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The Boy Mechanic: Volume 1 by Popular Mechanics

Part 11 out of 15

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is less apt to rust. For fastening the gunwales to the crossboards
use nails instead of screws, because the nails are not apt to
loosen and come out. The ribs, which are easily made of long,
slender switches of osier willow, or similar material, are next
put in, but before doing this, two strips of wood (b, b, Fig. 3)
should be bent and placed as in Fig. 3. They are used only
temporarily as a guide in putting in the ribs, and are not
fastened, the elasticity of the wood being sufficient to cause
them to retain their position. The osiers may average a little
more than 1/2 in. in thickness and should be cut, stripped of
leaves and bark and put in place while green and fresh. They are
attached to the bottom by means of shingle nails driven through
holes previously made in them with an awl, and are then bent down
until they touch the strips of ash (b, b, Fig. 3), and finally cut
off even with the tops of the gunwales, and notched at the end to
receive them (B, Fig. 4). Between the cross-boards the ribs are
placed at intervals of 2 or 3 in., while in other parts they are
as much as 5 or 6 in. apart. The ribs having all been fastened in
place as described, the loose strips of ash (b, b, Fig. 3) are
withdrawn and the framework will appear somewhat as in Fig. 1. In
order to make all firm and to prevent the ribs from changing
position, as they are apt to do, buy some split cane or rattan,
such as is used for making chair-bottoms, and, after soaking it in
water for a short time to render it soft and pliable, wind it
tightly around the gunwales and ribs where they join, and also
interweave it among the ribs in other places, winding it about
them and forming an irregular network over the whole frame. Osiers
probably make the best ribs, but twigs of some other trees, such
as hazel or birch, will answer nearly as well. For the ribs near
the middle of the boat, twigs 5 or 6 ft. long are required. It is
often quite difficult to get these of sufficient thickness
throughout, and so, in such cases, two twigs may be used to make
one rib, fastening the butts side by side on the bottom-board, and
the smaller ends to the gunwales, as before described. In drying,
the rattan becomes very tight and the twigs hard and stiff.

The frame-work is now complete and ready to be covered. For this
purpose buy about 18 yd. of very strong wrapping-paper. It should
be smooth on the surface, and very tough, but neither stiff nor
very thick. Being made in long rolls, it can be obtained in almost
any length desired. If the paper be 1 yd. wide, it will require
about two breadths to reach around the frame in the widest part.
Cut enough of the roll to cover the frame and then soak it for a
few minutes in water. Then turn the frame upside down and fasten
the edges of the two strips of paper to it, by lapping them
carefully on the under side of the bottom-board and tacking them
to it so that the paper hangs down loosely on all sides. The paper
is then trimmed, lapped and doubled over as smoothly as possible
at the ends of the frame, and held in place by means of small
clamps. It should be drawn tight along the edges, trimmed and
doubled down over the gunwale, where it is firmly held by slipping
the strips of ash (b, b) just inside of the gunwales into notches
which should have been cut at the ends of the cross-boards. The
shrinkage caused by the drying will stretch the paper tightly over
the framework. When thoroughly dry, varnish inside and out with
asphaltum varnish thinned with turpentine, and as soon as that has
soaked in, apply a second coat of the same varnish, but with less
turpentine; and finally cover the laps or joints of the paper with
pieces of muslin stuck on with thick varnish. Now remove the loose
strips of ash and put on another layer of paper, fastening it
along the edge of the boat by replacing the strips as before. When
the paper is dry, cover the laps with muslin as was done with the
first covering. Then varnish the whole outside of the boat several
times until it presents a smooth shining surface. Then take some
of the split rattan and, after wetting it, wind it firmly around
both gunwales and inside strip, passing it through small holes
punched in the paper just below the gunwale, until the inside and
outside strips are bound together into one strong gunwale. Then
put a piece of oil-cloth in the boat between the cross-boards,
tacking it to the bottom-board. This is done to protect the bottom
of the boat.

Now you may already have a canoe that is perfectly water-tight,
and steady in the water, if it has been properly constructed of
good material. If not, however, in a few days you may be
disappointed to find that it is becoming leaky. Then the best
remedy is to cover the whole boat with unbleached muslin, sewed at
the ends and tacked along the gunwales. Then tighten it by
shrinking and finally give it at least three coats of a mixture of
varnish and paint. This will doubtless stop the leaking entirely
and will add but little to either the weight or cost.

Rig the boat with wooden or iron row locks (B, B, Fig. 5),
preferably iron, and light oars. You may put in

[Illustration: Off for a Hunt]

several extra thwarts or cross-sticks, fore and aft, and make a
movable seat (A, Fig. 5.) With this you will doubtless find your
boat so satisfactory that you will make no more changes.

For carrying the boat it is convenient to make a sort of short
yoke (C, Fig. 5), which brings all the weight upon the shoulders;
and thus lightens the labor and makes it very handy to carry.

** To Hang Heavy Things on a Nail [323]

Boys will find many places around

[Illustration: Double Nails]

the house, where a hook to hang things on will be a great
convenience. Instead of buying hooks use wire nails, and if driven
as shown in the cut, they will support very heavy weights. Drive
the lower nail first.

** A Home-Made Elderberry Huller [324]

As we had only one day to pick elderberries, we wanted to get as
many of them as we could in that time. We could pick them faster
than they could

[Illustration: Details of the Elderberry Huller]

be hulled by hand so we made a huller to take along with us to
hull the berries as fast as they were picked. We procured a box
and made a frame, Fig. 1, to fit it easily, then made another
frame the same size and put a piece of wire mesh between them as
shown in Fig. 2, allowing a small portion of the mesh to stick out
of the frames. The top frame would keep the berries from rolling
or jumping off, and the bottom frame kept the wire mesh and frame
from being shaken off the box. The projecting edges of the mesh
would keep the frame on the top edge of the box. The top view of
the frame is shown in Fig. 1 and the end in Fig. 5, and the box on
which the frame rests in Fig. 3. The actual size of the wire mesh
used is shown in Fig. 4. One person could hull with this huller as
many berries as two persons would pick.
--Contributed by Albert Niemann, Pittsburg, Pa.

** How to Make a Bulb on a Glass Tube [324]

As a great many persons during the winter months are taking
advantage of the long evenings to experiment in one way or
another, the following method of forming bulbs on glass tubes may
be of interest. A common method is to heat the part to be formed
and by blowing in one end of the tube gradually expand the glass.
This way has its drawbacks, as many are not sufficiently familiar
with the work to blow a uniform blast, and the result is, a hole
is blown through the side of the tube by uneven heating or

A good way to handle this work, is to take the tube and 1 or 2 in.
more in length than the finished article is to be and place one
end over an alcohol flame, and by holding a spare piece of tubing
against the end allow them both to come to a melting heat, then
pull apart and instead of breaking off the long thread thus
formed, simply hold it in the flame at an angle of 45 deg. and
melt it down and close the end at the same time. Close the other
end with the same operation; this makes the tube airtight.

Gradually heat the tube at the point where the bulb is to be
formed, slowly turning the tube to get a uniform heat. The air
inside of the tube becoming heated will expand, and the glass,
being softer where the flame has been applied, will be pushed out
in the shape of a bulb. A great deal of care should be taken not
to go to extremes, as the bulb will burst with a loud report if
the heat is applied too long. The best results are obtained by
heating the glass slowly and then the bulb can be formed with
regularity. This is an easy way to make a thermometer tube. After
the bulb is formed, the other end of the tube can be opened by
heating, drawing out and breaking the thread like glass.
--Contributed by A. Oswald.

** How to Make a Sconce [325]

A sconce is a candlestick holder, so made that it has a reflector
of brass or copper and is to hang upon the wall. The tools
necessary are a riveting hammer, file, metal shears, rivet punch,
flat and round-nosed pliers, screwdriver and sheet brass or copper
No. 23 gauge.

To make the sconce proceed as follows: First, cut off a piece of
brass so that it shall have 1/2 in. extra metal all around;
second, with a piece of carbon paper, trace upon the brass lines
that shall represent the margin of the sconce proper, also trace
the decorative design; third, with a nail set make a series of
holes in the extra margin about 3/4 in. apart and large enough to
take in a 3/4-in. thin screw; fourth, fasten the metal to a thick
board by inserting screws in these holes; fifth, with a
twenty-penny wire nail that has had the sharpness of its point
filed off, stamp the background of the design promiscuously. By
holding the nail about 1/4 in. above the work and striking it with
the hammer, at the same time striving to keep its point at 1/4 in.
above the metal, very rapid progress can be made. This stamping
lowers the background and at the same time raises the design.
Sixth, chase or stamp along the border of the design and
background using a nail filed to a chisel edge. This is to make a
clean sharp division between background and design. Seventh, when
the stamping is complete remove the screws and metal from the
board and cut off the extra margin with the metal shears. File the
edges until they are smooth to the touch.

The drip cup is a piece of brass cut circular and shaped by
placing the brass over a hollow in one end of a block. Give the
metal a circular motion, at the same time beat it with a
round-nosed mallet. Work from the center along concentric rings
outward, then reverse.

The candle holders may have two, three, four, or six arms, and are
bent to shape by means of the round-nosed

[Illustration: Completed Sconce; Shaping the Holders; Riveting]

pliers. The form of the brackets which support the drip cups may
be seen in the illustration.

Having pierced the bracket, drip cup, and holder, these three
parts are riveted together as indicated in the drawing. It will be
found easier usually if the holder is not shaped until after the
riveting is done. The bracket is then riveted to the back of the
sconce. Small copper rivets are used.

It is better to polish all the pieces before fastening any of them
together. Metal polish of any kind will do. After the parts have
been assembled a lacquer may be applied to keep the metal from

** How To Make a Hectograph [326]

[Illustration: Making Copies with the Hectograph]

A hectograph is very simply and easily made and by means of it
many copies of writing can be obtained from a single original.
Make a tray of either tin or pasteboard, a little larger than the
sheet of paper you ordinarily use and about 1/2 in. deep. Soak 1
oz. of gelatine in cold water over night and in the morning pour
off the water. Heat 6-1/2 oz. of glycerine to about 200 deg. F. on
a water bath, and add the gelatine. This should give a clear
glycerine solution of gelatine.

