American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 94
y sufficient current to operate an instrument such as an ordinarysounder on long telegraph lines. It is found more economical to employ a main linerelay having a much larger number of convolutions, and a light armature, not designedto produce a large volume of sound, and then to cause this relay to… … THE WESTERN ELECTRIC SOUNDER. ern Electric sounder. One point of difference between these sounders is that fig. 49is supplied with a spiral spring s; that in fig. 50, with a retractile spring. Fig. 51,represents the Victor sounder. In this the trunnion of the lever rests on pins, orpoints, instead…
Telegraph
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