82 



H. F. Blanford — On tlie relations of cloud 



[No. 2, 





Chakrata and 



ROORKEE. 



Ranikhet and 

 Bareilly. 



Pachmarhi and 

 hoshangabad. 





II 



Mean tem- 

 perature 

 anomaly. 



o . 



a a 



o o 



Mean tem- 

 perature 

 anomaly. 



o 



<D eg 



a a 

 IS 



Mean tem- 

 perature 

 anomaly. 





— 007 

 —•019 

 + •011 

 —•035 

 —•044 

 + •055 

 + 042 

 + •031 

 + •024 

 + •009 

 + •067 

 + •028 



+ 20 

 + 13 



— 0-4 

 + 36 

 + 43 

 —2'6 

 —1-5 

 —2-0 



—2-5 



— 1-3 



—•010 

 —•014 

 + 007 

 —•038 

 —•048 

 + •046 

 + •044 

 + •030 

 + •017 

 + •002 

 + •037 

 + •015 



+ 2-7 

 + 1-5 

 —0-4 

 + 3-5 

 + 5-4 

 —1-6 

 —1-9 

 —16 

 —01 

 —04 

 —2-7 

 —2-4 



—•002 

 + •041 

 + •014 

 —•021 

 —•015 

 + •014 

 + •001 

 + •014 

 + •021 

 + •009 

 + •034 

 + •024 



+ 03 





+ 09 



March 



—1-7 





+ 0-8 



May 



+ 07 





—1-8 





+ 0-4 





—1-3 





—11 



October 



—1-6 

 —4-9 



December 



—51 







Considering the character of the data, that they can be regarded, at 

 best, as affording rough approximations to the mean condition of the 

 atmospheric stratum dealt with, as regards both density and temperature, 

 and that variations of superincumbent pressure and humidity are entirely 

 left out of account, the opposite march of temperature and density, exhibited 

 by this table, is sufficiently striking, and affords a very satisfactory con- 

 firmation of the fundamental postulate. With respect to the higher atmo- 

 spheric strata, direct evidence is of course wanting ; but it may fairly be 

 inferred that the variations of temperature therein, are at least as influen- 

 tial, relatively, on the density, as in the lower atmosphere here dealt with. 



If these views be admitted, the frequent concurrence of a diminished 

 density in the lower strata with an increased density of the higher, and 

 vice versa, resolves itself into this, that the temperature of the higher and 

 lower strata tend to vary at opposite directions, the one being in excess 

 when the other is in defect ; and the discussion of the problem resolves 

 itself into that of the processes by which the temperatures of the lower 

 and higher strata are respectively influenced. 



The conditions which principally affect variations of temperature on 

 the land, (in India) have already been discussed. It has been shown thab 

 the most influential of these are the presence or absence of cloud and the 

 evaporation of rainfall. That, excepting in one or two of the winter 

 months, an increase of cloud is accompanied by a reduction of temperature, 

 and, at all seasons, without exception, the evaporation of rain produces a 

 similar effect. But the effect of cloud and the precipitation of rain, on the 

 temperature of the higher atmospheric strata, must be of precisely the 



