Mohave County miner., 1911-06-03

 zine with the new cy finders required, and today everything is working with the regularity of a clock. Before the actual hoisting of one was commenced, experimental work was carried on for more than a week, to make sure that there would not be the slightest hitch when the ore was loaded. The Noun tain View is today bringing to the surface from 1000 to 1900 tons of ore day by the air plant operated by cleo tricity.
 While compressed air has been used to very limited extent for hoisting purposes, the Anaconda company en- joys the distinction of being the first big mining company in America to operate the system on such a large scale. Some people had little faith in the successful working of the new sys- tem, but the officials of Anaconda company and the installing company never had any doubt as to its success.
 The plant consists of three direct connected variable capacity air con- pressors, each with capacity of 7,500 cubic feet of free air per minute. When operated at full capacity 36O0 horse power is required to drive these compressors. They are of the latest type intercooler design. They are of the most efficient compressors the company has ever constructed and have both high and low pressure cyl finders. They are self-starting and start as compound engine, the air first entering the high pressure cylin- der, from which it is exhausted into the low pressure cylinder, and from the low pressure it is exhausted into the atmosphere. When the compress sor attains its normal speed the cur rent is thrown on, the valve gear is reversed and the machine is at once converted into an air compressor.
 Tbe fly wheel of each of the three compressors is 25 feet in diameter and weighs 9 tons. It is keyed on to the main shaft, which is 22 inches in diam eter and weighs II tons It is direct driven by ''sinkless' motor, the fly wheels making 75 revolutions mIn- ute Piston rods extend through the cylinders and travel on tail carriers, which relieve the bottoms of the cyl finders from pressure and consequent friction. The compressors are pro- vided with an automatic system of oiling.
 In the process of compression the air is cooled between the low and high pressure cylinders, the cylinders being water jacketed. The water for the cooling jackets is received from a tower some distance away from the | compressor room, on an elevation, where It is cooled by means of cleo tricity driven fans. There is no doubt the whole plant is the most extensive of its kind ever constructed and the fact that it has been put into commis- sion after a few preliminary tests is a source of great qualification not only to the builders, but to the officials of the company.
 Now that the Mountain View is ID successful working order, the Dia- mond mine has been closed down and the new system installed. The next to be equipped will be the High Ore. In time it is intended to install the equipment in every mine owned by the company.
 Only rough estimate can yet be given as to the saving it is expected will be brought about by the substitu- tion of air for steam, but it is generally believed that it will amount to about one cent a pound in the cost of the production of copper.
 It is also the intention of the Ana conda company to bring about a fur ther saving by installing electrically driven pumps in the mines and by do- ing all underground hauling by cleo tricity.-Boston Commercial.