106 



Captain Newbold on the Temperature of 



month of May, to be 6°, viz., from 82° to 88° ; and in the Indian 

 Ocean, from latitude 12'' to 19°, so much as 8°-5., viz., from 78° to 

 87°'5. In the straits of Malacca, in latitude 2° N., it ranged from 

 80° to 85°-2. 



On some parts of the west coast of India (where 123i inches of 

 rain falls during the year), during the monsoon, the surface of the 

 sea is considerably cooled by the freshets from the numerous rivers 

 and streamlets that descend from the lofty mountains of the Ghauts. 

 Off Honawer, lat. 14° 16' N., the temperature of the sea, during 

 the dry season, was 85°-5 ; during the monsoon it fell to 79°; ave- 

 rage temperature of the rain-water at the time 75°*7 ; of rivers 66°. 

 From its inferior specific gravity, the fresh muddy water from the 

 hills floats on the surface of the sea, to considerable distances, with- 

 out being intimately blended. In the depth of the monsoon, near 

 Mangalore, in 1839, the water was observed to be nearly fresh a 

 mile off the coast ; and I have seen the Mediterranean discoloured 

 by the turbid inundation of the Nile to a distance of nearly 40 miles 

 from the Damietta embouchure. 



Mean Temperature of India. — Colonel Sykes, in his statistics of 

 the Deccan, has already noted one remarkable feature touching the 

 mean temperature of places at elevations on the tableland of India, 

 namely, that it is much higher than the mean for the same places, 

 calculated agreeably to Meyer's formula. To the instances that he 

 has cited of this fact, of places on the plateau of the Deccan, may be 

 added the following, occurring on the tableland of South India. 



Feet above 

 the Sea. 



Lat. N. 



Observed 

 Mean. 



Calculated 

 Mean . 



Difference 



Hydrabad.... 



Nagpore 



Bellary 



Bangalore.... 

 Seringapatam 



1720 

 1101 

 1600 

 3000 

 2412 



O / 



17 15 

 21 10 

 15 5 

 12 57 

 12 25 



SO- 

 SO- 

 80-5 

 74-39 

 77-06 



74-72 

 74-26 

 76-12 

 73-05 

 74-93 



5-28 

 5-74 

 4-38 

 1-34 

 2-13 



Among the principal causes of this differential height of tempe- 

 rature — a difference more remarkable when compared with the in- 

 dications afforded by the improved formulae of Brewster, D'Aubuisson» 

 and Atkinson — may be enumerated the physical aspect and extent 

 of the elevated plains on which the places stand, — the rapidity with 

 which the drainage water passes off, and consequent little evapora- 

 tion, — the comparatively flat or gently undulating surface, — its 

 bareness of vegetation during great part of the year, — the non-in- 

 fluence of alterations of land and sea breezes, by which places near 

 the sea are cooled, — the partial influence of the monsoon, and scan- 



