluid
iron or of hard, quick-setting metal. This peculiarity is owing to the
affinity between molten iron or steel and carbon. The molten metal tends
to absorb the carbon as it flows over it, thus causing the fabric to hug
the metal closely. It is somewhat analogous to the effect of pouring
mercury over zinc. You know that when mercury is poured upon a board, it
runs in a globular form, it does not "wet" the board, so to speak; but
when poured upon a plate of clean zinc, it flows like water and wets
every portion of the zinc, or, as we say, it amalgamates with the zinc.
So when molten iron is poured into an ordinary sand mould, which has
been faced with this refractorily carbonized fabric, it wets every
portion of it, tending to absorb the carbon, and doubtless would do so
if it remained fluid long enough, but as the metal cools almost
immediately, there is no appreciable destruction of the fibers.
The casting which I shall now exhibit represents a very interesting and
novel experiment. In this case, the piece of lace, having open meshes a
little larger than a pin's head, instead of being laid upon one face of
the mould, was suspended in it in such a way as to divide it into two
equal parts. Two gates or runners were provided, leading from the
"sinking head" to the bottom of the mould, one on each side of the lace
partition. The molten iron was poured into the sinking head, and flowing
equally through both runners, filled the mould to a common level. The
lace, which was held in position by having its edges embedded in the
walls of the mould, remained intact. When the casting was cold, it was
thrown upon the floor of the foundry and separated into two parts, while
the lace fell out uninjured, and the pattern was found to be reproduced
upon each face of the casting.
The question naturally arises, Why did not the iron run through the
holes and join together? The answer may be found in the fact that the
thin film of oxide of iron, or "skin," as it is popularly called, which
always forms on the surface of molten iron, was caught in these fine
meshes, and thus prevented the molten metal from joining through the
holes. I have repeated the experiment a number of times, and find that
the meshes must be quite small (not over one fiftieth of an inch),
otherwise the metal will reunite.
I think that this observation explains the cause of many obscure flaws
found in castings, sometimes causing them to break when subjected to
quite moderate strains. We frequently find little "cold shot," or
metallic globules, embedded in cast iron or steel, impairing the
strength of the metal, and it has long been asked, "What is the cause of
this defect?" The pellicles have been carefully analyzed, under the
supposition that they might be alloys of iron and nickel, or some other
refractory metal, but the analysis has failed to substantiate this
theory. Is it not probable that in the process of casting, little drops
of molten metal are sometimes splashed out of the stream, which
immediately solidify and become coated with a skin of oxide, then
falling back into the stream of rapidly cooling metal, they do not
remelt, neither do they weld or amalgamate with the mass, owing to this
protective coating, thus forming dangerous flaws in the casting?
The process of carbonizing the delicate fabrics, leaves, grasses, etc.,
is as follows: The objects are placed in a cast iron box, the bottom of
which is covered with a layer of powdered charcoal or other form of
carbon, then another layer of carbon dust is sprinkled over them, and
the box is covered with a close fitting lid. The box is next heated
gradually in an oven, to drive off moisture, and the temperature slowly
raised until the escape of blue smoke from under the lid ceases. The
heat is then increased until the box becomes white hot. It is kept in
this glowing condition for at least two hours. It is then removed from
the fire, allowed to cool, and the contents are tested in a gas flame.
If they have been thoroughly carbonized, they will not glow when removed
from the flame, and the fibers may even be heated white hot before
Of course, the method employed to carbonize the materials is suspectible
of variation, but the scientific principles involved are unchangeable,
(1) Partial exclusion of air and substitution therefor of a carbon
(2) Slow heating to drive off moisture and volatile elements.
(3) Intense and prolonged heating of the partly charred objects to
eliminate remaining foreign elements, and to change the carbon from the
combustible form of ordinary charcoal to a highly refractory condition.
NOTE.--Fig. 1 is photographed from a white iron casting made upon
carbonized coarse lace; the lower portion of the plate shows the lace
embedded in the iron. Fig. 2 is a casting in gray iron upon lace laid on
an iron plate. Fig. 3 is a casting in hard iron upon lace laid on dand.
Fig. 4 is a casting in gray iron upon a piece of thin summer dress goods
with machine embroidery.
* * * * *
RECENT PROGRESS IN GAS ENGINEERING.
At the recent meeting of Scottish gas managers Mr. A. Macpherson, of
Kirkcaldy, the chairman, said:
THE REGENERATIVE SYSTEM OF RETORT FIRINGS.
For me to attempt, with the time at my disposal, to do full justice to
many important points which have cropped up since our last meeting, and
which will, no doubt, have been engaging your individual attention,
would be impossible. But I think there can be no doubt that, although at
our last meeting we had a very full and interesting discussion on the
different systems of regenerative retort settings, still we might very
profitably spend a little time to-day in hearing the experience of those
who have had some of the systems introduced into their works since then,
or who may have gained further experience with the system they were then
working, or have introduced improvements or modifications thereon.