Place the tray so that it is perfectly level and pour in the
gelatinous composition until it is nearly level with the edge of
the tray. Cover it so the cover does not touch the surface of the
composition and let it stand six hours, when it will be ready for

Make the copy to be reproduced on ordinary paper with aniline ink;
using a steel pen, and making the lines rather heavy so they have
a greenish color in the light. A good ink may be made of methyl
violet 2 parts, alcohol 2 parts, sugar 1 part, glycerine 4 parts,
and water 24 parts. Dissolve the violet in the alcohol mixed with
the glycerine; dissolve the sugar in the water and mix both

When the original copy of the writing is ready moisten the surface
of the hectograph slightly with a sponge, lay the copy face down
upon it and smooth down, being careful to exclude all air bubbles
and not shifting the paper. Leave it nearly a minute and raise one
corner and strip it from the pad, where will remain a reversed
copy of the inscription.

Immediately lay a piece of writing paper of the right size on the
pad, smooth it down and then remove as before. It will bear a
perfect copy of the original. Repeat the operation until the
number of copies desired is obtained or until the ink on the pad
is exhausted. Fifty. or more copies can be obtained from a single

When through using the hectograph wash it off with a moist sponge,
and it will be ready for future use. If the surface is impaired at
any time it can be remelted in a water bath and poured into a tray
as before, if it has not absorbed too much ink.

** How to Make a Sailomobile [326]
By Frank Mulford, Shiloh, N. J.

I had read of the beach automobiles used on the Florida coast;
they were like an ice boat with a sail, except they had wheels
instead of runners. So I set to work to make something to take me
over the country roads.

I found and used seven fence pickets for the frame work, and other
things as they were needed. I spliced two rake handles together
for the mast, winding the ends where they came together with wire.
A single piece would be better if you can get one long enough. The
gaff, which is the stick to which the upper end of the sail is
fastened, is a broomstick. The boom, the stick at the bottom of
the sail, was made of a rake handle with a broomstick spliced to
make it long enough. Mother let me have a sheet, which I put down
on the floor and cut into the shape of a mainsail. The wind was
the cheapest power to be found, thus it was utilized; the three
wheels were cast-off bicycle wheels.

I steer with the front wheel, which was the front wheel of an old
bicycle with the fork left on. The axle between the rear wheels is
an iron bar which cost me 15 cents, and the pulley which raises
and lowers the sail cost 5 cents. Twenty cents was all I spent,
all the rest I found.

A saw, hammer, and brace and bit were the tools used. Slats made
the seat and a cushion from the house made it comfortable, and in
a week

[Illustration: Sailomobile for Use on Country Roads]

everything was ready for sailing.

Once it was started with only my little cousin in it and I had to
run fast to catch up.

** A Home-Made Magic Lantern [328]

The essential parts of a magic lantern are a condensing lens to
make the beam of light converge upon the slide to illuminate it
evenly, a projecting lens

[Illustration: Lantern House]

with which to throw an enlarged picture of the illuminated slide
upon a screen and some appliances for preserving the proper
relation of these parts to each other. The best of materials
should be used and the parts put together with care to produce a
clear picture on the screen.

The first to make is the lamp house or box to hold the light. Our
illustration shows the construction for an electric light, yet the
same box may be used for gas or an oil lamp, provided the material
is of metal. A tin box having dimensions somewhere near those
given in the diagrammatic sketch may be secured from your local
grocer, but if such a box is not found, one can be made from a
piece of tin cut as shown in Fig. 1. When this metal is bent at
right angles on the dotted lines it will form a box as shown in
Fig. 2

[Illustration: Magic Lantern Details]

which is placed on a baseboard, 1/2 to 3/4 in. thick, 8 in. wide,
and 14 in. long. This box should be provided with a reflector
located just back of the lamp.

Procure a plano-convex or a bi-convex 6-in. lens with a focal
length of from 15 to 20 in. and a projecting lens 2 in. in
diameter with such a focal length that will give a picture of the
required size, or a lens of 12-in. focus enlarging a 3-in. slide
to about 6 ft. at a distance of 24 ft.

The woodwork of the lantern should be of 1/2-in., well seasoned
pine, white wood or walnut and the parts fastened together with
wood screws, wire brads, or glue, as desired. The board in which
to mount the condensing lens is 16 in. wide and 15 in. high,
battened on both ends to keep the wood from warping. The board is
centered both ways, and, at a point 1 in. above the center,
describe a 9-in. circle with a compass and saw the wood out with a
scroll or keyhole saw. If a small saw is used, and the work
carefully done, the circular piece removed will serve to make the
smaller portion of the ring for holding the condensing lens. This
ring is made up from two rings, A and B, Fig. 3. The inside and
outside diameters of the ring B are 3/8 in. greater than the
corresponding diameters of ring A, so when fastened together
concentrically an inner rabbet is formed for the reception of the
lens and an outer rabbet to fit against the board C in and against
which it rotates being held in place by buttons, DD.

A table, E, about 2 ft. long is fastened to the board C with
brackets F and supported at the outer end with a standard. The
slide support, G, and the lens slide, H, are constructed to slip
easily on the table, E, the strips II serving as guides. Small
strips of tin, JJ, are bent as shown and fastened at the top and
bottom of the rectangular opening cut in the support G for holding
the lantern slides.

All the parts should be joined together snugly and the movable
parts made to slide freely and when all is complete and well
sandpapered, apply two coats of shellac varnish. Place the lamp
house on the bottom board behind the condensing lens and the
lantern is ready for use.

The proper light and focus may be obtained by slipping the movable
parts on the board E, and when the right position is found for
each, all lantern slides will produce a clear picture on the
screen, if the position of the lantern and screen is not changed.
--Contributed by Stuart Mason Kerr, St. Paul, Minn.

** A Quickly Made Lamp [329]

A very simple lamp can be made from materials which are available
in practically every household in the following manner: A cheap
glass tumbler is partly filled with water and then about 1/2 in.
of safe, light burning oil, placed on the water. Cut a thin strip
from an ordinary cork and make a hole in the center to carry a
short piece of wick. The wick should

[Illustration: Lamp]

be of such a length as to dip into the oil, but not long enough.
To reach the water. The upper surface of the cork may be protected
from the flame with a small piece of tin bent over the edges and a
hole punched in the center for the wick. The weight of the tin
will force the cork down into the oil. The level of the oil should
be such as to make the flame below the top of the tumbler and the
light then will not be blown out with draughts. The arrangement is
quite safe as, should the glass happen to upset, the water at once
extinguishes the flame.
--Contributed by G. P. B.

** How to Make a Paper Aeroplane [329]

A very interesting and instructive toy aeroplane can be made as
shown in the accompanying illustrations. A sheet

[Illustration: Folding the Paper]

of paper is first folded, Fig. 1, then the corners on one end are
doubled over, Fig. 2, and the whole piece finished up and held
together with a paper clip as in Fig. 3. The paper clip to be used
should be like the one shown in Fig. 4. If one of these clips is
not at hand, form a piece of wire in the same shape, as it will be
needed for balancing purposes as well as for holding the paper
together. Grasp the aeroplane between the thumb and forefinger at
the place marked A in Fig. 3, keeping the paper as level as
possible and throwing it as you would a dart. The aeroplane will
make an easy and graceful flight in a room where no air will
strike it.
--Contributed by J.H. Crawford, Schenectady, N. Y.

** Bronze Liquid [329]

Banana oil or amyl acetate is a good bronze liquid.

** A Wrestling Mat [330]

The cost of a wrestling mat is so great that few small clubs can
afford to own one. As we did not see our way

[Illustration: Made of Bed Mattresses]

clear to purchase such a mat, I made one of six used bed
mattresses (Fig. 1) purchased from a second-hand dealer. I ordered
a canvas bag, 12 ft. 3 in. by 12 ft. 9 in., from a tent company,
to cover the mattresses. The bag consisted of two pieces with the
seam along each edge. The mattresses were laid side by side and
end to end and the bag placed on and laced up as shown in Fig. 2.
--Contributed by Walter W. White, Denver, Colo.

** A Pocket Voltammeter [330]

Remove the works and stem from a discarded dollar watch, drill two
3/16 in. holes in the edge, 3/4 in. apart, and insert two
binding-posts, Fig. 1, insulating them from the case with
cardboard. Fold two strips of light cardboard, 1/2 in. wide, so as
to form two oblong boxes, 1/2 in. long and 3/16 in. thick, open on
the edges. On one of these forms wind evenly the wire taken from a
bell magnet to the depth of 1/8 in. and on the other wind some 20
gauge wire to the same depth. Fasten the wire with gummed label,
to keep it from unwinding.

Glue the coils to the back of the case and connect one wire from
each binding-post as shown in Fig. 2, while the other two wires
are connected to an induction coil lead which is inserted in the
hole from which the stem was removed. Fasten a brass-headed tack
to the case at the point F with sealing wax or solder and bend a
wire in the shape shown in Fig. 3 to swing freely on the tack.
Attach a piece of steel rod, 3/4 in. long, in the center coil, C,
Fig. 2.

A rubber band, D, connects the steel rod C with the top of the
watch case. The ends of the rubber are fastened with sealing wax.
The rubber keeps the pointer at zero or in the middle of the
scale. Do not use too strong a rubber. A dial may be made by
cutting a piece of stiff white paper so it will fit under the
crystal of the watch. An arc is cut in the paper, as shown in Fig.
1, through which the indicator works.

