Diurnal Variation of Temperature. 101 
then, under the erroneous idea that a certain number of 
terms of the Lambert-Bessel interpolation-formula can give the 
law of the diurnal variation of temperature, it has in many cases 
been sought to deduce therefrom the values for intermediate 
hours, or for the maxima or minima,.... we cannot wonder at 
the failure of such calculations.” 
“The application of Bessel’s formula to represent the daily 
course of the temperature has, thus far, much more hindered than 
advanced our knowledge of the same.” 
at its use. The immediate origin of his strongly expressed 
may be determined depends upon the form of the curve in their 
Vicinity. Inasmuch as the minimum usually precedes sunrise 
y only a small interval, while the maximum generally pre- 
cedes sunset by a very considerable one, a want of symmetry in 
the shape of the curve near the two daily extremes ought to 
