1887.] H. F. Blanford — Influence of Indian Forests on the Rainfall. ] 1 



stations of each pair is hardly enough to shew the full influence of forest 

 in the one case, or to exclude it in the other ; and it can only be expected 

 that, under such circumstances, any difference depending on that influence 

 will be very small. 



There are two such pairs within about 6 miles of Dehra Dun, on the 

 skirts of the Sivalik forests, the one at the Ramgarh, the other at the 

 Rajah's forest. In the case of the Ramgarh forest, at which the obser- 

 vatories have been longest in existence, the two observatories are 750 

 yards apart ; the outer 400 yards from the forest boundary, the inner 

 350 yards from it. At each station, there are two rain-gauges, the one 

 on the ground, the other at a height of 60 feet, being perched on the 

 summit of a scaffold, which raises it above the tops of the neighbouring 

 trees. The rain-gauges are Symon's pattern, 5 inches in diameter, and 

 the measurements are all made with the same measure glass. The 

 observer has been regularly trained in his duties (which include keeping 

 4 registers of temperature and humidity, under corresponding condi- 

 tions), and his work seems to have been regularly performed. The 

 results for the years 1884 and 1885 are given in the following table : — 







Lower gauges. 



Upper gauges. 



Montlis. 



Outer. 



Inner. 



Diff. 

 I— 



Outer. 



Inner. 



Diff. 

 I-O 



June 1884 



3-66 



4-07 



+ 0-41 



3-61 



3-88 



+ 0-27 



July „ 



25-64 



26-46 



+ 0-82 



24-72 



26-44 



+ 1-72 



August 



... 



2118 



21-74 



+ 0-56 



19-88 



21-23 



+ 1-35 



September 







17-53 



18-78 



+ 1-25 



17-19 



18-01 



+ 0-82 



October 



J 



0-28 



0-39 



+ 011 



0-26 



0-37 



+ 0-11 



November 



... 



























December 



, . . • «• 

















 65-66 













Total 



68-29 



71*44 



+ 315 



69-63 



+ 4-27 



January 1885 



4-20 



4-48 



+ 0-28 



4-56 



4-63 



+ 0-07 



February „ 



0-85 



0-70 



— 015 



0-77 



0-67 



— 0-10 



March. „ 



0-48 



0-39 



— 0-09 



0-42 



0-36 



-0-06 



April „ 



0-44 



0-55 



+ 0-11 



0-45 



0-50 



+ 0-05 



May , 



5-35 



5-99 



+ 0-64 



5-06 



5-79 



+ 0-73 



June „ 



10-31 



10-76 



+ 0-45 



9-75 



10-61 



+ 0-86 



July „ 



9-81 



9-90 



+ 009 



9-27 



9-88 



+ 0-61 



August „ 



44-64 



44-91 



+ 0-27 



43-56 



44-45 



+ 0-89 



September „ 



6-24 



5-51 



— 0-73 1 



6-06 



5-47 



-0-59 



October , ,. 



























November „ 



























December „ 



3-45 



3-49 



+ 0-04 



3-48 

 83-38 



3-52 



+ 0-04 



Total 



85-77 



86-88 



+ 0-91 



85-88 



+ 2-50 



