The Boy Mechanic: Volume 1
Part 10 out of 15
into the shell with a discarded fountain pen filler. Set in a cool
place until the wax hardens. The most delicate shells treated in
this manner can be handled without fear of breaking, and the
transparency of the wax will not alter the color, shading, or
delicate tints of the egg.
--Contributed by L. L. Shabino, Millstown, South Dakota.
** Homemade Phonograph 
Make a box large enough to hold four dry cells and use it as a
base to mount the motor on and to support the revolving cylinder.
Anyone of the various battery motors may be used to supply the
power. The support for the cylinder is first made and located on
the cover of the box in such a position that it will give ample
room for the motor. The motor base and the support are fastened by
screws turned up through the cover or top of the box. The location
of these parts is shown in Fig. 1.
The core for holding the cylindrical wax records is 4-1/2 in. long
and made of wood, turned a little tapering, the diameter at the
small or outer end being 1-5/8 in., and at the larger end, 1-7/8
in. A wood wheel with a V-shaped groove on its edge is nailed to
the larger end of the cylinder. The hole in the core is fitted
with a brass tube, driven in tightly to serve as a bearing. A rod
that will fit the brass tube, not too tightly, but which will not
wobble loose, is threaded and turned into the upper end of the
support. The core with its attached driving wheel is shown in Fig.
3. The dotted lines show the brass bearing and rod axle. The end
of the axle should be provided with a thread over which a washer
and nut are placed, to keep the core from coming off in turning.
The sound box, Fig. 2, is about 2-1/2 in. in diameter and 1 in.
thick, made of heavy tin. The diaphragm, which should be of thin
ferrotype tin, should be soldered to the box. The needle is made
of a piece of sewing needle, about 1/8s in. long, and soldered to
the center of the diaphragm. The first point should be ground
blunt, as shown in the sketch. When soldering these parts
together, take care to have the diaphragm lie perfectly flat and
not made warping by any pressure applied while the solder is
The tin horn can be easily made, attached to the sound box with a
piece of rubber hose and held so it will swing the length of the
record by a rod attached to the top of the box, as shown.
The motor can be controlled by a small three or four-point battery
[Illustration: Phonograph and Construction of Parts]
--Contributed by Herbert Hahn, Chicago, Ill.
** A Substitute for a Compass 
An easy way to make a pencil compass when one is not at hand, is
to take a knife with two blades at one end, open one to the full
extent and the other only halfway. Stick the point end of the
fully open blade into the side of a lead pencil and use the
half-open blade as the center leg of the compass. Turn with the
knife handle to make the circle.
--Contributed by E. E. Gold. Jr. Victor, Colo.
[Illustration: Pencil on the Knife Blade]
** A Novel Rat Trap 
[Illustration: Rat Trap]
A boy, while playing in the yard close to a grain house, dug a
hole and buried an old-fashioned fruit jug or jar that his mother
had thrown away, says the Iowa Homestead. The top part of the jug
was left uncovered as shown in the sketch, and a hole was b r 0
ken in it just above the ground. The boy then placed some shelled
corn in the bottom, put a board on top, and weighted it with a
The jug had been forgotten for several days when a farmer found
it, and, wondering what it was, he raised the board and found nine
full-grown rats and four, mice in the bottom. The trap has been in
use for some time and is opened every day or two and never fails
to have from one to six rats or mice in it.
** A Nut-Cracking Block 
[Illustration: Holes in the Block for Nuts]
In the sketch herewith is shown an appliance for cracking nuts
which will prevent many a bruised thumb. To anyone who has ever
tried to crack butternuts it needs no further recommendation. The
device is nothing more than a good block of hardwood with a few
holes bored in it to fit the different sized nuts. There is no
need of holding the nut with the fingers, and as hard a blow may
be struck as desired. Make the depth of the hole two-thirds the
height of the nut and the broken pieces will not scatter.
--Contributed by Albert O'Brien, Buffalo, N. Y.
** A Jelly-Making Stand 
Every housewife who makes jelly is only too well acquainted with
the inconvenience and danger of upsets when using the old method
of balancing a
[Illustration: Cheesecloth Strainer on Stand]
jelly-bag on a couple of chairs stood on the kitchen table, with
the additional inconvenience of having a couple of chairs on the
kitchen table out of commission for such a length of time.
The accompanying sketch shows how a stand can be made from a few
pieces of boards that will help jelly makers and prevent the
old-time dangers and disadvantages. The stand can be stood in the
corner of the kitchen, or under the kitchen table where it will be
out of danger of being upset.
--Contributed by Lyndwode, Pereira, Ottawa, Can.
** How to Make an Egg-Beater 
There is no reason why any cook or housewife should be without
this eggbeater, as it can be made quickly in any size. All that is
needed is an ordinary can with a tight-fitting cover-a
baking-powder can will do. Cut a round piece of wood 3 in. longer
than the length of the can. Cut a neat hole in the cover of the
can to allow the stick to pass through, and at one end of the
stick fasten, by means of a flatheaded tack, a piece of tin, cut
round, through which several holes have been punched. Secure
another piece of heavier tin of the same size, and make
[Illustration: Made Like a Churn]
a hole in the center to pass the stick through. Put a small nail 2
in. above the end of the dasher, which allows the second tin to
pass up and down in the opposite direction to the dasher. This
beater will do the work in less time than the regular kitchen
--Contributed by W. A. Jaquythe, Richmond, Cal.
** Cart Without an Axle 
The boy who has a couple of cart wheels is not always lucky enough
to have an axle of the proper length to fit the wheels. In such a
case the cart can be constructed as shown in the illustration.
This cart has no axle, each wheel being attached with a short pin
for an axle, on the side and at the lower edge of the box. The
outer end of the pin is carried on a piece of wood extending the
full length of the box and
[Illustration: Wheels Fastened to the Box]
supported by crosspieces nailed to the ends, as shown.
--Contributed by Thos. De Loof, Grand Rapids, Mich.
** An Illuminated Target 
My youthful nephews some time ago were presented with an air rifle
and it worked so well that it became necessary for me to construct
a target that would allow the fun to be carried on at night.
I reversed a door gong, screwed it on the inside of a store box,
and fitted two candles on the inside to illuminate the bullseye.
The candles, of course, were below the level of the bullseye. The
position of the candles and gong are shown in Fig. 1. At night the
illuminated interior of the bell could be
[Illustration: FIG. 1; FIG. 2; Target for Night Shooting]
plainly seen as shown in Fig. 2.
--Contributed by James M. Kane, Doylestown, Pa.
** Sawing Sheet Metal 
Sheet metal placed between two boards in the jaws of a vise and
clamped tightly, can be sawed easily with a hacksaw.
*8 Feed Box for Chickens 
The sketch shows the construction of a feed box designed to
prevent the scattering of feed and give the coward
[Illustration: Chicken Feed Box]
rooster as much chance to fatten as the game cock. The base may be
made of a 1/2-in. board, 1 ft. wide and 3 ft. long, although any
of the dimensions may be varied to suit special requirements. The
ends are semi-circular pieces with a notch, 1/4 in. deep and 3 in.
wide, cut in the center of the rounding edge. The ends are
connected together with a piece of wood set in the notches. The
strip of wood is 1/4 in. thick, 2 in. wide and as long as the box.
Notches 1/8 in. wide and 1/8 in. deep are cut on the under side of
this piece of wood, 1-1/2 in. apart. Heavy pieces of wire are bent
in the form of a semi-circle, as shown. The wires are set in the
1/8-in. notches cut on the under side of the top piece of wood.
The ends of the wires are set in holes in wood pieces joining the
bases of the end pieces. The baseboard and top are separable.
--Contributed by Maurice Baudier, New Orleans, La.
** A Book Rest 
A book that does not open flat is rather inconvenient to write in
when one of its sides is in the position shown in Fig. 2. A
wedge-shaped piece of
[Illustration: Book Back Holders]
metal, stone or wood, as shown in Fig. 1, will, when placed as in
Fig. 3, raise the sloping half to the level of the other pages.
Cover the block with rubber, wide rubber bands or felt, to prevent
its scratching the desk top. The block can also be used as a
** Window Shelf for Flower Pots 
On the ledge formed by the top part of the lower sash of the
window I fitted a board 7 in. wide into each side of the casing,
by cutting away the ends. I placed a small bracket at each end of
the shelf, so that it would fit solidly against the lower window
sash to support the weight of the plants.
[Illustration: Shelf in Window]
One of the brackets I nailed to the shelf and the other I held in
place with a hinge, the reason being that if both were solid, the
shelf could not be put on the window, as one end must be dropped
in place before the other. Such a shelf will hold all the plants a
person can put on it. When not in use, it can be removed without
marring the casing.
--Contributed by G. A. Wood, West Union, Ia.
** Magnet for the Work Basket 
Tie a ribbon or strong string to the work basket and fasten a
large magnet to the other end. Needles, scissors, etc., can be
picked up without any trouble. This device is very convenient for
--Contributed by Nellie Conlon, Worcester, Mass.
** Knife Made from a Hack-Saw Blade 
A very serviceable knife with excellent cutting qualities can be
made easily from a discarded hack-saw blade. The dimensions given
in the sketch make a knife of convenient size.
The saw teeth are ground off on an emery wheel or grindstone to a
smooth edge parallel with the back edge. For the handle, take two
pieces of hard wood, dressing one surface of each piece, and cut a
groove as wide and thick as the saw blade. Place the blade in the
groove and glue the two dressed sides of the wood together. After
the glue has dried, the blade can be pulled out of the groove and
the wood shaped to any desired form. A small wood-screw is put
through one side of the handle to prevent the blade from sliding.
