. The practical telephone handbook and guide to the telephonic exchange . thetaste of the proprietors of the land on Fig. 332.—Spur In-which they are erected. sulator The poles used are mostly Norwegian or Swedish firs, felledin the winter months, when the sap is least plentiful. Creosoting.—Before use, the poles should be subjected tosome preservative process, of which many have been suggestedand tried, but the only one which has so far given satisfaction1is creosoting. This consists in placing the poles in air-tightcylinders after they have been thoroughly seasoned, and forc-ing into the por
. The practical telephone handbook and guide to the telephonic exchange . thetaste of the proprietors of the land on Fig. 332.—Spur In-which they are erected. sulator The poles used are mostly Norwegian or Swedish firs, felledin the winter months, when the sap is least plentiful. Creosoting.—Before use, the poles should be subjected tosome preservative process, of which many have been suggestedand tried, but the only one which has so far given satisfaction1is creosoting. This consists in placing the poles in air-tightcylinders after they have been thoroughly seasoned, and forc-ing into the pores of the timber a quantity of creosote, anoily and antiseptic product of coal-tar. About 12 lbs. ofcreosote should be absorbed per cubic foot of timber. Thisprocess, if properly carried out, effectually protects the polefrom wet-rot, which attacks unprotected poles at the groundline, where are great alternations of temperature andmoisture. Poles up to 75 or 80 feet in length can now be longer poles are required two should be scarfed together,. 338 PRACTICAL TELEPHONE HANDBOOK the top of one and the bottom of a smaller one being fittedtogether for some 8 or 10 feet, and then firmly clamped withiron bands. A minor objection to creosoted poles is that they cannotbe properly painted, as the oil oozes out. Their appearanceis not, therefore, prepossessing. Sizes of Poles.—Poles are supplied in two classes, light andstout. The former are for use on routes which are not expectedto reach to more than four wires and the latter for all routeslikely to attain to more than four wires. Tables giving thesizes, cubical contents and weights are given on page tables are based on a weight of 56 lbs. per cubic foot forcreosoted poles, of which 44 lbs. is for the timber and 12 the creosote. Larch poles, which are used where paintingis required, weigh about 34-5 lbs. per cubic foot and squarepitch pine poles, which are sometimes demanded in residentiald
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Keywords: ., bookcentury1900, bookdecade1900, booksubjecttelephone, bookyear19
