History, theory, and practice of the electric telegraph (1866)
Prescott, George B.(George Bartlett),1830-1894 · Boston, Ticknor and Fields · leaf 139
on the mahogany frame, H, Fig. 61. The escapement-wheel revolves on a vertical shaft, which passesthrough the iron plate, and has fixed on it therea hollow pulley. This pulley contains within it afriction apparatus, consisting of two brass clampsenclosing two pieces of leather moistened withoil,… … HOUSES PBINTIXG TELEGRAPH. 121 The escapement-wheel has fourte&i teeth, each one of whichcauses two motions of the escapement, which will make twenty-eight for a single revolution of the wheel, which is shown inFig. 65. When in operation, the piston to which is attached the escape-ment arm 8,…
Telegraph
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