[139]. Wiper and lever motion.

[140]. Twisted bar with sliding bush, which travels from end to end of the bar, and being prevented from turning, causes the bar to turn on its axis to the amount of its twist.

[141]. Crank pin and slotted lever; gives a variable speed with quick return.

[Larger plate.]

[142]. Spiral radius bar for opening valve. The valve is lifted off its seat by the radial motion of the lever against the inclined radius bar.

[143]. Crank pin and slotted lever motion, with slot arranged for irregular or intermittent motion.

[144]. Eccentric and slotted arm. The pin at the top of the arm has both a vertical and horizontal motion, causing it to trace an ellipse, the pin upon which the slot runs being fixed.

[145]. Wiper and lever motion, with rubbing plate; used for Cornish valves, &c.

[146]. Stamp mill.