Now take your boat, and at each end of the keel fix a small brass plate having a hole drilled in it (FF, [Fig. 5]), 41⁄2 in. apart, and fix another plate drilled in the same way at C, about 23⁄4 in. from the stem of the boat. Take two pieces of wire 5 in. long and bend one end of each into an eye and the other end into a hook, crosswise with regard to the eye, and hook a wire into each of the plates FF, on the keel of the boat, and connect the other ends with the pulleys B and B by two small brass screws passing into the fronts of BB, as shown in [Fig. 5], and arrange the pulleys so that one of the pivots shall be up while the other is down.
Fig. 7.
All these joints and connections must work freely, although not loosely. The two pulleys, BB, you must connect with a cord passing round both. The pitch of the vessel is regulated by the distance the pivot screws are from the centres of the pulleys, which should be about half an inch. You must next make the regulating gear or fly E ([Fig. 5]). To do this you must take out the pin from the left-hand lower corner of the frame-plate and prise up the plate and take out the fourth wheel near R ([Fig. 5]), and on the spindle of it fix a pulley, which can be readily done in the following manner. Cut a small notch in one side of the hole in the centre of the pulley just large enough to admit a piece of your wire. Solder about half an inch of this wire along one side of the spindle about the middle of it, and force the pulley on to the spindle over this piece, and it will jamb lightly and be keyed to it. [Fig. 7] will show you how to cut the hole in the pulley.
Now return the wheel to its place and re-fasten the frame-plate. Next you must make the fly E. Get a small brass pulley about 1⁄4 in. in diameter, and to it solder a strip of tin cut to the shape shown, but being wider in proportion at the ends, say 1 in. wide and 4 in. long. Twist the ends of this fly askew like the fans of a screw propeller, so that it will catch the wind in revolving. Now fix a block of wood to the bottom of the case and fix the fly to it by a small brass screw passing through its centre, so that it works freely and is 31⁄2 in. from the centre of the driving pulley R and level with it. Fasten a block of wood to the back of the case, in which you must fix the screw N ([Fig. 5]) for the lever O to pivot on. You must next make the starting gear. This is shown in [Fig. 8].
Fig. 8.
As we require the pulleys BB to revolve about twelve times, and as they are attached to the minute-hand spindle, the hour-hand spindle will revolve once. Therefore, on this spindle fix behind the pulley B, by soldering, a circular plate of tin or brass, a little larger than the pulley, and cut in one edge of it a slot a quarter-inch deep and one-eighth of an inch wide. Make your lever as before, but long enough for the hook to catch in the teeth of the wheel C, [Fig. 8]; and solder a piece of tin to the lever, to fall at the same time into the slot in the disc A, [Fig. 8]. This piece of tin must be long enough to keep the hook free of the teeth of the wheel C during the revolution of the disc A. The length of the other part of the lever is to be the same as for the windmill. [Fig. 6] shows an end view of the machinery. K is a wire connecting the keel with the lever Q, and helps to give the rolling motion so suggestive to voyagers.