American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 445
of the receipt of the call, various, so-called, return signals,to be actuated, automatically, or by the clerks in that office, have been devised, and,in some instances, put into service, one of which, the Van Size return signal box, willnow be described. THE VAN SIZE EETURx siGXAL Eox.— Rctum… … CONNECTIONS—VAN SIZE RETURN SIGNAL. The mechanical and electrical portions of this box are nearly identical with theordinary call box. 1 he bell b, relay R, register g, etc., at the left of figure are as-sumed to be in a central office, co. The return signal apparatus proper is placed inthe bottom…
Telegraph
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