Diurnal Variation of Temperature. 115 
at 3" 22™ The mean discordance 0°'—C. deduced from the 
temperature for the maximum or minimum, within moderate 
imits,—we may not only infer with confidence the constants of 
rp sed term, but may often deduce very fair values for the 
third, 
nder ordinary circumstances this is not difficult, and it may 
therefore be well to consider the present state of our knowledge 
regarding the epochs of daily maximum an minimum. 
will endeavor to avoid misplaced refinements of calculation, 
since attempts at minuteness in determining these epochs are 
or the most part justified neither by the nature of the phe- 
nomenon nor by the character of the observations: but will 
take into consideration only the unmistakable fact of the case. 
mining them with the minuteness which belongs to the epoch 
either of a sharply defined or of a tolerably regular phenome- 