To calibrate the instrument, first mark the binding-post A, which
is connected to the coil of heavy wire, for amperes and the other
post, V, to the coil of small wire for volts. Connect the lead and
the post marked A to one, two and three cells and each time mark
the place of the pointer on the dial. Take corresponding readings
on a standard ammeter and mark the figures on the dial. The volt
side of the dial may be calibrated in the same manner, using a
voltmeter instead of the ammeter. The place where the

[Illustration: Voltammeter in a Watch Case]

indicator comes to rest after disconnecting the current is marked
--Contributed by Edward M. Teasdale, Warren, Pa.

** A Film Washing Trough [331]

[Illustration: Washing a Negative Film]

The washing of films without scratching them after they are
developed and fixed is very difficult in hot weather. A convenient
washing trough for washing full length films is shown in the
accompanying sketch. The trough must be made for the size of the
film to be washed. Cut a 1/4-in. board as long as the film and a
trifle wider than the film's width. Attach strips to the edges of
the board to keep the water from spilling over the sides.

Cut a hole in one side of a baking powder can about half way
between the top and bottom, large enough to admit a fair-sized
stream of water from a faucet. Then solder the cover to the can
and punch a number of holes about 1/4 in. apart along the opposite
side from where the large hole was cut. Place this can on one end
of the trough, as shown, with the large hole up.

Some heavy wire bent in the shape of a U and fastened to the under
side of the trough at the can end will furnish supports to keep
that end of the trough the highest and place the opening in the
can close beneath the water faucet. A common pin stuck through one
end of the film and then in the trough close to the can will hold
it in position for washing. Five minutes' washing with this device
is sufficient to remove all traces of the hypo from the film.
--Contributed by M. M. Hunting, Dayton, O.

** Wood Burning [331]

[Illustration: Burnt Wood]

Burnt wood work done with an ordinary reading glass and the sun's

** The Diving Bottle [331]

This is a very interesting and easily performed experiment
illustrating the transmission of pressure by liquids. Take a
wide-mouthed bottle and fill almost full of water; then into this
bottle place, mouth downward, a small vial or bottle having just
enough air in the bottle to keep it barely afloat. Put a sheet of
rubber over the mouth of the large bottle, draw the edge down over
the neck and wrap securely with a piece of string thus forming a
tightly stretched diaphragm over the top. When a finger is pressed
on the rubber the small bottle will slowly descend until the
pressure is released when the

[Illustration: Pressure Experiments]

small bottle wilt ascend. The moving of the small bottle is caused
by the pressure transmitted through the water, thus causing the
volume of air in the small tube to decrease and the bottle to
descend and ascend when released as the air increases to the
original volume.

This experiment can be performed with a narrow-necked bottle,
provided the bottle is wide, but not very thick. Place the small
bottle in as before, taking care not to have too much air in the
bottom. If the cork is adjusted properly, the bottle may be held
in the hand and the sides pressed with the fingers, thus causing
the small bottle to descend and ascend at will. If the small
bottle used is opaque, or an opaque tube such as the cap of a
fountain pen, many puzzling effects may be obtained. --Contributed
by John Shahan, Auburn, Ala.

** How to Make an Inexpensive Wooden Fan [332]

Select a nice straight-grained piece of white pine about 1/4 in.
thick, 3/4 in. wide and 4 in. long. Lay out the design desired and
cut as shown in Fig. 1, and then soak the wood in hot water to
make it soft and easy to split. Cut the divisions very thin with a
sharp knife down to the point A, as shown in the sketch, taking
care not to split the wood through the part left for the handle.
The fan is then finished by placing each piece over the other as
in Fig. 2. This will make a very pretty ornament.
--Contributed by Fred W. Whitehouse, Upper Troy, N.Y.

[Illustration: Cutting the Wood and Complete Fan]

** Combination Telegraph and Telephone Line [332]

The accompanying diagrams show connections for a short line system

[Illustration: Wiring Diagram]

(metallic circuit) of telegraph where a telephone may be used in
combination on the line. The telephone receivers can be used both
as receivers and transmitters, or ordinary telephone transmitters,
induction coils and battery may be used in the circuit with a
receiver. If a transmitter is used, its batteries may be connected
in circuit with a common push button which is held down when using
the telephone. On a 1000-ft. line, four dry cells will be
sufficient for the telegraph instruments and two cells for the
--Contributed by D. W. Milter.

** How to Make a Miniature Windmill [333]

The following description is how a miniature windmill was made,
which gave considerable power for its size, even in a light
breeze. Its smaller parts, such as blades and pulleys, were
constructed of 1-in. sugar pine on account of its softness.

The eight blades were made from pieces 1 by 1-1/2 by 12 in. Two
opposite edges were cut away until the blade was about 1/8 in.
thick. Two inches

[Illustration: Details of Miniature Windmill Construction]

were left uncut at the hub end. They were then nailed to the
circular face plate A, Fig. 1, which was 6 in. in diameter and 1
in. thick. The center of the hub was lengthened by the wooden
disk, B, Fig. 1, which was nailed to the face plate. The shaft C,
Fig. 1, was 1/4-in. iron rod, 2 ft. long, and turned in the
bearings detailed in Fig. 2. J was a nut from a wagon bolt and was
placed in the bearing to insure easy running. The bearing blocks
were 3 in. wide, 1 in. thick and 3 in. high without the upper
half. Both bearings were made in this manner.

The shaft C was keyed to the hub of the wheel, by the method shown
in Fig. 3. A staple, K, held the shaft from revolving in the hub.
This method was also applied in keying the 5-in. pulley F, to the
shaft, G, Fig. 1, which extended to the ground. The 2-1/2-in.
pulley, I, Fig. 1, was keyed to shaft C, as shown in Fig. 4. The
wire L was put through the hole in the axle and the two ends
curved so as to pass through the two holes in the pulley, after
which they were given a final bend to keep the pulley in place.
The method by which the shaft C was kept from working forward is
shown in Fig. 5. The washer M intervened between the bearing block
and the wire N, which was passed through the axle and then bent to
prevent its falling out. Two washers were placed on shaft C,
between the forward bearing and the hub of the wheel to lessen the

The bed plate D, Fig. 1, was 2 ft. long, 3 in. wide and 1 in.
thick and was tapered from the rear bearing to the slot in which
the fan E was nailed. This fan was made of 1/4-in. pine 18 by 12
in. and was cut the shape shown. The two small iron pulleys with
screw bases, H, Fig. 1, were obtained for a small sum from a
hardware dealer. Their diameter was 1-1/4 in. The belt which
transferred the power from shaft C to shaft G was top string, with
a section of rubber in it to take up slack. To prevent it from
slipping on the two wooden pulleys a rubber band was placed in the
grooves of each.

The point for the swivel bearing was determined by balancing the
bed plate, with all parts in place, across the thin edge of a
board. There a 1/4-in. hole was bored in which shaft G turned. To
lessen the friction here, washers were placed under pulley F. The
swivel bearing was made from two lids of baking powder cans. A
section was cut out of one to permit its being enlarged enough to
admit the other. The smaller one, 0, Fig. 6, was nailed top down
with the sharp edge to the underside of the bed plate, so that the
1/4-in. hole for the shaft G was in the center. The other lid, G,
was tacked, top down also, in the center of the board P, with
brass headed furniture tacks, R, Fig. 6, which acted as a smooth
surface for the other tin to revolve upon. Holes for shaft G were
cut through both lids. Shaft G was but 1/4 in. in diameter, but to
keep it from rubbing against the board P, a 1/2-in. hole was bored
for it, through the latter.

The tower was made of four 1 by 1 in. strips, 25 ft. long. They
converged from points on the ground forming an 8-ft. square to the
board P at the top of the tower. This board was 12 in. square and
the corners were notched to admit the strips as shown, Fig. 1.
Laths were nailed diagonally between the strips to strengthen the
tower laterally. Each strip was screwed to a stake in the ground
so that by disconnecting two of them the other two could be used
as hinges and the tower could be tipped over and lowered to the
ground, as, for instance, when the windmill needed oiling.
Bearings for the shaft G were placed 5 ft. apart in the tower. The
power was put to various uses.

** How to Make a Telegraph Instrument and Buzzer [334]

The only expenditure necessary in constructing this telegraph
instrument is the price of a dry cell, providing one has a few old
materials on hand. Procure a block of wood about 6 in. long and 3
in. wide and take the coils out of an old electric bell. If you
have no bell, one may be had at the dealers for a small sum.
Fasten these coils on the blocks at one end as in Fig. 1. Cut a
piece of tin 2 in. long and 1/2 in. wide and bend it so the end of
the tin

[Illustration: Home-Made Telegraph Instrurment]

when fastened to the block will come just above the core of the
coil. Cut another piece of tin 3 in. long and bend it as shown at
A, Fig. 2. Tack these two pieces of tin in front of the coils as
shown in the illustration. This completes the receiver or sounder.

To make the key, cut out another piece of tin (X, Fig. 1) 4 in.
long and bend it as shown. Before tacking it to the board, cut off
the head of a nail and drive it in the board at a point where the
loose end of the tin will cover it. Then tack the key to the board
and connect the wires of the battery as in Fig. 1. Now, move the
coils back and forth until the click sounds just the way you wish
and you are ready to begin on the Morse code.

When tired of this instrument, connect the wire from the coils to
the key to point A and the one connected at the point under the
key to B, leaving the other wire as it is. By adjusting the coils,
the receiver will begin to vibrate rapidly, causing a buzzing
--Contributed by John R. McConnell.

** How to Make a Water Bicycle [335]

Water bicycles afford fine sport, and, like many another device
boys make, can be made of material often cast off by their people
as rubbish. The principle material necessary for the construction
of a water bicycle is oil barrels. Flour barrels will not do-they
are not strong enough, nor can they be made perfectly airtight.
The grocer can furnish you with oil barrels at a very small cost,
probably let you have them for making a few deliveries for him.
Three barrels are required for the water bicycle, although it can
be made with but two. Figure 1 shows the method of arranging the
barrels; after the manner of bicycle wheels.

