American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 657
s shown in Fig. 419^. SAG.—As regards the amount of sag to be allowed between poles, (a feature of line construction which is considered of great importance in other countries) it may be said that, in much of the recent construction w^ork in this country, the sag has been virtually dispensed with,… … HELVIX TIE. wm^ WIRE STRINGING. 545 a stretch between poles of but 130 feet. It has been found that the percentage of breaks in the case of tightly strung wire has been no greater than in the case ofwire erected with a specified sag. Further, the after work of taking up slack,due to expansion, is…
Telegraph
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