National Geographic : 1934 Dec
Photograph by John Tee-Van SKILLED HANDS TIE ON THE COMMUNICATIONS CABLE At intervals of 100 feet the rubber-sheathed strand carrying the telephone and electric power lines is fastened to the main supporting wire. Formerly iron clamps were employed, but these were discarded in favor of rope, which could be cut in case a quick ascent became necessary. Photograph byDavid Knudsen INSPECTION OF TELEPHONES PRECEDES EACH DESCENT Hundreds of messages pass upand down theslender wires that constitute the only communication with theoutside world. Five seconds isthelongest period of silence permittedbetween calls; forthose oneach endoftheline must know constantly thatalliswell.