After completing the
[Illustration: Details of Handle]
handle, the blade is put back into the groove and sharpened to a
--Contributed by H. A. Hutchins, Cleveland, Ohio.
** Killing Mice and Rats 
A simple and inexpensive means for killing mice and rats is to
leave yeast cakes lying around where they can eat them.
--Contributed by Maud McKee, Erie, Pa.
** Roller Coaster Illusion Traveling Up an Incline 
A toy car with a paddle wheel and a shaft on both ends traveling
upward on a chute in which water is flowing down, is shown in the
accompanying sketch. The paddle wheels travel in a reverse
direction causing the ends of the axles to roll on the edge of the
chute, thus carrying the car up the incline. If a rack is used on
each side of the chute and a small pinion on the
[Illustration: Car Travels Uphill]
ends of the axles, a positive upward movement of the car will be
--Contributed by W. S. Jacobs, Malden; Mass.
** Block for Planing Octagonal Wood Pieces 
The little device shown in the illustration will be found very
useful in any workshop. Two or three of them will be necessary for
planing long pieces. Each one is made of a hardwood block, 1 in.
square and 4 in. long. A notch is cut in one side, as shown in
Fig. 1, so a piece of wood which has been planed square will fit
in it. Put a screw in the end of each piece and fasten it down to
the bench. If desired, a tenon may be made on the bottom of each
block, as shown in Fig. 2, to fit a mortise cut in the bench.
Place the blocks far enough apart so the board to be planed will
rest firmly in the notches.
[Illustration: The Notch Holds the Wood]
Plane the board square first and then place it in the notches and
plane the corners down to the proper dimensions.
--Contributed by Willie Woolsen, Cape May Point, N.J.
** A Letter Holder of Pierced Metal 
The letter holder shown in the illustration will be found
convenient for holding out-going letters that await the postman's
coming. It can be made of either copper or brass and need not
[Illustration: Finished Letter Holder]
be of very heavy material. Gauge 22 will be sufficiently heavy.
One sheet of metal, 6 by 9-1/2 in., a board on which to work it,
and an awl and hammer, will be needed. Prepare a design for the
front. If one such as is shown is to be used,
[Illustration: Layout for the Metal]
make one-quarter of it first, and then get the other parts by
folding on the center lines and tracing. This will insure having
all parts alike. The letters can be put on afterward.
Fasten the metal to the board, using tacks and nailing outside of
the required space, in the waste metal. Trace the design on the
metal with carbon paper; or, if desired, paste the paper design
right on the metal. With an awl pierce the metal between the
marginal line and the design, as shown. The holes should be
uniform along the outlines but should be pierced promiscuously
otherwise. On the back, only the marginal line is to be pierced.
Remove the metal, together with the paper if the latter was pasted
to the metal, and trim off the surplus metal where the tacks had
been placed. File off any sharpness so that the hand may not be
injured in handling it. Place the metal on the edge of a table or
between two boards, and bend on the two lines indicated in the
drawing, to right angles.
A good finish is obtained by just letting the copper age with its
natural color. If any polishing is required, it should be done
before the metal is fastened to the board and pierced.
** Imitating Ground Glass 
Make a mixture of white lead in oil, 1 part; varnish, 3/4 part;
turpentine, 1/4 part, and add sugar of lead as a dryer. Make a
very thin paint of this and use a broad, flat brush, says Master
Painter. With care you may succeed in getting the paint on quite
evenly all over, which is desirable. One coat will do. If it
becomes necessary to remove this coating for renewal, it may be
effected by an application of potash lye, or the old may be
renewed by a coating of a mixture of 2 parts hydrochloric acid, 2
parts white vitriol, 1 part sulphate of copper (blue vitriol) and
1 part of gum arabic, applied by means of a brush.
** Draw before Cutting 
A detail drawing made of a piece of furniture before starting the
work will often save time and mistakes.
** Making "Spirits" Play a Violin 
A very pretty trick, that can be worked in your own parlor, will
produce as much sensation as a fake "medium." In all appearance, a
violin, mandolin or guitar, placed on a table, will begin to
produce music simply through stamping the foot and a few passes of
the hand. The music will not sound natural, but weird and distant.
The trick is done by placing the end of a small stick on a music
box in the basement of the house and allowing the other end to
pass up through the floor and table top so it will project about
1/16 in. The stick may be placed by the side of, behind or through
the center of a table leg. Be careful not to have any obstruction
in the way of the stick. The instrument is placed sideways on the
protruding end of the stick. The "fake" work of invoking the
"spirit" is performed and ended by stamping the foot, which
signals the operator in the basement to start the machine, and the
violin seemingly produces music without anyone touching it.
So impressive are the results, that many people really think the
spirits of the departed are playing the violin with unseen hands.
The music is transmitted through the stick from the music box to
[Illustration: The Music Produced by the Phonograph is Transmitted
to the Viohn on the Second Floor by the Aid of a Long Stick]
** Sizing a Threaded Hole 
It sometimes becomes necessary to transfer the size of a threaded
hole from some out-of-the-way place to the shop in order to make a
piece to fit it. With proper tools this is easy; without them, it
might be difficult. One thing is always at hand and that is wood.
Whittle a stick tapering until it starts in the hole. Then turn it
into the hole and a fair thread will be made on the wood. The
stick can be carried in the pocket without risk of changing the
size, as would be the case with ordinary calipers.
** Leaded-Glass Fire Screen 
The main frame of the fire screen shown in Fig. 1 is made from two
pieces of 1/2-in. square bar iron. The longest piece, which should
be about 5-1/2 ft. long, is bent square so as to form two
uprights, each 28 in. long and measuring 26 in. across the top.
The bottom crosspiece can be either riveted or welded to the
uprights. Two pairs of feet, each 6 in. long and spread about 8
in. apart, are shaped as shown in Fig. 2. These are welded to the
lower end of the uprights.
The ornamental scrollwork on the frame is simple and effective,
and is easy to construct, says Work, London. The scrolls are
attached to the frame by means of 3/16-in. round-head machine
screws. The leaf ornament at the
[Illustration: Completed Fire Screen and Parts]
termination of the scroll is shaped and embossed as shown in Fig.
3. The metal used for the scrolls is 3/16 in. thick by 1/2 in.
wide. The leaf ornament is formed by turning over the end of a
piece of metal and working it together at a welding heat, and then
shaping out the leaf with' a chisel and files, after which they
are embossed with a ballpeen hammer.
The center is made from colored glass of special make for leaded
work. The design is formed in the lead, of which a cross section
is shown in Fig. 4. Use care to give the lead a symmetrical
outline. The design should be drawn full size on a large sheet of
heavy paper and the spaces to be occupied by the lead cut out so
as to leave the exact size and shape of each piece of paper the
same as wanted for each piece of glass. These are used as patterns
in marking the glass for cutting. The glass is cut the same as
ordinary window glass. The glass, lead, border and special flux
can be purchased from an art glass shop.
After the glass is cut, the work of putting the pieces together
with the lead between them is begun. Secure a board as wide as the
screen--several narrow boards put together will do and begin by
placing one vertical side border, A, Fig. 5, and the base border,
B, on it as shown. Place the corner piece of glass, C, in the
grooves of the borders, cut a long piece of lead, D, and hold it
in place with two or three brads or glazier's points. The piece of
lead E is cut and a small tenon joint made as shown in Fig. 6.
While the piece of lead D, Fig. 5, is held by the brads, the piece
E can be fitted and soldered. The soldering is done with a hot
soldering iron and wire solder, using rosin as a flux, or, better
still, special flux purchased for this purpose. After the joints
are soldered, the piece of glass F is put in place and the lead
held with brads as before until the cross leads are fitted and
soldered. The brads are then removed, the glass piece as shown by
the dotted lines put in, and the leads around it held with brads
until the crosspieces are put in and soldered. This method is
pursued until the glass is complete, then the two remaining
vertical and top pieces of border are put on and all corners
The leaded glass is held in the iron frame by means of eight
U-shaped clips, as shown in Fig. 7. A hole is drilled in the frame
for the retaining screw, the latter being tapped to the base of
the clip. Special screws may be made with ornamental heads, as
shown in Fig. 8, and used for securing the side scrolls and clips
** A Revolving Teeter Board 
[Illustration: Details of Teeter Board ]
The accompanying sketch shows the details of a revolving teeter
board for the children's playground that can be constructed in a
few hours. Secure a post, not less than 4 in. square and of the
length given in the drawing, and round the corners of one end for
a ring. This ring can be made of 1-in. strap iron and it should be
shrunk on the post. Bore a 3/4-in. hole in the end of the post for
the center pin to rest in. Make three washers 3-in. in diameter
and 1/4 in. thick and drill 3/4-in. holes through their centers.
Drill and countersink two smaller holes for 2-in. wood screws in
each washer. Fasten one of these washers to the top of the post as
shown. The post is now ready to be set in the ground. Coarse
gravel should be packed tightly about it to make it solid.
Concrete is much better if it can be secured.
To make the swivel you will need two 1/4 by 5 by 8-in. plates,
rounded at the top as shown, and two wood blocks, A and B, each
3-1/2 by 5 by 10 in. Drill the lower ends of the plates for four
2-1/2-in. lag screws and the upper ends for a 5/8-in. bolt. Fasten
the plates to the block B, then drill a 3/4-in. hole as shown and
fasten the two remaining washers to the block, one on each side
and central with the hole. Bore a 5/8-in. hole lengthwise through
the block A for the 5/8-in. rocker bolt. This bolt should be
11-1/2 in. long.
