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"The piston rods are furnished with racks, or teeth, and are worked by the toothed wheel a, which is turned backwards and forwards, by the lever and handle b. The exhaustion pipe c, leads to the plate on which the receiver stants. The valves v, n, u, and m, all open upwards." —Comstock, 1850

Air Pump

"The piston rods are furnished with racks, or teeth, and are worked by the toothed wheel a, which is…

Two racks carry the pistons and work with the pinion. The pinion is turned by a double-handed lever, which is moved alternately in opposite directions.

Double-barrelled Air-pump

Two racks carry the pistons and work with the pinion. The pinion is turned by a double-handed lever,…