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Scientific American Supplement, No. 598, June 18, 1887 by Various

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The Right Hon. Lord Rayleigh lately delivered a lecture at the Royal
Institution upon "The Colors of Thin Plates," a term which he explained was
applied to thin films of substances, such as oily films on the surface of
water or the equally familiar soap bubble. Although the reflection of
colors from the surface of a soap bubble is probably the most noticeable,
yet the "plate" which lends itself most readily for experiment is a film of
air confined between two sheets of glass. If a ray of white light be
reflected from the surface of the film upon a screen, the so-called
Newton's rings, a series of colored concentric rings, are obtained. If,
instead of reflected light, the ray of light transmitted through the film
of air be allowed to fall upon the screen, the same phenomenon is
observable, but the effect is very considerably minimized, owing to the
great preponderance of white light, which overlies as it were the colored
rings. Even in the first instance, as the lecturer was able to show later
on, the colors are not nearly so intense as they may be obtained, owing to
some white light being reflected from the surfaces of the two sheets of
glass. With regard to the appearance of the phenomenon, it is observed that
the part which corresponds to the thinnest part of the film is considerably
darker than the rest of the spectrum; around this is a bright ring of
white, succeeded by constantly increasing concentric rings of different
colors apparently repeating themselves. Lord Rayleigh also obtained the
same results with a film of a solution of soap and glycerine, but in this
case the dark portion was observed at the top of the spectrum, the other
colors arranging themselves in order in the soap film thinned by the force
of gravitation, thus showing that the colors vary according to the
thickness of the film. Another form of the experiment called forth a
considerable amount of applause from the audience. Lord Rayleigh caused a
gentle stream of air to play obliquely upon a soap film, so that the part
struck was moved forward and the whole film rotated. Then with the
alteration of the force of the current of air, which of course regulated
the centrifugal force, alternating thicknesses of film were obtained,
causing a varying display of beautiful colors and combinations of colors.
This last experiment also tended to prove that the bands of color are not
arranged in a certain order, but vary according to the thickness of the
film, a conclusion arrived at by Brewster, who observed that if a film
reflecting certain colors be carefully inverted so as not to disturb the
gravity, the colors reflected are also inverted. Lord Rayleigh explained
the phenomenon by referring to Young's wave theory of light. He regarded
the film as having two surfaces from which light is reflected, an anterior
exterior surface and a posterior interior surface. If a ray of light be
thrown upon the film, a part of the light is reflected from the first
surface, but the greater part is transmitted, and some of this is reflected
from the second surface, passes back through the film, and is combined with
the light reflected from the first surface. If then the light reflected
from the second surface be in the same state of vibration as that reflected
from the first surface, the effect of their combination will be to increase
the amount of light reflected from the first surface, but if otherwise, the
effect will be a partial neutralization of the light reflected from the
first surface. That is to say, if the retardation of the light which is
reflected from the second surface, owing to its twice traversing the
thickness of the film, be equivalent to a wave length of the vibration of
the light, it will increase the intensity of the light reflected from the
first surface. If, however, the retardation be only equivalent to half a
wave length, the intensity of the light will be decreased. Thus, then, with
a ray of monochromatic light it will be seen that the effect of difference
in the thickness of the film will be to alter the intensity of the
reflected ray, but with a white light composed of several colors the result
will be more complicated. As each color has a different wave length in
vibration, it will be seen that each color will act independently of the
others, and a certain thickness of film which, upon the combination of the
two reflected rays, will cause one particular color to be intensified, will
at the same time cause the other colors to be more or less obscured.

Thus as the thickness of the film is altered different colors preponderate,
causing the appearance of rings or bands, according to the nature of the
experiment. The dark appearance on the screen corresponding to the thinnest
part of the film is probably due to refraction of the ray of light
reflected from the second surface, consequent in its passing from a rare
into a denser medium, and again from the denser medium into the rare, which
refraction Lord Rayleigh considers to effect a retardation equivalent to
half a wave length. Lord Rayleigh supported this theory of the formation of
Newton's rings by several interesting experiments. A beam of light was
intercepted by two of Nicol's prisms, one of which acted as a polarizer and
the other as an analyzer of the light, so that no light was able to pass
through both on to the screen. Between the two prisms a double refractive
lens was now placed, in this case a double concave lens of selenite, when
the same series of concentric rings observed with the film of air was
obtained on the screen, only much more intense, while a wedge of selenite
gave the bands of color in the same order as with the soap bubble.

But perhaps the most striking proof of the dependence of the colors upon
the thickness of the film was shown by the reflection of a beam of light
from a piece of mica composed of twenty-four very attenuated plates
overlapping each other. With each layer a marked gradation in color was

The remainder of the lecture was devoted to an explanation of the
determination of the chromatic relations of the colors of the spectrum.
Lord Rayleigh at this point made a rather startling statement that any
color can be produced by two other colors. As an example of such a
formation, a ray of white light was passed separately through a solution of
yellow chromate of potash and an alkaline litmus solution, throwing
respectively a yellow and violet-blue color upon the screen. When the ray
was made to pass through the two solutions successively, an orange-yellow
color was obtained upon the screen, which color Lord Rayleigh asserted to
be made up of red and green rays. To prove this, the ray of white light was
decomposed by means of a prism, and the decomposed rays passed through the
two solutions. The one solution was found to exclude all the yellow and
orange rays from the spectrum, while the other excluded all the blue and
violet rays, so that when the ray had passed through both solutions, only
the red and green rays were left. If, instead of allowing the decomposed
ray of light to pass through a slit, and thus obtain definite bands in the
spectrum, the ray was passed through a circular hole, the red and green
colors overlapped each other on the screen, forming by their combination
the identical orange-yellow color obtained with the primary white light. It
was then stated that if three definite positions be taken in a spectrum in
the red, green, and violet bands respectively, and these positions be
represented by the corners of an equilateral triangle (Clerk Maxwell's
triangle), it has been mathematically determined in what position within
this triangle the colors of Newton's rings would fall. Lord Rayleigh, by
means of a diagram and the selenite wedge, showed that the relations to the
three standard colors in practice were identical with the position assigned
them by theory.

In conclusion, the lecturer showed a piece of glass, the surface of which
had been decomposed, a ray of light transmitted through which showed upon
the screen patches of very pure color. These he considered to be due to the
glass consisting of a number of thin plates, some of which had been removed
by the decomposition.

* * * * *


From time to time, serious accidents have taken place, and the progress of
work stopped, by the sudden snapping of driving belts in machinery, and, as
a general rule, it is found that the collapse is attributable either to
faulty leather or insecure joining. A great improvement of the leather
intended for belts has been brought about during the last few years, by the
introduction of improved processes for currying and the subsequent
treatment. Paterson has worked successfully a patent for rendering belt
leather more pliable, and lessening the tendency to stretch. Under this
treatment the leather is either curried or rough dried, and then soaked in
a solution of wood, resin, and gum thus, or frankincense, first melted
together, and then dissolved, by the application of heat, in boiled or
linseed oil. The leather, after this process, is soaked in petroleum or
carbon bisulphide containing a little India-rubber solution, and is finally
washed with petroleum benzoline. Should the mixture be found to be too
thick, it is thinned down with benzoline spirit until it is about the
consistency of molasses at the ordinary temperature. The leather so
prepared is not liable to stretch, and can be joined in the usual way by
copper riveting, or the ends can be sewn. A good material for smaller
belts, and for strings and bands for connecting larger ones, is that
recently patented by Vornberger, in which the gut of cattle is the basis.
After careful cleansing, the gut is split up into strands, and treated with
a bath of pearlash water for several days. The strands are then twisted
together, and after being dipped in a solution of Condy's fluid, are dried.
They are then sulphured in a wooden box for twenty-four hours, after which
the twisting can be completed. They are by this process rendered pliable,
and can be used in this state for stitching the leather ends of larger
belts, or can be stiffened by plunging them into a bath of isinglass and
white wine vinegar. After drying they are susceptible of a fine polish,
emery cloth being usually employed, and the final "finish" is given to the
material with gum arabic and oil.