Procure an old bicycle frame and make for it a board platform
about 3 ft. wide at the rear end and tapering to about 2 ft. at
the front, using cleats to hold the board frame, as shown at

[Illustration: Water, Bicycle Complete]

the shaded portion K. The construction of the barrel part is shown
in Fig. 2. Bore holes in the center of the heads of the two rear
barrels and also in the heads of the first barrel and put a shaft
of wood, through the rear barrels and one through the front
barrel, adjusting the side pieces to the shafts, as indicated.

Next place the platform of the bicycle frame and connections
thereon. Going back to Fig. 1 we see that the driving chain passes
from the sprocket driver L of the bicycle frame to the place
downward between the slits in the platform to the driven sprocket
on the shaft between the two barrels. Thus a center drive is made.
The rear barrels are, fitted with paddles as at M, consisting of
four pieces of board nailed

[Illustration: Barrel Float for Bicycle]

and deated about the circumference of the barrels, as shown in
Fig. 1.

The new craft is now ready for a first voyage. To propel it, seat
yourself on the bicycle seat, feet on the pedals, just as you
would were you on a bicycle out in the street. The steering is
effected by simply bending the body to the right or left, which
causes the craft to dip to the inclined side and the affair turns
in the dipped direction. The speed is slow at first, but increases
as the force is generated and as one becomes familiar with the
working of the affair. There is no danger, as the airtight barrels
cannot possibly sink.

Another mode of putting together the set of barrels, using one
large one in the rear and a small one in the front is presented in
Fig, 3. These two barrels are empty oil barrels like the others.
The head holes are bored and the proper wooden shafts are inserted
and the entrance to the bores closed tight by calking with hemp
and putty or clay. The ends of the shafts turn in the wooden frame
where the required bores are made to receive the same. If the
journals thus made are well oiled, there will not be much
friction. Such a frame can be fitted with a platform and a raft to
suit one's individual fancy built upon it, which can

[Illustration: Another Type of Float]

be paddled about with ease and safety on any pond. A sail can be
rigged up by using a mast and some sheeting; or even a little
houseboat, which will give any amount of pleasure, can be built.

** How To Make a Small Searchlight [336]

The materials required for a small searchlight are a 4-volt lamp
of the loop variety, thin sheet brass for the cylinder, copper
piping and brass tubing for base. When completed the searchlight
may be fitted to a small boat and will afford a great amount

[Illustration: Searchlight]

of pleasure for a little work, or it may be put to other uses if

Make a cylinder of wood of the required size and bend a sheet of
thin brass around it. Shape small blocks of boxwood, D, Fig. 1, to
fit the sides and pass stout pieces of brass wire through the
middle of the blocks for trunnions. Exactly through the middle of
the sides of the cylinder drill holes just so large that when the
blocks containing the trunnions are cemented to the cylinder there
is no chance of contact between cylinder and trunnion, and so
creating a false circuit.

The trunnion should project slightly into the cylinder, and after
the lamp has been placed in position by means of the small wood
blocks shown in Fig. 1, the wires from the lamp should be soldered
to the trunnions. It is best to solder the wire to the trunnions
before cementing the side blocks inside the cylinder.

Turn a small circle of wood, A, Fig. 2, inside the cylinder to fit
exactly and fasten to it a piece of mirror, C, Fig. 2, exactly the
same size to serve as a reflector. Painting the wood with white
enamel or a piece of brightly polished metal will serve the
purpose. On the back of the piece of wood fasten a small brass
handle, B, Fig. 2, so that it may readily be removed for cleaning.

In front of cylinder place a piece of magnifying glass for a lens.
If a piece

[Illustration: Front View; Side View]

to fit cannot be obtained, fit a glass like a linen tester to a
small disc of wood or brass to fit the cylinder. If magnifying
glass cannot be had, use plain glass and fit them as follows:

Make two rings of brass wire to fit tightly into the cylinder,
trace a circle (inside diameter of cylinder) on a piece of
cardboard; place cardboard on glass and cut out glass with a glass
cutter; break off odd corners with notches on cutters and grind
the edge of the glass on an ordinary red brick using plenty of
water. Place one brass ring in cylinder, then the glass disc and
then the other ring.

For the stand fill a piece of copper piping with melted rosin or
lead. When hard bend the pipe around a piece of wood which has
been sawed to the shape of bend desired. Then melt out the rosin
or lead. Make an incision with a half-round file in the under side
of the tube for the wires to come through. Make the base of wood
as shown in Fig. 1. One half inch from the top bore a hole large
enough to admit the copper pipe and a larger hole up the center to
meet it for the wires to come down.

If it is desired to make the light very complete, make the base of
two pieces of brass tube--one being a sliding fit in the other and
with projecting pieces to prevent the cylinder from going too far.
The light may then be elevated or lowered as wished. On two
ordinary brass terminals twist or solder some flexible wire, but
before doing so fix a little bone washer on the screws of the
terminal so as to insulate it from the tube. When the wires have
been secured to the terminals cover the joint with a piece of very
thin india rubber tubing, such as is used for cycle valves. The
two wires may now be threaded down the copper tube into the base,
and pulled tight, the terminals firmly fixed into the tubes; if
too small, some glue will secure them. To get the cylinder into
its carriage, put one trunnion into the terminal as far as it will
go and this will allow room for the other trunnion to go in its

** Electric Alarm that Rings a Bell and Turns on a Light [337]

The illustration shows an alarm clock connected up to ring an
electric bell, and at the same time turn on an electric light to
show the time. The parts indicated are as follows: A, key of alarm
clock; B, contact post, 4 in. long; C, shelf, 5-1/4 by 10 in.; D,
bracket; E, electric bulb (3-1/2 volts) ; S, brass strip, 4-1/2
in. long, 3/8 in. wide and 1/16 in. thick; T, switch; F, wire from
batteries to switch; G, wire from bell to switch; H, wire from
light to switch; I, dry batteries; J, bell; X, point where a
splice is made from the light to wire leading to batteries from
brass strip under clock. Push the switch lever to the right before

To operate this, set alarm key as shown in diagram, after two
turns have been made on the key. When alarm goes off, it turns
till it forms a connection by striking the contact post and starts
the electric bell ringing. Throw lever off from the right to
center, which stops bell ringing. To throw on light throw levers
to the left. The bell is then cut out but the light remains on
till lever is again thrown in the center,

[Illustration: Details of Alarm Construction]

In placing clock on shelf, after setting alarm, be sure that the
legs of clock are on the brass strip and that the alarm key is in
position so it will come in contact with the contact post in back
of clock. The contact post may be of 1/4-in. copper tubing, or
1/4-in. brass rod.

The advantage of this is that one can control the bell and light,
while lying in bed, by having the switch on the baseboard, near
the bed, so it can be reached without getting out of bed.
--Contributed by Geo. C. Brinkerhoff, Swissvale, Pa.

** How to Hold a Screw on a Screwdriver [337]

A screw that is taken from a place almost inaccessible with the
fingers requires considerable patience to return it with an
ordinary screwdriver unless some holding-on device is used. I have
found that by putting a piece of cardboard or thick paper with the
blade of the screwdriver in the screw head slot, the screw may be
held and turned into places that it would be impossible with the
screwdriver alone.
--Contributed by C. Chatland, Ogden, Utah.

** How to Make a Lead Cannon [338]

Any boy who has a little mechanical ability can make a very
reliable cannon for his Fourth-of-July celebration by following
the instructions given here:

[Illustration: Lead Cannon Construction]

Take a stick--a piece of curtain roller will do--7 in. long. Make
a shoulder, as at A, Fig. 1, 4 in. from one end, making it as true
and smooth as possible, as this is to be the muzzle of the cannon.
Make the spindle as in Fig. 1, 1/4 in. in diameter. Procure a good
quality of stiff paper, about 6 in. wide, and wrap it around the
shoulder of the stick, letting it extend 3/4 in. beyond the end of
the spindle, as at B, Fig. 2. Push an ordinary shingle nail
through the paper and into the extreme end of the spindle, as at
A, Fig. 2. This is to form the fuse hole.

Having finished this, place stick and all in a pail of sand, being
careful not to get the sand in it, and letting the opening at the
top extend a little above the surface of the sand. Then fill the
paper cylinder with melted lead and let cool. Pull out the nail
and stick, scrape off the paper and the cannon is ready for
mounting, as in Fig. 3.
--Contributed by Chas. S. Chapman, Lanesboro, Minn.

** Homemade Electric Bed Warmer [338]

The heat developed by a carbon-filament lamp is sufficiently high
to allow its use as a heating element of, for instance, a bed
warmer. There are a number of other small heaters which can be
easily made and for which lamps form very suitable heating
elements, but the bed warmer is probably the best example. All
that is required is a tin covering, which can be made of an old
can, about 3-1/2 in. in diameter. The top is cut out and the edge
filed smooth. The lamp-socket end of the flexible cord is inserted
in the can and the shade holder gripped over the opening. A small
lamp of about 5 cp. will do the heating.

A flannel bag, large enough to slip over the tin can and provided
with a neck that can be drawn together by means of a cord, gives
the heater a more finished appearance, as well as making it more
pleasant to the touch.

** Making a Fire with the Aid of Ice [338]

Take a piece of very clear ice and melt it down into the hollow of
your hands so as to form a large lens. The illustration shows how
this is done. With the lens-shaped ice used in the same manner as
a reading glass to

[Illustration: Forming the Ice Lens]

direct the sun's rays on paper or shavings you can start a fire.
--Contributed by Arthur E. Joerin.

** How to Make a Crossbow and Arrow Sling [339]

In making of this crossbow it is best to use maple for the stock,
but if this wood cannot be procured, good straight-grained pine
will do. The

[Illustration: Details of the Bow-Gun and Arrow Sling]

material must be 1-1/2 in. thick, 6 in. wide and a trifle over 3
ft. long. The bow is made from straight-grained oak, ash, or
hickory, 5/8 in. thick, 1 in. wide and 3 ft. long. A piece of oak,
3/8 in. thick, 1-1/2 in. wide and 6 ft. long, will be sufficient
to make the trigger, spring and arrows. A piece of tin, some nails
and a good cord will complete the materials necessary to make the

The piece of maple or pine selected for the stock must be planed
and sandpapered on both sides, and then marked and cut as shown in
Fig. 1. A groove is cut for the arrows in the top straight edge
3/8 in. wide and 3/8 in. deep. The tin is bent and fastened on the
wood at the back end of the groove where the cord slips out of the
notch; this is to keep the edges from splitting.

