ELKCTHIC WKLDING DEVELOPMENT. . 285 



jjla^'s, ill iimny ins(<inc('s, iniich iiigemiity. In tlu'se luachines the 

 <liity of Ihc attondant is limitod to the iiiei-c phicingj of the pieces 

 between (he ehuui)ing jaws, just before they are chinijjed, and the 

 work is characterized b}' rapidity and by uniformity of the results. 



More completely automatic still are machines for the production 

 of wire fencino^ and for the consecutive wehling of the links of 

 chains. In these tlie operation, once started, goes on uninterruptedly 

 so long as (he work holds out or until the stock luidergoing opera- 

 tion is exhausted. In tlie fence machines, of which 15 are now in 

 existence, galvanized iion Avires are fed from reels parallel to one 

 another, at distances apart depending on the mesh desired. These 

 nuiy correspond to the warp in weaving. Transversely to these and 

 at intervals corresponding to the mesh selected are fed wires, cut 

 from a reel, Avhich transverse wires are the verticals in the finished 

 fence itself and correspond to the weft in weaving. A series of 

 small welders are automatically brought into operation to weld each 

 transverse wire to the longitudinals where the two cross. This done, 

 the w^eb so formed moves forward, the operation repeats itself, and 

 so on continuously. The welding is in this case practically instan- 

 taneous, and all of the movements of the machine are entirely 

 automatic. 



In this way it is possible for a single nuichine to turn out many 

 thousands of feet of fencing per day with a width of mesh from 2 

 or 3 inches up. Less wire is used than where the joints are made by 

 twists or loops, and the stability or fixedness of position of such 

 joints as are made is much more assured. Figure 1, plate iii, will 

 give some idea of the neatness of this product of the electric welding 

 loom. 



A\Tiile in most cases of electric welding the joint forms what is 

 jcnown as a butt w^eld, with a burr or extension of metal at the joint, 

 which, according to conditions, is either allowed to remain or is 

 forged down or dressed off, there is no difficulty in making lap welds 

 electrically, and some of the recent work of the electric welder is of 

 that character. AVhile, too, the usual welding concerns pieces of 

 (he same metal, as iron to iron, steel to steel, or copper to copper, 

 combination wields of different metals are made with facility in many 

 cases, as when brass and iron are united. 



In the working of high-carbon steels the usual precautions to 

 prevent burning or injury to the metal are, of course, required; but, 

 on account of the delicacy of heat control, they are more easily 

 adopted. 



Quite recently automatic chain welders have been put into use, and 

 electrically-welded chain work will probably soon attain an impor- 

 tance not second to the other principal applications wdiich have been 

 brieflv described. 



