ATMOSPHEROLOGY. — jTEMPEllATUIlE. 369 



^d. That the mean of the highest and lowest 



temperature, occurring in every month during one 



year, corresponds with the mean temperature of 



that year, generally to within two or three degrees ; 



and in a series of years to the fraction of a degree. 



At Okak, on the coast of I^abrador the mean 



temperature of the year 1779-80, from 1460 



observations, was 31°.0, the mean of the highest 



and lowest observations, |_ — gi — J = 32.3, 

 differing 1°.3 from the mean ; and at tlie same 

 place in 1777-8, the mean temperature was 

 24°. 7, and that of the monthly extremes 

 27°. 7, difference 3°.0. At Nain, on the same 

 coast, the mean temperature in 1779-80 

 was 30°.3 ; the mean of the monthly extremes, 

 J- 6u_^ ] = 30°.8, difference 0°.5 ; and at the 



same place in 1777-8, the mean temperature 

 was 24°.6, and the mean of the extremes 27°.95 

 difference 3°.3. 

 4//?, Tliat the mean of the greatest heat and 

 greatest cold, which occur in any fixed place, in 

 temperate climates, in any particular year or pe- 

 riod of years, affords a temperature which, in many 

 instances, corresponds very nearly, with the mean 

 temperature of that period. 



In London, from tlie Royal Society's register, the 

 greatest cold which was observed in the 20 

 years included between 1795 and 1814, was 4% 

 VOL. I. A a 



