580 "I- 



North America. — Philadelphia. Lat. 39° 58' N. Long. 75° 1 1' W. Greenw. 



Corrections to be applied to the Means of the Hours of Observation to obtain the true 

 Mean Temperatures of the respective Days, Months, and of the Year. — Guyot. 



Degrees of Fahrenheit. 



16 



