Page:Popular Science Monthly Volume 92.djvu/460

 444 Popular Science Monthly

How to Make a Watch-Charm of Marble, Agate or Granite

��A SMALL cross made of marble, agate or granite makes an attractive watch-charm. The process of shaping it

���Dimensions of the cross to be made; also how it is to be drilled and cut from marble

��is very simple. It can be done with a file. First flatten the piece from which it is to be cut, by rubbing it on a sand stone; then mark the pattern on the sanded side with a file point. Next file to your lines with a flat-faced file, holding the piece in a vise. Bore a hole in the upper portion of the finished cross by means of a fiddle drill. A piece of a darning needle flat- tened and pointed as at A serves as a bit. The butt end is also flattened, so it will not turn, and imbedded in the end of a hard wood stick, A small, loose-fitting metal cap, B, makes a hand rest and permits the shank to turn. The bow is a hardwood stick. Its ends are joined by means of a stout string. With the hand on li, the bow is pushed back ;ind forth, and the metal point will soon drill through the stone. Keep it wet as you drill. Leather squares, C, tacked to the bench, hold the piece of stone firmly. The charm is polished by rubbing with fine-grained

��marble and finally given an oil rubbing with a piece of felt. Any amateur may attempt this dainty piece of work in all confidence. Ordinary carefulness is the chief requirement that makes for success in making this attractive watch-charm. — John L. Dougheny.

��A Small Steam Engine Used as an Air Compressor

IN a small machine-shop some metal tanks were ready to ship when the order came to test them under 60 lb. air pressure. There was no air compressor at hand and no time or money to get one. But the tanks were all tested that day just the same. There was in the shop a 6-horsepower steam engine undergoing repairs. This engine was belted up to the line shaft with a piece of pipe between the steam chest and one of the tanks. A gate valve was put in this line and a pressure gage was attached to the tank. Then the engine was started, and air was pumped into the tank until the gage registered the 60 lb. In this vay, each tank was thoroughly tested at no great cost.

A Portable Board Roller for Circular Saw Feed

THE illustration shows how a wheel- wright used a discarded wringer- roller in the construction of a board sHde or rest, used in conjunction with a circular saw. The rubber of the roller evidently

���Rubber roller from a wringer used on a special horse to make a board roller

exercised brake enough on the boards to prevent sudden spurts during the process of sawing. James M. Kane.

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