Miller, Kempster Blanchard, 1870-1933 · New York : McGraw publishing company · leaf 861
y bedivided into two classes, namely, multiple duct and single duct.The multiple duct conduit is made up in a variety of ways, someof which are shown in cross-section in Fig. 615, loaned by theH. B. Camp Company. For telephone purposes, the duct openingis either round and 3^ to 4 inches in… … FIG. 6I6.-SINGLE AND QUADRUPLE TILE. walls of one inch, and a horizontal shelf across the middle, one inchthick. This divided the pipe into two ducts, one above the other, eachabout 4| inches high by 10 wide. Into each duct were drawn threecables, two side by side, and one on top of these two.…
Telephone
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
