[1591]. Irregular or elliptical gear.

[1592]. Lever combination to obtain an even tension from a spring throughout its motion.

[Larger plate.]

[1593]. Scroll spur gear.

[1594]. Scroll gear for obtaining a variable pull from a weight.

[1595]. Variable friction gear. The pinion can be moved up or down from the centre to the outside of disc to vary the speed.

[1596]. Owen’s compound lever variable pressure air pumps. The pressure increasing and speed decreasing as the pistons rise to the top of their stroke.

[1597]. 2-speed gear by one belt. One loose pulley B carries a transverse mitre wheel, which, gearing into the fixed mitre wheel A, drives the mitre wheel pulley C keyed to shaft at twice the speed of pulley B when the belt is on B; by shifting the belt to pulley C, the speed is 1 to 1. The third pulley is loose for running idle.

[1598]. 2-speed bevel gear with three wheels and sliding shaft, by which either pair can be put into gear.