218 



THE WORLD'S ADVANCE 



distorting the parts to be milled, and 

 holds them rigidly, requiring but little 

 pressure on the screw, U. The jaws, C 



and D, can be used their entire circum- 

 ference before being replaced, making 

 the upkeep comparatively small. 



Handy Sandpaper Holder 



A handy sandpaper holder can be 

 made from two blocks of wood, one of 

 which is y 2 " thick and the other %" 



thick, both being of the same length. 

 The width is optional. With a marking 

 gauge, lines should be scribed y%' in from 

 the edge of the j" block. Drill a 3/16" 

 hole through the exact centre of the 24" 

 block and fasten the two blocks together 

 with a round-head brass screw. Where 

 the scribed lines cross on the surface of 

 the thin block, drive No. 16 steel brads, 

 }" long, through into the thick block, 

 and another brad in the centre of each 

 of the long sides, or six brads alto- 

 gether. These brads are for the pur- 

 pose of holding the sandpaper in place. 

 With a gauge cut grooves along each of 

 the edges of the thick block for finger 

 holds. The sandpaper should be clamped 

 in place as shown. 

 Contributed by 



A. P. H. PAUL. 



Substitute for Filter Paper 



In case of a lack of filter paper for use 

 in experiments in chemistry, a very good 

 substitute is found in sanitary paper 

 towels which are now in such common 

 use. Cut the paper into circles the de- 

 sired size, and it will be found to do the 

 work practically as well as the regular 

 filter. 



Contributed by S. H. SAMUELS. 



A Rubber Name Stamp 



A rubber name stamp can be made 

 quite easily if the following directions 

 are observed. The name should be writ- 

 ten on a waxed zinc plate, care being 

 taken that the wax is cut completely 

 through. Hydrochloric acid should be 

 painted over the wax and allowed to 

 eat its way half through the plate which 

 should be y& inch thick. Hot water 

 should be poured on the plate to remove 

 the wax. The rubber should be pressed 

 into the etched lines and vulcanized. 



This suggestion is given as an im- 

 provement upon the method described by 

 Mr. E. F. Hallock in a previous issue. 



Contributed by 



W. CHRISTNAGEL. 



Cutting Small Gears in a Lathe 



A gear-cutting tool for the amateur 

 mechanic is shown in the accompanying 

 illustration. The body of the tool con- 



sists of a ij" steel rod about 15" in 

 length. This rod should be centered at 

 both ends in the lathe. At the centre 

 of the rod, two small holes should be 

 drilled. One of these should be filed 

 out square to accommodate the cutting 

 tool and the other threaded for a lock 

 bolt. The material for the cog is a disc 

 of metal of the desired diameter. It 

 should be clamped in a slide rest and 

 turned as the succeeding teeth are cut. 

 Contributed by F. P. DICKQVER. 



