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"Under intense pressure, the smaller threads on the screw may break. Therefore a larger screw with a threaded bottom is used for strength. As the larger screw turns, the smaller screw ascends tightly into the larger." —Quackenbos 1859

Hunter's Screw

"Under intense pressure, the smaller threads on the screw may break. Therefore a larger screw with a…

"An apparatus devised by Mach for the illustration of the pendular motions of the particles of a medium transmitting waves of any kind, longitudinal or transverse, stationary or progressive." — Avery, 1895

Line of pendulums

"An apparatus devised by Mach for the illustration of the pendular motions of the particles of a medium…

The stationary member of 12-cylinder splitdorf distributor.

Splitdorf Distributor

The stationary member of 12-cylinder splitdorf distributor.