Canvas and woven fabrics, coated with India-rubber, are also now being used
for driving belts and for covering machine rollers. As this material can be
made in one piece, without the necessity of a joint, it is uniform in
strength, and is recommended as a substitute for leather belts requiring
joints. A patented material of this description is due to Zingler, who
boils the canvas or similar woven fabric under pressure in a solution of
tungstate of soda for three hours. It is then transferred to a bath of
acetate of lead solution, and drained, dried, and stretched. When in this
condition it is coated, by means of a spreading machine, with repeated
layers of a composition consisting of India-rubber, antimony sulphide,
peroxide of iron, sulphur, lime, asbestos, chalk, sulphate of zinc, and
carbonate of magnesia. When a sufficient thickness of this composition has
been applied, it is vulcanized under pressure at a temperature of 250 deg. F.,
or a little higher. The material produced in this manner is said to have
the strength and durability of the best leather belts. Attempts have
recently been made to obtain a glue suitable for joining the ends of
driving belts, without the use of metal fastenings or sewing, and Messrs.
David Kirkaldy & Son have reported favorably on such a belt glue, which is
being introduced by Mr. W.V. Van Wyk, of 30 and 31 Newgate street, E.C. In
the test applied by them, a joint of this "Hercules glue," as it is called,
in a 4 in. single belt was stronger than the solid leather. When a tensile
stress of 2,174 lb., equivalent to 2,860 lb. per square inch of section,
was applied, the leather gave way, leaving the joint intact. Belts
fastened by a scarf joint with this glue are said to be of absolutely the
same thickness and pliability at the joint as in the main portion of the
belt, and thus insure freedom from noise and perfect steadiness. The
instructions for use are simple, and it requires only fifteen minutes for
the joint to set before being ready for use. From a rough chemical analysis
of the sample submitted to us, we find that it consists of gelatine, with
small amounts of mineral ingredients. Josef Horadam, some few years ago,
patented in Germany a process for preserving glues from decomposition, by
the addition of from 8 to 10 per cent. of magnesium or calcium chlorides.
The addition of these salts does not impair in any way the strength of the
glue, but prevents it from decomposing, and it may be that the "Hercules
glue" is preserved in a similar manner.

A cement of this nature, if thoroughly to be relied on, must be of great
value, although the great variation in the quality of leather, apart from
the difficulty hitherto experienced of securely connecting the ends
together, opens a wide field for a material of uniform composition, and
capable of being made in one piece in suitable lengths for driving belts
and other machine gear.--_Industries._

* * * * *


A large crowd was present recently at the inauguration of the statue of
Denis Papin, which took place in the court of the Conservatoire des Arts et
Metiers, under the presidency of Mr. Lockroy, Minister of Commerce and the

[Illustration: DENIS PAPIN.]

In the large hall in which the addresses were made there were several
municipal counselors, the representatives of the Minister of War, Captains
Driant and Frocard, several members of the Institute, and others. A
delegation from the Syndical Chamber of Conductors, Enginemen, and Stokers,
which contributed through a subscription toward the erection of the statue,
was present at the ceremony with its banner. Mr. Lanssedat, superintendent
of the Conservatoire, received the guests, assisted by all the professors.
Mr. Lanssedat opened the proceedings by an address in which he paid homage
to the scientists who were persecuted while living, to Denis Papin, who did
for mechanics what Nicolas le Blanc did for chemistry, and to those men
whose entire life was devoted to the triumph of the cause of science.

After this, an address was delivered by Mr. Lockroy, who expatiated upon
the great services rendered by the master of all the sciences known at that
epoch, who was in turn physician, physicist, mechanician, and
mathematician, and who, in discovering the properties of steam, laid the
foundation of modern society, which, so to speak, arose from this
incomparable discovery.

Speeches were afterward made by Mr. Feray d'Essonnes, president of the
Syndical Chamber of Conductors, Enginemen, and Stokers, and by Prof.
Comberousse, of the Central School, who broadly outlined the life of Papin.

Along about four o'clock, the Minister of Commerce and the Industries,
followed by all the invited guests, repaired to the court, and the veil
that hid the statue was then lifted amid acclamation.

Papin is represented as standing and performing an experiment.

Upon the pedestal is the following inscription:

BORN IN 1647, DIED ABOUT 1714,
IN 1690


The inauguration is due to the initiative of Mr. Lanssedat, for it was he
who in 1885 suggested the national subscription, which was quickly raised.

Denis Papin was born at Blois on the 22d of August, 1647. He was the son of
a physician. After the example of his father and of several of his
relatives, he studied medicine and took his degree; but his taste for
mathematics, and especially for experimental physics, soon led him to
abandon medicine.

It was in 1690 that he published in the _Actes_ of Leipsic the memoir which
will forever and irrevocably assign to him the priority in the invention of
steam engines and steamboats, and the title of which was: "New method of
cheaply obtaining the greatest motive powers."

In 1704, Papin, poor and obliged to do everything for himself, finished his
first steamboat; but for want of money he was unable to make a trial of it
until August 15, 1707. The trial was made upon the Fulda and Wera,
affluents of the Weser.

The operation succeeded wonderfully, and, shortly afterward, Papin, being
desirous of rendering the experiment complete, put his boat on the Weser;
but the stupid boatmen of this river drew his craft ashore and broke it and
its engine in pieces.

This catastrophe ruined Papin, and annihilated all his hopes. The great
man, falling into shocking destitution, broken down and conquered by
adversity, returned to England in 1712 to seek aid and an asylum.

Everywhere repulsed, he returned to Cassel about 1714, sad and discouraged;
and the man to whom we owe that prodigy, the steam engine, that instrument
of universal welfare and riches, disappeared without leaving any trace of
his death.--_Le Monde Illustre._

* * * * *



[Footnote: _Authorities consulted in preparing this paper:_ "Analysis of
Ornament," Wornum; "Truth, Beauty, and Power," Dresser; "Lectures on Art."
F.W. Moody; "Hopes and Fears for Art," Wm. Morris; "Ornamental Art," Hulme;
"Manuals of Art Education," Prang.]

By MISS MARIE R. GARESCHE, St. Louis High School.

Decoration is the science and art of beautifying objects and rendering them
more pleasing to the eye. As an art, individual taste and skill have much
to do with the perfection of the results; as a science, it is subject to
certain invariable laws and principles which cannot be violated, and a
study of which, added to familiarity with some of the best examples, will
enable any one to appreciate and understand it, even if lacking the skill
and power to create original and beautiful designs.

The study of decoration offers many advantages. It cultivates the
imagination and the taste; it develops our capacity for recognizing and
enjoying the beautiful in both nature and art; it adds to the pleasure and
refinement of life. Practically, its importance can hardly be
overestimated, as it enters into almost all the industrial pursuits. We can
think of but few classes of objects, even the most simple, in which some
attempt at ornamentation is not made.

Ornament is one of the principal means of enhancing the value of the raw
material. A piece of carved wood, or an artistically decorated porcelain
vase, worth perhaps many hundred dollars, if reduced to the commercial
value of the material of which they are composed would be valued at but a
few dollars or cents. The higher the ornamentation ranks, from an artistic
point of view, the greater becomes the value of the article to which it is
applied. Knowledge of good designs is thus evidently important, to the
purchaser of the object ornamented as well as to the designer who planned
it. This can only be attained by cultivation.

To know and appreciate the best ornament should be an aim set forth in any
scheme of general education. This knowledge and appreciation can be
obtained by studying the application of the laws and principles of
ornamental art as exemplified in the works of masters, and also by
endeavoring to apply these principles in designs of our own creation.


We can only arrive at a knowledge of these principles by a consideration of
the object. In other words, nature and history must be studied. First,
_nature_, for she is the primary source and origin of all good ornament,
whether ancient or modern; and if, as in everything else, we would not
become servile imitators and weak copyists, we must go to the fountain
head. Second, _history_, for by the study of the ornament of past ages we
will not only become acquainted with the highest developments of which
ornamental art is capable, but will moreover broaden our views as to its
object and scope, and will stimulate our own imagination and invention, by
leading us to the contemplation of the myriad beautiful and protean forms
it has assumed, when surrounding conditions, such as religion, climate,
temperament, nationality, etc., have been different. Knowledge of historic
ornament will also prevent the imposition on the public, so common in our
day, of weak and unworthy productions which claim to be based on classic
originals, and which constitute a great stumbling block to the progress and
appreciation of good art. The result is somewhat analogous to that produced
upon conscientious but ill-informed minds, who make every effort to
appreciate and enjoy the spurious productions of a great author, not
knowing that they are not genuine.


I. _Object of Ornamental Art._--The object or purpose of ornament, as in
the other fine arts, is to please. In music and poetry this enjoyment is
conveyed to the mind through the ear; in the decorative and pictorial arts,
through the eye. Generally, the meaning that we find in such productions,
the appeal that they make to the understanding or feelings, is as great a
source of interest to us as their intrinsic beauty. Poetry and vocal music
are greatly dependent for their effect upon the meaning they convey in
words; painting and sculpture, upon the ideas or sentiments they suggest.
In all four, however, and most decidedly in music unaccompanied by words,
the appeal is frequently made almost exclusively to the aesthetic sense, the
mind or intellect remaining almost dormant under the impression. Gems of
rhythmical verse, such as Poe's "Bells," "The Raven," Whistler's
"Symphonies in Color," nameless forms in statuary, expressionless save in
the mere beauty of their proportions and curves, and, as has been stated,
nearly the entire field of instrumental music, are cases in point. In the
ornamental and decorative arts, as well as in architecture (from which they
are indeed inseparable), beauty alone, in like manner, should be the
principal aim and purpose. In the former, of course, it is indispensable
that such should be the case, as they are entirely subordinate and
accessory in their nature, their only _raison d'etre_ being to beautify or
render more agreeable objects already created for some purpose.

