Part 3

First cut out your holes. To do this get a cigar-box lid and draw out the three figures, taking care that the length of the side of the square and the length of the side of the triangle and the length of the diameter of the circle are equal. Now, using your fret saw, cut out these holes very neatly and precisely.

For the block you need a small cylinder of wood: an odd piece of broken broom handle will do admirably. This must be cut and finished with glass-paper so that it will fit the circular hole exactly. Now saw a piece just as long as the cylinder is wide. This looked at in one way gives an exact square which will fit the second hole. Thus two holes are catered for.

Finally, for the third hole the cylinder must be tapered on two sides. To do this draw a diameter at one end and then gradually pare away a flat surface till the triangular section is obtained.

Fig. 59 shows how the block, when turned in different ways, fits the three holes.

Another toy which can be made quite easily from cigar-box wood is

_A Model Signal._--First cut two strips of wood, half an inch wide and as long as you can get them, which will be 8 or 9 in. These will stand upright on a base board, and form the sides of the standard. Now between these two you must glue shorter pieces of half-inch strip, so as to make the standard solid at the top and bottom, and leave a hollow slot, 1 in. long, in which the signal arm will fit and work up and down (Fig. 60).

Now cut out and paint a signal arm, about 2-1/2 in. long. Fix this by means of a pin passing through the two sides of the standard, and through the arm about 3/4 in. from the square end. If it does not move easily in the slot, take off the top surface with glass-paper. Before fixing the signal arm in position, bore a small hole 1/4 in. from the square end, and knot in a piece of twine or thin wire to act as a connection between the movable arm and the controlling lever (Fig. 61).

At the base of the standard fix the controlling lever. This consists of a small strip, with a pin passing through one end into the standard. Adjust the length of the twine or wire, so that when the signal arm is down, the lever is horizontal; and when the lever is pressed down, the arm rises. You can make a little contrivance for fixing the lever by erecting a small post close to the standard, and gluing on two stops, under which to rest the free end of the lever in its two positions (Fig. 62).

If you prefer it, you can have the controlling lever at a distance from the signal post. You will then need a longer wire, and a little pulley wheel at the base of the standard. You must exercise your own ingenuity for this.

Another interesting little scientific toy, which has the additional advantage of being useful, is the _Weather House_, or the _Man and Woman Barometer_. This consists of a little house with two doorways, at which appear two figures, one in fine weather, and the other in dull (Fig. 63).

With patience and care this is not very difficult to make. For the house itself you can use an old cigar box, or, if you prefer it, you can make the entire house in cardboard. This is, of course, easier, but not very durable. If you are going to use the cigar box, you will need first to cut the lid and bottom into something like the shape of a house end. You will then have to nail the lid down, and add two slanting pieces for the sides of the roof: and that will complete the house.

However, before you nail down the lid and put on the roof, you will need to understand the mechanism. First you will bore a round hole in the top of the roof, just behind the front gable. This hole is for a round peg to which the revolving base is attached.

The actual mechanism of the toy consists of a piece of catgut (an old violin string, or a tennis-racket string). This passes through the centre of a small flat piece of wood on which the two figures are balanced. Just in front of the string a piece of wire (a bent hairpin will do admirably) is fixed, so as to form a loop through which the catgut can pass (see Fig. 64). The other end of the catgut is fixed to the peg which fits in the hole in the roof.

For the man and woman you can use two of the grotesque figures cut from clothes pegs. Screws passed through the revolving base will secure the figures firmly and at the same time add a little weight, and so improve the balance.

When there is moisture in the air the catgut will twist. You must fit together the different parts and then, by turning the peg to right or left, adjust the position of the figures so that the lady appears in fine weather and the gentleman in wet.

A toy of unfailing attraction for boys--and girls as well--is

_The Marble Board._--This may be quite a simple affair--such as a boy can carry in his pocket for use in the playground--just a piece of wood, such as a cigar-box lid, with a number of holes cut along one edge, and a handle added (Fig. 65); or it may be a much more elaborate form intended for use as a table game.

In this latter case there is a front board, similar to that in the simple form; but behind each hole there is a little compartment for the collection of the marbles (Fig. 66). To make this you need two pieces of wood, about 2 in. wide, and as long as the table is broad: any sort of wood will do. These are for the front and back of the contrivance. The front must next be marked out for the marble holes, allowing about 1 in. for the hole and 1 in. for the space between. Of course, the wider the spaces between the more difficult it becomes to score. These holes must then be cut out by means of a fret saw, or, if you do not possess one, by means of saw and chisel. The back and front must then be secured in position by means of end-pieces nailed or screwed on. These should be about 3 in. long.

