Appendix A. METEOROLOGY OF SOANE. 369 



The upper course of the Soane being in some places confined, 

 and exposed to furious gusts from the gullies of the Kymore hills, 

 and at others expanding into a broad and flat valley, presents 

 many fluctuations of temperature. The mean temperature is much 

 above that of the lower parts of the same valley (below Tura), the 

 excess amounting to 5°4. The nights and mornings are cooler, 

 by 1°2, the days hotter by 10°. There were also 10° increase of 

 range during the thirteen days spent there ; and the mean range 

 from day to day was nearly as great as it was on the hills of 

 Bengal. 



There being much exposed rock, and the valley being swept by 

 violent dust-storms, the atmosphere is drier, the mean saturation- 

 point being '454, whereas in the lower part of the Soane' s course it 

 was '516. 



A remarkable uniformity prevails in the depression of thermo- 

 meters exposed to nocturnal radiation, whether laid on the earth, 

 grass, or freely exposed ; both the mean and maximum indication 

 coincide' very nearly with those of the lower Soane valley and of the 

 hills. The temperature of tufts of green barley laid on the ground 

 is one degree higher than that of short grass ; Argemone and 

 Calotropis leaves maintain a still warmer temperature ; from the 

 previous experiments the Argemone appeared to be considerably the 

 cooler, which I was inclined to attribute to the smoother and 

 more shining surface of its leaf, but from these there would seem 

 to be no sensible difference between the radiating powers of the 

 two plants. 



VOL. II. I? B 