It must not be imagined that such artistic impressions--viz., where the
appeal is made almost solely to the aesthetic sense, regardless of the
reason, judgment, or feelings--are necessarily of a lower order. Their
effect is almost analogous to that which nature herself produces upon
us--the starry heavens, the mighty ocean, the tender flower. The
impression, whether the object belongs to the domain of nature or art, may
be a merely sensuous one; and if it stops there, as it certainly does for
the majority of people, it ranks without doubt far below productions where
the aesthetic element is only used to stimulate and heighten the appeal to
the mind or the feelings. But if it extend beyond, and makes the sensuous
impression but the parting link to the contemplation of ideal, abstract
beauty, without the intermediate aid of the heart or the reason, it is the
shortest and quickest road toward the realization of the infinite, and
makes us indeed feel that it is but a short step "from nature up to
nature's God." Thus architecture, which embodies, more than any other of
the space arts, principles of abstract beauty, has been with reason called
the noblest of them all.

However, ornamental and architectural forms frequently do convey a meaning,
which we term symbolism in art. If this symbolism does not detract from the
first object of ornament--viz., to beautify--it is perfectly legitimate and
proper. It is impossible to fully appreciate many phases of art, as, for
instance, the Egyptian and the early Christian, if we leave out of sight
the symbolism which pervades them.

While beauty, or capacity for pleasing the eye, may be very definitely said
to be the aim of ornamental art, it is difficult to arrive at a universal
standard as to what constitutes beauty. What pleases one person will not
always please another. The child loves glittering objects and gaudy
combinations, which the mature taste of the man declares extravagant and
unharmonious. Savages decorate their weapons, utensils, and their own
persons with ornaments that appear uncouth and barbarous to civilized

Besides these differences in taste, which are due to different degrees of
mental development, and which can consequently be easily disposed of, we
find among highly civilized and cultured nations, at different periods, a
great diversity of tastes. These varying and sometimes apparently
conflicting products of ornamental art we designate as styles, viz.,
Egyptian style, Greek style, Gothic style, etc. So marked are the
differences between them that we can sometimes tell at a glance to what
period and to what style a small fragment of decoration belongs.

Notwithstanding these differences, which at first may appear very great, a
careful study of the best styles--those that achieved the greatest and most
lasting popularity--will reveal the fact that they are all based upon
certain fundamental laws and principles, and that all are good, bad, or
indifferent according as they conform to or violate these principles. These
essentials having been preserved, the opportunities for the exercise of
individual or national taste are almost boundless.

II. _Position of Ornament._--The position that ornament occupies is
necessarily a secondary one, as it cannot exist independently, but is
always applied to objects created for some purpose entirely independent of
their capacity for pleasing. This gives us one of the great underlying
principles that should characterize all ornament, viz., _it must be
subordinate to the object which it adorns, and must not detract from its
use_. We often see this rule violated in personal, household, and
architectural decoration--windows so overloaded with projecting cornices
and lattice work as to almost exclude light and air; knife handles carved
so elaborately that it is impossible to grasp them firmly; styles of dress
in form or color that impede the motions of the wearer, and make the
clothes, rather than the personality of the wearer, the most noticeable
feature. From this principle there is but a step to another: _All ornament
should be modest and moderate_. It must not obtrude itself, and a great
profusion and ostentation in its application is always a sign of degeneracy
and bad taste. Of course some objects, from their nature, position, and
use, will admit of greater and more elaborate ornament than others.

Ornament, being entirely subordinate, should not conceal the construction
of the object. In architecture it should follow the leading lines of the
building, and should emphasize, or at least suggest, the construction. If
architectural in character, it should so enter into the construction of the
building that it could not be taken away without injuring it.

We must feel that a column, no matter how beautiful, is supporting
something. A floor, always a plane surface, must not be tiled or decorated
in any way to express relief. This would apparently destroy the essential
constructive quality of a floor, viz., flatness. For the same reason, all
shams, such as painted arches, pillars, etc., are not legitimate. As long
as they do not actually exist, they are evidently not necessary to the
construction, and have no purpose save an imaginary decorative one, and in
the words of Owen Jones, _construction must be decorated--not decoration

III. _Scope of Ornament._--The scope of ornamental art is almost boundless.
It is applied to objects large and small, adapted to the most various uses,
constructed of the most different materials. As the ornamentation is always
to be subordinate to the object, considerations regarding size, use,
position, material, etc., must govern it. An ornament that would be
admirable applied to one object, might be detestable if applied to another.
A design cannot be made without reference to its future application.

First: The material must be considered. Heavy and hard materials, such as
wood and stone, will not admit of as delicate curves and lines as textile
fabrics, such as cotton and woolen goods, laces, etc.

Second: The manner in which the article is to be made, whether by weaving,
cutting, carving, casting, etc.

Third: The position the object is to occupy. If elevated or otherwise
remote from the eye, elaborate finish and minute detail are useless.
Ornamental art, from time immemorial, has attained its greatest excellence
and exercised its greatest influence in connection with architecture.

In fact, the study of ornament is inseparable from that of architecture. It
is upon architectural forms that the greatest artists have in all ages
expended their greatest efforts and skill, and in a treatise on historic
ornament they are decidedly the most interesting and important object of

IV. _Material of Ornament._--The two great sources of ornament are geometry
and nature. The latter includes the former; for not only must natural
forms, in order to be available as material for ornament, be first
conventionalized, or reduced to regular, symmetrical, geometric outlines,
but any and all designs, whether the unit of repetition be geometric or
conventional, must be founded upon geometric construction. This refers to
the regularity, repetition, and distribution of parts; so that every good
design, if reduced to its principal lines of construction, would exhibit
but a few geometric lines and inclosing spaces. Many designs are not only
geometric in their basis or plan, but make use of geometric figures as the
units or materials of design. Such designs, however, rank lower than those
in which natural forms conventionalized are taken as the subjects of
repetition; and as the ornament rises in the scale toward perfection, even
the geometric basis becomes less and less apparent, and sinks into a
decidedly subordinate position; so that in many of the most perfect
specimens it can be traced only in a few leading lines of the composition.
Its presence, however, is necessary, and is the foundation, if not the most
important element, of beauty in the design.


While the natural world, including leaves, flowers, animals, etc., is the
greatest source of ornament, it is generally the opinion of the best
authorities, derived from the study of the best styles and by a
consideration of the principles of fitness and propriety which underlie the
entire physical and moral world, that natural forms in ornamental and
decorative art should not be literally copied or imitated. That is the aim
of painting, sculpture, and the other representative arts, where the object
is to present something to the eye which will suggest at once the actual
presence of the object. To produce that effect, the object, whether animal
or vegetable, is represented as much as possible in the actual
circumstances of its existence, surrounded by the necessary conditions of
its well-being and growth. A frame is placed around it, to shut it off as
much as possible from other surroundings, and thus help us delude ourselves
that we are in the presence of the real thing, either as it would impress
us through our senses or our imagination.

But in ornamental art the case is entirely different. As it is to be
applied and consequently subordinated to something, and does not exist for
itself, it would be impossible, except in very rare instances, to introduce
in a design a natural object in a realistic manner and not violate some
important law of its growth or the conditions of its well-being. For
instance, to exactly repeat a certain rose, with all the accidents of its
growth, many times in a carpet is not natural. Nature never repeats
herself. Moreover, to tread on that which is supposed to suggest to us real
roses is barbarous. It would really be outraging and distorting nature
while pretending to be her faithful disciple and imitator.

We not only derive from nature the most important materials for our
designs, but also the various modes of arranging this material. Various
modes of repetition--radical, bilateral, etc.--were all probably suggested
by some natural arrangement observed in flowers, leaves, etc. Of these
different arrangements it is curious to note that the bilateral is more
characteristic of the higher forms of nature and the radiating of the
lower. The leading principles of ornament--symmetry, proportion, rhythm,
contrast, unity, variety, repose, etc.--are all exemplified in natural
forms. The latter have also suggested many of the most important
architectural forms. The Gothic cathedral, with its clustered columns
branching and forming pointed arches overhead, was probably suggested by a
grove of trees with overarching branches and boughs. The idea of the column
was derived from the papyrus plant, a species of reed growing in the river
Nile. The bud or flower suggested the capital of the column; the stalk, the
shaft; and the bulbous root, the pedestal. The blue vault of the sky
undoubtedly suggested the dome, etc.

The following are a few of the leading principles of ornamental art as set
forth by Owen Jones in his _Grammar of Ornament_, a fine work,
magnificently illustrated, whose perusal could hardly fail to delight the
most indifferent:

"All good ornamental art should possess fitness, proportion, harmony, the
result of all which is repose."

