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.