National Geographic : 1910 Dec
990 THE NATIONAL GEOGRAPHIC MAGAZINE assigned to each mule-one man ahead with the lead-rope, the other behind to steady the load and prevent it from swing , ing and see-sawing. Heavy . pieces like these were handled in relays, changing mules about every two hours. S The method of handling ca c bles is shown in Picture 1o, which is of 2,300 feet of seven eighths-inch steel aerial tram way cable on 12 mules. "The coils were made up and tied with wire in the factory before shipping, each mule-load being divided into two parts, with o about 12 feet of cable between 4 each pair of coils. The coils were so arranged that each a mule-load was about 236 pounds or 144 feet of one-inch, 230 pounds or 192 feet of seven eighths-inch, 240 pounds or 354 feet of five-eighths-inch cable. The largest piece (about 4,000 feet) of one-inch cable required 26 mules for its transport. One : man was assigned to each two J mules. The mule at the head of the line was controlled by a a lead-rope, and each mule's lead rope was fastened to. the pack of the mule in front of it. In o this way they were kept at a uniform pace, and with the men distributed as indicated the en tire train could be stopped sim o ultaneously when necessary to tighten up the cinches or for other purposes."* Z Picture 9 shows a tube-mill head-plate casting (in the lead), weight 200 pounds, and a tube a mill roller bearing, 385 pounds. d The latter was an awkward piece to handle, not so much due to its weight as that it rested high on the "lomillos," a small wooden crib made of four p 4 by 4-inch blocks, which rests * "Mule-Back Transportation of Sectionalized Machinery," by F. C . Robert and Walter W. Bradley, Mining and Scientific Press, May 29, I909.