For the purpose of inducing a discussion on this subject, I will give
you the result of the working of the bench of retorts which I erected
three years ago on the Siemens system. As I stated last year, my
experience up to that time had not been altogether a happy one, but one
of sunshine and cloud alternately. I am glad to be able to say, however,
that since then I have had nothing but the utmost satisfaction in the
working of the regenerative settings. The chief difficulties I have
before experienced were of a mixed nature--choked ascension pipes,
entailing considerable loss of gas; the choking of the orifices from
which the secondary heated air issued to join the producer gas; and the
eating away, in a "scooped-out" sort of fashion, of the brick lining of
the producers at the points where the primary air entered. These, I am
pleased to be able to say, I am now completely clear of; and this has
had the effect of converting what was before a considerable source of
annoyance and anxiety into as perfect a working bench of retorts as any
one could desire.
The results I have obtained have caused me much surprise, being far in
excess of anything I ever anticipated; and the saving effected will
materially assist in compensating for the greatly reduced value of
residuals. I may state that I have used 30 per cent. of fuel on an
average, saved from 25 to 30 per cent. on stokers' wages, and increased
my production of gas per ton of coal; while the regularity of the heats
was a pleasure to look upon.
As showing what I have been able to accomplish, I will give you a few
details. I was able regularly to produce 10,000 cubic feet of gas per
mouthpiece in 24 hours--the size of my retorts being 18 by 13 inches by
9 feet long, inside measure; and on a sudden dullness coming on, with an
increase of first class cannel I produced from 33 retorts 357,000 cubic
feet, or at the rate of 11,500 feet per mouthpiece in 24 hours. With 32
retorts I made as much gas as would have required 42 retorts to produce
on the old system. But I know that even this can be excelled; and I am
aware that there are works where, by the introduction of retorts
measuring 21 by 15 inches, instead of 18 by 13 inches--and which, I may
say, can be put quite easily into the same arch--a production of 12,000
cubic feet per mouthpiece can be obtained. This will, of course, still
further reduce the cost of production.
With such an experience, gentlemen, I think it is almost needless for me
to add that I am a strong advocate of the regenerative system. I have
often heard it asked, "But can the system be profitably adapted to small
works?" In answer to this, I will say I have proved that it can. During
last summer the manager of a small gas works in my neighborhood called
on me regarding the working of this system, and expressed a desire, if
it was at all possible to adapt it to his present settings without much
expense, to try it. I must say I admired his progressive spirit and
pluck; and, after a somewhat lengthy conversation with him, during which
I gathered the full details of his working and his requirements, I
determined to encourage him in his desire to prove if it could be
successfully applied to a works of the size mentioned. The present
setting consisted of three [semicircle] retorts in one arch; and one of
his stipulations to me was: "You must so contrive the setting that if it
should prove a failure I can reconvert it into the old system in a few
hours." I at once saw that the stipulation was reasonable, or he might
be caught in a fix in midwinter. But, with true "Scotch caution" and
forethought, he was, while anxious to experiment, determined not to be
"caught napping." After some consideration, I prepared a sketch for him
of how I thought it could be done, and at the same time comply with his
stipulation; and having received full explanations, he set about it, and
has had it working now for something like six months. His experience has
been somewhat similar to that of most of those who have gone in for the
new system. It did not answer very well at first. But after a little
manipulation and experience in the proper working and management, it is
now acting in first rate style, and is saving fuel, with better and more
regular heats; and this although it is not constructed in such a way as
to yield the best possible results, owing to the before mentioned
stipulation having to be considered and allowed for in construction.
In answer to an inquiry I made the other day, the gentleman referred to
informed me that he has now had this setting in operation for six
months. He has three retorts, 14 by 16 inches, and 8 feet long, in an
oven carbonizing 2 cwt. of coal every four hours; the heats are higher
and more regular; and the retorts easier kept clear of carbon. The coke
drawn from the top retort is sufficient for fuel. My oven would hold
four retorts; and the same fuel would heat this number just as well as
the three. I used only the coke from Cowdenheath parrot coal for this
setting; but had to mix it with Burghlee coke for the old system of
No doubt most of you will have noticed the satisfactory results obtained
by Mr. Hack, of the Saltley Gas Works, Birmingham, and by Mr. McMinn, of
Kensal Green, with the furnaces employed by them for gaseous firing
without recuperation, whereby they are enabled to save fuel and
carbonize more coal per mouthpiece than with the old system. Still they
admit that the saving by this setting is only in fuel, with increased
production, but without any economy of labor--one of the points in favor
of regenerative setting being a saving of at least 25 per cent. in the
latter respect. Even where regenerative settings cannot be had, I think
the system of using gaseous fuel is well worthy the attention of
managers; the expense of altering the existing settings to this method
being very small.
