International Library of Technology · Scranton, International Textbook Co. · leaf 130
■^-3 Pipe. Concrete 6tn/ck. ^BocA water t/a/i/e. Fig. 17. in. The roof should be of either arched brick or structural … Fig. 18. iron, supporting some form of cast-iron manhole cover, ofwhich there are several types on the market. 15 ELECTRIC TRANSMISSION. 15 21. Fig. 17 shows a cross-section of a ventilated man-hole well suited for ordinary power-distribution work. Ithas been found better, on the whole, to provide…
Electrical engineering
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