The next piece of work is the adjustment of the partitions. For these cigar-box wood is best. You can either cut these partitions to the exact distance between the front and the back, and glue them into position; or else you can make them a little larger, and fit them into grooves cut into the front and back: but that is a nice little piece of carpentry for you.

When you have done this, all that is necessary is to give the whole thing a coat of paint, and place numbers over the various holes--taking care that you do not put all the high numbers together.

Boards similar to this are used in the Colonies for a game known as "Bobs." Larger balls are used, and propelled by means of a cue as in billiards. If you can obtain the balls, this is a delightful game, and one well worth making.

_A Wooden Wind Wheel_ for the garden is a splendid little model to make--interesting in itself, but doubly desirable because so much can be done with it. Of course, it can be made quite small and very simple, and still provide unending amusement to smaller brothers and sisters; but for our own purpose it is just as well to make a larger and stronger specimen, one which can be employed as a power station for the working of smaller toys.

The main parts are: (1) a circular hub, about 2-1/2 to 3 in. in diameter, and 1 to 1-1/4 in. in thickness (for the smaller varieties a cotton reel will do admirably); (2) six or eight sails, each about 6 or 7 in. long and 3 in. wide at the extreme end, tapering down to a little more than the width of the hub at the other; (3) a hardwood axle; and (4) a driving wheel. For this last a cotton reel will do splendidly, especially one of those with wide flanges and a slender centre. The general arrangement is shown in Fig. 67.

The cutting of the hub is not a very difficult matter if you have a fret saw. It should be cut across the grain if you can get a suitable piece of wood. The sails also are quite easy to make. For these you cannot beat cigar-box wood. The cutting of the grooves in the hub for the insertion of the sails is the most trying piece of work. These grooves should be just large enough to allow the sails to fit tightly, and should be cut at an angle of 45° across the hub. The sails should then be glued in with carpenter's glue.

For the axle secure a piece of round wood, such as an odd length of half-inch dowel-rod. This should be cut to a length of about 4-1/2 to 5 in. On this should be fixed the wheel itself, and, at a sufficient distance to prevent the sails catching the string, the bearing wheel. A French nail in each end of the axle will then secure it in position between the side supports and secure an easy running.

If you have a play shed in the garden, this apparatus can be erected at the top of a high post projecting through or at the side of the roof. The driving strings can then pass through a hole in the roof or the wall, and the power can be transmitted by a double pulley wheel and another driving string. If you have no play shed, it is not at all difficult to rig it up outside a window. You can try that, and prove your own inventive abilities.

_How to use the Wind Power Machine._--One thing which this mechanism will drive in good fashion is an overhead tramway system--a very pretty little toy when in working order.

For this all that is required is a number of cotton reels, a length of stout cord, and one or two of the model trams described on page 21. If you care to, you can make proper "standards" for the cotton reels. Fig. 68 shows such an arrangement. The flat base is for heavy weights when the system is rigged up on a table or other place where nails cannot be used. These reels must turn freely to allow the easy passage of the cable. In one place there must be a double reel (Fig. 69) for the transmission of the power. The lower reel will act as the ordinary cable wheel, while the other, glued firmly to it, will carry the driving belt from the wind machine described above.

The model trams must be fixed to the cable. This is done by means of two wires, fixed to the pole of the tram and twined round the cable. When this is connected up and the cable drawn tightly round the standard reels, the vehicles circulate rapidly on what is really a complete model tramway system.

Another interesting contrivance to which the wind power can be harnessed is

_A Roundabout._--This attractive little toy can be made quite readily from one or two reels, and four ordinary wooden skewers.

The first thing required is a base board, for which any tolerably smooth and heavy piece of wood will suffice. Now in the centre of this fix an upright piece of thick wire (a knitting needle will do); and glue on a cotton reel at the base of this.

In order to secure the absolutely smooth running of the roundabout it will be necessary to improvise some sort of "bearings." For this there is nothing better than two hard glass beads. If one of these beads be sunk into the top of the reel just mentioned, and the other fixed in the bottom of another loose reel, the upper one will revolve freely on the lower (Fig. 70). This loose reel will be the driving wheel of the contrivance and will hold the power band from the wind wheel. Fixed to this running wheel, and immediately above, will be another reel for the actual merry-go-round. Into the sides of this uppermost reel bore four holes, and insert the pointed ends of the four skewers, arranging them so that all four are at right angles. The running will be facilitated if another glass bead is sunk in the top of this reel.