The teeter board is made of a 2 by 12-in. plank about 12 ft. long.
It should be slightly tapered from the center to the ends. Two
styles of hand holds are shown, but the one on the left is the one
most generally used. The handles are rounded at the ends and are
fastened to the board with lag screws or bolts. The block A is
fastened to the board with lag screws and should be a working fit
between the wo plates where it is held by means of the 5/8-in.
bolt. The center pin is 3/4-in. in diameter and about 9 in. long.
--Contributed by W. H. Dreier, Jr., Camden, N. J.
** Home-Made Pot Covers 
Empty thread spools and the tins used as extra inside covers in
lard cans are usually thrown away, but these can be put to good
use as kettle covers, if they are made up as follows: Saw the
spool in half as shown, make a hole in the center of the tin and
run a screw or nail through the spool and the tin; then flatten
its end on the under side. This will make an excellent cover for a
--Contributed by Maurice Baudier, New Orleans, La.
[Illustration: Pot Covers]
** An Outdoor Gymnasium Part I-The Horizontal Bar 
Gymnastic apparatus costs money and needs to be housed, because it
will not stand the weather. Gymnasiums are not always available
for the average boy who likes exercise and who would like to learn
the tricks on horizontal and parallel bars, horse and rings, which
all young athletes are taught in regular gymnastic courses.
Any small crowd of boys--even two--having a few simple tools, a
will to use them and the small amount of money required to buy the
[Illustration: Adjustable Horizontal Bar
wood, bolts and rope, can make a first class gymnasium. If trees
are convenient, and some one can swing an axe, the money outlay
will be almost nothing. The following plans are for material
purchased from a mill squared and cut to length. To substitute
small, straight trees for the squared timbers requires but little
changes in the plans.
The most important piece of apparatus in the gymnasium is the
horizontal bar. Most gymnasiums have two: one adjustable bar for
various exercises and a high bar for gymnastic work. The outdoor
gymnasium combines the two. The material required is as follows: 2
pieces of wood, 4 in. square by 9-1/2 ft. long; 4 pieces, 2 by 4
in. by 2 ft. long; 4 pieces, 1 by 7 in. by 6-1/2 ft. long; 4
filler pieces, 3/4 by 3 in. by 3 ft. 9 in. long and 1 piece, 2-1/2
in. square by 5 ft. 7 in. long. This latter piece is for the bar
and should be of well seasoned, straight-grained hickory. It makes
no difference what kind of wood is used for the other pieces, but
it is best to use cedar for the heavy pieces that are set in the
ground as it will take years for this wood to rot. Ordinary yellow
pine will do very well. The four 7-in. boards should be of some
hard wood if possible such as oak, hickory, maple, chestnut or
ash. The other material necessary consists of 2 bolts, 1/2 in. in
diameter and 7 in. long; 16 screws, 3 in. long; 4 heavy screw eyes
with two 1/2-in. shanks; 50 ft. of heavy galvanized wire: 80 ft.
of 1/4-in. manila rope and 4 pulley blocks. Four cleats are also
required but these can be made of wood at home.
Draw a line on the four 7-in. boards along the side of each from
end to end, 1-1/4-in. from one edge. Beginning at one end of each
board make pencil dots on this line 5 in. apart for a distance of
3 ft. 4 in. Bore holes through the boards on these marks with a
9/15-in. bit. Fasten two of these boards on each post with the
3-in. screws, as shown in the top view of the post Fig. 1, forming
a channel of the edges in which the holes were bored. Two of the
filler pieces are fastened in each channel as shown, so as to make
the space fit the squared end of the bar snugly. The ends of the
boards with the holes should be flush with the top of the post.
This will make each pair of holes in the 7-in. boards coincide, so
the 1/2-in. bolt can be put through them and the squared end of
Select a level place where the apparatus is to be placed and dig
two holes 6 ft. apart, each 3 ft. deep and remove all loose dirt.
The ends of the posts not covered with the boards are set in these
holes on bricks or small stones. The channels formed by the boards
must be set facing each other with the inner surfaces of the posts
parallel and 5 ft. 8 in. apart. The holes around the posts are
filled with earth and well tamped.
The hickory piece which is to form the bar should be planed,
scraped and sandpapered until it is perfectly smooth and round
except for 3 in. at each end. Bore a 9/16-in. hole through each
square end 1-1/4 in. from the end. The bar may be fastened at any
desired height by slipping the 1/2-in. bolts through the holes
bored in both the bar and channel.
Each post must be well braced to keep it rigid while a person is
swinging on the bar. Four anchors are placed in the ground at the
corners of an imaginary rectangle 9 by 16 ft., in the center of
which the posts stand as shown in Fig. 2. Each anchor is made of
one 2-ft. piece of wood, around the center of which four strands
of the heavy galvanized wire are twisted, then buried to a depth
of 2 ft., the extending ends of the wires coming up to the surface
at an angle.
The heavy screw eyes are turned into the posts at the top and
lengths of ropes tied to each. These ropes or guys pass through
the pulley blocks, which are fastened to the projecting ends of
the anchor wire, and return to the posts where they are tied to
cleats. Do not tighten the guy ropes without the bar in place, as
to do so will strain the posts in the ground. Do not change the
elevation of the bar without slacking up on the ropes. It takes
but little pull on the guy ropes to make them taut, and once
tightened the bar will be rigid.
[Illustration: Ground Plan]
Oil the bar when it is finished and remove it during the winter.
It is well to oil the wood occasionally during the summer and
reverse the bar at times to prevent its becoming curved. The wood
parts should be well painted to protect them from the weather.
** Electrostatic Illumination 
Anyone having the use of a static machine can perform the
following experiment which gives a striking result. A common
tumbler is mounted on a revolving
[Illustration: Illuminated Tumbler]
platform and a narrow strip of tinfoil is fastened with shellac
varnish to the surface of the glass as follows: Starting beneath
the foot of the glass from a point immediately below the stem, it
is taken to the edge of the foot; it follows the edge for about 1
in. and then passes in a curve across the base, and ascends the
stem; then it passes around the bowl in a sinuous course to the
rim, which it follows for about one-third of its circumference;
after which it descends on the inside and terminates at the
bottom. The tinfoil on the outside of the glass is divided by
cutting with a knife every 1/8 in., the parts inside and beneath
the glass being left undivided. Current is then led from a static
machine to two terminals, one terminal being connected to one end
of the tinfoil strip, and similarly the second terminal makes
contact with the other end. As soon as the current is led into the
apparatus, a spark is seen at each place where the knife has cut
through the tinfoil. If the tumbler is rotated, the effect will be
as shown in the illustration. A variety of small and peculiar
effects can be obtained by making some of the gaps in the tinfoil
larger than others, in which case larger sparks would be produced
at these points. The experiment should be carried out in a
darkened room, and under these circumstances when nothing is
visible, not even the tumbler, the effect is very striking.
** Balloon Ascension Illusion 
By C. W. Nieman
In these days of startling revelations in air-craft flight we are
prepared to see any day some marvelous machine driven bird cutting
figure-eights all over the sky above our heads. One boy recently
took advantage of this state of expectancy to have an evening's
harmless amusement, through an illusion which deceived even the
most incredulous. He caused a whole hotel-full of people to gaze
open mouthed at a sort of "Zeppelin XXIII," which skimmed along
the distant horizon, just visible against the dark evening sky,
disappearing only to reappear again, and working the whole crowd
up to a frenzy of excitement. And all he used was a black thread,
a big piece of cardboard and a pair of field glasses.
He stretched the thread between two buildings, about 100 ft.
apart, in an endless belt, passing through a screweye at either
end. On this thread he fastened a cardboard "cut-out" of a
dirigible, not much to look at in daytime, but most deceptive at
dusk. By pulling one or the other string he moved the "airship" in
either direction. He took the precaution of stretching his thread
just beyond a blackberry hedge and thus kept over-inquisitive
persons at a safe distance. He also saw to it that there was a
black background at either end so that the reversing of the
direction of the craft would not be noticed.
In attracting the crowd he had a confederate stand looking at the
moving ship through a field glass, which at once gave the
suggestion of distance, and materially heightened the illusion.
When the interest of the crowd, which at once gathered, was at its
height, the "aeronaut" pulled his craft out of sight and let the
disillusion come when the light of day laid bare his fraud.
** A Cork Extractor 
The device shown in the sketch is for removing a cork or stopper
from a bottle whether full or empty where the cork has been pushed
inside. A wire about No. 14 gauge is bent as shown at B, Fig. 1,
to fit the index finger and the other end filed to a point C, and
turned in a spiral D, so the point will be on top. Insert this
tool in the bottle as shown in Fig. 2 and place the end D under
the cork and pull up. The cork will come out easily. --Contributed
by Maurice Baudier. New Orleans. La.
[Illustration: Cork Extractor]
** An Outdoor Gymnasium Part II-Parallel Bars 
Parallel bars hold a high place in the affection of those who
frequent gymnasiums as the best apparatus for development of the
back and shoulder muscles, as well as a promoter of ease and grace
of movement. The outdoor "gym" can have a set of these bars with
very little more labor than was required for the horizontal bar.
