338 



Scientific Intelligence. 



[No. 8, NEW SEEIES. 



At Agra I was enabled, through the kind assistance of Colonel 

 J. T. Boileau, the Chief Engineer, to ascertain the temperature of 

 the earth nearly 50 feet below the surface. The insensible ther- 

 mometer was sunk in a small shaft dug for the purpose, and 

 remained buried there for a fortnight before it was taken up. The 

 temperature was, from the 22nd of February to the 4th of March, 

 28° 3' centigrade, equal to 82° 9' Fahrenheit. The temperature 

 thus observed accords, within one degree, with the temperature of 

 the earth at about 60 feet below the surface, ascertained at Be- 

 nares in April 1855. The temperature at one metre below the 

 surface at Agra was only 25 degrees centigrade, as the upper strata 

 had been cooled by the influence of the past cold season. 



The temperature of the wells at Agra was always a little lower 



Wells colder than than that of the g round > tnus directly as- 

 the temperature of the certained. As an average of several wells 

 ground. from a } ar g e quantity of water was 



constantly drawn for domestic purposes and irrigation, I obtained 

 27° 6' to 27° 8' centigrade. 



The temperature of water in wells, which are but little used, is 

 considerably cooler than that of wells from which water is con- 

 stantly drawn, as the cold air which sinks down during the night 

 into the wells, cools stagnant water much more than it can do the 

 water of wells which is constantly removed. 



As a curious phenomenon connected with Physical Geography, 

 I finally beg to mention the way in which 

 glS^Ce^ral the j un S les are distributed in Central In- 



dia. 



The base and slope of the hills, and the valleys between them, 

 are generally covered with very dense and extensive jungles, but 

 the summit of the flat hills and small plateau which occur in 

 many localities, are nearly always quite bare and destitute of trees 

 and jungly vegetation. I had been informed by my brothers, that 

 this very curious phenomenon occurs all along the Southern parts 

 of the Cossyah and Jynteah Hills, and on the $ plateau of the 

 Neilgherries. 



This phenomenon seems to be due, in part, to the very strong 



