METEOROLOGY OF i8q7. 
59 
§6o. The dates of the highest and lowest temperatures 
for the different years, and the observed temperatures are 
shown in table ii. Considerable variation is shown in the 
dates of the highest temperature, partly in the case of the 
deeper depths especially from the effect of flooding from ir- 
rigation waters. The date of minimum is less subject to 
extraneous influences. As the temperatures are observed 
at 7 a. m. and 7 p. m. only, the highest and lowest tempera- 
tures of the day of the shallow thermometers are not not 
observed and the diurnal variation would slightly affect 
these readings. For the deeper thermometers the diurnal 
fluctuation is very small. 
WEEKLY 
SOiL TEMPERATURES. 
