ClipArt ETC
"In the differential pulley, an endless chain is reeved upon a solid wheel that has two grooved rims and is carried in a fixed block above, and upon a pulley below." — Avery, 1895

Differential Pulley

"In the differential pulley, an endless chain is reeved upon a solid wheel that has two grooved rims…

"Machetes pugnax. Ruff. Reeve. Combatant. Gambetta. Varied above with black, brown, buff and chestnut, the sides of rump white; under parts white, breast and sides and crissum black, spotted with white; tail brown, barred with chestnut and white; quills dusky, with shafts; wing-coverts ashy-brown. Bill blackish, flesh-colored at base; legs dingy yellow; warty excrescences yellow; feathers of the ruff endlessly varied in color." Elliot Coues, 1884

Ruff

"Machetes pugnax. Ruff. Reeve. Combatant. Gambetta. Varied above with black, brown, buff and chestnut,…