766 



An Improved Grinder for Gas- 



Engine Valves 



AFTER a gas-engine has been used 



±\. for a time, the vaKes, especiall\' 



the exhaust members, are apt to become 



pitted and scored. In some cases, this 



Popular Science Monthli/ 

 A 



An abrasive wheel supported on a ball 

 bearing shaft for valve-grinding purposes 



roughening is so pronounced that it is 

 almost impossible to grind the valves 

 into a correct seating by the usual 

 emery-and-oil process. The valve grind- 

 ing will be considerably facilitated if the 

 valve-heads are surfaced off. 



An improved grinder for this purpose, 

 recently marketed, is shown in the accom- 

 panying drawing. An abrasive wheel is 

 supported on a ball-bearing shaft driven 

 by encased gearing in such a way that 

 its speed is fourteen times that of the 

 valve-head and its direction of rotation 

 opposite. The valve is carried by an 

 automatic, adjustable rotating chuck 

 which insures that the valve will be 

 properly centered, this being dri\en by 

 a small pulley from any available 

 power. 



The abrasive wheel is properly be\cled 

 to make sure that the angularity of the 

 vaKe-head will not be changed. A 

 cenlt-ring device is included to exert 

 pressure on the \al\e-head and bring it 

 in contact with the wheel. An integral 

 wheel -dresser is also a part of the device. 

 The tool shown has a capacity for valve- 

 stems from 5/16 in. to 1/2 in. in 

 diameter and valve-heads from i 1/2 to 

 3 in., this range taking in most of 

 the valve sizes in automobile engines. 



H' 



Fire - and-Water Proof Cement for 

 Mending Stove Fire- Brick 



ERE is a formula for a cement 

 which will repair fire-brick in stoves 

 and furnaces, and which can be used even 

 where there is an intense heat. Take 3 

 parts of fire clay and i part iron filings 

 and mix with strong \-inegar until a putty- 

 like mass is formed. If theccmient is used 

 to fill up \ ery small cracks and crexices, 

 it should be thinner. If iron filings can- 

 not be secured, fine iron borings will be 

 just as good. If it is desrrefl to use the 

 cement in a furnace for melting metals, 

 the following mixture will give better 

 results: i part iron borings, 2 parts fire 

 clay, and i part fire sand. Mix with 

 vinegar in the manner described. 



A Revolving Telephone Index on 

 the Transmitter 



EVERY user of 

 certain persons to cal 



a telephone has 

 more or less 

 frequently whose numbers may not 

 be readily remembered. A list of 

 these numbers ma>' not be large 

 and to look them up in the telephone 

 book requires some time. A ver\ handy 



The disk is fastened loosely 

 in position directly behind 

 the telephone mouthpiece 



luimlirrs 

 disk .md 



and ruMt littlt- index Im .1 liw 

 can be written t)n a canlbo.ird 

 slipped on the neck of the telepiione 

 mouthpiece. It has six di\isions and is 

 fitted loosely so that it can be turned. 

 The mouthpiece is unscrewed and taken 

 off to place the disk in position. 



