Fig. 3.
You will now want a pulley wheel (B, [Fig. 3]). One of the wooden sheaves used in Venetian blinds for the cords to run over will do very well indeed, or if you possess a lathe you can turn one for yourself. It should be 11⁄2 in. in diameter and 1⁄4 in. thick, having a small hole right through the centre, of a size to fit tightly on the hour spindle of your works. [Fig. 2] represents the frame after the wheels not required have been removed. [Fig. 3] represents the starting lever and pulley. This pulley must have a notch 1⁄4 in. deep cut in one rim, for the hook of the lever to fall into and stop the machinery. This pulley must not be more than 11⁄2 in. in diameter, or you will not be able to get at the winding-up pin.
The frame carrying the wheels must now be mounted in its place under the horizontal partition. For this purpose fasten with screws a block of wood to the floor board, or back of the case, in such a position that the front of the frame is about 51⁄2 in. from the front of the case, and so that the centre of the wooden wheel is about 4 in. from the horizontal partition, and immediately under the spindle carrying the sails of the mill. The horizontal partition must have a slot cut in it, inside the mill, for the connecting cord to pass. The frame is to be fastened to the supporting block by screws, but before doing this you must make the all-important starting and stopping lever.
Get a piece of iron wire 1⁄8 in. thick, and about 10 in. long. Flatten one end and bend down about half an inch of this end to form a hook, standing about at right angles to the length; place this hook in the notch of the wheel when it is a little beyond the centre of the pulley, as seen in the cut, and cut the wire to such a length that the other end of it will be about 1 in. from the side of the case, when the gear is in position. Drill a hole crosswise through the wire about 3 in. from the hook, and fasten a small wire to the gear-frame, standing at right angles to it, about 21⁄2 in., measured horizontally from the spindle of the pulley, and near the top. This is for the lever to turn on, as shown in the cut. At the free end of the lever solder a piece of tin bent up on three sides like a small tray, with the edge not bent at the extreme end. This tray or scoop should be about 11⁄2 in. square, and is to catch the penny as it is dropped in.
The hooked end of the lever must be weighted, to slightly outbalance the other part, so that the hook will drop into the notch in the pulley. The frame can now be put in its place and fixed to the block with screws. Bend the long end of the lever till the scoop is 31⁄2 in. from the under side of the partition. In bending the lever you must also see that the scoop is horizontal, or the penny will not remain in it long enough to start the gear. Now connect the spindle of the sails and the wooden pulley-wheel by passing a silk cord or fine string round both tightly, and knotting the ends together.
Now on winding up the spring and pressing down the lever the works will start into motion and the sails will revolve. The speed can be regulated by placing the sails at such an angle that they will offer more or less resistance to the air.
The slot in the door for the insertion of the penny must be cut three-quarters of an inch below the upper edge of the wooden partition, and inside you must fasten a tin trough to conduct the penny to the scoop at the end of the lever. This trough must slope downwards to the edge of the scoop, or the penny will not fall into it, but remain just inside the hole.
The model is now complete, and works as follows: The spring having been wound up and the door closed, the works are kept from moving by the hook of the lever catching in the notch of the pulley, but on a penny being put into the hole, and sliding into the scoop at the other end of the lever, its weight presses down the scoop end and lifts the hooked end out of the notch in the pulley, which turns round, and continues to do so, carrying the sails of the mill round with it till the notch again comes under the hook, which (the penny having fallen out of the scoop into the drawer) falls into it and stops the machinery, giving one revolution of the pulley for a penny. The pulley being twelve times larger than the spindle of the sails, these will revolve twelve times each time the model is started. The model will work about 204 times each time it is wound up.
A Model Cutter Yacht.
Having finished the windmill to your satisfaction, we will now turn our attention to the construction of a model requiring rather more complex machinery. This is shown at [Fig. 4], and represents a cutter-yacht sailing on the port tack, on a lee shore; which, if carefully made, so as to produce the effect of the rolling and pitching of a real yacht upon a real sea, will catch many a penny.