30 



Mr Molin, An examination of Searle's method 



to the weights of the two empty pans (5 grm. each) was so rapid 

 that I was hardly able to measure, for instance, 3T by using a 

 stop watch. I have, therefore, not been able to take account of 

 any pivot friction. This cause of error would, at any rate, produce 

 effects much smaller than those actually found. 



§ 5. From the results for M = 205 grm. given in Table 1 we 

 find the mean value 



-q = TIA:-1 dyne sec. cm.-^, 



for the temperature of + 19-8° C. To show how t] depends upon 



0,1 Qi 03 0^ q5 Q« Cr7 <;» <^9 ^O -p V^ t^ y^ \5 1/5 ^7 1^ 



the angular velocity O = 27t/T, the values of 17 and Q, obtained 

 from the first three series, have been plotted in Diagram 3. The 

 curve drawn among the plotted points suggests that the relation 

 between -q and Q. can be expressed in the form 



7] = 274-7 + <f) exp (- AO^). 



To find the constants cf), A and x, I considered the equation 



log, [rj - 274-7) - log,^ - A^^' (4) 



