418 



Profs. Percy Frankland and Marshall Ward. 



Curve 112, p. 402. 

 Doubling periods : 



1. 47 -25 94 -5 n '= 2.4 P.M. 2.44 P.M. = 40 minutes at 26 '527 '0 C. 



2. 94 -5 189 -0 = 2.44 3.32 = 47 27 '027 '25 C. 



This was now too long to measure under this power, so I changed 

 to the Zeiss C : 



3. 189378 M = 3.32 P.M. 4.20 P.M. = 47 minutes at 27 -127-5 C. 



Or, calculated back : 



382 -5 191 -25 /* = 48 minutes at 27 '25 27 '5 C. 



191-2595-5 ,, = 47 27 '00 27 '25 C. 



95-5 47-75 = 42 26-5 27'0C. 



After 4.20, I let the temperature rise as follows : 



Temp. 



Time. C. 



4.30 P.M. = 28-0 

 4.45 = 29-0 

 8.0 = 32-0 

 8.25 = 32-4 



And at 8.25 chose a segment to measure under the C (each divi- 

 sion = 7'5 fi) as follows : 



The doubling periods were as follows : 



1. 41 -2582 -5 ^ = 8.25 A.M. 9.20 A.M. = 55 minutes at 32 -433 '132 -25 CL 



Or, taking 60 /* as the initial length : 



60120 M = 8.52 A.M. 10.10 A.M. = 78 minutes at 32 '75 32 *25 32 '75 C. 