A mortise is cut for the bow at a point 9-1/2 in. from the end of
the stock, and one for the trigger 12 in. from the opposite end,
which should be slanting a little as shown by the dotted lines. A
spring, Fig. 2, is made from a good piece of oak and fastened to
the stock with two screws. The trigger, Fig. 3, which is 1/4 in.
thick, is inserted in the mortise in the position when pulled
back, and adjusted so as to raise the spring to the proper height,
and then a pin is put through both stock and trigger, having the
latter swing quite freely. When the trigger is pulled, it lifts
the spring up, which in turn lifts the cord off the tin notch.

The stick for the bow, Fig. 4, is dressed down from a point 3/4
in. on each side of the center line to 1/2 in. wide at each end.
Notches are cut in the ends for the cord. The bow is not fastened
in the stock, it is wrapped with a piece of canvas 1-1/2 in. wide
on the center line to make a tight fit in the mortise. A stout
cord is now tied in the notches cut in the ends of the bow making
the cord taut when the wood is straight.

The design of the arrows is shown in Fig. 5 and they are made with
the blades much thinner than the round part.

To shoot the crossbow, pull the cord back and down in the notch as
shown in Fig. 6, place the arrow in the groove, sight and pull the
trigger as in shooting an ordinary gun.

The arrow sling is made from a branch of ash about 1/2 in. in
diameter, the bark removed and a notch cut in one end, as shown in
Fig. 7. A stout cord about 2-1/2 ft. long is tied in the notch and
a large knot made in the other or loose end. The arrows are
practically the same as those used on the crossbow, with the
exception of a small notch which is cut in them as shown in Fig.

To throw the arrow, insert the cord near the knot in the notch of
the arrow, then grasping the stick with the right hand and holding
the wing of the arrow with the left, as shown in Fig. 9, throw the
arrow with a quick slinging motion. The arrow may be thrown
several hundred feet after a little practice.
--Contributed by O. E. Trownes, Wilmette, Ill.

** A Home-Made Vise [340]

Cut two pieces of wood in the shape shown in the sketch and bore a
3/8-in. hole through both of them for a common carriage bolt.
Fasten one of the pieces to the edge of the bench with a large
wood screw and attach the other piece to the first one with a
piece of leather nailed across the bottom of both pieces. The nut
on the carriage bolt may be tightened with a wrench,

[Illustration: Details of a Home-Made Bench Vise]

or, better still, a key filed out of a piece of soft steel to fit
the nut. The edges of the jaws are faced with sheet metal which
can be copper or steel suitable for the work it is intended to

** Temporary Dark Room Lantern [340]

Occasionally through some accident to the regular ruby lamp, or
through the necessity of, developing while out of reach of a
properly equipped dark room, some makeshift of illumination must
be improvised. Such a temporary safe light may be made from an
empty cigar box in a short time.

[Illustration: Lantern]

Remove the bottom of the box, and nail it in position as shown at
A. Remove one end, and replace as shown at B. Drive a short wire
nail through the center of the opposite end to serve as a seat for
the candle, C. The lamp is finished by tacking two or more layers
of yellow post-office paper over the aperture D, bringing the
paper well around to the sides and bottom of the box to prevent
light leakage from the cracks around the edges, says Photo Era.
The hinged cover E, is used as a door, making lighting and
trimming convenient. The door may be fastened with a nail or piece
of wire. It is well to reinforce the hinge by gluing on a strip of
cloth if the lamp is to be in use more than once or twice. This
lamp is safe, for the projecting edges of A and B form
light-shields for the ventilation orifice and the crack at the top
of the hinged cover, respectively. Moreover, since the flame of
the candle is above A, only reflected and transmitted light
reaches the plate, while the danger of igniting the paper is
reduced to a minimum.

** Runny Paint [340]

The paint will sag and run if too much oil is put in white lead.

** Camps and How to Build Them [341]

There are several ways of building a temporary camp from material
that is always to be found in the woods, and whether these
improvised shelters are intended to last until a permanent camp is
built, or only as a camp on a short excursion, a great deal of fun
can be had in their construction. The Indian camp is the easiest
to make. An evergreen tree with branches growing well down toward
the ground furnishes all the material. By chopping the trunk
almost through, so that when the tree falls the upper part will
still remain attached to the stump, a serviceable shelter can be
quickly provided. The cut should be about 5 ft. from the ground.
Then the boughs and branches on the under side of the fallen top
are chopped away and piled on top. There is room for several
persons under this sort of shelter, which offers fairly good
protection against any but the most drenching rains.

The Indian wigwam sheds rain better, and where there are no
suitable trees that can be cut, it is the easiest camp to make.
Three long poles with the tops tied together and the lower ends
spaced 8 or 10 ft. apart, make the frame of the wigwam. Branches
and brush can easily be piled up, and woven in and out on these
poles so as to shed a very heavy rain.

The brush camp is shaped like an ordinary "A" tent. The ridge pole
should be about 8 ft. long and supported by crotched uprights
about 6 ft. from the ground. Often the ridge pole can be laid from
one small tree to another. Avoid tall trees on account of
lightning. Eight or ten long poles are then laid slanting against
the ridge pole on each side. Cedar or hemlock boughs make the best
thatch for the brush camp. They should be piled up to a thickness
of a foot or more over the slanting poles and woven in and out to
keep them from slipping. Then a number of poles should be laid
over them to prevent them from blowing away. In woods where there
is plenty of bark available in large slabs, the bark lean-to is a
quickly constructed and serviceable camp. The ridge pole is set up
like that of the brush camp. Three or four other poles are laid
slanting to the ground on one side only. The ends of these poles
should be pushed into the earth and fastened with crotched sticks.
Long poles are then laid crossways of these slanting poles, and
the whole can be covered with brush as in the case of the brush
camp or with strips of bark laid overlapping each other like
shingles. Where bark is used, nails are necessary to hold it in
place. Bark may also be used for a wigwam and it can be held in
place by a cord wrapped tightly around the whole structure,
running spiral-wise from the ground to the peak. In the early
summer, the bark can easily be removed from most trees by making
two circular cuts around the trunk and joining them with another
vertical cut. The bark is easily pried off with an ax, and if laid
on the ground under heavy stones, will dry flat. Sheets of bark, 6
ft. long and 2 or 3 ft. wide, are a convenient size for camp

The small boughs and twigs of hemlock, spruce, and cedar, piled 2
or 3 ft. deep and covered with blankets, make the best kind of a
camp bed. For a permanent camp, a bunk can be made by laying small
poles close together across two larger poles on a rude framework
easily constructed. Evergreen twigs or dried leaves are piled on
this, and a blanket or a piece of canvas stretched across and
fastened down to the poles at the sides. A bed like this is soft
and springy and will last through an ordinary camping season
without renewal. A portable cot that does not take up much room in
the camp outfit is made of a piece of heavy canvas 40 in. wide and
6 ft. long. Four-inch hems are sewed in each side of the canvas,
and when the camp is pitched, a 2-in. pole is run through each hem
and the ends of the pole supported on crotched sticks.

[Illustration: Camp Details]

Fresh water close at hand and shade for the middle of the day are
two points that should always be looked for in. selecting a site
for a camp. If the camp is to be occupied for any length of time,
useful implements for many purposes can be made out of such
material as the woods afford. The simplest way to build a crane
for hanging kettles over the campfire is to drive two posts into
the ground, each of them a foot or more from one end of the fire
space, and split the tops with an ax, so that a pole laid from one
to the other across the fire will be securely held in the split.
Tongs are very useful in camp. A piece of elm or hickory, 3 ft.
long and 1-1/2 in. thick, makes a good pair of tongs. For a foot
in the middle of the stick, cut half of the thickness away and
hold this part over the fire until it can be bent easily to bring
the two ends together, then fasten a crosspiece to hold the ends
close together, shape the ends so that anything that drops into
the fire can be seized by them, and a serviceable pair of tongs is
the result. Any sort of a stick that is easily handled will serve
as a poker. Hemlock twigs tied around one end of a stick make an
excellent broom. Movable seats for a permanent camp are easily
made by splitting a log, boring holes in the rounded side of the
slab and driving pegs into them to serve as legs. A short slab or
plank can easily be made into a three-legged stool in the same

Campers usually have boxes in which their provisions have been
carried. Such a packing box is easily made into a cupboard, and it
is not difficult to improvise shelves, hinges, or even a rough
lock for the camp larder.

A good way to make a camp table is to set four posts into the
ground and nail crosspieces to support slabs cut from chopped wood
logs to form a top. Pieces can be nailed onto the legs of the
table to hold other slabs to serve as seats, and affording
accommodation for several persons.

** Brooder for Small Chicks [343]

A very simple brooder can be constructed by cutting a sugar barrel
in half and using one part in the manner

[Illustration: Brooder for Young Chicks Kept Warm with a Jug of
Boiling Water]

described. Line the inside of the half barrel with paper and then
cover this with old flannel cloth. Make a cover for the top and
line it in the same manner. At the bottom cut a hole in the edge,
about 4 in. deep and 4 in. wide, and provide a cover or door. The
inside is kept warm by filling a jug with boiling water and
setting it within, changing the water both morning and night. When
the temperature outside is 10 deg. the interior can, be kept at 90
or 100 deg., but the jug must be refilled with boiling water at
least twice a day.

