American horological journal, devoted to practical horology (1869)
Miller, George B · New York, G. B. Miller · leaf 16
from this it will be seen thatwhen the roller jewel comes to the positionof 5° in front of the tooth, at which time the unlocking of the detent takes place and thewheel falls, the two front surfaces of toothand jewel will exactly coincide; the tooth willneither fall on its point nor with its… … chronometer is generally found wanting. Thehollow must be deep enough to allow a toothof the wheel to pass through without touch-ing, must extend over an arc of the circum-ference of the roller of 45° (or the degrees ofleverage obtained) and be distributed so thattwo-thirds of it will be from o,…
Clocks and watches
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![An illustration from Cheiro's language of the hand : complete practical work on the sciences of cheirognomy and cheiromancy, containing the system, rules, and experience of Cheiro [pseud.] fifty-five full-page illustrations, and over two hundred engravings of lines, mounts, and marks (1900)](https://img.insideoutlibrary.com/img/200/ia-cheiroslanguageo00hamo-226-60.webp)