"Construction should be decorated. Decoration should never be purposely

"All ornament should be based upon geometrical construction."

"Harmony of form consists in the proper balancing and contrast of the
straight, the inclined, and the curved."

"In surface decoration all lines should flow out of a parent stem. Every
part, however distant, should be traced to its branch or root. Natural

"All junctions of curved lines with each other, or with straight lines,
should be tangential to each other. Natural law."

"Natural forms, as subjects of ornament, should not be imitated, but should
be conventionalized."


The origin of all attempts at decorating or beautifying objects lies in the
universal love of mankind for the beautiful. Once the necessaries of life
provided for, man instinctively, the world over, turns his attention toward
gratifying this feeling, by improving and decorating the forms around
him--his arms, utensils, dwelling, or his own person. The history of every
nation proves this, and no matter how rude, and even ugly, their efforts
may seem to us, we are bound to recognize in them the same motives that
actuated the builders of the Parthenon or of St. Peter's at Rome. This
awakening and gratification of the aesthetic sense seems to be the first
advance from a condition of mere animal existence, in which food, shelter,
and comfort are the only considerations, to tastes and desires that are
higher and, consequently, more impersonal.

The term historic ornament is applied to the various styles of ornamental
art which have flourished at various periods in the world's history, from
the Egyptian, dating from the 14th century B.C., to those that exist at the
present day. Their number is, consequently, almost unlimited, and we will
confine ourselves to the consideration of a few of the principal ones
only--those that have achieved the most enduring fame, or those that
exercised the most marked influence upon succeeding styles.

In considering the various styles, we must always bear in mind that, with
the exception of the Egyptian, all show very markedly the influence of the
styles that preceded them, being very often merely an outgrowth or
development of a preceding one. Thus the Greeks borrowed many forms from
the Egyptians. The Romans simply adapted and elaborated the Greek style,
etc. So that while each style is usually known by certain prominent
characteristics, it does not follow that these characteristics are peculiar
to it alone.[1] They may be found in other styles, though not to such a
great extent. While similar features will thus be seen to run through many
styles, each will usually be found to possess an individuality of its own.
Every nation, like every individual, possesses different wants and
capabilities, and will develop itself accordingly. Differences in religion,
climate, manners, customs, etc., will cause differences in their art and
literature, the most lasting monuments of their morals, taste, and

[Footnote 1: "Rudiments of Architecture and Building," through courtesy of
H.C. Baird.]

It is rather by the study of the art and literature of a people that we
arrive at a true knowledge of them than from the perusal of mere historic
facts concerning them--when they lived, who conquered them, etc.



_Egyptian._--Characteristics: symbolic, severe,
simple, grand, massive. Conventional forms of lotus,
papyrus, etc. Oblique lines.

_Greek._--Characteristics: aesthetic, simple,
harmonious, beautiful. Conventional forms, anthemion,
acanthus. Ellipse.

_Roman._--Characteristics: elaborate, rich, costly.
Conventional forms, acanthus scroll, monsters. Circle.

MEDIEVAL. 300 A.D.--1300 A.D.

_Byzantine._--Symbolic, rich, elaborate. Conventional
forms, principal architectural feature--dome.

_Saracenic._--Gorgeous coloring, graceful curves.
Forms entirely geometric. Arabesque, geometrical
tracery, interlacing.

_Gothic._--Imposing, grand. Pointed arches, clustered
columns, vaulted roof, spire buttress. Forms both natural
and conventional. Stained glass.


_Renaissance._--Mixture of classic and mediaeval
elements. Result not generally good.

_Cinquecento._--AEsthetic, revival of true classic
principles. Beautiful curves, fine proportions
and distribution. Conventional animal and plant
forms. Human figure.

_Louis Quatorze._--Sparkling, glittering. Absence
of color, want of symmetry.


Ancient art is also known as classic, a term which, in architecture,
sculpture, painting, and music, is almost synonymous with _good_ and
_admirable_. Taken as a whole and at its best, classic art has never been
surpassed. The designs of the Greeks, Romans, and Egyptians, and even the
forms of their buildings, are still copied at the present day.

The horizontal line is a marked feature of classic art. It is visible in
the leading lines of their architecture, in the frequency of horizontal
borders, friezes, etc. It accords admirably with the constructive features
of classic architecture, and thus conforms to the important decorative
principle that ornament should emphasize rather than disguise construction.

1. _Egyptian Art._--The oldest of which we have any record dates from 1800
B.C. Egyptian art is symbolic, that is to say, the forms were chosen not so
much on account of their beauty as for the purpose of conveying some
meaning. The government of Egypt being almost entirely in the hands of the
priests, these symbols were generally of a religious character, signifying
power and protection. The principal ones were: The lotus, signifying
plenty, abundance; the zigzag, symbolic of the river Nile; the winged globe
or scarabaeus, signifying protection and dominion, usually placed over doors
of houses; the fret, type of the Great Labyrinth, with its three thousand
chambers, which was, in its turn, symbolic of the life of a human soul.

The column originated with the Egyptians. It was at first heavy, broad
compared to its length, and was usually covered with hieroglyphics. The
architecture of Egypt, of which the principal forms are pyramids, sphinxes,
obelisks, and temples, is characterized by massiveness of material,
grandeur of proportion, and simplicity of parts--a style well suited to its
flat, sandy soil, though it would look heavy and out of place in a country
where nature had herself supplied the elements of grandeur and massiveness
in the form of lofty mountains or mighty forests. Egyptian art greatly
influenced all the succeeding styles, and to this time is unsurpassed in
many of its qualities.

2. _Greek Art._--The next great historic style is the Greek. Its spirit
differed entirely from the Egyptian, being aesthetic and not symbolic. Its
sole aim was to create beautiful forms, without any thought of attaching to
them a meaning. It adopted many Egyptian forms, such as the lotus, fret,
and scroll, but divested them of all symbolism or significance. The most
characteristic feature of Greek ornament is the anthemion, a
conventionalized flower form resembling our honeysuckle bud, which was
usually alternated with the lotus or lily form bud. The Greeks also
borrowed the column and flat arch from the Egyptians, but changed it to a
more slender, graceful form. The three principal orders of Greek
architecture are named from the style of the column used that characterized
them, viz., the Corinthian, the Doric, the Ionic. Of these the Doric is the
simplest and the Corinthian the most elaborate.

For harmony of proportions, elegance of form, and simplicity of detail,
Greek architecture and ornament has probably never been surpassed. These
qualities are admirably displayed in the Parthenon, a temple in Athens,
dedicated to Venus. Though in ruins, it is still one of the greatest
attractions to travelers in Greece. A very fine collection of fragments
taken from it is to be seen in the British Museum. They are known as the
Elgin marbles.

The most flourishing period of Greek art, as will be found in the history
of almost all nations, was identical with the most flourishing period of
its literature and general welfare.

3. _Roman Art._--In the 6th century B.C. the Greeks, already on the
decline, were conquered by the Romans, a nation hardier and more powerful,
though ruder and less civilized than themselves. The conquerors recognized
this, and immediately set to work to copy or steal from their vanquished
foes everything that might enhance the beauty and splendor of their own
city. Greek artists were transported to Rome and placed in charge of the
most important public works. Roman art is, consequently, but a development
or adaptation of the Greek. It is noticeable, however, that it almost
completely ignored the most characteristic and popular of the Greek
forms--for example, the anthemion--and adapted those, such as the acanthus
and the scroll, which had been considered of minor importance among the
Greeks. They added another to the three orders of the Greek architecture,
viz., the Composite, the most elaborate of all, being a combination of the
Ionic and the Corinthian. This leads us to consider the leading features of
Roman ornament--richness and profusion. With the acanthus and scroll as
their principal units of design, they elaborated and enriched every form
that would admit of it. The most elaborate Greek example cannot compare in
this respect to the simplest Roman. The Roman style of architecture was
very similar to the Greek, though more massive in its proportions, probably
on account of the larger number of people to be accommodated. The details
were also bolder and the curves fuller. They used the round arch to a great
extent. The column of Trajan and the Forum are fine examples of their


The Roman empire, after having reigned as mistress of the world for upward
of five centuries, commenced to show signs of decay. Its people had
gradually lost the sturdy spirit of independence, endurance, and courage
which had characterized their forefathers, and had degenerated into a race
of effeminate slaves and cowards. Ostentation became the feature of their
art; immorality and luxury, of their mode of living. They thus fell an easy
prey to the rude but vigorous barbarians of the North. The latter, rude and
uncivilized as they were, extended the contempt they had for the nation
they had conquered to their works of art as well, and mutilated or
destroyed them whenever they could lay hands on them.

