What is "intermittent gearing"

Intermittent \In`ter*mit"tent\, a. [L. intermittens, -entis, p. pr. of intermittere: cf. F. intermittent.] Coming and going at intervals; alternating; recurrent; periodic; as, an intermittent fever.
--Boyle.

Intermittent fever (Med.), a disease with fever which recurs at certain intervals; -- applied particularly to fever and ague. See Fever.

Intermittent gearing (Mach.), gearing which receives, or produces, intermittent motion.

Intermittent springs, springs which flow at intervals, not apparently dependent upon rain or drought. They probably owe their intermittent action to their being connected with natural reservoirs in hills or mountains by passages having the form of a siphon, the water beginning to flow when it has accumulated so as to fill the upper part of the siphon, and ceasing when, by running through it, it has fallen below the orifice of the upper part of the siphon in the reservoir.