33 



found which conospomlod (<• f;ivrii dptlfclions, <.r in othor wonls the stress diafrram of these 

 springs up to a. o(l,(l(M)-p()inid load, which corrospoiids to a litth- more tliaii (uie inch dastic dctloctioii. 

 By repeating- this test ou the l()(»,0(H>-pouiiil universal or weighing machine, and then on the huge 

 beam machine, nnd i)h«tting the. stress diagianis ohtaiiied froiii each, not only can tliese rnacliincs 

 he compared with eacli other, but botii can l)e coini)ared or calii)rated with tiic Emery machine at 

 the Watertown Arsenal. 



In Fig. 5 the three curves corresponding to tlu> three m;i<-liincs are given. They are so nearly 

 coincident that it is shown that not only is the universal l(H>,()(M)-poiind Kiehle machine correctly 

 graduated, but that the method used of weighing the loads ou the beam machine by means of the 

 universal machine results in no appreciable error. This test can be api>lie(l at any time, and proof 



Uellectiuu in iuclles. 



Kk;. 5. — .Sl.iniilardizing tests with oaliliiatiii;; spiinj^s. 



readings have been made at frequent intervals. The beam machine is greatly simplified by thus 

 dispensing with all attached weighing apparatus, which would be greatly in the way in the 

 handling of lai'ge l)cams sometimes weighing over 1,()(M) ])oun(ls. 



tSmoll hcama. — The small beams which are nominally I inches scjuare and (in inches long 

 between supports are tested on the small beam-testing machine, shown on Plate iii. This machine 

 was designed originally for testing cast i ion beams, the load at one eml or one-half the load at 

 the center being weighed on a i)air of ordinary i)latform scales. The deflections are read oil' to 



17244— No. « .'5 