The material required is as follows:
[Illustration: Detail of the Parallel Bars]
4 posts, preferably cedar, 4 in. square and 6 ft. long;
2 base pieces, 4 in. square and 5-1/2 ft. long;
2 cross braces, 2 by 4 in. by 2 ft. 2 in. long;
2 side braces, 2 by 4 in. by 7 ft. 8 in. long;
4 knee braces, 2 by 4 in. by 3 ft. 8 in. long;
2 bars of straight grained hickory, 2 by 3 in. by 10 ft. long;
4 wood screws, 6 in. long;
4 bolts, 8 in. long; 8 bolts, 7 in. long and
1 doz. large spikes.
To make the apparatus, lay off the bases as shown in the end view
and bevel the ends at an angle of 60 deg. Chisel out two notches 4
in. wide and 1 in. deep, beginning at a point 9 in. from either
side of the center. These are to receive the lower ends of the
posts. Bevel two sides of one end of each post down to the width
of the finished bar--a little less than 2 in. Cut notches in these
ends to receive the oval bars. Bevel the ends of the knee braces,
as shown in the diagram, and fasten the lower ends to the beveled
ends of the bases with the spikes. Fasten the upper ends of the
knee braces to the uprights with the 8-in. bolts put through the
holes bored for that purpose, and countersinking the heads. Lay
the whole end flat on the ground and make a mark 2-1/2 ft. from
the bottom of the base up along the posts, and fasten the end
braces with their top edges flush with the marks, using four of
the 7-in bolts. Finally toe-nail the base into the ends of the
posts merely to hold them in position while the whole structure is
Two endpieces must be made. These sets or ends of the apparatus
are to be buried in trenches dug to the depth of 2-1/2 ft., with
the distance between the two inner surfaces of the posts, which
face each other, of 7 ft. After the trenches are dug, additional
long, shallow trenches must be made connecting the posts to
receive the side braces. The function of these side braces is to
hold both ends together solidly. It is necessary to bury these
braces so they will be out of the way of the performer. The side
braces are bolted to the posts just below the cross braces, so the
bolts in both will not meet. The bars are dressed down so that a
cross section is oval as shown in the end view. They are to be
screwed to the notched ends of the uprights with the 6-in. screws.
The holes should be countersunk so they can be filled with putty
after the screws are in place. The bars should be well oiled with
linseed oil to protect them from the weather, and in the winter
they should be removed and stored.
Every piece of wood in this apparatus can be round and cut from
trees, except the bars. If using mill-cut lumber, leave it
undressed, and if using round timber leave the bark upon it as a
protection from the weather. It is well to paint the entire
apparatus, save the bars, before burying the lower part of the end
pieces. The wood so treated will last for years, but even
unpainted they are very durable. Be sure to tamp down the earth
well about the posts. A smooth piece of ground should be selected
on which to erect the apparatus. (To be Continued.)
** Combined Ladle and Strainer 
When using a strainer in connection with a ladle the operation
[Illustration: Ladle and Strainer]
hands. A convenient article where a ladle and strainer are needed
is to swing a cup-shaped strainer under the bowl of a ladle as
shown in the illustration. The strainer can be held in place with
small bands that fit loosely over the handle and a small tip
soldered to the ladle. These will allow the ladle to be turned,
leaving the strainer always in position. A large sized ladle,
equipped with a strainer, is just the thing for painters to dip
and strain paint, while a small one is of great assistance to the
housewife for dipping and straining soups, jellies, etc.
--Contributed by W. A. Jaquythe, Richmond, Cal.
** Cleaning Gloves 
A solution consisting of 1 dr. of sodium carbonate and 1 qt. of
milk makes an excellent cleaner for motorists' gloves.
** Turpentine in Cutting Oil 
When cutting steel or wrought iron in a lathe, milling machine,
drill press or planer, it is sometimes necessary to leave a smooth
surface. Oil, or various cutting compounds of oil, is used for
this purpose and to keep the surface cool. If a little turpentine
is added to the oil, it will greatly assist in leaving a smooth
surface. A proportion of one-quarter turpentine is good.
** Center of Gravity Experiment 
This experiment consists of suspending a pail of water from a
stick placed upon a table as shown in the accompanying sketch. In
order to accomplish this experiment, which seems impossible, it is
necessary to place a stick, A, of sufficient length,
between the end of the stick on the table and the bottom of the
pail. This makes the center of gravity somewhere near the middle
of the stick on the table, thus holding the pail as shown.
** Lathe Accuracy 
A heavy lathe cut will not do accurate work.
** An Outdoor Gymnasium PART III-The Horse 
The German horse is that peculiar piece of apparatus which is
partly a horizontal obstruction to leap over, partly a barrier for
jumps, partly a smooth surface of long and narrow dimensions over
and about which the body may slide and swing, and partly an
artificial back for the purpose of a peculiar style of leap frog.
[Illustration: The German Horse]
To make a horse for the outdoor "gym" requires no difficult work
save the preparation of the top or body of the horse. The making
of the regular gymnasium horse requires a very elaborate
wood-working and leather upholstering plant, but the one used for
outdoor work can be made of a log of wood. Procure from a saw
mill, wood yard or from the woods, one-half of a tree trunk from a
tree 9 to 15 in. in diameter--the larger the better. The length
may be anywhere from 4 to 7 ft., but 5 ft. is a good length.
The round part of this log must be planed, scraped and sandpapered
until it is perfectly smooth, and free from knots, projections and
splinters. Hand holds must be provided next. These are placed 18
in. apart in a central position on the horse. Make two parallel
saw cuts 2 in. apart, straight down in the round surface of the
horse until each cut is 9 in. long. Chisel out the wood between
the cuts and in the mortises thus made insert the hand holds. Each
hand hold is made of a 9-in. piece of 2 by 4-in. stud cut rounding
on one edge. These are well nailed in place.
The body of the horse is to be fastened on top of posts so that it
may be adjusted for height. It is not as difficult to make as the
horizontal and parallel bars. The material required is as follows:
Two posts, 4 in. square by 5 ft. long; 2 adjusting pieces, 2 by 4
in. by 3 ft. 3 in. long; 1 cross brace, 2 by 4 in. by 3 ft. long;
2 bases, 4 in. square by 5-1/2 ft. long; 4 knee braces, 2 by 4 in.
by 3 ft. long; two 1/2-in. bolts, 1 in. long, to fasten the knee
braces at the top; ten 1/2-in. bolts, 7 in. long, 4 to fasten the
knee braces at the bottom, 2 to fasten the cross brace and 4 to be
used in fastening the adjusting pieces to the posts.
To construct, layout the bases as shown in the drawing, making the
mortises to receive the bottom ends of the posts exactly in the
center, and cut a slanting mortise 6 in. from each end to receive
the ends of the knee braces. Bevel the ends of the knee braces and
fasten the upper ends of each pair to the post with one 9-in.
bolt. Fasten the lower ends to the base with the 7-in. bolts.
The upper end of each post should have 5/8-in. holes bored through
it parallel to the base at intervals of 3 in., beginning 1-1/2 in.
from the top and extending down its length for 2 ft. 4-1/2 in. The
adjusting pieces are to be bored in a similar manner after which
they are to be mortised into the under side of the horse top 15
in. from each end, and secured with screws put through the top and
into the end of the adjusting pieces.
The bases with their posts and knee braces are buried 2 ft. 4 in.
in the ground, parallel to each other and the same distance apart
as the adjusting pieces are mortised in the horse top. When the
ground has been filled in and tamped hard, the cross brace should
be bolted in position with its lower edge resting on the ground
and connecting the two posts.
The height of the horse from the ground is adjusted by changing
the bolts in the different holes connecting the two adjusting
pieces with the two posts. Much pleasant and healthful gymnastic
exercise can be had in competitive horse jumping and leaping, the
handles providing a way to make many different leaps through, over
and around, including not only those made to see who can go over
the horse from a standing or running start at the greatest height,
but who can go over at the greatest height when starting from the
"toeing off mark" farthest away from the horse. This horse should
be located on level ground having smooth space about it for
** Spoon Rest for Kettles 
A rest for keeping spoons from slipping into kettles can be made
[Illustration: Spoon Rest]
a strip of metal bent as shown in the illustration. The spring of
the metal will make it easy to apply to the kettle. The spoon
placed in the rest will drain back into the kettle. The cover can
be placed on without removing the spoon.
--Contributed by W. A. Jaquythe, Richmond. Cal.
** Reason for Bursting of Gun Barrels 
Gun barrels do not burst without a cause and usually that cause is
one of which the shooter is entirely ignorant, but nevertheless,
no one is responsible but himself, says the Sporting Goods Dealer.
Gun barrels can only burst by having some obstruction in the
barrel or by overloading with powder. Any gun barrel can be burst
by misuse or by carelessly loading smokeless powder, but no barrel
will burst by using factory loaded ammunition, provided there is
no obstruction or foreign substance inside the barrel. When a gun
barrel bursts at the breech or chamber, it is caused by an
overloaded shell, and when it bursts in the center or near the
muzzle, it is caused by some obstruction, such as a dent, snow,
** Hand Sled Made of Pipe and Fittings 
The accompanying sketch shows how an ordinary hand sled can be
made of 3/4-in. pipe and fittings. Each runner is made of one
piece of pipe bent to the proper shape. This can be accomplished
by filling the pipe with melted rosin or lead, then bending to the
shape desired, and afterward removing the rosin or lead by
heating. Each joint is turned up tightly and well pinned or
brazed. One of the top crosspieces should have right-hand and
left-hand threads or be fitted with a union. Also, one of the top
pieces connecting the rear part to the front part of each runner
must be fitted in the same way. The top is fastened to the two
crosspieces. Such a hand sled can be made in a
[Illustration: Parts Made of Pipe Fittings]
few hours' time and, when complete, is much better than a wood
--Contributed by James E. Noble, Toronto, Ontario.
