108 



TEMPERATUEE OF THE EARTH IN 



Average Temperature, deduced from the Observations made in 

 1838, 1839, 1844, 1845, 1846, and 1847. 



From the data in the preceding tables it appears that the 

 average mean temperature of the earth for the years 1838, 1839, 

 1844, 1845, 1846, and 1847, was, at 1 foot below the surface, 

 50' 27' ; and at 2 feet below the surface, 50° 70'. The differ- 

 ence of these is therefore scarcely half a degree, and this was in 

 favour of the greater average warmth at the lower depth. 



The mean temperature of the air in the shade for the same 

 period was 49' 21'. Compared with this, the temperature at 1 

 foot deep averaged nearly 1 degree warmer. The average tem- 

 perature at 2 feet deep was nearly 1^ degree above that of 

 the air. 



The highest temperature indicated by the ground thermo- 

 meter at 1 foot deep was 69', on the 25th and 26th of July, 

 1844; and the lowest 32^°, on the 9th of February, 1838. 

 The range of temperature was consequently 36^ degrees. At 

 2 feet deep the highest temperature was 66^", August 1st, 1847 ; 

 and the lowest 35', on various days between the 21st of January 

 and the 9th of February, 1838. The range was 31^ degrees, 

 being less by 5 degrees than that of the 1 foot deep thermometer. 



The highest atmospheric temperature in the shade, during the 

 above period, was 95°, July 5th, 1846; and the lowest 4^° be- 

 low zero, January 20th, 1838. Consequently the range of tem- 



