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Show ' I I A Steel Cutting Saw. ! I General Manager Putter of the Home- I stead mills of Carnegie Brothers & Co. I has invented a cold saw for the purpose : , of sawing iron and steel, which has : proved a great success, and is creating considerable interest For some years , an instrument has been in use known as j the hot saw that is, it could only cut ! metal that had been heated to redness, but it is not equal to the new saw j brought out by Mr. Potter. The hot , saw leaves a burr on one edge, but the j j new cold eaw does clean, smooth work ' and is not very expensive, j A reporter had a talk with a gentleman gentle-man who had seen the saw at work a ' short time ago, and secured from him the following description of the new in-' in-' vention: The instrument itself is simply a circular saw of fine steel, tempered i somewhat hard, and about one-quarter j ) of an inch in thickness at the periphery, j j It is ground slightly fhinnerat its center 1 to clear itself easier in a deep cat It is made to revolve at a slow speed, while the old hot saw was run at a high rate of speed, and did its work by means of j the intense friction created rather than j by the teeth. It cuts but one inch a minute. j The machine differs from the ordinary circular saw in this respect, that it is 1 not the work that moves up to the saw, 1 ; but the work is fixed stationary and the j saw is made to travel along the table through it. It is driven by a worm j wheel and screw of some four or five I feet in length, along which it can be 1 moved easily by hand screw gear or by self acting feed gear. The saw runs in I a tank of solution, and the greatest care ; . is necessary in regard to the quality of 1 , the materials of this solution. It is I made up of ten pounds of whale oil soap, ! fifteen pounds of sal soda, two gallons of . lard oil, with water added to make forty ' gallons of mixture. The new saw will be used in cutting the armor plates for ; the government the proper size. Pittsburg Pitts-burg Dispatch. |