Fritts, Charles Edgar. [from old catalog] · Philadelphia, The Keystone · leaf 68
ed in water, and tempered either in cyanide, (72,103,) or boiling oil, (66,) thus giving the steel rim the sametemper as a hair spring. (120.) Figs. 6 and 7 show the balanced, the disc A^ thecaps C, C, and clamp D. The disc can be made nearly as wideas the rim, and have a slot cut in one side to…
Clocks and watches
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