This spirit of antagonism was strengthened upon their conversion to
Christianity, and everything that savored of paganism in art or literature
was severely proscribed. For the heathen forms, whose only aim and object
was beauty, were substituted religious symbols, the cross and other
implements of the passion, the lily, the fish, the aureole, etc., whose
object was to recall to the faithful the mysteries of religion. Gradually,
however, as the artistic feelings of the new people became awakened,
principles of beauty commenced to be regarded, and, while symbolism
remained an important feature of European art until the period of the
Renaissance, and even then was not entirely superseded, magnificent
artistic results were obtained.

1. _Byzantine Art._--The principal of the early mediaeval art developments
was the Byzantine. It flourished principally in the eastern part of Europe.
In the west it was known, with a few variations, as the Lombard and the
Norman. All three are often included under the term Romanesque.

Byzantine art was essentially Christian in its spirit and motives. It used
religious symbols extensively, but incorporated in its ornament a few pagan
elements, such as the acanthus and the scroll. Natural forms were always
conventionally treated. Its coloring was rich and gorgeous. The principal
features of its architecture were the dome and round arch. The plan of the
churches was often in the form of a Greek or Latin cross, with the dome
placed over the intersection of the two arms. The church of St. Sophia, in
Constantinople, is the most magnificent example of Byzantine architecture
and ornament. Although now a Mohammedan mosque, it is, probably, in the
motive and spirit that actuated its construction, the most Christian
building in the world.

2. _Saracenic Art._--Developed from the Byzantine by the Moors and the
Saracens. It differs from it, however, in one important respect. While the
Byzantine makes use of numerous conventionalized plant and animal forms,
the Saracens and Moors were forbidden by their religion, the Mohammedan, to
copy in any manner the form of any living thing, animal or vegetable. They
were thus limited entirely to geometric forms, which, however, often fall
insensibly into flower and leaf forms. Interlacing bands and curves of
intricate pattern, and exhibiting the peculiar Moorish curve, are very
characteristic of Saracenic ornament. Inscriptions were frequently
interwoven in this tracery.

The coloring was gorgeous, consisting principally of blue, red, and gold.

The principal arches used were the pointed and the horseshoe arch. The
Alhambra Palace in Spain is the most famous example of Saracenic ornament
and architecture.

3. _Gothic Art._--Gothic art grew out of the Byzantine, all the symbolic
elements being retained. It is divided into many different varieties.

In the earliest the round arch was used, but the later and more perfect
styles having employed the pointed arch almost exclusively, the latter
became characteristic of Gothic art generally. It is a style of
architecture and ornament usually applied to churches, and well adapted to
moist and cold climates on account of the sloping roof. Clustered columns,
the spire or belfry, the arched roof, and the division of the interior into
nave, transept, and choir, are leading features. Natural as well as
conventional treatment of plants is another important characteristic.


The Gothic style flourished principally in England, France, and parts of
Germany. Nearly all the principal cathedrals and churches in these
countries, and many in our own, are built after this style. The most
beautiful example in this country is St. Patrick's Cathedral, in New York.
The finest specimen in the world is probably the Cathedral of Cologne,
which was commenced in the 14th century, but was not completed until many
years later.


In the 15th century a remarkable revival occurred in literature and the
fine arts, showing a decided tendency to return to the old classic ideas of
the Greeks and Romans. After an almost complete neglect, which lasted for
centuries, artists and men of letters turned their attention to the long
neglected relics of pagan civilization as worthy of study for their
intrinsic beauty alone. Symbolism was relegated to a minor position, and
beauty was once more cultivated for its own sake. This epoch is termed the
Renaissance--which literally means a rebirth or revival.

1. _Renaissance Style._--The term Renaissance is also applied to one of the
early styles which came into vogue at this time. It flourished principally
in southern Europe. It is not a pure style, but marks a transition period
from the old popular Gothic and Saracenic forms to the revivified classic.
It naturally exhibits a queer mixture of conflicting elements--classic and
mediaeval thrown together without much regard to propriety or fitness. It
still showed traces of symbolism.

2. _The Cinquecento Style._--The Renaissance reached its most perfect
development in the Cinquecento or the 15th century style. It followed the
Quatrocento or 14th century style. Entirely untrammeled by symbolism, and
with the whole field of classic and mediaeval ornament to glean from, its
aim was to develop a perfect style of ornament. The best examples of this
period are founded on the soundest principles of ornamental art. Nothing
that could be turned into an element of beauty was neglected. Animals, real
and fictitious, flowers, leaves, fruit, the human form, etc., were
conventionalized and made to contribute their part to enhance the beauty of
the whole. Some of the principal characteristics of the Cinquecento style
are the delicate arabesque scroll work, the profusion and beauty of the
curves, its admirable variations of standard classic ornaments, such as the
anthemion and scroll. The coloring, also, was one of its most pleasing
features. This style flourished principally in Italy and France. Farnese
Palace and the tombs of the Medicis are noted examples.

3. _The Louis Quatorze._--This style succeeded the Cinquecento, but was
far inferior to it. It arose in Italy, and while preserving generally the
materials of the style that preceded it, it added as characteristic
features the scroll and the shell. Its principal object was to create
brilliant and startling effects in light and shade. Color was, in
consequence, decidedly secondary, gilding being used everywhere. The Palace
of Versailles, near Paris, is a gorgeous example of this style. Everything
in it is glittering and sparkling. Mirrors are everywhere placed to
intensify this effect. This style was followed by the Louis Quinze,
inferior to it in every respect, and in which symmetry, at least in detail,
seems to be carefully avoided. It still further degenerated into the
Rococo, the most extravagant and exaggerated of all the historic styles,
and which prevailed in the latter part of the 18th and the beginning of the
19th century.

The present century cannot boast of any great characteristic style in
either architecture or ornament. Whether it is only in a course of
development, and what will be the results, time only can show. All styles
are now in vogue, hence the importance of accurate knowledge on the
subject. To be able to judge of and appreciate the best, and to profit by
the labors of those gone before us, at the same time imparting
individuality and character to our own design, should be the aim and object
of the study of decoration, and it should enter into any scheme of general
education and culture.--_Journal of Education_.

* * * * *


This accumulator is of the Plante type, and is modified so as to obtain a
more rapid formation, a larger surface, and a symmetrical distance of the
plates from each other. If into an alkaline bath saturated with litharge
(added in excess) we plunge two lead electrodes and pass in a current of
suitable tension and intensity, there is deposited upon the anode a layer
of peroxide of lead varying in thickness with the intensity of the current,
and more or less rich in oxygen according to the intensity of the bath,
while the cathode is covered with a stratum of reduced lead. The liquid of
the bath supplies material for both deposits, while in galvanoplastic
operations the anode supplies it to the cathode. The principle of the
formation consists in introducing in an efficacious manner currents of a
great intensity, and thus abridging its duration.

Of two plates thus treated, the one becomes positive, and is covered with a
thick layer of peroxide of lead. On leaving the bath it undergoes various
preparations and several washings, and is then fit to be mounted along with
others to form an accumulator ready to be charged and to work. The second,
or negative, plate is covered with a thick sponge of lead. It is carefully
washed, preserved in water with exclusion of air, and submitted to a very
considerable pressure. After this operation it presents the appearance of
ordinary sheet lead, but though the physical porosity has disappeared, the
chemical porosity is intact, and this alone comes into play in
accumulators. When a negative plate is constructed in this manner, it is
ready to be combined with the positives to form an accumulator.

The inventor has sometimes put into the bath at the positive pole negative
plates prepared as just described. They become very easily peroxidized, but
they have the grave defect of requiring two preparations in place of one.
To secure an accumulator against any leakage from plate, the solderings and
the entire plates must be submerged in the liquid, so that nothing projects
up out of the acidulated water except two strong rods for making contact.
These rods are covered with an insulating varnish from their origin to
above the point where they issue from the liquid. The plates are of a
rectangular form (Fig. 1). They are sloped out at one corner, and as two
plates in juxtaposition are cut together, when they are separated the
sloping out of the one serves for the handle of the other. This handle is
doubled back on the plate which is suspended in the bath, so that the part
which has to be soldered does not undergo any preparation. A hole pierced
in this corner of the plate serves to receive a square rod of lead, which
connects the plates together and supports one of the poles or contacts of
the accumulator. At the point of soldering the doubled-down handle gives a
double thickness, and the margins of the plate are folded in such a manner
as to insure their solidity.

[Illustration: FIG. 1.]