** Emergency Magnifying Glass 
When in need of a microscope in the study of botany, one may be
made in the following manner: Bend a small wire or the stem of a
leaf so as to form a small loop not larger than the ordinary drop
Loop Inclosing a Drop of Water
When this is done place a drop of clear water in the loop and the
microscope is complete. This temporary device will prove valuable
where a strong magnifying glass is not at hand.
--Contributed by Arthur E. Joerin, Paris, France.
** Bent-Iron Pipe Rack 
Strips of soft iron, 1/4 or 3/16 in. in width and 1/32 in.
thick, are used in
[Illustration: Design of a Rack]
making the pipe rack shown in Fig. 1. This material can be
obtained from any local hardware dealer who carries bar iron in
Draw a full-size sketch of the design on paper, then run a string
over each part, which, when straightened out, will give the
length. The scrolls are bent with a pair of round-nose pliers.
These, with a pair of flat-nose pliers, are all the tools
necessary. The part for holding the pipes is shown in Fig. 2. The
end elevation, at E and F, shows how the rack is fastened to the
main frame of the rack.
--Contributed by J. W. Vener, Boston, Mass.
** To Clean Silver 
A good method to clean silver of any kind is to place the articles
in an aluminum vessel and add a few pieces of zinc. Hot water is
added and the silver boiled until clean. It is best to use soft
water. The tarnish is removed by the electrolytic action of the
zinc on the aluminum and the silver, and the latter will take on a
bright luster. This method of cleaning will not injure oxidized or
black silver, nor that which is partly oxidized.
** Sharpening Skates with a File [306
Two methods are shown in the sketches for filing skates-one for
hollow filing and the other for filing flat
[Illustration: Filing a Flat Surface]
and straight across the blade. The method shown in Figs. 1 and 2
is for filing the blade flat. The device for holding the skates
consists of a board on which four blocks, AA and BB, are nailed.
These blocks are fastened on the board in the relative positions
of the heel and sole on a shoe. The skates are clamped on them in
the same manner as on a shoe. A flat file is drawn across both
blades of the skates as shown. After the roundness is cut down on
the edges of the blades the skates are removed and the file is
drawn along the sides to remove the
[Illustration: Filing a Curved Surface]
burr. Skates filed in this way have flat surfaces with sharp
Some skaters like a hollow-ground skate and the method shown in
Figs. 3 and 4 can be used for filing a slightly curved surface in
the blade. A piece of tin or sheet metal is shaped over a round
file as shown in Fig. 3. The manner of filing the curves is shown
in Fig. 4. The piece of metal is held over the file and blade of
the skate as the file is worked.
** Lines and Letters Made with a Carpenter's Pencil 
The sketch shows some unusual work made with a carpenter's
pencil. If the flat lead is notched with a three-cornered file
(Fig. 1), two parallel lines may be drawn at one stroke, or
various rulings may be made, as shown in Fig. 2. Broad lines can
be made, as shown in Fig. 3, or unequal widths as in Fig. 4.
[Illustration: Pencil Points and Their Work]
In Figs. 2, 5 and 6 are shown lines especially adapted for the
bookkeeper or draftsman. If one lacks the ability to draw old
English letters with a pen, the letters may be first drawn with a
carpenter's pencil (Fig. 7) and the outlines marked with ink and
finally filled in. Narrow lines are made with points cut as in
Figs. 8 and 9. A little practice with the carpenter's pencil in
making these letters will enable the student to finally produce
them with the pen used for the purpose.
** Insulating Aluminum Wire 
Aluminum wire plunged hot into a cold solution of carbonate of
soda becomes coated with a strong layer of oxide which forms an
excellent insulator to electricity.
** How to Build an Ice-Yacht 
Condensed from an article by H. Percy Ashley in Rudder.
The plans and specifications shown in the illustrations are for
making a 400-ft. class ice-yacht, having a double cockpit to
accommodate four persons. The weight of the persons in the forward
cockpit keeps the boat from rearing when in a stiff breeze. The
forward cockpit can be removed if necessary. The materials used
[Illustration: Ice-Yacht Complete]
white pine; center, clear spruce; sides, white oak caps; runner
plank, basswood, butternut or oak; cockpit, oak; runners, chocks,
etc., quartered white oak. All the iron work should be first-grade
Swedish iron, with the exception of the runners, which are soft
It is not necessary to go into detail with the measurements as
they are plainly shown in the sketches. The backbone is 37-1/2 ft.
over all, 12 in. in the center, 5 in. stern, 3-1/2 in. at the
nose; width 4-1/2 in. All wood should be selected from the best
grades, well seasoned and free from checks. In Fig. 1 is shown the
complete ice-yacht with general dimensions for the sail and main
parts. Other dimensions are shown in Fig-, 2. The backbone is
capped on the upper and lower edges full length with strips of
oak, 4-1/4 in. wide and 5/8 in. thick. The lengthwise side strips
of spruce are 1-1/4 in. thick. The filling-in pieces placed
between the side pieces are of seasoned white pine, leaving the
open places as shown in Fig. 2. The parts are put together with
hot glue and brass screws.
The runner plank should be placed
[Illustration: Details of the Ice-Yacht Parts]
with the heart of the wood up, so as to give the natural curve
from the ice so that it will act as a spring. The plank is 16 in.
wide in the center, 14 in. at the ends; 4-1/8 in. thick at the
center and 2-3/4 in. at the ends.
Details of the runners are shown in Figs. 3, 4, 5, 6, 7, 8 and 9.
The cast iron shoes are filed and finished with emery paper,
making the angle on the cutting edge 45 deg. on both sides. The
runners are 7-1/4 in. wide over all and 2-1/8 in. thick. The soft
iron casting is 2-1/4 in. deep. The shoes are fastened by 5/8-in.
machine bolts. These are shown in Figs. 3 and 9. The rudder is
2-3/4 in. thick, 5 in. deep, including wood and iron, and 3 ft.
long. The cast iron shoe is 1-7/8 in. deep and fastened on with
four 1/2-in. machine bolts. A brass plate, 1/4 in. thick, 2 in.
wide and 7 in. long, is inserted on each side of the runners as
shown in Fig. 9. Three holes are drilled through for a 3/4-in.
riding bolt that can be shifted as desired for rough or smooth
ice. The runner chocks and guides are 1-7/8 in. thick and 4-1/2
in. deep. They are set in the runner plank 1/4 in. and fastened
with glue and 1/2-in. lag screws. These are shown in Figs. 6 and
The aft cockpit is stationary, while the fore or passenger cockpit
can be removed at will. Both cockpits are the same size, 42 in.
wide and 7 ft. long over all. Each one has a bent rail, 1-1/2 in.
by 4 in., grooved 1/2 in. by 7/8 in. before bending. The flooring
is of oak, 1-1/2 in. thick and 4 in. wide, tongue-and grooved. The
forward cockpit is made in halves and hung on the backbone with
wrought-iron straps and bolts. These are shown in Figs. 41, 43 and
44. Two pieces of oak, 1/2 in, by 4 in. are fastened with screws
to the flooring, parallel with the backbone in the forward
cockpit. The runner plank which passes under this cockpit gives it
The spars should be hollow and have the following dimensions:
Mast, 23 ft. 3 in.; heel, 3-3/4 in. ; center, 5-1/4 in.; tip, 4
in. ; boom 23-1/2 ft.; heel, 3-3/4 in. ;center, 4 in.; tip, 2-7/8
in. at ends; gaff, 12-1/2 ft.; center, 3-1/2 in.; ends, 2-1/2 in.;
jib-boom, 10-1/2 ft.; 1-3/4 in. at the ends, 2-1/8 in. at the
center. The gaff is furnished with bent jaws of oak, Fig. 17, and
the main boom with gooseneck, Fig. 12.
Galvanized cast-steel yacht rigging, 5/16 in. in diameter, is used
for the shrouds; jibstay, 3/8 in. in diameter; runner plank guys,
5/16 in. in diameter; bobstay, 3/8 in. in diameter; martingale
stay, 1/4 in. in diameter. The throat,and peak halyards are 3/8
in. in diameter; jib halyards, 1/4 in. in diameter.
The main sheet rigging is 9/16-in. Russian bolt rope; jibs,
7/16-in. manila bolt rope, 4-strand; jib-sheet, 3/8-in. manila
bolt rope. Four 1/2-in. bronze turnbuckles, Fig. 34, are used for
the shrouds; one 5/8-in. turnbuckle for the jibstay and one for
the bobstay; four 3/8-in. turnbuckles for the runner plank stays,
and one for the martingale stay.
Two rope blocks for 3/8-in. wire rope, Fig. 10, are used for the
peak and throat, and one block for the wire rope 1/4 in. in
diameter for the jib halyard. Four 6-in. and one 7-in. cleats,
Fig. 18, are used. The blocks shown in Fig. 11 are used for the
main and jib sheets. The steering arrangement is shown in Figs. 4
and 5. The tiller is 3-1/2 ft. long; rudder post, 1-1/4 in. in
diameter; shoulder to lower end of jaws, 4 in.; depth of jaws,
2-7/8 in.; length of post including screw top, 12 in. The rubber
washer acts as a spring on rough ice.
In Figs. 13, 14, 15 and 16 are shown metal bands for the nose of
the backbone, and Figs. 19, 20, 21, 22 and 23 show the saddles
that fit over the backbone and hold the runner plank in place.
