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. 



