| OCR Text |
Show The Uses of Aluminum. Aluminum Is now finding consider-ublo consider-ublo employment In this country ns a substitute for coppor as an electrical conductor In connection with tho transmission of power over long distances. dis-tances. Ono of tho most Important of theso lnstnllntlons Is tho transmission transmis-sion of 12,000 horse-power from the Snoqunlmlo falls to Scattlo and Tn-coma, Tn-coma, a dlstanco of moro than 40 miles. In this scheme nn alloy of aluminum with l', per cent of coppor has boon used, tho llghtnoss and strength or this alloy enabling spaus of ICO foot to bo made with safety. A great saving In tho number of poles Is thus effected, which Is said to bo 1 ono of the principal advantages gained. I Many other transmission schemes In which aluminum Is used or about to bo employed might bo mentioned. Besides tho saving in poles, nlumlnum affords a much smaller weight of conductor, nnd Is cheaper than copper. In lound numbers, for equnl conductivity, tho section of nn aluminum cablo is onn and a half times that of a copper ono, tho weight Is half and tho tensile strength three quarters. It Is tho decreased de-creased weight which, In splto of tho smnllcr tcnsllo stron.gth, allows longer spans to bo used, nnd this effect can , bo inado mora marked by tho uso of a sultablo alloy possessing Increased strength without much diminished conductivity or much higher specific gravity. |