There are two sets of these. A chock should be sunk in the runner
plank at each side to connect with the backbone to keep it from
slipping sidewise as the boat rises in the air. The martingale
spreader is shown in Figs. 24 and 25. Straps through which the
ring bolts for the shrouds pass on the ends to fasten the
turnbuckles for the runner plank guys are shown in Figs. 26 and
27. The bobstay spreaders are shown in Figs. 28, 29 and 30. In
Fig. 31 is shown the top plate for the rudder post and in Figs. 32
and 33, the lower plate for same. The mast step is shown in Figs.
35, 36 and 37. Two positions of the jib traveler are shown in Fig.
38. The anchor plate for the bobstay under the cockpit is shown in
Figs. 39 and 40.
At the nose and heel the runner plank guys end in a loop. The
bobstay has a loop at the nose and ends in a turnbuckle that
fastens to the anchor plate under the cockpit, aft. The shrouds,
jibstay and martingale have loops at the masthead and are spliced
bare over solid thimbles. The loops are finished in pigskin and
served with soft cotton twine over the splice and varnished. The
parceling is done with insulating tape. Serve the tiller with soft
cotton twine and ride a second serving over the first. For the
halyards hoisting use a jig shown in Fig. 46. The thimble shown in
Fig. 47 is made by splicing the rope to the thimble at running
part of halyard and passing back and forth through cleat and
thimble. This gives a quick and strong purchase and does away with
cumbersome blocks of the old-fashioned jig. The jib-sheet leads
aft to the steering cockpit. The main-sheet ends in a jig of a
single block and a single block with becket. Be sure that your
sail covers are large enough--the sail maker always makes them too
tight. The cockpit covers must fit tightly around the cockpit
rail. Many boats have sail and cockpit covers in one piece.
The woodwork may be finished as desired by the builder. The
dimensions of the sails are given in the general drawing, Fig. 1.
** Turning Lights On and Off from Any Number of Places 
This can be done by the use of any number of reversing switches
[Illustration: Wiring Diagram]
those shown at Band C. These are inserted between the two-way
switches A and D. Turning such a switch up or down connects the
four contact pieces either diagonally as at C, or lengthwise as at
B. The diagram shows connection from A to D, when the lamps will
be on, but by turning either of these four switches into its
alternative position, shown by the dotted lines, the circuit will
be broken and the lights extinguished. When this has been done,
the circuit may be restored and the lamps lighted again by
altering either of the four switches in exactly the same way, and
It will be observed that a reversing switch used in this way
practically undoes whatever is done by the other switches. In the
accompanying diagram only two reversing switches are shown and the
lights can be independently controlled from four distinct
positions. Any number of reversing switches can be placed between
the two-way switches A and D to increase the number of places from
which the lights could be turned on and off.
--Contributed by J. S. Dow, Mayfield, London.
** How to Make an Electric Pendant Switch 
It is often desired to use a pendant switch for controlling
clusters of incandescent lamps. When such a switch is not at hand,
a very good substitute can be made by screwing a common fuse plug
into a key socket and connecting the socket in series with the
lamps to be controlled. In this way you get a safe, reliable,
--Contributed by C. C. Heyder, Hansford, W. Va.
** Measure 
Never guess the length of a piece of work--measure it.
** Home-Made Water Motor 
The small water motor shown in the illustration is constructed in
the same manner as a German toy steam turbine. The wheel, which is
made of aluminum 1/16 in. thick and 7 in. in diameter, has 24
blades attached to it.
The lugs or extensions carrying the rim must be made from the
metal of the wheel, therefore a circle 8 in. in diameter must be
first described on the aluminum plate, then another circle 7 in.
in diameter within the first and then a circle for the base of the
blades, 3-1/2 in. in diameter. Twenty-four radial lines at equal
distances apart are drawn between the two smaller circles and a
1/4-in. hole drilled at the intersecting points of the radial
lines and the innermost circle.
Centrally between each pair of radial lines and between the two
outer circles, 1/2 by 3/8-in. lugs are marked out and the metal
cut away as shown in Fig. 1. A 1/8-in. hole is then drilled in the
center of each lug. Each division is separated by cutting down
each radial line to the 1/4-in. hole with a hacksaw. Each arm is
then given a quarter turn, as shown by the dotted lines in Fig. 2,
and the lug bent over at right angles to receive the rim. The rim
is made of the same material as the disk and contains twenty-four
1/8 in. holes corresponding to those in the lugs to receive brass
bolts 1/4-in. long.
The disks PP were taken from the ends of a discarded typewriter
platen, but if these cannot be readily obtained, they can be
turned from metal or a heavy flat disk used instead.
The casing was made from two aluminum cake pans whose diameter was
8 in. at the base, increasing to 9 in. at the rim. The centers of
these were located and a 1/4-in. hole drilled for the
[Illustration: Fig. 3]
shaft. The disks P are the same as used on the wheel. Six holes
1/8-in. in diameter were drilled through the flat part of the rims
while the two halves were held together in a vise. Bolts were
placed through these holes to join the casing when ready for
assembling. One side of the casing was then bolted to two 4-in.
ordinary metal shelf brackets which were
[Illustration: Details of Motor]
screwed to a substantial wood base. This kept one-half of the
casing independent of the main structure so that the wheel is
The nozzle was made of 1/2-in. brass pipe which was first filled
with molten babbitt metal. When the metal was cool, a 1/4-in. hole
was drilled halfway through the length of the tube, the hole being
continued through to the other end by means of a 1/8-in. drill.
The lower orifice was then slightly enlarged with a small taper
reamer, and the upper portion of the bore was reamed out almost to
the brass to make a smooth entrance for the water.
A fixture to hold this nozzle is shown in Fig. 3. It was cast of
babbitt metal in a wood mold. The hole for the nozzle was drilled
at an angle of 20 deg. to the plate part. An alternative and
perhaps easier way would be to insert the nozzle in the mold at
the proper angle and cast the metal around it. A hole was then cut
in one of the sides of the casing at a point 2-7/8 in. along a
horizontal line from the center. The nozzle fixture was then
bolted on with the exit orifice of the nozzle pointing downward
and through the hole in the casing.
Six 1/8-in. holes were drilled through the flat portions of the
rims while the two halves of the casing were held securely
together in a vise. Bolts were used in these holes to join the
The wheel was used on the dripboard of a kitchen sink and no
provision was made to carry off the spent water except to cut two
1/2-in. holes in the bottom of the casing and allowing the waste
to flow off directly into the sink.
--Contributed by Harry F. Lowe, Washington, D. C.
** Device for Baseball Throwing Practice 
Anyone training to be a baseball player will find the device shown
in the accompanying illustration a great help
[Illustration: Ball Bounding on Concrete Slabs]
when practicing alone. It consists of two cement slabs, one flat
and upright, the other curved and on the ground. The vertical slab
is fastened securely against a fence, barn or shed. The barn or
the shed is preferable, for if the slab is fastened to a fence,
the ball will bound over a great many times and much time will be
lost in finding it.
The player stands as far as he cares from the slabs and throws the
ball against the lower slab. The ball immediately rebounds to the
upright slab and returns with almost as great a force as it was
delivered. If the thrower does not throw the ball exactly in the
same spot each time, the ball will not rebound to the same place,
consequently the eye and muscles are trained to act quickly,
especially if the player stands within 15 or 20 ft. of the slabs
and throws the ball with great force.
This apparatus also teaches a person to throw accurately, as a
difference in aim of a few inches on the lower slab may cause the
ball to flyaway over the player's head on the rebound.
--Contributed by F. L. Oilar, La Fayette, Indiana.
** How to Mail Photographs 
Cut a piece of cardboard 1 in. longer and 1 in. wider than the
mount of the photograph and lay the picture on it in the center.
This allows a 1/2-in. border on all sides of the photograph. Punch
two holes 1 in. apart at A, B, C and D, Fig. 1, in the cardboard
border close to the edge of the picture. Put a string up through
the hole B, Fig. 2, then across the corner of the photograph and
down through the hole C and up through hole D, then to E, etc.,
until the starting point A is reached, and tie the ends.
The photograph will not get damaged, if it is covered with tissue
paper and placed with the face to the cardboard. The extension
border of cardboard prevents the edges of the mount from being
damaged and the corners
[Illustration: Back for Mailing Photo]
from wearing. Both cardboard and photograph are wrapped together
in paper, and the package is ready for mailing.
--Contributed by Earl R. Hastings, Corinth, Vt.
** A Mystifying Watch Trick 
Borrow a watch from one of the audience and allow the owner to
place it in the box, as shown in Fig. 1. This box should be about
3 in. long, 4 in. wide and 2-1/2 in. deep, says the Scientific
American. It should be provided with a hinged cover, M, with a
lock, N. The tricky part of this box is the side S, which is
pivoted at T by driving two short nails into it, one through the
front side and the other through the back, so that when S is
pushed in at the top, it swings around as shown in Fig. 1 and
allows the watch to slide out into the performer's hand. The side
S should fit tightly when closed, so that the box may be examined
without betraying the secret. As the side S extends down to the
bottom of the box, it facilitates the use of the fingers in
pulling outward at the lower pan while the thumb is pressing
inward at the top part. The side of the box opposite S should be
built up in the same way, but not pivoted.
Use a flat-bottom tumbler, A, Fig. 2, containing an inner cone, B,
for the reproduction of the watch. The cone is made of cardboard
pasted together so it fits snugly inside of the tumbler. The cone
is closed except at the bottom, then bran is pasted on the outside
surfaces to make the tumbler appear as if filled with bran when it
is in place. Place the tumbler with the cone inside on a table
somewhat in the background. Put some loose bran on top of the cone
and allow the cork, attached as shown in B, Fig. 2, to hang down
on the outside of the tumbler, away from the audience. A large
handkerchief should be laid beside the tumbler.