IMPROVEMENTS IN GAS PURIFICATION.
I must now, however, pass on to some other topics. After the proper
production of the gas, we have still the processes of purification to
consider, and how this operation can best be effected at the smallest
cost, combined with efficiency and the least possible annoyance to
residents in the immediate vicinity of gas works. I think all gas
engineers are agreed that in ammoniacal liquor we have a useful and
powerful purifying agent, although each one may have his own particular
idea of how this can be most efficiently applied--some advocating
scrubbers, others washers. But these are things which each one must
determine for himself. But in whatever way it is applied, we know that
it can be profitably used for this purpose; and I am not without hope
that it may soon be found possible to remove nearly all the impurities
by this means.
At present, however, this is not so. And consequently we have a variety
of other methods employed for the complete removal of the impurities.
But, by whatever means it is effected, it is unquestionably the duty of
the gas engineer to send out to the public an article from which the
whole of the impurities have been removed.
In Scotland, no doubt, our chief purifying material is lime, although I
know that several of our friends have for some time been using oxide of
iron, and perhaps they will favor us with their experience and a
statement of the relative cost of lime and oxide. I am not aware that
either the Hawkins method or the Cooper coal liming process has yet
received a trial from any Scotch gas engineer.
BURNERS AND REGENERATIVE LAMPS.
But even after we have been able to produce and send out gas of the
greatest purity, our troubles are frequently only beginning, as, very
often, consumers do not use, but simply waste and destroy the gas by bad
burners and fittings. Nothing, however, will convince them that they are
in any way to blame for the light being poor. I am certainly of opinion
that gas companies would do the public a service in supplying them with
suitable burners for the quality of gas that is being sent out for
consumption. I have myself for some years adopted this policy, and
almost invariably find that complaints cease and consumers are pleased
with the results.
We have now also so large a number of really good regenerative lamps
which give excellent results, and can be made in a great variety of very
neat and ornamental designs, that we ought to endeavor to the utmost of
our power to introduce them to the public, and, if possible, induce them
to use them not only in halls and similar places, but in their dwelling
houses, as with these lamps a most thorough and efficient system of
ventilation can be carried out, by which the heat that is so much
complained of in gas-lighted apartments is reduced to a minimum, and the
atmosphere of such apartments is rendered healthy and agreeable.
With such improved lamps at our command, I think we have nothing to fear
from the competition of the electric light, which during the past year
has not made any very startling advance--generally attributed by
electricians to the restrictive legislation under which they have been
placed. Let us hope this is now about to be removed. I am sure we all
rejoice that such is the case, as all we want is a "fair field and no
favor." We can with confidence await the result.
THE WELSBACH GAS LIGHT.
In the mean time, however, while electricity for lighting purposes has,
to say the least, not made any startling advances, we have, besides the
regenerative lamps before mentioned, the new Welsbach light, which is
exhibited before you to-day, by the kindness of Dr. Wallace; and if the
results said to be obtained by it are at all what they are represented
to be, we certainly have a new departure in gas lighting of no mean
order. Dr. Wallace--a gentleman who is well known to us as one well
qualified to test its merits--has found that the Welsbach burner
produces a light equal to more than 9 candles per cubic foot of gas of
25 candle power, thus nearly doubling the amount of light compared with
gas consumed in the ordinary way.
The construction and manufacture of the burner I have seen described in
these terms: Chemists have been diligently working for many years on the
problem of how to convert into light the highly condensed heat of the
Bunsen burner; and a Vienna chemist now claims to have solved it.
The first condition of the problem was to find a medium on which the
heat could be perfectly concentrated and raised to illuminating power.
Many experiments have been made with platinum in a Bunsen flame, and a
brilliant enough light has been produced, but at a cost altogether
outside commercial use. The Vienna chemist, Dr. Welsbach, has discovered
a composition which is as good a non-conductor--that is to say
concentrator--of heat as platinum, is much more durable, and a great
deal cheaper. The base of it is a peculiar clay, found in Ceylon, which
combines the indestructibility of asbestos with the non-conducting
property of platinum; and having found the incandescent medium, he has
next adapted it to the Bunsen burner.
In this arrangement there is the simplicity of genius. He gets a fine
cotton fabric woven into the shape of a cylinder, with a tapering point.
In its first stage it is about 2 inches in diameter; and after being
coated with the composition, it is subjected to a strong heat. This has
two effects--first, the cotton fiber is completely burned out, while the
composition retains the shape of the woven surface on which it was
moulded. Then the cylinder contracts and solidifies until it becomes
about the size of the forefinger of a glove. Dr. Welsbach calls this his
"mantle;" and by a simple arrangement he fits it on a Bunsen burner, and
places an ordinary lamp chimney over it. When the flame is applied, the
"mantle" becomes incandescent, and gives out a brilliant yellow light,
which, it may be said without exaggeration, will compare favorably with
any electric light yet put on the market.
