388 Dr BREWS r F.I! on the Register of the Thermometer. 



is a quarter of a degree of Fahrenheit, and that the differences 

 are most perceptible in the afternoon branch of the curve, be- 

 tween 4 p. M. and 8 P. M. 



We have no hesitation, however, in saying, that the mean of 

 a greater number of years will produce a close approximation to 

 the parabola. In 1824, the afternoon branch is irregular. In 

 1825. which was a year of uniform character, the afternoon 

 branch becomes more convex, and approaches closely to the pa- 

 rabolic branch ; so that the mean of 1 824 and 1 825 whicli we 

 have given in col. 2. of the Table, and contrasted with the pa- 

 rabolic abscissae, partakes of the irregularities of 1824, and thus 

 occasions a flatness in the curve, and consequently the differences 

 observed between 3 h P. M. and 8 h 27' P. M. 



