Viscosity of Solids and its Physical Verification. 197 



hold for pure platinum. The plan of comparison and tabula- 

 tion is the same as that explained for steel, in the remarks 

 preceding Table I. t here is small, and 2 ((f> + </>') large re- 

 latively to the data in Table I., because soft platinum is much 

 more liable to assume permanent set than annealed steel. 

 Moreover t is impressed negatively throughout ; the changes 

 of sign of (<£> — $') /t are explained in the text below the table. 

 and it is to this text that the letters a, b, . . . /, refer. 



Table III. — Viscous Detorsions of Plati 



6 = 6'. 





T 



Bernarks. 



Time. 



— 0' im 





% + 0'). 







x 10 3 . 



T 



cm. 







m. 





/=26-2 



-•0867 



a 



2 



- 000 



p = -0215 







9 



15 



27 



- 3-31 



- 4-42 



- 5-65 





-0344 





33 



- 5-89 





-•0652 



b 



2 

 17 



- 0-00 



- 359 





-■0556 





44 



- 4-20 





-0443 



c 



1 



4 



14 



28 



+ o-oo 



20-60 

 46-80 

 61-90 





-•0766 





44 



71-90 





-0436 



d 



2 



7 



17 



25 



43 



- 0-00 

 -22-20 

 -41-40 

 -50-20 

 —61-40 





-•0773 





54 



-65-80 





-•0383 



e 



3 



7 

 26 



47 



+ 000 



5-56 



19-60 



27-80 





-•0826 





55 



3000 



/=26-5 



-•0396 



f 



3 



- 000 



p = -0212 







8 

 13 

 29 

 37 



-10-90 

 -17-50 

 -2920 

 -3300 





-•0813 





46 



-3680 



The two wires of Table III. were originally identical, so that 

 the apparatus showed (j) — (f>' = 0. Both wires were then 



