AI'P. N° II.] METEOEOLOGICAL RESULTS. (53) 



I 



G. 



Formula referred to in p. 288, and 358. 



Let tlie mean temperature of the year be called T 



The mean temperature of January, - b 



The mean temperature of July, - c 



The mean temperature of April, - - d 



And the mean temperature of any other month, t 



Then c^ITl^ x 1.907 = cb. 

 or, c — {^^^Tx 1.907) = b. 

 (c^-T X 0.172) —T=d. 

 {c—H) X 0.044) -Jf b = t February. 

 ic^b X 0.188) + b = t March. 



And ((■ — b X decimal col. 5. Table F) + i = ^ of the cor- 

 responding month ; that is, the difference between the mean 

 temperature of January and that of July, multiplied into any 

 decimal of Table F (column 5.), and the amount added to the 

 temperature of January, gives the temperature of the month 

 with which the decimal used corresponds. 



Example. — The mean annual temperature of latitude 78° N. 

 is by observation 17", and the temperature of Jvily 37° ; requi- 

 red the mean temperature of January, and of the succeeding 

 months .'' 



Then, (by formula 2d), 37 —(37—17 = 20 x 1.907) = 

 — -0°.86, or nearly one degree below zero, the temperature of 

 January. 



And, (formula 4th), temperature of July 37° 

 Temperature of January, say — 1 



Difference, - 38x0.044=1.67 



Temperature of January, (add) - — 1 .00 



Mean temperature of February, - 0.67 



