"Seismoscope. a, heavy mass supported by loop at point near center of gravity; b, point on which upper side of loop rests; c, long needle projecting from upper side of loop; d, conducting-wire; e, binding-post; f, long arm of lever pivoted at k; g, point where end of lever rests on end of needle; h, mercury-cup." -Whitney, 1911

Seismoscope

"Seismoscope. a, heavy mass supported by loop at point near center of gravity; b, point on which upper…