** Faucet Used as an Emergency Plug [343]

A brass faucet split as shown at A during a cold spell, and as no
suitable plug to screw into the elbow after removing the faucet
was at hand, I drove a small cork, B, into the end of the faucet
and screwed it back in place. The cork converted the faucet into

[Illustration: A Tight-Fitting Cork Driven into a Cracked Faucet
Converted It into an Emergency Plug]

emergency plug which prevented leakage until the proper fitting to
take its place could be secured.
--Contributed by James M. Kane, Doylestown, Pa.

** Automatic Electric Heat Regulator [344]

It is composed of a closed glass tube, A, Fig. 1, connected by
means of a very small lead pipe, B, to another

[Illustration: Heat Regulator]

glass tube, C, open at the bottom and having five pieces of
platinum wire (1, 2, 3, 4 and 5), which project inside and outside
of the tube, fused into one side. This tube is plunged into an
ebonite vessel of somewhat larger diameter, which is fastened to
the base by a copper screw, E. The tube C is filled to a certain
height with mercury and then petroleum. The outer ends of the five
platinum wires are soldered to ordinary copper wires and
connections made to various points on a rheostat as shown. The
diagram, Fig. 2, shows how the connections to the supply current
are made. The apparatus operates as follows: The tube is immersed
in the matter to be heated, a liquid, for instance. As

[Illustration: Wiring Diagram Showing How the Connections to a
Source of Current Supply are Made]

the temperature of this rises, the air expands and exerts pressure
on the petroleum in the tube C so that the level of the mercury is
lowered. The current is thus compelled, as the platinum wires with
the fall of the mercury are brought out of circuit, to pass
through an increasing resistance, until, if necessary, the flow is
entirely stopped when the mercury falls below the wire 5.

With this very simple apparatus the temperature can be kept
constant within a 10-deg. limit, and it can be made much more
sensitive by increasing the number of platinum wires and placing
them closer together, and by filling the tube A with some very
volatile substance, such as ether, for instance. The petroleum
above the mercury prevents sparking between the platinum wire and
the mercury when the latter falls below anyone of them.

** Repairing a Washer on a Flush Valve [344]

When the rubber washer on the copper flush valve of a soil-basin
tank becomes loose it can be set by pouring a small quantity of
paraffin between the rubber and the copper while the valve is
inverted, care being taken to have the rubber ring centered. This

[Illustration: Flush Valve]

a repair that will not allow a drop ot water to leak out of the
--Contributed by Frank Jermin, Alpena, Michigan.

** Cleaning Discolored Silver [344]

A very quick way to clean silver when it is not tarnished, but
merely discolored, is to wash the articles in a weak solution of
ammonia water. This removes the black stains caused by sulphur in
the air. After cleaning them with the solution, they should be
washed and polished in magnesia powder or with a cloth. This
method works well on silver spoons tarnished by eggs and can be
used every day while other methods require much time and,
therefore, cannot be used so often.

** How to Make a Small Electric Motor [345]

The field frame of the motor, Fig. 1, is composed of wrought sheet
iron, which may be of any thickness so that, when several pieces
are placed together, they will make a frame 3/4 in. thick. It is
necessary to layout a template of the frame as shown, making it
1/16 in. larger than the dimensions given, to allow for filing to
shape after the parts are fastened together. After the template is
marked out, drill the four rivet holes, clamp the template, or
pattern, to the sheet iron and mark carefully with a scriber. The
bore can be marked with a pair of dividers, set at 1/8 in. This
will mark a line for the center of the holes to be drilled with a
1/4-in. drill for removing the unnecessary metal. The points
formed by drilling the holes can be filed to the pattern size. Be
sure to mark and cut out a sufficient number of plates to make a
frame 3/4 in. thick, or even 1/16 in. thicker, to allow for

After the plates are cut out and the rivet holes drilled, assemble
and rivet them solidly, then bore it out to a diameter of 2-3/4
in. on a lathe. If the thickness is sufficient, a slight finishing
cut can be taken on the face. Before removing the field from the
lathe, mark off a space, 3-3/8 in. in diameter, for the field core
with a sharp-pointed tool, and for the outside of the frame, 4-1/2
in. in diameter, by turning the lathe with the hand. Then the
field can be finished to these marks, which will make it uniform
in size. When the frame is finished so far, two holes, 3-3/8 in.
between centers, are drilled and tapped with a 3/8-in. tap. These
holes are for the bearing studs. Two holes are also drilled and
tapped for 1/4-in. screws, which fasten the holding-down lugs or
feet to the frame. These lugs are made of a piece of 1/8-in. brass
or iron, bent at right angles as shown.

The bearing studs are now made, as shown in Fig. 2, and turned
into the threaded holes in the frame. The bearing supports are
made of two pieces of 1/8-in. brass, as shown in the left-hand
sketch, Fig. 3, which are fitted on the studs in the frame. A
5/8-in. hole is

[Illustration: The Field-Coil Core is Built Up of Laminated
Wrought Iron Riveted Together]

drilled in the center of each of these supports, into which a
piece of 5/8-in. brass rod is inserted, soldered into place, and
drilled to receive the armature shaft. These bearings should be
fitted and soldered in place after the armature is constructed.
The manner of doing this is to wrap a piece of paper on the
outside of the finished armature ring and place it through the
opening in the field, then slip the bearings on the ends of the
shaft. If the holes in the bearing support should be out of line,
file them out to make the proper adjustment. When the bearings are
located, solder them to the supports, and build up the solder
well. Remove

[Illustration: The Bearing Studs are Turned from Machine Steel Two
of Each Length being Required]

the paper from the armature ring and see that the armature
revolves freely in the bearings without touching the inside of the
field at any point. The supports are then removed and the solder
turned up in a lathe, or otherwise finished. The shaft of the
armature, Fig. 4, is turned up from machine steel, leaving the
finish of the bearings until the armature is completed and
fastened to the shaft.

The armature core is made up as

[Illustration: The Assembled Bearing Frame on the Field Core and
the Armature Shaft Made of Machine Steel]

follows: Two pieces of wrought sheet iron, 1/8 in. thick, are cut
out a little larger than called for by the dimensions given in
Fig. 5, to allow for finishing to size. These are used for the
outside plates and enough pieces of No. 24 gauge sheet iron to
fill up the part between until the whole is over 3/4 in. thick are
cut like the pattern. After the pieces are cut out, clamp them
together and drill six 1/8-in. holes through them for rivets.
Rivet them together, and anneal the whole piece by placing it in a
fire and heating the metal to a cherry red, then allowing it to
cool in the ashes. When annealed, bore out the inside to 1-11/16
in. in diameter and fit in a brass spider, which is made as
follows: Procure a piece of brass, 3/4 in. thick, and turn it up
to the size shown and file out the metal between the arms. Slip
the spider on the armature shaft and secure it solidly with the
setscrew so that the shaft will not turn in the spider when truing
up the armature core. File grooves or slots in the armature ring
so that it will fit on the arms of the spider. Be sure to have the
inside of the armature core run true. When this is accomplished,
solder the arms of the spider to the metal of the armature core.
The shaft with the core is then put in a lathe and the outside
turned off to the proper size. The sides are also faced off and
finished. Make the core 3/4 in. thick. Remove the core from the
lathe and file out slots 1/4 in. deep and 7/16 in. wide.

The commutator is turned from a piece of brass pipe, 3/4 in.
inside diameter, as shown in Fig. 6; The piece is placed on a
mandrel and turned to 3/4 in. in length and both ends chamfered to
an angle of 60 deg. Divide the surface into 12 equal parts, or
segments. Find the centers of each segment at one end, then drill
a 1/8-in. hole and tap it for a pin. The pins are made of brass,
threaded, turned into place and the ends turned in a lathe to an
outside diameter of 1-1/4 in. Make a slit with a small saw blade
in the end of each pin for the ends of the wires coming from the
commutator coils. Saw the ring into the 12 parts on the lines
between the pins.

The two insulating ends for holding these segments are made of
fiber turned to fit the bore of the brass tubing, as shown in Fig.
7. Procure 12 strips of mica, the same thickness as the width of
the saw cut made between the segments, and use them as a filler
and insulation between the commutator

[Illustration: Armature-Ring Core, Its Hub and the Construction of
the Commutator and Its Insulation]

bars. Place them on the fiber hub and slip the hub on the shaft,
then clamp the whole in place with the nut, as shown in Fig. 3.
True up the commutator in a lathe to the size given in Fig. 6.

The brush holder is shaped from apiece of fiber, as shown in Fig.
8. The studs for holding the brushes are cut from 5/16-in. brass
rod, as shown in Fig. 9. The brushes consist of brass or copper
wire gauze, rolled up and flattened out to 1/8 in. thick and 1/4
in. wide, one end being soldered to keep the wires in place. The
holder is slipped on the projecting outside end of the bearing, as
shown m Fig. 3, and held with a setscrew.

The field core is insulated before winding with 1/64-in. sheet
fiber, washers, 1-1/8 in. by 1-1/2 in., being formed for the ends,
with a hole cut in them to fit over the insulation placed on the
cores. A slit is cut through from the hole to the outside, and
then they are soaked in warm water, until they become flexible
enough to be put in place. After they have dried, they are glued
to the core insulation.

The field is wound with No. 18 gauge double-cotton-covered magnet
wire, about 100 ft. being required. Drill a small hole through
each of the lower end insulating washers. In starting to wind,
insert the end of the wire through the hole from the inside at A
Fig. 1, and wind on four layers, which will take 50 ft. of the
wire, and bring the end of the wire out at B. After one coil, or
side, is wound start at C in the same manner as at A, using the
same number of turns and the same length of wire. The two ends are
joined at B.

The armature ring is insulated by covering the inside and brass
spider with 1/16-in. sheet fiber. Two rings of 1/16-in sheet fiber
are cut and glued to the sides of the ring. When the glue is set,
cut out the part within the slot ends and make 12 channel pieces
from 1/64-in. sheet fiber, which are glued in the slots and to the
fiber washers. Be sure to have the ring and spider covered so the
wire will not touch the iron or brass.

