MEMOIR OF DANIEL TREADWKI.L. 



119 



(or broad) 



an inch thick and of snch length that, whea wound into a c„ii. it SI," W« 

 rcqnn-cd for the hoop, after allowing for the waste in weldiag, foxing, and mkUw 



rmna horn hnnr* onm.lnrl 4-~ ^ 1 i » . . _ 



After i 



ends have been scarfed to a Ion? wedn form it is to In- hrVi In , , ,' V 



Mn f -f -7 "'™*r.^ ^ ~ U1 ^ u mcilcs ammeter, as a ribbon is wound upon n M.a 

 Next it is to be heated in a proper furnace to a good adding heat, and then, being pUoed upon 



mandrel 



swages, i is to be completely welded, or the several layers or coils aro to be made to form one 

 piece This may be done by compressing it with the swages, l,v i bydtoatatic press, o f by 



steam hammer. After it is properly welded and condensed in il.is way, and has ,,«U as low as 



< 



which is supported at both its ends by the upright studs of the heavy iron f. 



tine A', B. It ig 



C 



A 



B 



Fig. 1. 



Fig. 2. 



then to be hammered by the steam hammer C, until its internal diameter is enlarged to about 27 

 inches. The last part of the hammering is to be performed after the hoop has become cold. 

 Instead of operating in this way with the steam hammer, we may produce the same effect upon 



mill 



the housings, or frame. 



upon 



D, D (Figures 3 and 4) 



adjusted within it. These segments form a cylinder upon their outer surface, but inside they 



me. A solid conical plug, F, is fitted to be driven into this hollow cone within 



m 



the swages. With tL B , 



plug is driven by repeated blows into the hollow cone, by which operation the hoop is stretched 

 sufficiently to destroy all conflicting strains or tensions that might have been produce,] in it by 

 the hammering. The strain is thus reduced to a circumferential direction, and the hoop put as 

 near as possible into the condition of the hard wire, after it had been subjected to the first 

 series of strains. 



