so 



Meteorological Observations. 



[Jan. 



mountains, and that it is accompanied by a corresponding increase in 

 the range of the thermometer. We have elsewhere reasoned on this sub- 

 ject, and do not intend, in the present view of observed facts, to enter 

 into any theoretical discussions ; at any rate before doing so, it is to be 

 wished that we may be able to extend the table of comparisons to other 

 principal points on the continent of India ; it is evident that in calcu- 

 lating barometrical altitudes, by corresponding observations at distant 

 places, a corrective equation must be introduced, depending on the time 

 of year, having its maxima at the two solstices. 



We now come to the diurnal oscillation of the Barometer, for which 

 the same sources have furnished me with materials for framing a com- 

 parative table for five localities considerably distant from one another ; 

 we could have added Murshedabad to the list, but that the thermome- 

 tric series for that place was incomplete. At Seharanpur the horary 

 observations were confined to a single day, the fifteenth, of each month. 

 At Madras, to three similar days: at Benares perhaps the hour of the 

 minimum was not always exactly observed : thus a little irregularity 

 must be expected, but on the whole the results are wonderfully equable. 



Table V. Diurnal Oscillations of the Barometer and Thermometer at Calcutta, 

 with comparative observations at other places. 







Barometer at 32 . 





Thermometer . 



- 



5 c . 



3 3 "~ 

 - S* •_ 



3 





So 



* a . 



5 ° — 



~ "— ■£ 



„ o 5 



| g £ 



13 



a 



X 



s 



< 



<* 

 -a 



a 



x 



V 

 CO 



V 



10 



1* 



© 



daily ex- 



by regis- 



rmometer. 



■ £ ■ 



v « - 



- a 5 



- o 2 



*«- a 



. 



■A . »-■ 



© S 



a-* 



CO 



~ a c 



»£ 



e 



3 . 



* CN 





a, o 

 = to -a 



.S 



:: a > 



d 



s 'V 



u S 5 





x . 



co g 



*-> 



s s - 



x <3 o 



- e cS 



B 



-3 ~ * 





o c 





■*e c * 



-O 









O 



X K "3 



< 



"3 s 



Z "* *■ 

 2) 



— X "TZ 

 V 



CO 



X (N 



> * 

 < 



X ~ 

 (J 



deg. 



C •" - 



a> .5 .2 





inch. 



inch. 



inch. 



inch. 



inch. 



deg. 



deg. 



deg. 



deg. 



Jan.. . 



.072 



.144 



.123 



.097 



.103 



110 



9.4 



20.7 



17.8 



24.5 



Feb... 



.(170 



.126 



.117 



.103 



.093 



10.0 



16.8 



18.5 



19.2 



21.0 



Mar. 



.076 



.107 



.125 



.121 



.146 



7.0 



20.8 



14.0 



20.7 



260 



Apiil, 



.081 



.110 



.124 



.125 



.107 



9.0 



20.9 



14.6 



23.2 



31.0 



Way, 



.081 



.113 



.lib 



.124 



.160 



9.0 



20.4 



13.7 



21.9 



38.0 



June, 



.092 



.136 



.095 



.113 



.178 



9.0 



9.0 



7.6 



16.1 



31.5 



July, 



.097 



.133 



.090 



.077 



.103 



7.0 



6.6 



6.1 



9.0 



15.3 



Aug. 



.105 



.109 



.099 



.088 



.079 



7.0 



8.8 



5.9 



8.3 



11.5 



Sept. 



.094 



.145 



.101 



.103 



.123 



6.0 



7.8 



6.2 



10.3 



13.0 



Oct. . . 



.068 



.144 



.110 



.100 



.120 



8.0 



5.0 



8.4 



18.1 



31.5 



Nov.. . 



.071 



.127 



.107 



.107 



.147 



8.0 



6.7 



13.4 



16.8 



29.3 



Dec... 



Mean 



.071 



.126 



.114 



.098 



.124 



9.0 



8.5 



17.1 



16.3 



17.5 



tide | 



.081 



.126 



.110 



.105 



.120 



8.5 



10.6 



12.2 



16.6 



24.2 



With due allowance for the difference of sensibility in the instruments 

 the above table shews that the average diurnal tide of the Baromete 

 between the equator and 30* north latitude exceeds one-tenth of an inch, 

 and that it is progressively greater as the variation of temperature dur- 

 ing the day is also greater. With regard to the nocturnal tide of the 



