128 Climate and Altitude of Nastrabad. [Marcu, 
II.— Abstract of Observations of the Temperature, Pressure, and Hygro- 
metrical state of the Air at Nasirdbad. By Major T. Oliver. 
The barometer is the same I used at Delhi, and the observations 
have been reduced by the same quantity (.055), to make them compa- 
rable with those in the Surveyor General’s office. The thermometers 
are also the same. I have not been able to note the barometer at 10 
A. M. excepting for two or three months: the daily range appears to be 
about 0.10. The mean temperature of the day has throughout been 
taken as the mean of sunrise and 2h. 30 m. p. m.; and of the night, 
the mean of sunset and sunrise. I lately obtained from Calcutta one 
of Daniell’s hygrometers, intending to compare its dew-point indica- 
tions with the wet thermometer depressions in this dry climate; but I 
cannot procure ether that will produce a depression of more than 5° 
or 6° below what water will effect, and this of course is useless here, 
unless in the rains. We have already a sufficient number of comparisons 
of this sort in moist air, but it would be desirable to have them in the dry 
air of this part of the country. As the moist thermometer sinks 
sometimes as much as 40°, some freezing mixture must be requisite to 
get the dew-point in such cases, where I imagine the best ether 
would not answer the purpose. 
Regarding the Tables I now send, it will be observed, that in Table 
III, I confine myself merely to temperatures and wet thermometer de- 
pressions: these can be reduced at any time into tensions, when the 
subject may have undergone due investigation: in the mean time, 
the dew points and mean comparative tensions have been calculated, 
as in my former communication. 
Taste I.—Barometer reduced to 320; Temperature of the external Air 
and Deduced Elevation of Nastrabad above Calcutta. 
Year and | Barom. |Temp. 'Eleva-| Year and | Barom. |Temp. | Eleva- 
Month. 4 p.m. jof Air.|tion. Month. 4p.™. jof Air.} tion. 
In. © In. © Feet. 
Dec. 1830, ..| 28,513 | 72,8 28,467 | 65,2 1462 
Jan. 1831, .. SOON aA2e2 ,483 | 68,8 1430 
February, .. 398 | 68,4 ,365 | 69,6 1488 
March, . | 3338 | 85,1 »312| 79,7 | 1493 
April, 2 3).)0). 5230 | 95,3 3218 | 95,9 1526 
BYS pipers 117 |102,7 ,161] 98,2 1497 
June, .. ..-. 27,979 | 99,4 28,000 |100,1 1526 
July, é 28,003 | 94,5 27,951 | 91,4 | 1539 
August, .. .. 3040 | 87,2 28,032) 85,8 1425 
September, .. ,138 | 85,9 | 1493 [September,.. ,183 | 88,3 | 1504 
October, .... »278| 87,6 | 1444 [October, .... »340] 89,2 1466 
November,. . am 76,1 | 1431 {November, .. ,461| 81,3 | 1473 
Means, .. .. 28,246 | 85,6 | 1487 [Means, ....| 28,248] 84,5 1486 