The sloped out corner affords the free space necessary for the rod of the
opposite pole, and one and the same plate may be indifferently connected
either to the + or the - at the right or the left. The plates are made of
four different sizes: No. 1, 19 of which serve for an accumulator of 1
square meter; No. 2, 21, 25, or 29 of which serve for accumulators of 2, 3,
and 4 square meters; No. 3, which with 21, 25, or 29 plates composes
accumulators of 5, 6, and 7 square meters; and No. 4, which with 21, 23,
25, 27 or 29 plates forms accumulators of 8, 9, 10, 11, and 12 square

As the plates are entirely submerged in the liquid their entire surface is
active, and the entire surface being absolutely flat, it is sufficient to
preserve their respective distance at any one point in order to have it
everywhere alike. The weight of the plate depends on the intended duration
of the plate and its capacity. As for the negative plate, its thickness is
the most important factor of its capacity. The proportion has yet to be
established for daily practice. The inventor uses in practice positive
plates of 0.002 meter in thickness. On the other hand, the negative plates
have a body of only 0.001 meter in thickness, their greater thickness being
due only to the deposit of compressed lead. The rod which fixes the plate
to each pole (Fig. 2) is formed of a special alloy of lead and antimony,
not attacked by acid. This gives rigidity to the rod, and hinders it from
binding when the accumulator is taken out of its case. The copper piece
which surmounts it is fitted at its base with an iron cramp, which is fixed
in the lead, and above which is a wide furrow with two grooved parts, which
being immersed in the lead hinders the copper from slipping round under the
action of the screw. The rod is square, and is cast in a single piece.
Against one of its surfaces the ends of the connected plates press flatly
up. A square form has been selected to give more surface for soldering. The
soldering is autogenous (as in the lead chambers at vitriol works). The
soldering, as well as the entire plates, is entirely immersed in the
liquid, and to prevent any leakage an insulating varnish, perfectly proof
against the acid and the current, is laid over the rod from the part
soldered upward.

[Illustration: FIG. 2.]

If it is wished to lift the accumulator from its chest for any
verification, hooks passing between the plates seize hold of the rods, and
thanks to the rigidity of the antimony lead, they effect the removal of the
apparatus without bending the rods in the least. All the parts of the
plates must be kept at exactly the same reciprocal distances, and a
difference of only 0.001 meter between two points is sufficient to affect
the yield considerably. For an insulating material, wood, when plunged in
dilute acid, is preferred by the inventor. He makes a comb of wood, the
teeth of which vary according to the thickness of the plates to be lodged
between them. Fig. 3 represents a comb having 15/10 of a millimeter for the
negative plates and 25/10 for the positive plates.

[Illustration: FIG. 3.]

This appliance, which is 0.01 meter in thickness and 0.02 meter in width in
the back, is made very cheaply by machinery. The weight of the accumulator
bears entirely upon the back of the combs, which are all placed back
downward, and the number of which varies according to the size of the
plates. Small combs of wood clasp the plates at their extremities, and make
the entire accumulator quite compact and manageable. The entire accumulator
is shut up in a wooden chest, which the outer teeth of the comb serve to
insulate from the leaden chest, and to prevent any loss of electricity
along the sides.

Fig. 4 shows the arrangement of the side combs. A single glance at this
figure shows that it would be difficult to have more surface without having
recourse to curved, undulated, or folded plates, in which the distances are
variable, and consequently defective. In the Montaud accumulator, the
weight is simply proportional to the intended duration. For the notion, "So
much capacity and so much yield per kilo.," Montaud substitutes the notion,
"So much capacity or yield per square meter, the weight not being taken
into consideration." These Montaud accumulators are classified as follows:
They have from 1 to 12 square meters of surface, and the number
corresponding to the surface indicates its weight of useful lead, its
manner of charging, its capacity, and its manner of discharge.

[Illustration: FIG. 4.]

According to the inventor's experiments, the square meter of active surface
can receive a charging current of 10 amperes, and furnish on discharging a
current of the intensity of 20 amperes. For a "No. 10" accumulator we have
an active surface of 10 square meters, a charging current of 100 amperes,
and on discharging a current of 200 amperes. A square meter of lead of the
thickness of 0.001 meter weighs about 11 kilos.

As both surfaces of the lead are utilized, their weight is reduced to 51/2
kilos. A No. 10 therefore requires 55 kilos. of useful lead. It will be
seen that to increase the thickness of the sheet of lead merely augments
the duration of the accumulator, without affecting its capacity or its
manner of charging and discharging. Nos. 1, 2, 3, and 4 may be placed in
vessels of stoneware, glass, or ebonite, or in boxes of pitch pine, painted
with three coats of gum lac and lined with sheet lead. Nos. 5 to 12 are
only sent out in pitch pine boxes lined with lead. The box is supported on
feet of porcelain of the shape of a mushroom. If a drop of water falls upon
this foot, it cannot give a communication with the earth, since, falling
upon the broad part of the mushroom, it will glide off without running
along the foot, which serves as the stalk of the mushroom. A slip of glass
is placed under each foot; the part which supports the mushroom is covered
with an insulating varnish, which prevents the formation of climbing salts
and preserves the screws from rust. A common layer of insulating varnish is
applied under the head of the mushroom.

As regards the advantages of the Montaud accumulator we notice, first, its
longevity. Dr. D'Arsonval points out that the accumulators of the Plante
class have a great advantage over the Faure type as regards duration, and
that the most striking quality of the Montaud accumulator is its longevity.
The inventor has in his possession positive plates, five to six years old,
completely peroxidized, though there remains in the interior a thin core of
metallic lead sufficient to give passage to the current. The adhesion of
the peroxide is such that to detach it, it must be beaten with a hammer
upon an anvil. The next four points--i.e., the rapidity of charge; the
yield, much greater than that of any other system in proportion to its
surface; its small weight in comparison with its yield; and its capacity,
which for an equal weight is greater than that of any other accumulator. In
his experiments in September, 1885, Dr. D'Arsonval obtained with an
accumulator of 2 square meters of surface:

Useful capacity 40 ampere hours.
Total 62 " "
Surface 2 square meters
Charge 10 amp. per sq. meter.
Discharge 20 " " "
Useful weight of lead 10 kilos.

Representing a total capacity of six ampere hours per kilo., and of a
discharge of 5 amperes per kilo., or a total capacity of 81 ampere hours
per square meter, and a useful capacity of 20 ampere hours per square
meter. Subsequently the modification of the negative plate has greatly
improved these figures, which will certainly become much more advantageous
in future. The total capacity of an accumulator having exactly 13/4 meters of
surface has become 87 ampere hours, which if referred to an accumulator of
2 square meters of surface, would give the following results:

Useful weight of lead per sq. meter 51/2 kilos.
Total capacity of useful lead per kilo 9.1 amp. hr.
Total capacity per sq. meter 50 "
Useful capacity of per kilo of useful lead 6.23 "
Useful capacity per square meter 34.30 "
Current of charge per square meter 10 amp.
Current of charge per kilo, of useful lead 2 "
Current of discharge per sq. meter 20 "
Current of discharge per kilo, of useful lead 4.56 "

The next advantage of the Montaud accumulator is the ease with which it can
be taken out of its box and repaired without special tools and experience.
A capital defect in this respect has hitherto much interfered with the use
of accumulators. In case of accidents, several kinds of which are possible,
it is found very difficult to rectify the apparatus. The Montaud
accumulator is much less liable to accidents, on account of the firmness
and compactness of its construction, and if any accident happens, the
repairs are simple and easy. Lastly, the stout framework secures the
apparatus from any accident due to a disproportionate charge or discharge.
The peculiarities of the combs and rods already described solve this
problem. On September 8, 1885, Dr. D'Arsonval, professor at the College of
France, wrote as follows: "The Montaud accumulator is of the Plante type,
and is extremely well conceived from a mechanical point of view. The
wooden combs prevent the plates from coming in mutual contact, and give the
apparatus great solidity. The process of formation is ingenious and rapid.
To give 1 square meter a capacity of 20 ampere hours, there is required
only a quarter of an hour's treatment.

"To obtain the same result by Plante's method, months are required. The
entire experiments have been effected with No. 2, which has a surface of
two square meters. This apparatus, if charged to saturation, gives 62
ampere hours as its total capacity, and, as in the Plante, this capacity
constantly increases with use. The normal rule for the charge is 10 amperes
per square meter, and for the discharge double this quantity. This
apparatus has always given me on discharging 40 amperes at the E.M.F. of
1.85 volts during 60 or 65 minutes. The charge is effected in two hours up
to 20 amperes, without any appreciable loss of electricity.

"The points to be aimed at in an accumulator are longevity and energy, or,
rather, rapid yield per kilo. From both points of view accumulators of the
Plante type (and consequently those of Montaud) are far superior to those
of the Faure type. My opinion, therefore, is that the Montaud accumulator
is very practical, that it is a great improvement on the Plante type, and
that it can compete successfully with the other systems in use."--_Revue
Internationale de l'Electricite._

* * * * *


Mr. E. Gime, whose name is not unknown to our readers, sends us a
description of a certain number of meteorological apparatus to which he has
applied a peculiar method of registering that it is of interest to make


Mr. Gime in the first place has devised a "telemareograph," that is to say,
an apparatus designed to register at a distance the curve of the motions of
the tide in a given place. The structure of this device, shown
diagramatically in Fig. 1, is very simple. It is divided into two distinct
parts--a transmitter and a registering apparatus. The transmitter consists
of a long glass tube, A, closed at one end and communicating through the
other with a receptacle filled with mercury. A barometric vacuum is formed
in this tube. The level of the open receptacle corresponds exactly to the
level of the lowest tide.


