Engineering Wonders of the World
Volume I

122 ENGINEERING WONDERS OF THE WORLD. one section and coupling them up to that of the next section in the series. The uninitiated reader may suppose that, with a difference of level between the two terminals of over 12,500 feet, the force of gravity would suffice to work the traffic both ways, the descending laden cars hauling up the empty cars. On a short line this method is often employed. But here it had to be combined with the use of a steam-engine, owing to the variation in the weight of the ascending load of men, water, timber, machin- ery, and other supplies. The actual construction of a cableway in the rough, deso- late Cordilleras also presented many difficul- ties. An ordi- nary railway feeds itself as it grows, material being trans- ported over the completed part of the track for the length ahead. With this cableway the case was differ- ent, as a whole section had to be finished before anything could be moved over it, and therefore some independent form of transport was required. In addition to human carriers, 90 donkeys and 1,000 RAISING A COMPLETE TOWER ON ITS BASE. Difficulty of Transporting Material. mules—these last supplied by the Argentine Artillery Corps—were employed. Parts of the iron structural work for the towers to carry the cables were limited to about 330 lbs., a full load for a mule. Units which exceeded this weight had to be moved by gangs of men. The grade- men led the way, to dig and blast cuttings through the sharp mountain peaks to give a sufficiently large radius for the ropes. From one of these cuttings over 7,000 cubic yards of rock had to be shifted ; and at one point it was necessary to drive a tunnel 164 yards long by 13 J feet high and 14| feet wide through the peak of a very pointed hill. After the navvies came the masons,who built up the massive piers to carry the towers ; and behind them followed the tower erectors. Some of the towers were short enough to be as- sembled horizontally and tilted up bodily into their final posi- tions. But the taller structui to 140 feet in height, were built up on their bases story by story. As soon as all the towers Building the Towers. , ranging up