_A Sand-power Engine._--The large driving wheel consists of two circles
of thick cardboard, each about 6 in. across, firmly glued together.
These two circles are bevelled, and fixed facing inwards, so that a
groove is left in which the power band can run.
[Illustration: FIG. 76.]
Through the centre of the driving wheel thus fashioned a piece of
dowelling or old lead pencil is fixed, projecting 1/4 in. on one side,
and about 1-1/2 in. on the other. Nails are driven in the two ends of
this axle, and the wheel is suspended between supports, glued and
screwed firmly to a base board.
The flanged sand wheel is next constructed. For this, four oblong pieces
of cardboard, 1-1/4 in. wide and about 2 in. long, are cut out. A line
is scratched along each of these about 1/2 in. from the end, and the
cardboard bent so as to form a scoop to hold the sand for an instant.
These four flanges are then glued to the axle, and the side of the
driving wheel. If the sand wheel so made is not sufficiently firm, then
another small cardboard circle can be glued to the flanges, on the side
remote from the driving wheel: this will strengthen the wheel and in no
way interfere with the running.
All that is necessary now is to erect some sort of sand supply: for this
a large canister will do. A tiny hole must be punched in the bottom of
the tin, and a revolving trap made with another piece of tin. This is
simple enough: all you need to do is cut a piece of tin about 3/4 in.
long and 1/2 in. wide, and punch a hole in one end. This pierced tin
should then be placed so that the unbroken end of the slip covers the
supply hole. A forked rivet should then be passed through the hole in
the slip and through the bottom of the canister and fixed in place (Fig.
77); the trap can then be made to revolve, and the sand supply started
or stopped at will. The canister should be placed above the wheel so
that a thin stream falls on the flanges and turns the wheel.
[Illustration: FIG. 77.]
If a string be now passed round the outside edge of the driving wheel,
the mechanism can be harnessed to any toy and the motive power supplied.
For instance, the contrivance can be erected on a flat hull similar to
that shown in Fig. 83, page 70; and the power band, passing through a
hole in the centre of the hull, can be connected with the propeller by
means of a rod (in place of the elastic). The resultant machine, though
not highly efficient, is yet quite attractive.
Another material from which some delightful toys can be contrived is
"tin," or, as it is more correctly called, "tinned iron." This is the
stuff cocoa tins and mustard tins and many other articles are made of.
Perhaps the simplest toy we can commence with is
_A Rotating Snake._--For this secure a clean flat piece of thin tin--the
piece which the little patent cutter removes from the top of a round
cigarette tin will do admirably--and, using a soft lead pencil, draw on
it a spiral snake, such as is shown in Fig. 78. Now cut along the lines
with a stout pair of scissors, or else with a sharp-pointed knife. Pull
out the resultant spiral till it is stretched as in Fig. 79, and mount
it by means of the tail on an upright piece of pointed stout wire. The
serpent will rotate on this for a considerable time.
[Illustration: FIG. 78.]
[Illustration: FIG. 79.]
If you are good at bent-wire work, you will be able to make a wire stand
by which to fix it on a lamp chimney or gas globe: it will then revolve
continuously, and with considerable speed.
_A Tin-can Steam Roller._--This is a nice piece of metal work, and, when
finished well, provides a proper little toy. To construct it you need
several tins--a round tin, such as a cocoa tin, about 2 in. across and 4
in. long; an oblong tin, about 3-1/2 in. by 3 in. by 2 in., such as the
larger-sized mustard tins; a round cigarette tin, about 2-1/2 in. across
and 3-1/4 in. deep; two equal-sized tin lids from canisters, each about
4 in. across; and a cotton reel. These, the main items, when put
together, yield a model similar to that shown in Fig. 80.
[Illustration: FIG. 80.]
The fixing is quite a simple affair. With a pair of metal shears (or
strong scissors) you cut away a portion of the top of the cocoa tin, so
as to leave three tongues. Then on the side of the oblong mustard tin
you mark three lines to correspond with the three tongues, and cut them
through so as to form three slots into which the tongues may fit. Now,
if the tongues be bent outwards or inwards, then the two tins will hold
firmly together, and give the boiler and cab of the machine (Fig. 81).