Each slot of the armature is wound with about 12 ft. of No. 21
gauge double-cotton-covered magnet wire. The winding is started at
A, Fig. 5, by bending the end around one of the projections, then
wind the coil in one of the slots as shown, making 40 turns or
four layers of 10 turns each shellacking each layer as it is
wound. After the coil is completed in one slot allow about 2 in.
of the end to protrude, to

[Illustration: The Insulated Brush Holder and Its Studs for
Holding the Brushes on the Commutator]

fasten to the commutator segment. Wind the next slot with the same
number of turns in the same manner and so on, until the 12 slots
are filled. The protruding ends of the coils are connected to the
pins in the commutator segments after the starting end of one
coils is joined to the finishing end of the next adjacent. All
connections should be securely soldered.

The whole motor is fastened with screws to a wood base, 8 in.
long, 6 in. wide and 1 in. thick. Two terminals are fastened at
one side on the base and a switch at the other side.

To connect the wires, after the motor is on the stand, the two
ends of the wire, shown at B, Fig. 1, are soldered together. Run
one end of the field wire, shown at A, through a small hole in the
base and make a groove on the under side so that the wire end can
be connected to one of the terminals The other end of the field
wire C is connected to the brass screw in the brass brush stud.
Connect a wire from the other brush stud, run it through a small
hole in the base and cut a groove for it on the under side so that
it can be connected through the switch and the other terminal.
This winding is for a series motor. The source of current is
connected to the terminals. The motor can be run on a 110-volt
direct current, but a resistance must be placed in series with it.

** Protecting Tinware [347]

New tinware rubbed over with fresh lard and heated will never

** Another Optical Illusion [348]

After taking a look at the accompanying illustration you will be
positive that the cords shown run in a spiral toward the center,
yet it shows a series of

[Illustration: The Cord Is Not a Spiral]

perfect circles of cords placed one inside the other. You can test
this for yourself in a moment with a pair of compasses, or, still
more simply, by laying a point of a pencil on any part of the cord
and following it round. Instead of approaching or receding from
the center in a continuous line, as in the case of a spiral, you
will find the pencil returning to the point from which it started.

** Substitute for Insulating Cleats [348]

In wiring up door bells, alarms and telephones as well as

[Illustration: Insulators]

work the use of common felt gun wads make a very good cleat for
the wires. They are used in the manner illustrated in the
accompanying sketch. The insulated wire is placed between two wads
and fastened with two nails or screws. If one wad on the back is
not thick enough to keep the wire away from the support, put on
two wads behind and one in front of the wire and fasten in the
same manner as described.

** Electrically Operated Indicator for a Wind Vane [348]

The accompanying photograph shows a wind vane connected with
electric wires to an instrument at considerable distance which
indicates by means of a magnetic needle the direction of the wind.
The bearings of the vane consist of the head of a wornout bicycle.
A 1/2-in. iron pipe extends from the vane and is held in place by
the clamp originally used to secure the handle bar of the bicycle.
In place of the forks is attached an eight-cylinder gas engine
timer which is slightly altered in such a manner that the brush is
at all times in contact, and when pointing between two contacts
connects them both. Nine wires run from the timer, one from each
of the eight contacts, and one, which serves as the ground wire,
is fastened to the metallic body. The timer is set at such a
position that when the vane points directly north, the brush of
the timer makes a connection in the middle of a contact. When the
timer is held in this position the brush will make connections
with each of the contacts as the vane revolves.

The indicating device which is placed in a convenient place in the
house consists of

[Illustration: The Wind Vane, Magnets and Indicator]

eight 4-ohm magnets fastened upon a l-in. board. These magnets are
placed in a 10-in. circle, 45 deg. apart and with their faces
pointing toward the center. Covering these is a thin, wood board
upon which is fastened a neatly drawn dial resembling a mariner's
compass card. This is placed over the magnets in such a manner
that there will be a magnet under each of the eight principal
points marked on the dial. Over this dial is a magnetic needle or
pointer, 6 in. long, perfectly balanced on the end of a standard
and above all is placed a cover having a glass top. The eight
wires from the timer contacts connect with the outside wires of
the eight magnets separately and the inside wires from the magnets
connect with the metal brace which holds the magnets in place. A
wire is then connected from the metal brace to a push button, two
or three cells of dry battery and to the ground wire in connection
with the timer The wires are connected in such a manner that when
the vane is pointing in a certain direction the battery will be
connected in series with the coil under that part of the dial
representing the direction in which the vane is pointing, thus
magnetizing the core of the magnet which attracts the opposite
pole of the needle toward the face of the magnet and indicating
the way the wind is blowing. The pointer end of the needle is
painted black.

If the vane points in such a direction that the timer brush
connects two contacts, two magnets will be magnetized and the
needle will point midway between the two lines represented on the
dial, thus giving 16 different directions. Around the pointer end
of the needle is wound a fine copper wire, one end of which
extends down to about 1/32 in. of the dial. This wire holds the
needle in place when the pointer end is directly over the magnet
attracting it; the magnet causing the needle to "dip" will bring
the wire in contact with the paper dial. Without this attachment,
the needle would swing a few seconds before coming to a

The vane itself is easily constructed as can be seen in the
illustration. It should be about 6 ft. long to give the best
results. The magnets used can be purchased from any electrical
store in pairs which are called "instrument magnets." Any
automobile garage can supply the timer and an old valueless
bicycle frame is not hard to find. The cover is easily made from a
picture frame with four small boards arranged to take the place of
the picture as shown.

The outfit is valuable to a person who is situated where a vane
could not be placed so as to be seen from a window and especially
at night when it is hard to determine the direction of the wind.
By simply pressing the push button on the side of the cover, the
needle will instantly point to the part of the dial from which the
wind is blowing.
--Contributed by James L. Blackmer, Buffalo, N. Y.

** A Home-Made Floor Polisher [350]

An inexpensive floor polisher can be made as follows: Secure a
wooden box with a base 8 by 12 in. and about 6 in. high, also a
piece of new carpet, 14 by 18 in. Cut 3-in. squares out of the
four corners of the carpet and place the box squarely on it. Turn
three of the flaps of the carpet up and tack them securely to the
sides of the box. Before tacking the fourth side, fold a couple of
newspapers to the right size and shove them in between the carpet
and the bottom of the box for a cushion. Fill the box with any
handy ballast, making it heavy or light, according to who is going
to use it, and securely nail on the top of the box. The handle can
be made from an old broom handle the whole of which will be none
too long. Drive a heavy screw eye into the big end of the handle
and fasten to the polisher by a staple driven through the eye into
the center of the cover, thus making a universal joint. The size
of the box given here is the best although any size near that, if
not too high, will answer the purpose just as well. The box is
pushed or pulled over the floor and the padded side will produce a
fine polish.

** How to Make a Lady's Card-Case [350]

A card-case such as is shown here makes a very appropriate present
for any lady. To make it, secure a piece of "ooze" calf skin
leather 4-1/2 by 10-1/2 in. The one shown in the accompanying
picture was made of a rich tan ooze of light weight and was lined
with a grey-green goat skin. The design was stenciled and the open
parts backed with a green silk plush having a rather heavy nap.
The lining of goat skin need not cover more than the central
part-not the flies. A piece 4-1/2 by 5

[Illustration: Design for the Cover of Lady's Card-Case]

in. will be sufficient. A piece of plush 1-1/4 by 6 in. will be
enough for the two sides. Begin work by shaping the larger piece
of leather as shown in the drawing. Allow a little margin at the
top and bottom, however, to permit trimming the edges slightly
after the parts have been sewed together. A knife or a pair of
scissors will do to cut the leather with, though a special knife,
called a chip carving knife, is most satisfactory.

The next thing is to put in the marks for the outline of the
designs and the borders. A tool having a point shaped as in the
illustration is commonly used. It is called a modeling tool for
leather and may be purchased, or, one can be made from an ordinary
nut pick by taking off the sharpness with fine emery paper so that
it will not cut the leather. To work these outlines, first moisten
the leather on the back with as much water as it will take and
still not show through on the face side. Place the leather on some
level, nonabsorbent surface and with the tool--and a straightedge
on the straight lines--indent the leather as shown. The easiest
way is to place the paper pattern on the leather and mark on the
paper. The indentations will be transferred without the necessity
of putting any lines on the leather.

With the knife cut out the stencils as shown. Paste the silk plush
to the inner side, being careful not to get any of the paste so
far out that it will show. A good leather paste will be required.

[Illustration: Leather Tools]

Next place the lining, fold the flies along the lines indicated in
the drawing. Hold the parts together and stitch them on a
sewing-machine. An ordinary sewing-machine will do if a good stout
needle is used. A silk thread that will match the leather should
be used. Keep the ooze side of the lining

[Illustration: Complete Card Case]

out so that it will show, rather than the smooth side. With the
knife and straightedge trim off the surplus material at the top
and bottom and the book is ready for use.

** Home-Made Fire Extinguisher [351]

Dissolve 20 lb. of common salt and 10 lb. of sal ammoniac in 7
gal. of water, and put the solution in thin glass bottles, cork
tightly and seal to prevent evaporation. The bottles should hold
about 1 qt. If a fire breaks out, throw one of the bottles in or
near the flames, or break off the neck and scatter the contents on
the fire. It may be necessary to use several bottles to quench the

** Crutch Made of an Old Broom [352]

An emergency crutch made of a worn-out broom is an excellent
substitute for a wood crutch, especially when one or more crutches
are needed for a short time, as in cases of a sprained ankle,
temporary lameness, or a hip that has been wrenched.

Shorten and hollow out the brush of the broom and then pad the
hollow part with cotton batting, covering it with a piece of cloth
sewed in place. Such a crutch does not heat the arm pit and there
is an elasticity about it not to be had in the wooden crutch. The
crutch can be made to fit either child or adult and owing to its
cheapness, can be thrown away when no longer needed. --Contributed
by Katharine D. Morse, Syracuse, N. Y.