For decorative effect a pretty frosted globe is used; and by varying the
globe a pure white or a pure yellow may be obtained. It is also added
that there is no act of Parliament required for it, nor even a
provisional order of the Board of Trade. No streets have to be broken up
in order to lay down pipes; and no wires have to be hung across the
roofs of protesting householders.
The whole apparatus can be got ready to fit on an ordinary gas bracket;
and two or three spare frames with "mantles" can be kept in the house in
case of accident. Whoever sees the Welsbach incandescent light in
operation will readily admit that it is the "coming light." It has
beauty, brilliancy, purity, and economy all on its side.
Let us hope (added the chairman) this description is not overdrawn; but
of this you will later on have an opportunity of judging for yourselves.
No doubt the general or even partial adoption of this light would have a
tendency to reduce the consumption of gas, as a smaller quantity would
be required to produce the same amount of illumination. Nevertheless,
gas engineers will hail it with approval if it in any way tends to
popularize the use of gas, and helps to increase the comfort and improve
the sanitation of our houses, churches, halls, etc. Moreover, gas is
continually being adopted for fresh purposes; and we can confidently
look forward to an almost unlimited field in the rapid and ever
increasing use of gas as a fuel and for cooking purposes, as well as for
motive power. The new and really excellent gas engines now being brought
into the market will, no doubt, create a healthy rivalry, and tend to
cheapen these useful machines, and so bring them within the reach of
many persons who have hitherto been prevented from employing them by
their considerable first cost.
PARAFFIN AS A RIVAL OF COAL GAS.
But while the day has gone by when any one of us fears the electric
light as a possible rival, we are not insensible to the fact that
paraffin oil, from its present low-price, is a rival which we cannot
afford to despise. And more especially is this the case in many of the
smaller towns and villages, where the charge for gas is of necessity
higher than in the larger towns.
Doubtless, with oil there is not the same cleanliness as with gas; while
there is also more trouble, attention, and considerable danger attending
its use. Still, in these "hard times," most people are inclined to adopt
the cheapest article, even at the cost of these drawbacks, so as to make
their money go as far as possible.
But not only as an illuminant is it being brought into direct
competition with gas, but also as a fuel and for cooking purposes, as
well as for motive power. And I am inclined to think that the sooner we
set about trying to solve the problem of how to meet this new
competitor, the better.
OIL IN GAS MAKING.
A new departure has also recently taken place in the adoption of oil for
gas making purposes. This, of course, is more fraught with danger to the
coal master than to gas companies, inasmuch as, should this prove to be
a more economical raw material from which to produce illuminating gas
than coal, our present coal gas works could be easily remodeled and
turned into oil gas works. This process has recently been introduced
into a village in Fifeshire. And I have made it a point to visit and
inspect the works, which have been converted into an oil gas works, so
that I might be able to lay a few particulars before you. The process,
however, has not been in operation long enough to enable me to give you
much information on the subject, especially in the way of details of
cost, working expenses, or permanency of the gas under varying and low
temperatures. The patentees claim that they can produce 100 cubic feet
of 60 candle gas from a gallon of oil, or at a cost of 3s. 11d. per
1,000 cubic feet for oil, fuel, and labor; no more expense being
incurred, as the gas does not require purification.
At Colinsburgh (the village alluded to), I was informed that the man
sent by the patentees could produce 100 cubic feet of gas per gallon of
oil; but they had no means of testing the illuminating power. The gas
company's own servant, however, only produced 80 cubic feet per gallon,
which they attributed to his want of experience in knowing the proper
heat at which to work the retorts. Whether or not this was so I cannot
tell; but of this I am certain, that the statement made that the gas
does not require purification will not bear investigation. When I tested
it for sulphureted hydrogen and for ammonia, both were indicated in such
an unmistakable manner as none of us would care to see in our coal gas
as sent out to the consumer.
PRICES OF RESIDUAL PRODUCTS.