Before bending these, however, it is necessary to bore a hole in the
under side of the boiler for the fixing of the front roller. This is
attached to the boiler by means of a narrow strip of tin bent twice at
right angles, and kept in place by means of a forked brass rivet or a
strong brass paper fastener so that it will revolve freely. This narrow
strip of tin just fits over the cigarette tin--a piece of knitting
needle being used as axle, passing through holes bored in the centre of
the bottom and lid of the tin, and through the ends of the slip.
For the larger rear wheels the lids of two canisters can be used, or, if
something is required giving a more definite impression of solidity, two
flat boot-polish tins can be substituted. Another piece of knitting
needle passes through the centre of these, and through holes in the
sides of the cab, and so acts as axle. This is kept in place by means of
dabs of sealing wax.
For the stack you can use a long thin cotton reel, or, better still, you
can fix on another small tin by the method shown in Fig. 81.
[Illustration: FIG. 81.]
The turning of the front wheel can be regulated by means of two strings
passing from the two right-angle strips through a hole into the cab. If
you can fix the strings to a piece of wood as shown in Fig. 82, you will
be able to steer properly. A hole in the bottom of the cab, and a piece
of wood stretched tightly across the top, should enable you to set up
the steering apparatus.
[Illustration: FIG. 82.]
_A Working Motor Boat._--To construct a motor boat that will travel a
considerable distance is not really a difficult matter. All that is
necessary is a piece of board for a hull, a wood or metal propeller, and
a yard or two of strong elastic: these, carefully adjusted, will do all
that is necessary.
For the hull, a piece of 5/8 in. or 3/4 in. board, about 18 in. long
will do. This can be cut to the boat shape by means of a pocket knife or
a spokeshave, and finished off with glass-paper. It should be
sharp-pointed at the bows, about 3 in. to 4 in. at the centre, tapering
down to a width of 2 in. at the stern. In the centre of the hull nail a
block of wood, and to it glue two funnels (Fig. 83). For these, the odd
lengths cut off from bamboo curtain poles will do admirably; or, if
these be not obtainable, a couple of incandescent-mantle cases will
suffice.
[Illustration: FIG. 83.]
The adjustment of the motive power is the difficult task. First, you
will need to purchase a couple of yards of suitable elastic: this is
sold at most large toy shops, and costs usually a penny a yard. To fix
this into place beneath the hull you will need to construct two metal
supports. If you can get an old tin box made from metal sufficiently
stout, that will do; if not, then you had better buy a piece of sheet
brass, No. 20 gauge: 6 in. by 4 in. will be ample. Draw out these
supports as shown in Figs. 84 and 85, and bend them into shape as in
Figs. 86 and 87--one for the bow and one for the stern. Screw on the bow
one about 1-1/2 in. or 2 in. from the point, and the stern one in the
middle of the end.
[Illustration: FIG. 84.]
[Illustration: FIG. 85.]
[Illustration: FIG. 86.]
[Illustration: FIG. 87.]
Now into the bow support fix a loop of stout wire to hold the rubber
strands, making it sufficiently large to rest against the sides and so
prevent turning. At the stern support adjust the propeller bearings. On
the care with which these are adjusted depends largely the success of
the model. Take a piece of wire (1/16-inch brass is best) and bend it as
in Fig. 88, introducing a hard smooth glass bead. This "bead" runs more
freely against the metal, and so facilitates the working. Now stretch
the elastic between the two loops, arranging it so that there are six or
eight strands. To work the model, turn the propeller round and round
till the strands of elastic are very tightly twisted, place on the
surface of the water, and then release the propeller. Fig. 83 shows the
completed model.
[Illustration: FIG. 88.]
All boys love a toy that "goes"; and so a short account showing how to
make
_A Steamboat_ that will actually travel on the water will be very
welcome. Our boat, which in reality is not a "steam" boat, inasmuch as
no steam is generated, is very simple in its construction and possesses
neither wheels nor pistons nor cranks, nor any of the things that one
associates with a steamer.
