Institute and college, pusa, for i9io-ii. 27 



Meteorology. — In addition to the ordinary meteorolo- 

 gical records, the record of evaporation, which was men- 

 tioned in the last annual report, is being maintained. A 

 record of soil temperatures has also been commenced dur- 

 ing the year and will yield information as to diurnal and 

 seasonal variations of temperature. Self-recording hygro- 

 meter and barometer will also be set up. Most of the in- 

 formation provided by these records will become im- 

 mediately useful in connection with one or other investiga- 

 tions at the Institute. 



Drainage Data. — These are being continued, and the 

 first several years' records together with those of the Cawn- 

 pore gauges have been written up for publication. Among 

 the deductions which have been possible are the follow- 

 ing : — {a) The amount of water draining away annually 

 varies with the rainfall, it being large in wet years ; but the 

 amount which evaporates from bare fallow soil is almost 

 constant for any one place. At Cawnpore about 18'' of 

 water thus evaporates per annum, at Pusa about 28"; the 

 corresponding figure at Rothamsted is about 15". The ex- 

 planation for the larger amount evaporating at Pusa than 

 at Cawnpore probably lies chiefly in the nature of the soil, 

 but this is a matter which remains to be demonstrated. 

 ih) Drainage from cropped land is naturally affected by the 

 extra factor — the crop — and the drainage data have yielded 

 some very interesting information in regard to it. On the 

 one hand a crop transpires large amounts of water; on the 

 other its presence acts as a " shield " to the moisture of the 

 surface soil preventing it, in a measure, from evaporating. 

 Thus the crop introduces into the question two factors, 

 which are mutually opposed to one another, and the amount 

 of drainage occurring from cropped land will be greater (^r 

 less according to the magnitude of their respective in- 

 fluences. The effect of good crops growing on the Pusa 

 and Cawnpore gauges has been to reduce direct evaporation 

 to two-thirds or one-half of what the soil would have suffer- 

 ed had no crop been present. How much this " protective " 

 effect is, when converted into inches of water, naturally de- 