What is of far more real consequence to us than the possible change from
coal gas to oil gas, however, as long as we remain manufacturers of the
former, is the value of our residual products, which has suffered so
great and sudden a decline in value, for which various remedies have
been proposed, though none of them, I regret to say, have as yet
restored anything like the former value. A statement of the highest
prices realized for coal tar products, and a comparison with those
obtained on the 30th of March last year and at the same time this year,
may not be uninteresting:
| | Highest | Price on | Price on |
| | Price | March 30, | March 30, |
| | | 1886 | 1887 |
| | per gal. | per gal. | per gal. |
| | L | s. | d. | L | s. | d. | L | s. | d. |
|Crude naphtha | 0 | 4 | 0 | 0 | 0 | 41/2 | 0 | 0 | 81/2 |
|Benzol (90 per cent.)| 0 | 15 | 0 | 0 | 1 | 4 | 0 | 2 | 6 |
|Solvent naphtha | 0 | 2 | 6 | 0 | 1 | 0 | 0 | 1 | 2 |
|Burning naphtha | 0 | 1 | 7 | 0 | 0 | 101/2 | 0 | 0 | 10 |
|Creosote oil | 0 | 0 | 3 | 0 | 0 | 03/4 | 0 | 0 | 1 |
| | | | |
| | per ton. | per ton. | per ton. |
| | L | s. | d. | L | s. | d. | L | s. | d. |
|Pitch | 1 | 14 | 0 | 0 | 15 | 0 | 0 | 12 | 6 |
|Sulphate of ammonia | 21 | 5 | 0 | 13 | 10 | 0 | 11 | 10 | 0 |
This shows a great fall in value from highest to lowest, which seems to
have been touched last year, except in the case of pitch and sulphate of
ammonia, both of which have marked a considerable decline, even since
last year, but it is pleasing to note that the others have shown at
least some slight improvement--crude naphtha and benzol having during
the year risen nearly one hundred per cent. in value. Let us hope that
this is the precursor of a general rise in value from which we shall all
profit. For the purpose of bringing about this much desired end, I
understand that some of the gentlemen present to-day have been burning
their tar in the retort furnaces, and as it will be interesting to know
what success they have attained, I hope some of them will favor us with
their experience on this subject.
In conclusion, let me express the hope that the time is not far distant
when the general trade of the country will attain to its wonted
prosperity, by which every branch of industry will benefit--ours among
the number; and that the hard times we have experienced, now for a
considerable number of years, may not again return.
Discussion next took place regarding the Welsbach incandescence gas
light, which was opened by Mr. McGrilchrist, who remarked on the very
fragile and tender nature of the "mantle," and expressed a hope that in
this direction improvement might be looked for. It was certainly a
beautiful light, and as to its consumption, he stated that the lamp then
shown to the meeting was only burning two cubic feet of gas per hour. [A
voice: Two and two-tenths.] He felt satisfied that it would enable the
manufacturers of gas to compete with paraffin oil, so that with Glasgow
gas they could have such a light as they saw at the rate of 4d. for
about fifty hours.
Mr. W. Key (Tradeston Gas Works) made a statement giving the results of
inquiries he had made at St. Enoch Station Hotel, where the light has
for some time been on exhibition. From the answers given to his
inquiries he spoke rather disparagingly of the lamp, but chiefly on
account of the expense involved in renewing the "mantles" and the glass
chimneys. He admitted, however, that the lamps which he had seen were
placed very unfavorably, being exposed to the action of somewhat violent
draughts, and he subsequently remarked that the lamp was of such a
nature as to effect the complete combustion of the carbon contained in
the gas. The burner must, therefore, be regarded as a great boon--as
_the_ burner, in short.
Mr. D.M. Nelson (Glasgow) gave his experience gained in connection with
the light, remarking that one of the great drawbacks to it was the very
great rarity of the mineral from which the zirconium was obtained. So
scarce was it that it would become dearer than platinum and more
valuable than gold if the lamp came into general use. The light which
the lamp gave out, though it possessed intensity, was deficient in
diffusibility as compared with that given out from ordinary flat flame
gas burners, and this was another objection to it. He argued at some
length against the financial aspects of the scheme which was being
promoted to buy up the Welsbach patents, and to introduce the lamp into
this country. His advice to his friends was not to have anything to do
with the Welsbach company, and, as investors, to be very careful in
accepting all the statements made about the light, which he predicted
would not be a financial success.
Mr. McCrae was strongly opposed to any discussion being raised in regard
to the question being considered in its financial aspects. They, as gas
engineers, did not require to trouble themselves with the doings of
investors. He regarded the Welsbach burner as an improved appliance for
consuming gas. It was an invention which was quite new to him, and as he
was not in possession of any facts which would enable him to condemn it,
he thought they ought, at least, to give it a fair trial. Referring to
the fragile nature of the "mantle," he remarked that there were minds at
work aiming at giving a purer and more brilliant light from gas, and so
far he was of opinion that the light before them was a success. His
opinion as to the diffusibility of the light emitted from the burner
differed from that of Mr. Nelson, as he considered the light possessed
that quality in a high degree. He had no doubt that the minds already at
work on the incandescent light would seek out means for improving the
* * * * *
To varnish chromos, take equal quantities of linseed oil and oil of
turpentine; thicken by exposure to the sun and air until it becomes
resinous and half evaporated; then add a portion of melted beeswax.
Varnishing pictures should always be performed in fair weather, and out
of any current of cold or damp air.