The whole motive power is supplied by one or two candle ends, and a bent
piece of strong metal tubing. This last can scarcely be called either
"odds" or "ends"; and you will probably have to purchase it at a shop
selling model-engine fittings, but a few pence will cover the cost. You
must get an eight-inch piece of solid drawn copper or brass tubing, with
an inside diameter of 1/8 in. (_N.B._--Do not let the man sell you
soldered tubing, for it will certainly crack when you bend it.)
The next operation is the most difficult: it is bending the tube to the
shape shown in Fig. 89. This must be done very gently, otherwise you
will crack or dent it. The loop shown should have a diameter of about
5/8 to 3/4 of an inch.
[Illustration: FIG. 89.]
The actual boat itself can be of any shape. If you happen to have an old
wooden hull suitable to the purpose, use that; if not, then a flat hull
similar to that described on page 70 will do quite well. Fix the bent
tubing at the stern of the boat, so that the two open ends project over
the edge and dip beneath the surface of the water (Fig. 90). Two pieces
of wire bent as in Fig. 90_a_ will hold the tubing in place.
[Illustration: FIG. 90.]
All that you need do now is place the candles under the loop of the tube
and heat it. (If you have a tiny spirit lamp, that will act more
effectively, of course.) The heat from the candles makes the air in the
tube very hot. This hot air is expelled from one arm of the tube; and a
current of water rushes up one arm of the tube and down the other with
considerable force. It is this current that causes the boat to move.
_Another Working Steamboat._--This time our boat will merit its
name--for we shall have a boiler, and generate a supply of steam.
If you look at Fig. 91 you will get a good idea of the construction of
this model, and realise how simple it really is. The boiler is provided
by a medium-sized flat oblong tin, with the lid soldered down so that it
is steam tight. For the purpose of putting water into the boiler when
necessary, a hole is bored in the lid, and a cork fitted tightly.
[Illustration: FIG. 91.]
In one end of the boiler, and towards the top, you must make a pin hole.
When the water boils well, the steam is expelled through this tiny hole
with considerable force; and to this is due the motion of the craft.
The remainder of the fitting up is soon done. A flat hull similar to
that described on page 70 is prepared, and four flat-headed nails driven
in, so that the four corners of the boiler can each stand on a nail
head. The rudder is cut from an old piece of tin, and pressed into a
knife-cut made in the centre of the stern of the hull.
The boiler is placed into position with the steam hole facing the stern,
and lighted candle ends are then placed underneath the boiler--as many
as possible; for the more the candles the greater the heat, and
consequently the greater the force of steam. It will help matters along
considerably if the boiler is first of all filled with hot water,
instead of cold; but be careful not to scald yourself in doing this.
When steam is up, the boat should travel along at quite a comfortable
pace.
Apart from the materials dealt with there are numerous little fragments.
A pane of glass is broken, for instance, and in most cases all the
pieces are thrown away. Now this is quite unnecessary, for from them can
be made some
_Japanese Wind Bells._--Probably most boys and girls have heard or seen
the jolly little "wind bells" which the Japanese people make, and which
many English folk now hang in their houses. As they are made simply of
slips of glass and pieces of wool or string, there is not much
difficulty in their construction; and they are worth all the trouble you
take, for their merry little tinkle is a pleasing sound.
The slips of glass--they are generally little rectangles, varying from 1
in. to 2 in. in width, and 2 in. to 4 in. in length--are suspended so
that when a gentle breeze disturbs them the corners strike gently. To
secure a proper suspension, you can either take a board, 6 in. square,
and hang the strings from it, or you can make a conical wire frame,
about 6 in. across, and hang the pieces of wool (or string) from the two
rings (Fig. 92). The pieces of glass, which can be of any shape and
size, should be fixed by means of sealing wax. It is usual to give the
glass slips a few dabs of colour, so as to give a brighter effect at
night. If you can introduce one or two pieces of coloured glass, the
same effect will result.
[Illustration: FIG. 92.]
Other _broken_ things, too, can be turned to account.