Figs. [107]-[108] are what are known as Spanish bartons.
[Fig. 108] is a combination of two fixed and one movable pulley.
Figs. [111]-[113] are different arrangements of pulleys. The following rule applies to these: In a system of pulleys where each is embraced by a cord attached to one end of a fixed point, and at the other to the centre of the movable pulley, the effect of the whole will be the number 2 multiplied by itself as many times as there are movable pulleys in the system.
Figs. 108, 109, 110, 111, 112. Other combinations of blocks and pulleys
[Fig. 114]. Endless chain for maintaining power on going barrel, to keep a clock going while winding, as during that operation the action of the weight or mainspring is taken off the barrel. The wheel to the right is the going wheel, and that to the left the striking wheel. P is a pulley fixed to the great wheel of the going part, and roughened to prevent a rope or chain hung over it from slipping. A similar pulley rides on another arbour, p, which may be the arbour of the great wheel of the striking part, attached by a ratchet and click to that wheel, or to the clock frame if there is no striking part. The weights are hung as may be seen, the small one being only large enough to keep the rope or chain on the pulleys. If the part b of the rope or chain is pulled down, the ratchet-pulley runs under the click, and the great weight is pulled up by c, without taking its pressure off the going wheel at all.
[Fig. 115]. Triangular eccentric, giving an intermittent reciprocating rectilinear motion, often used for the valve motion of steam-engines.
[Fig. 116]. Ordinary crank-motion.