1876.] H. F. Blanford — Comparisons of Dew-point Temperature. 119 



2. An account of Experiments made in 1875 and 1876, in various ^;«rfs 

 of India for the purpose of comparing the observed Temperature of the 

 Deio-point toith that computed from the 'Psychrometer hy different 

 methods of reduction. — By H. P. Blajstpobd, Esq., F. G. S. 



(Abstract) . 

 This paper described tbe results of a series of experiments made at 

 various stations in Madras, the N. W. Provinces and the Punjab, during 

 the dry season, for the purpose of comparing the observed hygrometric 

 state of the atmosj)here, as ascertained by the use of Regnault's hygrometer, 

 with that computed from the readings of the dry and wet bulb thermome- 

 ters. This comparison has long been a desideratum, since the formulae by 

 which the vapour tension, &c., are computed from the temperatures of the 

 air and of an evaporating surface, make certain assumptions which have not 

 been sufficiently verified ; and although in the more humid atmosphere and 

 low temperatures of Europe, the results of the formulae are found to agree 

 fairly well with the direct observation of the dew-point, it is by no means 

 certain that such is also the case in the dry hot climate of India. The 

 results of the comparison have shewn that the psychrometric method is liable 

 to many disturbing influences, but that on the mean of a large number of 

 observations, the dew-j)oint computed by August's formula, with Eegnault's 

 constants, from the readings of the dry and wet bulb thermometers, exposed 

 under an open shed, agree fairlj'' well with the results of the direct dew-point 

 determinations. Apjohn's formula gives a vapour-tension and humidity 

 somewhat too high, and Glaisher's factors give too low a result in a damp 

 atmosphere and too high in a di'y one. 



The paper will be published in full in the Journal Part II, No. 2. 



3. List of Bi7Hls collected on the expedition into the Bafla mils, Assam ^ 

 together loith those obtained in the adjacent Burrang Terai. — By Major 



H. H. Godwin-Atjsten, F. E. G. S., F. Z. S. 



(Abstract) . 



Tho collection of which this paper is an account, was made by the 

 author while in charge of the survey party attached to the force which, 

 under Brigadier-General Stafford, C. B., penetrated during the winter of 

 1874—75 into the Dafla Hills. 



The list shows that the author was tolerably successful, 29 birds (in- 

 cluding two new forms) being added to those recorded in his previous 

 pajiers on the avifauna of the N. E. Frontier, notwithstanding that he was 

 only able to explore the small portion of the Eastern Himalaya extending 

 from E. Long. 93° to Long. 9-1°, on Lat. 27° — a distance of about 60 miles, 

 exclusive of the district of Durrang lying at the base of the hills. The hills 

 of the Dafla country are described as clad from summit to base with dense 



