[Fig. 202]. Common windmill, illustrating the production of circular motion by the direct action of the wind upon the oblique sails.
[Fig. 203]. Ordinary steering apparatus. Plan view. On the shaft of the hand wheel, there is a barrel on which is wound a rope, which passes round the guide-pulleys, and has its opposite ends attached to the tiller, or lever, on top of the rudder; by turning the wheel, one end of the rope is wound on and the other left off, and the tiller is moved in one or the other direction, according to the direction in which the wheel is turned.
[Fig. 204]. Capstan. The cable or rope wound on the barrel of the capstan is hauled in by turning the capstan on its axis by means of handspikes or bars inserted into holes in the head. The capstan is prevented from turning back by a pawl attached to its lower part and working in a circular ratchet on the base.
Fig. 203. Cable Fig. 204. Capstan
[Fig. 205]. Lewis bolt for lifting stone in building. It is composed of a central taper-pin or wedge, with two wedge-like packing pieces arranged one on each side of it. The three pieces are inserted together in a hole drilled into the stone, and when the central wedge is hoisted upon it, it wedges the packing pieces out so tightly against the sides of the hole as to enable the stone to be lifted.
Figs. 205, 206. Lewis bolts, for lifting stones