178 H. F. Blanford— On the Climate of Bengal. [Nov. 



Dr. Waldie then exhibited one of the Spencer's cups and explained that 

 the water was completely filtered before it reached the cups and so there 

 could not possibly be any upward filtration ; all that the cups could do 

 was to prevent more than a certain quantity of water passing in a given 

 time, which could be done equally well or better by other arrangements. 

 The cup had been actually tried during the whole rainy season of 1869 

 and the conclusions come to had been derived from these experiments. 



Mr. H. B. Fenwick C. E., in charge of the Water Works at Palta, gave 

 a brief description of some experiments made with the Spencer's cups which 

 proved conclusively that they would not answer the purpose intended. 



Mr. Fenwick said, that at Mr. Clark's suggestion he had tried the cups ; 

 a filter 12'X12' was constructed at Palta fitted with four of Spencer's regu- 

 lating cups and was supplied from the same source as the large filters. The 

 discharge was found to be in proportion to that of the large filters as 3 to 1 ; 

 the materials were then removed and four of the holes in each regulating cup 

 stopped up, the discharge then amounted to 2f to 1 ; two more were then 

 stopped up, thereby reducing the original ten holes to four in each cup, and the 

 discharge was then 2 to 1 in proportion to that from the large filters. Dur- 

 ing the rainy season the water which flowed from this filter was very much 

 inferior in transparency to that from the large filters during the same period, 

 in fact it was very inferior to that from the large filters at their worst. 



4. On the Climate of Bengal. — By H. F. Blanford Esq. 



Although Bengal is situated for the most part without the tropical 

 zone, its climate is characteristically tropical. The mean temperature of 

 the whole year varies between 80° in Orissa and 71° in Asam ; that of 

 Calcutta being 79°. 



In the annual range of the temperature, as well as in point of humidity 

 and rainfall, the eastern and western portions of the province are strongly 

 contrasted. In Kachar, nearly 200 miles from the sea, the mean temperature 

 of June is 82°, that of January 645°, and the highest and lowest temperatures 

 recorded during 5 years, viz., 99° and 43° shew an absolute range of 56° 

 only. At Chatgaon, on the sea coast, the recorded range does not exceed 

 49°. On the other hand, Patna has a mean temperature of 87 - 2° in June 

 and 60-7° in January ; and in 1869, the highest and lowest temperatures 

 registered were 116--'i° on the 12th May, and 369° on the 3rd and 4th of 

 January ; the absolute range of this single year was therefore 794°. It is pro- 

 bable that some parts of Bihar, the neighbourhood of Gya for instance, 

 experience a range somewhat greater than that of Patna. 



The highest temperature recorded in Calcutta during the last 18 years 

 is 106°, which has been reached twice only ; viz., in May 1867 and again 

 in May of the present year. The lowest temperature 52 - 7° has been record- 