* * * * *
THE NEW BRITISH COINAGE AND JUBILEE MEDAL.
An important addition will be made to the coins now in circulation by
the issue of the double florin, the design of which is shown in one of
our engravings. The reverse is composed of crowned shields, bearing the
arms of the United Kingdom arranged in the form of a cross between
scepters, a device which was first adopted for coins of Charles II. It
was designed by Thomas Simon, the greatest of all English engravers, and
it remains to be seen whether this handsome coin will be generally
popular. The reverse of the florin will for the future bear the same
During the past year her majesty was pleased to signify her pleasure
that a portrait medallion, by Mr. J.E. Boehm, R.A., modeled from life,
should be substituted for the effigy which the coins have hitherto
borne. In the new effigy, her majesty appears crowned and veiled, with
the ribbon and star of the garter and the Victoria and Albert order. The
legend "Victoria Dei Gratia Britanniarum Regina, Fidei Defensor" is
variously arranged on the different coins, according to the exigencies
of the design.
The opportunity has at the same time been taken, with her majesty's
approval, for making certain alterations in the designs for the reverses
of some of the coins by abandoning those which did not appear to possess
sufficient artistic merit to warrant their retention. The reverse of the
sovereign will still bear the design of St. George and the Dragon, by
Pistrucci, first adopted for the sovereigns of George IV., and the
reverses of the half-sovereign and threepence remain unchanged, except
that the crown has been assimilated to that used for the new effigy. The
St. George and the Dragon design will be resumed for the five-pound
piece, the double sovereign, and the crown, this design having been
adopted for these pieces when originally struck. The half-crown will
bear the same reverse as that coin bore when first issued, a design of
considerable merit, by Merlin. During the last half century public taste
appears to have been satisfied, both in this country and abroad, with
some such insignificant design as a wreath surrounding words or figures
indicating the value of the coin; and the shilling and sixpence have,
during the present reign, been examples of this treatment. They will in
future, like the half-crown, bear the royal arms, crowned, and
surrounded by the garter.
The queen was further pleased to command that the fiftieth anniversary
of her majesty's accession should be commemorated by the issue of a
medal. The effigy for this medal, which is also from a medallion by Mr.
Boehm, has a somewhat more ornate veil than that on the coin; and on the
bust, in addition to the Victoria and Albert order, is shown the badge
of the imperial order of the crown of India. The reverse is a beautiful
work by Sir Frederic Leighton, President of the Royal Academy, of which
the following is a description: "In the center a figure representing the
British empire sits enthroned, resting one hand on the sword of justice,
and holding in the other the symbol of victorious rule. A lion is seen
on each side of the throne. At the feet of the seated figure lies
Mercury, the God of Commerce, the mainstay of our imperial strength,
holding up in one hand a cup heaped with gold. Opposite to him sits the
Genius of Electricity and Steam. Below, again, five shields, banded
together, bear the names of the five parts of the globe, Europe, Asia,
Africa, America, and Australasia, over which the empire extends. On each
side of the figure of Empire stand the personified elements of its
greatness--on the right (of the spectator), Industry and Agriculture; on
the left, Science, Letters, and Art. Above, the occasion of the
celebration commemorated is expressed by two winged figures representing
the year 1887 (the advancing figure) and the year 1837 (with averted
head), holding each a wreath. Where these wreaths interlock, the letters
V.R.I. appear, and, over all, the words 'In Commemoration.'"
The issue of both the new coins and the medal began on June 21, the day
appointed for the celebration of her majesty's jubilee.--_Illustrated
[Illustration: THE NEW BRITISH COINAGE AND JUBILEE MEDAL.
1. Half Crown. 2 and 3. Double Florin, reverse and obverse. 4. Double
Sovereign. 5. Shilling. 6. Sixpence. 7 and 8. Jubilee Medal.]
* * * * *
BRICKS AND BRICKWORK.
[Footnote: A recent lecture delivered at Carpenters' Hall, London Wall,
By Professor T. ROGER SMITH, F.R.I.B.A.
Timber, stone, earth, are the three materials most used by the builder
in all parts of the world. Where timber is very plentiful, as in Norway
or Switzerland, it is freely used, even though other materials are
obtainable, and seems to be preferred, notwithstanding the risk of fire
which attends its use. Where timber is scarce, and stone can be had,
houses are built of stone. Where there is no timber and no stone, they
are built of earth--sometimes in its natural state, sometimes made into
bricks and sun-dried, but more often made into bricks and burned.
