346 



Scientific Intelligence. [No. 8, new series. 



At Agra N. 1 14 E. 



„ Meerut N. 1 28 E. 



Meteorology. 



In Assam the variations of the temperature of the Brahmapoo- 

 tra, observed from Debrooghur to its ramifications in the Delta, 

 was a particularly interesting object. I also had occasion to make, 

 besides the regular observations on temperature, moisture and 

 pressure of the air, several experiments on the thermic influence 

 of surfaces covered with grass and tree jungle ; besides Dr. Sim- 

 mons, at Gowahatty, kindly assisted me by making, during my 

 absence, observations on the ozone contained in the air, with 

 papers identic with those used by myself. 



These observations are continued for the next year. The fol- 

 lowing Table contains* the temperature found in the Brahmapoo- 

 tra in its ramification and in the Delta from Debrooghur to Cal- 

 cutta. The daily variations, even in Upper Assam, scarcely ex- 

 ceeded O. 5 degrees C. — 0. 9 degrees F., but occasionally differ- 

 ences of 2 to 3 degrees F. are found even in the very current 

 caused in some cases by differences of depth, in others by lateral 

 rivers discharging themselves in the Brahmapootra. 



I choose for the Table the temperature of the rivers at 11 a. m., 

 this hour representing very nearly the * * of the twenty-four 

 hours for the water ; for the temperature of the air for the same 

 reason the temperature at 9 a. m. was selected. Errors of the zero 

 points of the Thermometers, Nos. 29, 70 and 88 are corrected-! 



* A second series during the hot season is made now by my Assistant, 

 Mr. Adams, on his way down from Sudiya. 



f For the Hooghly, at Calcutta, I was furnished with observations on 

 the monthly variations of the temperature at high and low water by the 

 kind assistance of Mr. Schiller. The observations are now continued by 

 Dr. Thomson. 



