NO. 17.] 



TEMPERATURE OF THE AIR. 



469 



Smoothing the numbers D. f . m. by the formula t = Vi (a -|- 2& + c) and 

 taking the periodical diurnal minima and maxima, their values and epochs, 

 we obtain the numbers given in the foUovvfing Table. The coordinates of the 

 minima and maxima have been computed by a parabolic formula.^ 



The Table gives, for the months during which the Fram was drifting in 

 the ice (reckoned from the 14*'^ October, 1893), the mean Latitude and Long- 

 itude, the periodical diurnal Minima and Maxima with the corresponding time, 

 in hours and tenths, and the periodical diurnal Range as the difference 

 between the Maximum and Minimum. 



' Laying a parabolic curve with vertical axis parallel to the ordinates (values of D. f. m.) 



through the lowest and highest values of D. f. m. (b) and its adjacent values (a 



and c), we get for the minimum or maximum (the apex of the parabola), Abscissa 



c—a 

 Z=V4'5_i/ (^ J. g) hours, and ordinate Y=b + ^U(c—a)X degrees. 



