Handbook for the use of electricians in the operation and care of electrical machinery and apparatus of the U. S. seacoast defenses .. (1904)
United States. War Dept · Washington, Govt. print. off. · leaf 205
199. Waier=tiKhi Outlet Box and Ulass Cilobe. … 153 HANDBOOK FOR ELECTRICIANS. i clay conduit set in concrete. Both of these ducts connect manholes about 250 feet apait and will last indefinitely. (2) Wrought-iron pipe duct (figs. 201-3), in 20-foot lengths, of 3 to 4 inches diameter, i inch thick, dipped in tar to prevent rust, are jointed by a…
Electric machinery · Searchlights · Coast defenses
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