London is one of the places that occupies a spot which has long ceased
to yield timber, and yields no stone, so we fall back on earth--burnt
into the form of bricks. Brick was employed in remote antiquity. The
Egyptians, who were great and skillful builders, used it sometimes; and
as we know from the book of Exodus, they employed the forced labor of
the captives or tributaries whom they had in their power in the hard
task of brick making; and some of their brick-built granaries and stores
have been recently discovered near the site of the battle of
The Assyrians and Babylonians made almost exclusive use of brickwork in
erecting the vast piles of buildings the shapeless ruins of which mark
the site of ancient Nineveh and of the cities of the valley of the
Euphrates. Their bricks, it is believed, were entirely sun-dried, not
burnt to fuse or vitrify them as ours are, and they have consequently
crumbled into mere mounds. The Assyrians also used fine clay tablets,
baked in the fire--in fact, a kind of terra cotta--for the purpose of
records, covering these tablets with beautifully executed inscriptions,
made with a pointed instrument while the clay was soft, and rendered
permanent by burning. We don't know much about Greek brickwork; but it
is probable that very little brick, if any, was made or used in any part
of Greece, as stone, marble, and timber abound there; but the Romans
made bricks everywhere, and used them constantly. They were fond of
mixing two or more materials together, as for example building walls in
concrete and inserting brickwork at intervals in horizontal layers to
act as courses of bond. They also erected buildings of which the walls
were wholly of brick. They turned arches of wide span in brickwork; and
they frequently laid in their walls at regular distances apart courses
of brick on edge and courses of sloping bricks, to which antiquaries
have given the name of herring-bone work.
The Roman bricks are interesting as records, for it was customary to
employ the soldiers on brick making, and to stamp the bricks with names
and dates; and thus the Roman bricks found in this country give us some
information as to the military commanders and legions occupying
different parts of England at different periods. Flue bricks, for the
passage of smoke under floors and in other situations, are sometimes
found. The Roman brick was often flat and large--in fact, more like our
common paving tiles, known as foot tiles, only of larger size than like
the bricks that we use. They vary, however, in size, shape, and
thickness. Not a few of them are triangular in shape, and these are
mostly employed as a sort of facing to concrete work, the point of the
triangle being embedded in the concrete and the broad base appearing
outside. After the Roman time, brick making seems to have almost ceased
in England for many centuries.
It is true we find remains of a certain number of massive brick
buildings erected not long after the Norman conquest; but on examination
it turns out that these were put up at places where there had been a
Roman town, and were built of Roman bricks obtained by pulling down
previous buildings. The oldest parts of St. Albans Abbey and portions of
the old Norman buildings at Colchester are examples of this sort.
Apparently, timber was used in this country almost exclusively for
humble buildings down to the 16th century. This is not surprising,
considering how well wooded England was; but stone served during the
same period for important buildings almost to the exclusion of brick.
This is more remarkable, as we find stone churches and the ruins of
stone castles in not a few spots remote from stone quarries, and to
which the stone must have been laboriously conveyed at a time when roads
were very bad and wheel carts were scarce.
About the time of the Tudors, say the reign of Queen Elizabeth, the
making of bricks was resumed in England, and many dwelling houses and
some few churches were built of good brickwork in that and succeeding
reigns. We find in such buildings as Hampton Court Palace, St. James'
Palace, and Chelsea Hospital examples of the use of brickwork in
important buildings near London at later dates. The fire of London, in
1666, gave a sudden check to the use of timber in house building in the
metropolis. Previous to that date the majority of houses had been of a
sort the most ornamental examples of which were copied in "Old London"
at the Colonial Exhibition. The rebuilding after the fire was largely in
brick; and in the suburbs, in the latter part of the 17th and the 18th
centuries, many dignified square brick mansions, with bold, overhanging
eaves and high roofs and carved ornaments, entered through a pair of
florid wrought iron high gates, were built, some few of which still
linger in Hampstead and other suburbs. The war time at the beginning of
this century was a trying time for builders, with its high prices and
heavy taxes, and some of the good-looking brick buildings of that day
turn out to have been very badly built when they are pulled about for
alterations. With the rapid, wonderful increase in population and wealth
in this metropolis during the last 50 years a vast consumption of bricks
has taken place, and a year or two back it was reported by the
commissioners of police that the extensions of London equaled in a year
70 miles of new house property, practically all of brick. Brick were
heavily taxed in the war time which I have referred to, and the tax was
levied before burning.
There was a maximum size for the raw brick, which it was supposed served
to keep bricks uniform, and the expectation was entertained that when
the duty came off, many fancy sizes of bricks would be used. This has
not, however, turned out to be the case. The duty has been taken off for
years; but the differences in the size of bricks in England are little
more than what is due to the different rate of shrinkage of brick earth
under burning. It must not, however, be supposed that they have always,
and in all countries, been of about the same dimensions.