Pieces of iron wire projecting sufficiently in the interior to establish
good contacts with the column of mercury are fastened one millimeter apart
to the inner surface of the tube. These iron contacts are connected with
the divisions of a rheostat, R, arranged in a tight compartment surrounded
with paraffine, near the tube.

This rheostat is interposed in the general circuit. It is connected through
one extremity with the line, and through the other with a disk of copper,
which has a surface of one square meter, and is immersed in the sea.

The line, L, insulated like an ordinary telegraph wire, is prolonged as far
as to the registering station.

The registering apparatus consists of a solenoid, S, that acts upon a soft
iron core suspended by a cord from the extremity, _x_, of the beam of a
balance. This cord passes between the channels of two rollers designed,
despite the motion of the beam, to keep the core in a vertical position in
the center of the solenoid.

The opposite arm of the balance carries a sliding weight, _i_, that moves
over a graduated scale and is designed to balance the core, N, in a certain
position in regulating the motions of the curve. At its extremity it
carries a style that bears against the drum, T, on which the paper is wound
that is to receive the mareometric curve.

The solenoid, S, is interposed in the general circuit, being connected on
the one hand with the line, L, and on the other with a very constant
battery of an electromotive force proportioned to the resistance of the

Through the electrode that remains free, the battery is grounded with so
great care that no variation in resistance can be produced thereby. If the
station is near the sea, the conductor of this electrode may be run to a
copper disk, having the same surface as the one at the transmitting
station. With this description, the operation of the apparatus may be
easily understood.

At low water, the pressure of the atmosphere balances a column of mercury
rising in a glass tube to a height proportionate to such pressure. In
measure as the level of the water rises, the pressure on the mercury in the
receptacle increases, and causes the metal to rise in the tube. The higher
the level of the sea, the less becomes the sum of the resistances of the
rheostat, since the column of mercury puts in short circuit all the
divisions of the rheostat, whose contacts are comprised in the height of
the column.

From these variations in the resistance of the circuit naturally result
variations in the current from the battery, B, at the registering station.
To the variations in intensity of the current in the circuit there
correspond variations in the attraction of the solenoid for the core that
transmits these motions to the balance that carries the registering style,
which latter amplifies or reduces them.

The same transmitter suffices for various registering stations arranged in
series, as shown in Fig. 2.

The variations in the resistance of the circuit, due to variations in the
temperature, and the variations in the height of the column of mercury, due
to atmospheric variations, etc., are, according to the inventor, of no

It would evidently be possible, on the same principle, to construct an
apparatus for registering the indications of a thermometer at a distance.

Such is the principle of Mr. Gime's apparatus. We do not believe that they
are entirely closed to criticism. What, in fact, are the conditions
essential for their proper working? Evidently: (1) the constancy of the
battery used; (2) a rigorously accurate adjustment. This latter condition,
is easily realized; but the same is not the case with the former. Of what
elements shall this constant battery be formed?

Mr. Gime recommends the use of the Latimer-Clark elements. Every one knows
that the Latimer-Clark element is now the best standard of electromotive
force; but let us not forget that this is on condition of its being
employed in open circuit. Now, it is not a question here of an open
circuit, nor even of infinitely weak currents, since in the line we have a
solenoid whose core must set in motion a whole system of connected pieces.
We do not see any possibility of employing Latimer-Clark elements; on the
contrary, it seems to us indispensable to select piles of large discharge,
since the solenoid, S, will attract nothing at all unless a notable
quantity of energy is expended in it.

Is there a pile of this kind so constant as not to render a rigorously
accurate adjustment illusory? Therein lies the entire question, and for our
part we hesitate to pronounce ourselves in the negative.--_La Lumiere

* * * * *


SALPETRIERE.--Painted by M. Andre Brouillet.--M. Dochy. Engraver.]


We reproduce the picture of Mr. Andre Brouillet, which was in the Salon of
1887; and that the subject may be better understood, we give the
accompanying sketch and description. This picture is very interesting, not
only from an artistic point of view, but also as a representation of
students and spectators of all ages admirably grouped around a great master
of science when most interested in his work. We borrow from _Matin-Salon_
Mr. Goetschy's explanation of the picture:

"The hall in which the lesson is given is lighted by two large windows
opening on one of the courts of the hospital. The Professor stands at the
right of the picture, his head uncovered, one hand close to his body and
the other extended slightly in a gesture which is familiar to him, his
audience being before him. At his side is Mr. Babinski, chief of the
clinic, supporting a person afflicted with hysteria. Near the latter stands
a nurse and assistant who watches every movement of the patient. This is
Mother Bottard, a good, intelligent, and devoted woman, who is well known
to all those present.

"The auditors have arranged themselves at the students' tables, some seated
on the chairs and stools which furnish the room, and others standing, but
all following closely the teaching of the master, and at the same time
watching the _subject_. The picture is full of life and motion, and yet is
very exact. The head and shoulders of the subject are beautifully and
correctly drawn. The artist has brought together many men who are well
known in literature and science."--_Le Monde Illustre_.

* * * * *



Having hit upon the following method of mentally computing the day of the
week for any given date, I send it you in the hope that it may interest
some of your readers. I am not a rapid computer myself, and as I find my
average time for doing any such question is about 20 seconds, I have little
doubt that a rapid computer would not need 15.

Take the given date in 4 portions, viz., the number of centuries, the
number of years over, the month, the day of the month.

Compute the following 4 items, adding each, when found, to the total of the
previous items. When an item or total exceeds 7, divide by 7, and keep the
remainder only.

_The Century Item_.--For old style (which ended September 2, 1752) subtract
from 18. For new style (which began September 14) divide by 4, take
overplus from 3, multiply remainder by 2.

_The Year Item_.--Add together the number of dozens, the overplus, and the
number of 4's in the overplus.

_The Month Item_.--If it begins or ends with a vowel, subtract the number
denoting its place in the year from 10. This, plus its number of days,
gives the item for the following month. The item for January is "0;" for
February or March (the 3d month), "3;" for December (the 12th month), "12."

_The Day Item_ is the day of the month.

The total thus reached must be corrected by deducting "1" (first adding 7,
if the total be "0"), if the date be January or February in a leap year;
remembering that every year divisible by 4 is a leap year, excepting only
the century years, in new style, when the number of centuries is _not_ so
divisible (e.g., 1800).

The final result gives the day of the week, "0" meaning Sunday, "1" Monday,
and so on.


1783, _September_ 18.

17 divided by 4 leaves "1" over; 1 from 3 gives "2;" twice 2 is "4."

83 is 6 dozen and 11, giving 17; plus 2 gives 19, i.e. (dividing by 7),
"5." Total 9, i.e., "2."

The item for August is "8 from 10," i.e., "2;" so, for September, it is "2
plus 3," i.e., "5." Total 7, i.e., "0," which goes out.

18 gives "4." Answer, "_Thursday_."

1676, _February_ 23.

16 from 18 gives "2."

76 is 6 dozen and 4, giving 10; plus 1 gives 11, i.e., "4." Total "6."

The item for February is "3." Total 9, i.e., "2."

23 gives "2." Total "4."

Correction for leap year gives "3." Answer, "_Wednesday_."


* * * * *


To the recently distributed government report on the mineral resources of
the United States for 1885.[1] Mr. G.F. Kunz contributes an interesting
chapter in which is recorded the progress made during that year in the
discovery and utilization of precious stones.

[Footnote 1: Mineral Resources of the United States: Calendar Year 1885.
Washington: Government Printing Office. 1888.]

In the summer of 1885, a remarkably large pocket containing fine crystals
of muscovite, with brilliant crystals of rutile implanted on them, was
found at the Emerald and Hiddenite Mining Company's works, at Stony Point,
N.C., and was sold in the form of cabinet specimens for $750. While the
soil overlying the rock was being worked, nine crystals of emerald were
found, all of which were doubly terminated, and measured from 1 inch to
3-1/8 inches in length and 1-2/3 inch in width. One of these crystals is
very perfect as a specimen, being of a fine light green color, and weighing
83/4 ounces. It is held by the company at $1,500, and the nine crystals
together at $3,000. Another of these crystals, doubly terminated, measures
21/2 inches by 11/12 of an inch, and is filled with large rhombohedral
cavities, which formerly contained dolomite. The only crystal from this
collection that has been cut into a gem was found in a pocket at a depth of
over 43 feet. In color it is of a pleasing light green, and it weighs
4-22/32 carats. No crystal of a finer color has as yet been found in the
United States, and the gem is held by the company at $200.

