OF OBSERVATIONS FOR TEMPERATURE. 



21 



Tbe corresponding values at Van Rensselaer Harbor have been inserted for com- 

 parison, and show a remarkable difference in the temperatures of spring and 

 autumn, at which seasons it was much colder at Van Rensselaer Harbor than at 

 Port Kennedy, whereas the mean Avinter temperature was lowest at Port Kennedy. 

 Tbe observations give the range between the summer and winter mean at Port 

 Kennedy 72°.4, and at Van Rensselaer Harbor C2°.0. According to Formula II 

 we find, as a close approximation, the warmest day July 20th, with T— +41°.0 

 and the coldest day January 19th, with T=—'dS°A; hence, tbe range of the 

 annual Huctuation 79°.4. The mean temperature of the year is reached on April 

 23d and October 22d. 



The annual fluctuation of the temperature, or the observed and computed monthly 

 (normal) means (corrected for index error), are represented in the annexed diagram 

 (A). The curve shows the computed, and the dots the observed, temperature. 



(A.) Annual Fluctuation of the Temperature of the Air at Port Kennedy. 

 4-40° F.{ 



+ 20° 



—20° 



-40° 



■wn 



■■in 



■■■■■■ill 



s o 5 * ^ s a j= « i? 5 i; 

 i-5fe*-«;gH,H,<io20^;c 



At middle of each month. 



