42 



THE POPULAR SCIENCE MONTHLY. 



will soften a metal sufficiently to allow it to be welded will, of 

 course, render the various solders fluid. 



The process is, moreover, on account of the extreme rapidity 

 with which welds may be made, and the ability to concentrate all 

 the heat at the point of union, a very economical one. Practical 

 commercial work has shown that the cost of the coal burned 

 under the boiler to produce the electricity is just about that of the 

 coal used in a forge to do the work in the old way, and that the 

 saving in time, and hence labor cost, is clear gain, to say nothing 

 of the cleanliness of the process, the freedom from deleterious ma- 

 terials in contact with the metal, such as sulphur and ash, and 

 the advantage of having the work always in clear view. How 

 great the saving in time is may be appreciated by the following 

 statement of actual work vouched for by Mr. Frederick P. Royce 

 and cited in a paper read by him before the National Association 

 of Carriage Builders : 



Axle Welding. 

 1" round axle requires 25 horse power for 



1" square 

 \\" round 

 1^" square 

 2" round 

 2" square 



30 " 



35 " 



40 " 



75 " 



90 " 



Tire Welding. 



45 seconds. 



48 " 

 60 " 

 70 " 

 95 " 

 100 " 



1" X A tire requires 11 horse power for 15 seconds. 



1 1 " V -L" ' 



2" X V " 

 2" X f" " 



23 

 23 

 23 

 29 

 42 



" 25 

 " 30 

 " 40 

 " 55 

 " 62 



The process, though only introduced into commercial work in 

 1888, has gone largely into use, and electric welders now form a 

 part of the regular equipment of the carriage and bicycle factory, 

 the boiler and tool shop, the wire mill, the yard of the ship- 

 builder, and the thousand and one establishments which have to 

 do with the working and shaping of metals. It has been applied 

 with marked success to the joining of the parts of railway frogs, 

 of chairs to rails, and other heavy work, and in ordnance work, 

 to the manufacture of shell and shrapnel. One of the most novel 

 uses to which the process has been put is now to be seen in Boston 

 on a section of the West End street railroad. This is the welding 

 of the ends of the rails together without removing them from 

 their places in the track, the object being to render the line of 

 rails efficient return conductors for the current used with the 

 trolley cars. To accomplish this the necessary apparatus is 

 mounted upon a car provided with driving motors to enable it to 