During the recent mining, the largest fine crystal of lithia emerald ever
found was also brought to light. It measures 23/4 inches by 3/5 of an inch
by 1/3 of an inch. One end is of a very fine color, and would afford the
largest gem of this mineral yet found, and one which would probably weigh
51/2 carats. With this there was a number of superior crystals and some
ounces of common pieces of the same mineral. The company estimates the
value of this entire yield of hiddenite at about $2,500.

There was also found a quantity of quartz filled with white byssolite,
forming very attractive specimens and valued at $250.

A number of beryls of a fine blue color, resembling the Mourne Mountain
specimens, were found near Mount Antero, Chaffee County, Col. One of these
was 4 inches long and 3/8 of an inch across, with cutting material in it.
The other crystals measured from 1 to 11/4 inch in length, and from 1/5 to
1/3 inch in width.

The large beryl mentioned by Mr. Kunz in the Mineral Resources for 1883 and
1884 has afforded the finest aquamarine of American origin known. It is
brilliant as a cut gem, and, with the exception of a few internal hair-like
striae, is absolutely perfect. It weighs 1333/4 carats, measures 1-2/5 x 1-2/5
x 4/5 inch, and is of a deep bluish green, equal to that of gems from any
known locality.

Mr. G.F. Breed, manager of the Valencia Mica Company, has cut nearly one
hundred aquamarines, ranging from 1/2 carat to 4 carats in weight, and of a
light blue color, from white beryls found in the company's mica mine at
North Grafton, N.H.

A number of fine, deep golden-yellow, blue, and green beryls, equaling any
ever found, have been taken by Mr. M.W. Barse from his mica mine between
New Milford and Litchfield, Conn. Some fine blood-red garnets from this
same locality have been cut into gems.

The largest phenacite crystal ever found is owned by Mr. Whitman Cross. It
was discovered at Crystal Park, Col., weighs 59 pennyweights 6 grains, and
measures 1-4/5 inch in length and 1-1/5 inch in thickness.

Thousands of garnet crystals, found at Ruby Mountain, near Salides, Col.,
have been made into paperweights and sold to tourists. Those that weigh a
few ounces sell for about ten cents each. One was sold that weighed 14
pounds. Apropos of garnets, the discovery, in the heart of New York city,
of as fine a crystal as was ever found on this continent, and weighing 9
pounds 10 ounces, may be mentioned as a matter of peculiar interest.

Several thousand dollars' worth of the wood jasper of Arizona has been cut
into paper weights, charms, and other objects, or polished on one side for
cabinet specimens. Numbers of these articles are now being cut and sold to
tourists along the line of the Atchison, Topeka, and Santa Fe Railroad.

The compact quartzite of Sioux Falls, Dakota, is being quarried and
polished for ornamental purposes. It is known and sold as "Sioux Falls
jasper," and is really the stone referred to by Longfellow in his Hiawatha
as being used for arrow heads. This stone takes a very high polish, and is
found in a variety of pleasing tints, such as chocolate, brownish-red,
brick-red, and yellowish. For the two years previous to 1885, $15,000 worth
of it was sold.

A remarkable mass of rock crystal has been received by Messrs. Tiffany &
Co. from a locality near Cave City, Va. Although this mass weighs 51
pounds, it is but a fragment of the original crystal, which weighed 300
pounds, and which was broken in pieces by the ignorant mountain girl who
found it. The fragment, as it is, will furnish slabs 8 inches square and
from 1/3 to 1 inch thick. The original crystal would have furnished a ball
from 41/2 to 5 inches in diameter, and almost perfect. A number of fine
agates of various kinds were found by Mr. F.C. Yeomans at the same

The meccanite from Cumberland, R.I., is often spotted with white quartz. It
has been cut into oval stones several inches in length, which take a fine
polish. This quality, coupled with its hardness, makes it a desirable
ornamental gem stone.

Mr. Kunz records the discovery, by himself, in the largest mass of the
Glorieta Mountain (Santa Fe County, N.M.), of pieces of peridot of
sufficient transparency to afford gems one-fifth of an inch in length.

Large quantities of turquoise from Los Cevillos, N.M., have been sold, both
as cabinet specimens and gems; but, unfortunately, many of those of the
finest color have been found to be artificially colored.

Malachite in large masses has been found at the Copper Queen mine at
Bisbee, Oregon. One of these masses weighed 15 pounds and others were quite
as large. All were of good enough quality and large enough for table tops.

In conclusion, Mr. Kunz says that "the National Museum collection of gems,
formed by Prof. F.W. Clarke, is now one of the most complete, for species,
in the United States, and as many of the gems are of more than average
merit, and all can have access to them, this is one of the best
opportunities afforded the student in this country."

* * * * *


[Illustration: THE BRAZIL NUT.]

Every one is acquainted with the hard-shelled, triangular fruit called the
Brazil nut, but there are, perhaps, but few who know anything about the
tree that produces it, or its mode of growth. The Brazil nut tree belongs
to a genus of Lecythidaceae of which there is only one species,
_Bertholletia excelsa_. This tree is a native of Guiana, Venezuela, and
Brazil. It forms large forests on the banks of the Amazons and Rio Negro,
and likewise about Esmeraldas, on the Orinoco, where the natives call it
_juvia_. The natives of Brazil call the fruit _capucaya_, while to the
Portuguese it is known as _castana de maranon_.

The tree is one of the most majestic in the South American forests,
attaining a height of 100 or 150 feet. Its trunk is straight and
cylindrical, and measures about 3 or 4 feet in diameter. The bark is
grayish and very even. At a distance, the tree somewhat resembles a
chestnut. Its branches are alternate, open, very long, and droop toward the
earth. The leaves are alternate, oblong, short petioled, nearly coriaceous,
about 2 feet long by 6 inches wide, entire or undivided, and of a bright
green color. The flowers have a two-parted, deciduous calyx, six unequal
cream-colored petals, and numerous stamens united into a broad, hood-shaped
mass, those at the base being fertile, and the upper ones sterile.

The fruit is nearly orbicular, and about 6 inches in diameter, and has a
hard shell about half an inch thick, which contains from 18 to 24
triangular, wrinkled seeds that are so beautifully packed within the shell
that when once disturbed it is impossible to replace them. When these
fruits are ripe, they fall from the tree and are collected into heaps by
troops of Indians called _Castanhieros_, who visit the forests at the
proper season of the year expressly for this purpose. They are then split
open with an ax, and the seeds (the Brazil nuts of commerce) taken out and
packed in baskets for transportation to Para in the native canoes. The
"meat" that the Brazil nut contains consists of a white substance of the
same nature as that of the common almond, and which is good to eat when
fresh, but which, by reason of its very oily nature, soon gets rancid.
Besides its use as an article of dessert, a bland oil, used by watchmakers
and artists, is obtained from the nut by pressure. Brazil nuts form a
considerable article of export from the port of Para, whence they are
sometimes called Para nuts.

The Brazil nut tree remained for a long time unknown to European botanists,
although the fruit has been from a very remote epoch consumed in large
quantities in certain southern countries of the New World. The first
description of the tree we owe to Humboldt and Bonpland, who established
the genus and species in the botanical part of the account of their voyage.
The genus is dedicated to the illustrious Berthollet.

"We were very fortunate," say these authors, "to find some of these nuts in
our travels on the Orinoco. For three months we had been living on nothing
but poor chocolate and rice cooked in water, always without butter, and
often without salt, when we procured a large quantity of the fresh fruits
of the _Bertholletia_. It was along in June, and the natives had just
gathered them."

The formation of a large woody fruit, often in the shape of an urn, from
which the top spontaneously separates in the form of a lid, is one of the
characteristics of the order Lecythidaceae, which includes the _Couronpita
Guianensis_, or "cannon ball tree"; the gigantic _Lecythis ollaria_, or
"monkey-pot tree," whose great woody pericarps serve as drinking vessels;
and the _Lecythis Zabucajo_, whose fruit is known in the market as sapucaia
nuts, and is greatly superior to the closely allied Brazil nuts as regards
flavor and ease of digestion.

All the trees of this order are natives of South America, and especially of

* * * * *


Mr. Tamburini some time ago observed that, during a period of lethargy, the
approach of a magnet produced in persons affected with hysterical hypnosis
a series of modifications of the respiratory functions and of

From some very careful experiments made by him and Mr. Righi in common,
upon the lady who was the principal subject of his observations, it results
that (1) it makes no difference whether the magnet be presented by its
poles or its neutral line; (2) that any mass of metal whatever acts like a
magnet; (3) that an electromagnet produces exactly the same effect whether
it be or be not excited by a current; and (4) that a glass tube filled with
cold or warm water likewise produces analogous effects, which disappear
when the water is raised to the temperature of the human body.

It seems, therefore, that the magnetic properties of the magnet count for
nothing in the phenomena observed.--_Journal de Physique_.

* * * * *



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