[Illustration: Crutch]

** Toy Darts and Parachutes [352]

A dart (Fig. 1) is made of a cork having a tin cap, a needle and
some feathers. The needle is run through the center of the cork A
and a pin or piece of steel is put through the eye of the needle.
Take a quantity of small

[Illustration: Dart Parts and Paper Parachute]

feathers, B, and tie them together securely at the bottom. Bore a
hole in the center of the cap C, and fasten the feathers inside of
it. Fasten the cap on the cork and the dart is ready for use. When
throwing the dart at a target stand from 6 to 10 ft. away from it.

The parachute is made by cutting a piece of paper 15 in. square
and tying a piece of string to each corner. The strings should be
about 15 in. long. Tie all four strings together in a knot at the
end and fasten them in the top of a cork with a small tack. It is
best to be as high as possible when flying the parachute as the
air currents will sail it high and fast. Take hold of the
parachute by the cork and run it through the air with the wind,
letting it go at arm's length.
--Contributed by J. Gordon Dempsey, Paterson, N.J.

** A Tool for Lifting Can Covers [352]

A handy tool for prying up varnish paint, syrup and similar can
covers car be made from an old fork filed down

[Illustration: Made of an Old Fork]

to the shape shown in the illustration. The end is filed to an
edge, but not sharp.
--Contributed by Ben Grebin, Ashland, Wis.

** Keeping Rats from a Chicken Coop [352]

After trying for months to keep the rats from tunneling their way
into my chicken coop by filling in the holes, laying poisoned meat
and meal, setting traps, etc., I devised a simple and effective
method to prevent them from doing harm.

My roosting coop is 5 by 15 ft. There is a 1-in. board all around
the bottom on the inside. I used wire mesh having 1/2-in. openings
and formed it into the shape of a large tray with edges 6 in.
high, the corners being wired, and tacked it to the boards. This
not only keeps the rats out, but prevents the chickens from
digging holes, thus helping the rats to enter.
--Contributed by John A. Hellwig, Albany, N. Y.

** Homemade Telephone Receiver [353]

The receiver illustrated herewith is to be used in connection with
the transmitter described elsewhere in this volume. The body of
the receiver, A, is made of a large wooden ribbon spool. One end
is removed entirely, the other sawed in two on the line C and a
flange, F, is cut on the wood, 1/8 in. wide and 1/16 in. deep. A
flange the same size is made on the end D that was sawed off, and
the outside part tapered toward the hole as shown. The magnet is
made of a 30-penny nail, B, cut to the length of the spool, and a
coil of wire, E, wound on the head end. The coil is 1 in. long,
made up of four layers of No. 22 gauge copper magnet wire,
allowing the ends to extend out about 6 in. The nail with the coil
is then put into the hole of the spool as shown. The diaphragm C,
which is the essential part of the instrument, should be made as
carefully as possible from ferrotype tin, commonly called tintype
tin. The diaphragm is placed between the flanges on the spool and
the end D that was sawed off. The end piece and diaphragm are both
fastened to the spool with two or three slender wood screws, as

A small wooden or fiber end, G, is fitted with two binding posts
which are connected to the ends of the wire left projecting from
the magnet winding. The binding posts are attached to the line and
a trial given. The proper distance must be found between the
diaphragm and the head of the nail. This can be accomplished by

[Illustration: Receiver]

the nail and magnet in the hole of the spool. When the distance to
produce the right sound is found, the nail and magnet can be made
fast by filling the open space with melted sealing wax. The end G
is now fastened to the end of the spool, and the receiver is ready
for use.

** How to Clean Jewelry [353]

To cleanse articles of silver, gold, bronze and brass use a
saturated solution of cyanide of potassium. To clean small
articles, dip each one into the solution and rinse immediately in
hot water; then dry and polish with a linen cloth. Larger articles
are cleaned by rubbing the surface with a small tuft of cotton
saturated in the solution. As cyanide of potassium is a deadly
poison, care must be taken not to have it touch any sore spot on
the flesh.

** Ornamental Iron Flower Stand [353]

The illustration shows an ornamental iron stand constructed to
hold a glass or china vase. This stand can be made by first
drawing an outline of the vase on a heavy piece of paper. The vase
is to have three supports. The shape of the scrolls forming each
support should be drawn on the paper

[Illustration: The Stand with Vase]

around the shape of the vase. A single line will be sufficient,
but care must be taken to get the shapes of the scrolls true. Take
a piece of string or, better still, a piece of small wire, and
pass it around the scroll shape on the paper. This will give the
exact length of the iron required to make the scroll. As sheet
metal is used for making the scrolls, it can be cut in the right
lengths with a pair of tinner's shears. Take a pair of round-nose
pliers, begin with the smallest scrolls, and bend each strip in
shape, using the flat-nose pliers when necessary to keep the iron
straight, placing it on the sketch from time to time to see that
the scrolls are kept to the shape required. The scrolls are
riveted and bolted together. The supports are fastened together
with rings of strip iron 3/8 in. wide, to which the supports are
fastened with rivets. The metal can be covered with any desired
color of enamel paint.

** How to Make a Coin Purse [354]

The dimensions for a leather coin purse are as follows: from A to
B, as shown in the sketch, 6-3/8 in.; from C to D, 4-1/4 in.; from
E to F, 3-1/2 in. and

[Illustration: Leather Design for a Purse]

from G to H, 3-1/4 in. Russian calf modeling leather is the
material used. A shade of brown is best as it does not soil
easily, and does not require coloring.

Cut out the leather to the size of the pattern, then moisten the
surface on the rough side with a sponge soaked in water. Be
careful not to moisten the leather too much or the water will go
through to the smooth side. Have the design drawn or traced on the
pattern. Then lay the pattern on the smooth side of the leather
and trace over the design with the small end of the leather tool
or a hard, sharp pencil. Trace also the line around the purse.
Dampen the leather as often as is necessary to keep it properly

After taking off the pattern, retrace the design directly on the
leather to make it more distinct, using a duller point of the
tool. Press or model down the leather all around the design,
making it as smooth as possible with the round side of the tool.
Work down the outside line of the design, thus raising it.

Fold the leather on the line EF. Cut another piece of leather the
size of the side ECBD of the purse, and after putting the wrong
sides of the leather together, stitch around the edge as
designated by the letters above mentioned. Do not make this piece
come quite up to the line EF, so that the coins may be more easily
put in and taken out. About 1 in. from the lines EF on the piece,
stitch in a strip of leather about 1/4 in. wide when stitching up
the purse, through which to slip the fly AGH.

** Window Anti-Frost Solution [354]

A window glass may be kept from frosting by rubbing over the inner
surface a solution of 55 parts of glycerine and 1,000 parts of 60
per cent alcohol. The odor may be improved by adding a little oil
of amber. This solution will also prevent a glass from sweating in
warm weather.

** How to Make a Turbine Engine [355]

In the following article is described a machine which anyone can
make, and which will be very interesting, as well as useful. It
can be made without the use of a lathe, or other tools usually out
of reach of the amateur mechanic. It is neat and efficient, and a
model for speed and power. Babbitt metal is the material used in
its construction, being cast in wooden molds. The casing for the
wheel is cast in halves--a fact which must be kept in mind.

First, procure a planed pine board 1 by 12 in. by 12 ft. long. Cut
off six

[Illustration: Fig. 2]

pieces 12 in. square, and, with a compass saw, cut out one piece
as shown in Fig. 1, following the dotted lines, leaving the lug a,
and the projections B and b to be cut out with a pocket knife.
Make the lug 1/4 in. deep, and the projections B, b, 1/2 in. deep.
The entire cut should be slightly beveled.

Now take another piece of wood, and cut out a wheel, as shown in
Fig. 2. This also should be slightly beveled. When it is finished,
place it on one of the square pieces of wood, with the largest
side down, then place the square piece out of which Fig. 1 was
cut, around the wheel, with the open side down. (We shall call
that side of a mold out of which a casting is drawn, the "open"
side.) Place it so that it is even at the edge with the under
square piece and place the wheel so that the space between the
wheel and

[Illustration: Fig. 1]

the other piece of wood is an even 1/8 in. all the way around.
Then nail the wheel down firmly, and tack the other piece

Procure a thin board 1/4 in. thick, and cut it out as shown in
Fig. 3; then nail it, with pins or small nails, on the center of
one of the square pieces of wood. Fit this to the two pieces just
finished, with the thin wheel down--but first boring a 3/4-in.
hole 1/4 in. deep, in the center of it; and boring a 3/8-in.

[Illustration: Fig. 3]

hole entirely through at the same place. Now put mold No.1 (for
that is what we shall call this mold) in a vise, and bore six
1/4-in. holes through it. Be careful to keep these holes well out
in the solid part, as shown by the black dots in Fig. 1. Take the
mold apart, and clean all the shavings out of it; then bolt it
together, and lay it away to dry.

[Illustration: Fig. 4]

Now take another of the 12-in. square pieces of wood, and cut it
out as shown in Fig. 4, slightly beveled. After it is finished,
place it between two of the 12-in. square pieces of wood, one of
which should have a 3/8-in. hole bored through its center. Then
bolt together with six 1/4-in. bolts, as shown by the

[Illustration: Fig. 5]

black dots in Fig. 4, and lay it away to dry. This is mold No.2.
Now take mold No.1; see that the bolts are all tight; lay it on a
level place, and pour babbitt metal into it, until it is full. Let
it stand for half an hour, then loosen the bolts and remove the

Now cut out one of the 12-in.-square pieces of wood as shown in
Fig. 5. This is the same as Fig. 1, only the one is left-handed,
the other right-handed. Put this together in mold No.1, instead of
the right-handed piece; and run in babbitt metal again. The
casting thus made will face together with the casting previously

Pour metal into mold No.2. This will cast a paddle-wheel, which is
intended to turn inside of the casting already made.

If there should happen to be any

[Illustration: Fig. 6]

holes or spots, where the casting did not fill out, fill them by
placing a small piece of wood with a hole in it, over the

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