32 



RECORD AND DISCUSSION OF TEMPERATURES. 



For the day or summer period we thus obtain the equations : — 



Whence i!m = — 15°.73, p = 5.918, and q = 

 + 0. 1 2 as resulting from the normal equations. 

 r=—15°.73 + 5.918 i? + 0.12 Q±0°.T 



May 

 June 

 July 



August 



4.]4°.'r8 = /m + 5p+ 45 

 + 30.7G =<™ + 8i3 + 2fy 

 + 38.18 =U+^p 

 + 31.59 =<,„ + 8p— 2f/ 



r=— 9°.18 + 4.832 « — 0.05 Q 



September + 13. 15 = tm + 5p — 4 5 

 For the spring months : — 



March _33°.54 = /,„ — 5|j + 4(7^ 

 April _ 9.48 =<m + 6g[- 



May +14.18 = (!,„ + 5;:> + 4^) 



For the autumn months : — 



September +13°. 15 = tm + 5^ — iq-\ 

 October _ 4.13 =/m — Ggi- 



November — 21.96 =tm — ^p — 4g) 



The above 3 values for t.^, jy, and q are represented by the formulce:- 



r=_4.91 + 3.510i? — 0.13 Q 



<„ = _15.'I3 +0.n?i +0.96?t'= 



p =+ 5.918- 

 q = + 0.12 . 



■ 0.220rt — 0.1942?i» 



■ O.Olrt — 0.022«^ 



Where n = number of months from the mid- 

 dle of July. For March n = — 2 ; for 



Nov. +2. 



The following table contains their computed values for each month (under 

 discussion). 



These differences between the observed and computed values are very nearly 

 within the probable uncertainty as given in a preceding table. 



For the winter season, the most simple interpolation seems to be the best that 

 can be adopted. We find for December 1st the temperature — 26°. 5, the mean of 

 the temperatures for November 15th and December 15th, and for March 1st, in 

 like manner ; the mean temperature — 30°. 0. The following table^ was used for 

 interpolation : — 



Mean temperature Dec. 1st . 



Jan. 15th 



" March 1st 



— 26°.5 



—28.2 



—30.0 



A = l°.7 



1.8 



• For the purpose of a ready comparison and uniformity of method, the following expression of the 

 annual variation of the temperature at Van Rensselaer Harbor is here inserted ; it compares directly with 

 similar expressions for other stations given by Kamtz and inserted in the article (Sir John Herschel's) 