After the watch has been placed in the box, Fig. 1, the performer
takes the box in his left hand, and while in the act of locking it
with his right hand secures possession of the watch as previously
explained. Tossing the key to the owner of the watch, the
performer places the box on a chair or table near the audience
and, with the watch securely palmed, walks back to get the
tumbler. Standing directly in front of the tumbler with his back
toward the audience, the performer
[Illustration: Parts for the Watch Trick]
quickly raises the cone with his right hand, lays the watch in the
bottom of the tumbler and replaces the cone.
The loaded tumbler and the handkerchief are then brought forward,
and the former is placed in full view of the audience with the
cork hanging down behind it. The performer calls attention to the
tumbler being full of bran and picks up some of it from the top to
substantiate his statement. He then spreads the handkerchief over
the tumbler, commands the watch to pass from the box into the
tumbler and the bran to disappear.
The box is then handed to the owner of the watch so that he may
unlock it with the key he holds. As soon as the box is found to be
empty, the performer grasps the handkerchief spread over the
tumbler, also the cork tied to the cone. Raising the handkerchief,
he carries up the cone within it, leaving the watch in the bottom
to be returned to its owner.
** Locking Several Drawers with One Lock 
A series or row of drawers can be secured with one lock by using
[Illustration: Drawer Lock]
device shown in the sketch. This method takes away several
dangling locks and the carrying of many keys. A rod is used
through the various staples over the hasps. The rod is upset on
one end and flattened to make sufficient metal for drilling a hole
large enough to insert the bar of a padlock. If the bar is made of
steel and hardened, it is almost impossible to cut it in two.
--Contributed by F. W. Bentley, Huron, S. Dak.
** Testing Small Electric Lamps 
The accompanying sketch shows the construction of a handy device
for testing miniature electric lights. The base is made to take in
an electric flash lamp battery. Two strips of brass, C and D, are
connected to the battery. The lamp is tested by
[Illustration: Lamp Tester]
putting the metal end on the lower brass strip and the side
against the upper one. A great number of lamps can be tested in a
short time by means of this device.
--Contributed by Abner B. Shaw, North Dartmouth, Mass.
** How to Make a Pin Ball 
The pin ball shown in the illustration is made of calfskin
modeling leather and saddler's felt. Two pieces of leather are
used, and one piece of felt, all three being cut circular to a
diameter of about 3 in. The felt may be about 1/2 in. thick, and
leather of a deep brown color is recommended.
Moisten the leather on the back side with as much water as it will
take without showing through the face. Lay it on a sheet of heavy
glass or copper, or other hard, smooth, nonabsorbent material.
Place the design, which has been previously prepared, over the
face of the leather. Indent the outline of the design with a
nutpick or any other pointed tool that will not cut the leather.
Remove the pattern, and go
[Illustration: Made of Leather and Felt]
over the outline again to deepen the tool marks.
The space between the border and the design is now stamped with a
cuppointed nail set, care being taken not to cut the leather,
especially if the tool be new. Rubbing the edges of the nail set
over a piece of emery paper will serve to dull them, if they are
When the designs have been worked on the leather, paste or glue
the leather to the two sides of the belt, and punch a hole in the
center through which to place a cord for hanging up the ball.
** Cleaning Woodwork 
An easy method of removing the dirt and old varnish at the same
time around a kitchen sink is told by a correspondent of National
Magazine as follows:
Make a soft soap from common yellow laundry soap, and when it is
almost cold stir in one tablespoonful of concentrated lye and
one-half cupful of kerosene. When the mixture becomes a heavy
paste, it is ready to be spread over the woodwork with a paint
brush. Allow the soap to remain for a day and a half, then wash it
off with plenty of hot water. The woodwork will be clean and ready
for varnishing when it dries out.
** Bill File Made of Corkscrews 
An ordinary corkscrew makes a convenient file for small bills or
memoranda. It may be thrown in any position without danger of the
papers slipping off. A rack to hold a number of files can be made
of a wood strip (Fig. 1) fitted with hooks or screw eyes cut in a
hook shape, as shown in Fig. 2,
[Illustration: Bill File]
Single bills may be separated from the others and will remain
separated as in Fig. 3.
--Contributed by James M. Kane, Doylestown, Pa.
** Ornamental Metal Inkstand 
The metal required for making this stand is 3/16 in. in width and
[Illustration: Inkstand and Details of Frame]
steel, brass or copper. The shaping is done as shown in Figs. 2
and 3. There are, in all, eight pieces to be bent. The two
supports are each formed of one piece of metal with the exception
that the end scroll pieces on the under side are made separately.
Eight rivets are required to fasten the two horizontal rings to
the supports. The glass receptacle can be purchased at a
** Holding Eyeglasses Firm 
Persons who wear noseglasses and who are troubled with excessive
perspiration, should chalk the sides of the bridge of the nose
before putting on the glasses. The latter will then never slip,
even in the warmest weather. If the chalk shows, use a pink stick,
which can be purchased from any art school or supply store.
Substitute for Gummed Paper 
Gummed paper is a great convenience in the home especially for
labels, but it is not always found among the household supplies.
The gummed portions of unsealed envelopes in which circulars are
received can be utilized for this purpose. Quite a large label may
be made from these envelope flaps.
** Repairing a Broken Phonograph Spring 
As I live a great distance from a railroad station, I did not care
to pay the price, and await the time necessary to deliver a new
phonograph spring to replace one that broke in my machine, and I
repaired the old one in a creditable manner as follows:
I forced the two ends of the break out where I could get at them,
then heated each end separately with a pair of red hot tongs and
turned a hook or lap on them the same as the joints in knock-down
stovepipes. When the ends were hooked together, the spring worked
as good as new. The heated portion did not affect the strength of
--Contributed by Marion P. Wheeler, Greenleaf, Oregon.
** Calls While You Are Out 
If you wish to know whether or not the door or telephone bell
rings during your absence, place a little rider of paper or
cardboard on the clapper in such a way that it will be dislodged
if the bell rings.
** A Small Bench Lathe Made of Pipe Fittings 
The most important machine in use in the modern machine or
wood-working shop is the lathe. The uses to which this wonderful
machine can be put would be too numerous to describe, but there is
hardly a mechanical operation in which the turning lathe does not
figure. For this reason every amateur mechanic and wood-worker who
has a workshop, no matter how small, is anxious to possess a lathe
[Illustration: Fig. 1-Details of Lathe]
sort. A good and substantial homemade lathe, which is suitable for
woodturning and light metal work, may be constructed from pipe and
pipe fittings as shown in the accompanying sketch.
The bed of this lathe is made of a piece of 1-in. pipe, about 30
in. long. It can be made longer or shorter, but if it is made much
longer, a larger size of pipe should be used. The head-stock is
made of two tees, joined by a standard long nipple as shown in
Fig. 1. All the joints should be screwed up tight and then
fastened with 3/16-in. pins to keep them from turning. The ends of
the bed are fixed to the baseboard by means of elbows, nipples and
flanges arranged as shown. The two bearings in the headstock are
of brass. The spindle hole should be drilled and reamed after they
are screwed in place in the tee. The spindle should be of steel
and long enough to reach through the bearing and pulley and have
enough end left for the center point. The point should extend
about 1-1/2 in. out from the collar. The collar can be turned or
shrunk on the spindle as desired. The end of the spindle should be
threaded to receive a chuck.
The tailstock is also made of two tees joined by a nipple. The
lower tee should be bored out for a sliding fit on the bed pipe.
The upper one should be tapped with a machine tap for the spindle
which is threaded to fit it. The
[Illustration: Fig. 2]
spindle has a handle fitted at one end and has the other end bored
out for the tail stock center. Both the tail stock and the
headstock centerpoints should be hardened. A clamp for holding the
tail stock spindle is made of a piece of strap iron, bent and
drilled as shown. It is held together by means of a small machine
screw and a knurled nut. The tee should have a slot cut in it
about one-half its length and it should also have one bead filed
away so that the clamp will fit tightly over it.
The hand rest is made from a tapering elbow, a tee and a forging.
The forging can be made by a blacksmith at a small expense. Both
[Illustration: Fig. 3]
tees of the handrest and the tailstock should be provided with
screw clamps to hold them in place.
The pulley is made of hardwood pieces, 3/4 or 1 in. thick as
desired. It is fastened to the spindle by means of a screw, as
shown in Fig. 2, or a key can be used as well.
Care must be taken to get the tailstock center vertically over the
bed, else taper turning will result. To do this, a straight line
should be scratched
[Illustration: Fig. 4-Chuck ]
on the top of the bed pipe, and when the tail stock is set exactly
vertical, a corresponding line made on this. This will save a
great deal of time and trouble and possibly some errors.
The two designs of chucks shown in Figs. 3 and 4 are very easy to
make, and will answer for a great variety of work.
As the details are clearly shown and the general dimensions given
on the accompanying sketches, it should not be a difficult matter
for the young mechanic to construct this machine.
--Contributed by W. M. Held, Laporte, Indiana.
** Holder for Flexible Lamp-Cord 
The holder is made of a round stick--a piece of a broom handle
will do--as shown in Fig. 1. It is about 1 in. long with two
notches cut out for the strands of the cord. These holders are
easily made and will answer the purpose almost as well as the ones
made in porcelain. Painting or enameling will improve not only
their appearance, but also their insulating properties.