The size and proportions of bricks have varied extremely in different
countries and in the same country at different periods. Some bricks of
unusual shapes have also been employed from time to time. Other
countries besides England possess districts which from various
circumstances have been more or less densely built on, but do not yield
much stone or timber; and, accordingly, brickwork is to be met with in
many localities. Holland and Belgium, for example, are countries of this
sort; and the old connection between Holland and England led to the
introduction among us, in the reign of William III., of the Dutch style
of building, which has been in our own day revived under the rather
incorrect title of Queen Anne architecture. Another great brick district
exists on the plains of Lombardy and the northern part of Italy
generally, and beautiful brickwork, often with enrichments in marble, is
to be found in such cities as Milan, Pavia, Cremona, and Bologna.
Many cities and towns in Northern Germany are also brick built, and
furnish good examples of the successful treatment of the material. In
some of these German buildings, indeed, very difficult pieces of
construction, such as we are in the habit of thinking can only be
executed in stone, are successfully attempted in brick. For example,
they execute large tracery windows in this material. Great brick gables,
often with the stepped outline known as crows' feet, are an excellent
architectural feature of these German brick-built towns. In parts of
France, also, ornamental brickwork was from time to time made use of,
but not extensively. It is not necessary to go very minutely into the
manufacture of bricks; but perhaps I ought to say a word or two on the
subject. Good brick earth is not simple clay, but a compound substance;
and what is essential is that it should burn hard or, in other words,
partly vitrify under the action of heat. The brick earth is usually dug
up in the autumn, left for the frosts of winter to break it up, and
worked up in the early spring.
The moulding is to a very large extent done by hand, sometimes in a wet
mould, sometimes in a dry sanded mould, and the bricks are first
air-dried, often under some slight shelter, as the rain or frost damages
them when fresh made; and then, when this process has made them solid
enough to handle, they are burned, and sorted into qualities. The
ordinary or stock brick of London and the neighborhood presents a
peculiarity the origin of which is not known, and which is not met with,
so far as I know, in other parts. Very fine coal or cinders is mixed
with the brick earth, and when the bricks are fired these minute
particles of fuel scattered through the material all of them burn, and
serve to bake the heart of the brick. Stock bricks are burnt in a clamp
made of the raw bricks themselves with layers of fuel, and erected on
earth slightly scooped out near the middle, so that as the bricks shrink
they drop together, and do not fall over sideways.
Most other varieties of bricks are kiln burnt. A very large number of
inventions for making bricks by machinery have been patented. If you
have occasion to look through the specifications of these patents, you
will find four or five main ideas appearing and reappearing, and only
here and there an invention which is to some extent different from the
others. A great majority of these inventions include machinery for
preparing the clay or brick earth, so that it may be dug up and filled
into a receptacle and worked up, screened from pebbles, and made fit for
use in a short time, so as not to have to wait a whole winter. This is
done in some sort of pug mill. A pug mill is a machine consisting of a
large cylinder with a central shaft passing through it from top to
bottom. Knives or blades are arranged spirally on the shaft, and other
blades project into the interior of the cylinder from the walls of it.
The material, after being screened, is fed into this at the top, and
properly moistened. The shaft is caused to rotate, and the blades divide
and subdivide the material, forcing it always downward, so that it at
last escapes at the bottom of the pug mill in a continuous stream of
moist, well worked up clay, issuing with some force. In one type of
machine this clay stream is forced through a square orifice, from which
it comes out of the section of a brick, and by a knife or wire or some
other means it is cut into lengths.
In another type of machine there is a large revolving drum working on a
horizontal axis, with open moulds all round its edge. The clay enters
these moulds, and there is an arrangement of plungers by which it is
first compressed within the mould and then forced out on to an endless
band or some other contrivance that receives it. A third type of machine
has the moulds in the flat top of a revolving table, which, as it turns,
carries each mould in succession first to a part where it is filled from
the pug mill, next to where its contents are compressed, and lastly to
where they are pushed out for removal. However made, the brick, when
moulded, dried, and burnt, and ready for market, belongs to some one
sort, and is distinguished from other sorts by its size, color, quality,
The sorts of brick that are to be met with in the London market are very
varied. To enumerate them all would make a tedious list; to describe
them all would be equally tedious. I will endeavor, however, to give
some idea of the most conspicuous of them. We will begin with that
family of bricks of which the London stock brick is the type. It has
been said these are clamp burnt, and almost all the internal
brickwork--and not a little of the external--of the metropolis is of
stock brickwork. A good London stock brick is an excellent brick for
general purposes, but cannot be called beautiful.
Considering the vast quantity of brickwork done in the metropolis, it is
a matter for congratulation that such sound materials as good stock
bricks, stone lime, and Thames sand are so easily procurable, and can be
had at a price that puts them within the reach of all respectable
builders. When a clamp has been burnt its contents are found to have
been unequally fired, and are part of them underburnt, part well burnt,
part overburnt. They are sorted accordingly into shuffs, grizzles,
stocks of two or three qualities, shippers, and burrs. Several sorts of