16 ROYAL SOCIETY OF CANADA 
VALUES OF THERMAL DIFFUSIVITY.—Continued. 






DIFFUSIVITY 
No. |---| Rain 
Period Depth of Soil 
of days per day 
20” to 60” 60” to 100” 20” to 100” 
1899 
October 26 to November 4 .......... 9 ‘0026 ‘0037 "0028 7-323 
November 4609 222.2 sess 5 "0082 ‘0045 0070 ‘122 
November 9) toes heads. oer 15 0048 “0032 ‘0041 ‘028 
November 24 to December 8......... 14 ‘0037 ‘0024 “0029 ‘021 
December 8110292700 cer 15 “0069 0028 0042 ‘136 
December 20 to January 7, 1900..... 15 “0035 “0026 ‘0029 ‘001 
1900 
Januaryu told PP seers eee 15 “0070 “0020 ‘0031 ‘078 
January 22 to February 15... . ....| 24 *0036 ‘0009 0014 ‘136 
February 24 to March 21............ 25 FREE 1001 MIRE “005 
April 560 16122040 metre PRE 11 “0039 ‘0186 ‘0106 ‘024 
PDA MO Oy WER See ec osnotornnoc: 13 ° "0053 "0062 0055 “030 




The accompanying plate will serve to illustrate the form of the 
curves from which these results have been derived. The heavier lines 
are the curves for the dates, which limit the periods for which the values 
of diffusivity have been computed. The lighter lines are the curves for 
intervening days, and have been used to obtain a better average value of 
the tangent directions at the upper and lower limits. 