All that remains now to complete the roundabout is to fix four figures--horses, boats, or similar--at one end of each skewer. These figures can be drawn on cardboard and cut out; or they can be sawn from fretwood.

Another interesting variation of this toy is the

_Fairy Light Wheel._--For this, instead of fixing figures at the ends of the skewers, obtain four egg shells, and suspend them by means of wires from the ends of the arms (Fig. 71). Now if little night-lights or odd ends of candle be placed in the egg shells and lighted, a very pretty effect is obtained when the whole is made to revolve.

A toy which is always welcome to boys and girls is

_A Pair of Scales._--Moreover this is a toy which can be made quite accurately with the aid of a few quite ordinary materials. To a pair of scales--or a balance, as it is sometimes called--there are generally these parts: (1) a balancing arm, generally called the beam; (2) an upright standard on which the beam is supported; (3) two scale pins, and chains (or strings) to suspend them; (4) a base board to which the upright standard is fixed. Fig. 72 shows the sort of thing we mean.

Now of these things not one presents any real difficulty. For the base board any piece of wood about a foot long, 5 in. wide, and 3/4 in. thick will do quite well. For the upright standard you require a piece of wood about 9 in. long and 1 in. square--one end of which must be fixed to the base board. The method of doing this will depend very largely on your degree of proficiency in the art of carpentry. If you know how to make a mortise and tenon joint, that will be the most suitable. If you cannot attain to that, then perhaps you can make a hole just as large as the standard, and sink the standard in the base. If you are not at all an expert, then you must just nail or screw your standard to the centre of the base.

Before you do this, however, there is something to be done to the other end. You must cut a slot 1/2 in. wide and 1-1/2 in. deep (Fig. 73_a_); then you must cut away small triangular pieces from the centres of the tongues left (Fig. 73_b_); and finally you must nail to the sides of the V so formed two little strips of tin (Fig. 73_c_).

The next thing to be constructed is the "beam." For this you will need a piece of fretwood (or other thin wood) about 9 or 10 in. long and about 1 in. wide. To support this on the metal V pieces you will need a thin piece of steel--such as a piece of an old pocket-knife blade. This will be driven through the centre of the beam, and will project equally on either side (Fig. 74). Remember, it must fit tightly; so when you cut the slot for it, do not make it too wide.

For the scale pans two canister lids will do quite well. Bore three holes in each of the rims--measuring off the distances with a compass, so that the holes are equally far apart, and suspend the pans by means of three strings passing into holes in the ends of the beam. If, when you have completed the work, the beam does not hang perfectly horizontal, then you must add weight or subtract weight from one side or the other. You can do this by paring off tiny pieces from the end of the beam, or you can stick on dabs of sealing wax till the correct balance is obtained.

If you cannot get any proper _weights_, then it is not a very difficult matter to make some. To do this, all that you need is to get some cardboard and a supply of sand, and to borrow a complete set of weights. First of all make a number of little cardboard cubes, having sides varying from 3/4 in. to 3 in. Draw each one out on cardboard (Fig. 75); cut it out; and bind up with gummed tape--leaving one side ungummed. On one pan of the balance put this thing, and on the other pan put a proper weight (say 1/2 oz). Now pour in sand into the little cube until it exactly balances the correct weight. When it does, wet the binding, and stick down the remaining side. Finally print the correct weight on one face of the cube.

In similar fashion you can proceed to make all the different weights that you are likely to require, from 1/2 oz. upwards. While not very substantial, these little weights will last quite a long time, if they are handled with care.

Engines of all sorts are always fascinating to boys and girls, and later on we shall describe some excellent ones. At this point we wish to describe what is possibly one of the simplest forms of engine known, and certainly one of the earliest. It is the engine driven by a flanged wheel, which itself is made to turn by the weight of something falling on the flanges. The commonest form of this wheel is the water wheel, where the weight of the water falling on the wheel causes the revolution.

As water is generally a "messy" thing to operate with, especially on such a contrivance as this, we have substituted something else.

For the working of very light toys, sand provides an alternative motive power. If a flanged wheel be made after the fashion of a water wheel, and a steady stream of sand allowed to descend on to the flanges, then the wheel will rotate as long as the supply of sand lasts, and the power may be transmitted by pulley wheels for the working of some simple mechanism.

Fig. 76 shows

_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.

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.

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.

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.

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.

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.

_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.