[Illustration: Ceiling-Cord Holder]
Several of them can be used along a line, as shown in Fig. 2.
--Contributed by M. Musgrove, Boissevain, Man.
** Support for Double Clotheslines 
Anyone using a double clothesline over pulleys will find the
arrangement shown in Fig. 1 for supporting the
[Illustration: Holder on a Clothesline]
lower line quite convenient. The support is made of a piece of
3/4-in. square or round wood which has a screw-eye turned into
each end. The line is run through these screw-eyes as shown in
--Contributed by W. W. UpDeGraff, Fruitvale, Cal.
** Hot Pan or Plate Lifter 
Unless a person uses considerable caution, bad burns may be
suffered when taking hot pies from an oven. If one reaches in and
takes hold of the pie pan with a cloth, the arm is liable to touch
the oven door and receive a
[Illustration: Lifter on Pie Pan]
burn. To obviate this, I made the device shown in the sketch for
lifting hot pie pans and plates. The handle is of pine about 18
in. long, and the two loops are made of heavy wire. The ends of
the first loop of wire are put through the handle from the back,
as shown, and then bent so as to stand out at an angle. The second
loop is hinged to swing free on the opposite side of the handle.
In use, the hinged side of the loop is dropped under one edge of a
plate or pan and the rigid loop is then hooked under the opposite
side. The weight of the pan or dish draws the loops together and
there is little or no danger of a spill. The same lifter will pick
up any size of plate or pan from a saucer to the largest pie
--Contributed by E. J. Cline, Ft. Smith, Ark.
** Weighting Indian Clubs 
An ordinary Indian club can be fixed so that different weights may
[Illustration: Indian Club]
without changing clubs. Each club is bored to receive lead washers
which are held in place by a spiral spring. A bolt is run through
from the handle end and fastened with a round nut. The lead
washers and spring slip over the bolt as shown in the
illustration. Changing the number of washers changes the weight of
--Contributed by Walter W. White, Denver, Colo.
** Venting a Funnel 
When using a tight-fitting funnel in a small-neck bottle, trouble
is usually experienced by the air causing a spill. This can be
easily remedied by splitting a match in half and tying the parts
on the sides of the stem with thread.
--Contributed by Maurice Baudier, New Orleans, La.
** Lubricating Woodscrews 
A screw may be turned into hardwood easily, by boring a small hole
and lubricating the screw threads with soft soap.
** To Make "Centering" Unnecessary 
For drilling a hole in a chucked piece, centering is just one
operation too many, if this method is followed:
First, face off the end of the piece, making a true spot at least
as big as the diameter of the drill. Put a center punch mark where
the tool lines indicate the center of revolution. This serves as a
rough guide for placing the drill between the tail stock center
and the work as usual. Clamp a tool in the tool-post and, on
starting the lathe, bring it in contact with the drill and keep it
firmly so until the drill is in fully up to the lips. This
prevents the drill from wobbling, and when once in true up to its
size, it cannot change any more than under any other starting
conditions. After being entered, the drill does not need the tool,
which should be backed out of contact.
** Fountain Pen Cap Used as a Ruler 
When it is necessary to draw a short line and there is no ruler at
[Illustration: Ruling Lines]
off the cap of your fountain pen and use it as a ruler. If the cap
is fitted with a retaining clip, all the better, as this will
prove a safeguard against slipping.
** Vanishing Handkerchief Trick 
The necessary articles used in performing this trick are the
handkerchief, vanishing wand, a long piece of glass tubing, a bout
1/2 in. shorter t h a n the wand, and a paper tube closed at one
end and covered with a cap at the other, says the Sphinx. The
handkerchief rod, shown at C, is concealed in the paper tube A
before the performance. The glass tube B, after being shown empty;
is put into the paper tube A, so that the handkerchief rod now is
within it, unknown to the spectators. The handkerchief is then
the opening of the tube and pushed in by means of the wand. In
doing this, the handkerchief and the rod are pushed into the wand,
as shown in D. After the wand is removed, the cap is placed over
the paper tube, and this given to someone to hold. The command for
the handkerchief to vanish is given, and it is found to be gone
when the glass tube is taken out of the paper cover. This is a
novel way of making a handkerchief vanish. It can be used in a
great number of tricks, and can be varied to suit the performer.
** Removing Glass Letters from Windows 
Glass letters are removed in the same way as metal letters, by
applying caustic soda or potash around the edges of the letters.
As the cement softens, manipulate the point of a pocket knife
under the edges of the letter until the caustic works completely
under and makes it easy to lift the letters. With care and
patience, every letter may be thus taken off without breakage.
** A Guitar That Is Easy to Make 
A guitar having straight lines, giving it an old-fashioned
appearance, can be made by the home mechanic, and if care is taken
in selecting the material, and having it thoroughly
[Illustration: Details of Guitar]
seasoned, the finished instrument will have a fine tone. The
sides, ends and bottom are made of hard wood, preferably hard
maple, and the top should be made of a thoroughly seasoned piece
of soft pine. The dimensioned pieces required are as follows:
1 Top. 3/16. by 14 by 17 in. 1 Bottom. 3/16 by 14 by 17 in. 2
Sides. 3/16 by 3-5/8 by 16-3/4 in. 1, End. 3/16 by 3-5/8 by 13-1/8
in. 1 End. 3/16 by 3-5/8 by 9-5/6 in. 1 Neck. 1 by 2-5/16 by
18-1/2 in. 1 Fingerboard 5/16 by 2-5/8 by 16 in.
Cut the fingerboard tapering and fasten pieces cut from hatpins
with small wire staples for frets. All dimensions for cutting and
setting are shown in the sketch. The neck is cut tapering from G
to F and from J to F, with the back side rounding. A drawknife is
the proper tool for shaping the neck. Cut a piece of hard wood,
1/4 in. square and 1-7/8 in. long, and glue it to the neck at F.
Glue the fingerboard to the neck and hold it secure with clamps
while the glue sets.
The brace at D is 1 in. thick, cut to any shape desired. The sides
are glued together and then the front is glued on them. Place some
heavy weights on top and give the glue time to dry. Fasten pieces
of soft wood in the corners for braces. Glue the neck to the box,
making it secure by the addition of a carriage bolt at A. A small
block C is glued to the end to reinforce it for the bolt. Glue
strips of soft wood, as shown by K, across the front and back to
strengthen them. The back is then glued on and the outside
smoothed with sandpaper.
Make the bottom bridge by using an old hatpin or wire of the same
size for E secured with pin staples. Glue the bridge on the top at
a place that will make the distance from the bridge F to the
bottom bridge E just 24 in. This dimension and those for the frets
should be made accurately. Six holes, 3/16 in. in diameter, are
drilled in the bottom bridge for pins. The turning plugs B and
strings can be purchased at any music store.
--Contributed by J. H. Stoddard, Carbondale,Pa.
** Greasing the Front Wheels of an Automobile 
The front wheel bearings of an automobile can be greased without
removing the wheels in the following manner: Remove the hub caps
and fill them with heavy grease and then screw them in place.
Continue this operation until the grease is forced between all the
bearings and out through the small clearance on the opposite side
of the wheels. This should be done at least once every month to
keep bearings well lubricated and free from grit. Dirt cannot
enter a well filled bearing as easily as muddy water can enter a
--Contributed by Chas. E. Frary, Norwalk, O.
** Removing Mold 
Mold on wallpaper can be removed at once by applying a solution of
1 part salicylic acid in 4 parts of 95% alcohol.
** HOW TO MAKE A PAPER BOAT 
A Light Boat That Can Be Easily Carried
[Illustration: The Paper Boat Is Light and Easy to Propel]
Now you might think it absurd to advise making a paper boat, but
it is not, and you will find it in some respects and for some
purposes better than the wooden boat. When it is completed you
will have a canoe, probably equal to the Indian's bark canoe. Not
only will it serve as an ideal fishing boat, but when you want to
combine hunting and fishing you can put your boat on your
shoulders and carry it from place to place wherever you want to go
and at the same time carry your gun in your hand. The material
used in its construction is inexpensive and can be purchased for a
Make a frame (Fig. 1) on which to stretch the paper. A board 1 in.
thick and about 1 ft. wide and 11-1/2 ft. long is used for a keel,
or backbone, and is cut tapering for about a third of its length,
toward each end, and beveled
[Illustration: Detail of Framework Construction]
on the outer edges (A, Fig. 2). The cross-boards (B, B, Fig. 2)
are next sawed from a pine board 1 in. thick. Shape these as shown
by A, Fig. 4, 13 in. wide by 26 in. long, and cut away in the
center to avoid useless weight. Fasten them cross-wise to the
bottom board as shown in Fig. 1 and 2, with long stout screws, so
as to divide the keel into three nearly equal parts. Then add the
stem and stern pieces (C, C, Fig. 2). These are better, probably,
when made of green elm. Screw the pieces to the bottom-board and
bend them, as shown in Fig. 2, by means of a string or wire,
fastened to a nail driven into the bottom. Any tough, light wood
that is not easily broken when bending will do. Green wood is
preferable, because it will retain the shape in which it has been
bent better after drying. For the gunwales (a, a, Fig. 3), procure
at a carriage factory, or other place, some tight strips of ash,
3/8 in. thick. Nail them to the crossboards and fasten to the end
[Illustration: Important Features of Construction]
(C, C,) in notches, by several wrappings of annealed iron wire or
copper wire, as shown in Fig. 3. Copper wire is better because it
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