1833.] 



Miscellaneous. 



657 



miles will press with a weight of 14.856,884,072 lbs on every square inch, and then 

 to get the height in inches, gained by the barometer, we have 14| lbs. to 30 inches, 

 (or general height of the barometer at the level of the sea nearly,) as 14. 85b*, 884, 072 

 lbs. to 30.217,4 inches nearly, or .217,4 decimal parts, rather more than £th of an 

 inch only for the measure of height, gained in the barometer, by the additional 

 weight of the 138th part of the total height of the atmosphere, caused by the 

 attraction of the sun and moon, in a similar manner, and in the same proportion, 

 as the tides are raised above the level of the sea. 



Very nearly the same answer is obtained, by considering the atmosphere so con- 

 densed, as to have its specific gravity equal to that of water ; for, instead of the 

 former height in miles, use 34 J feet height of water, which is equal to the pressure 

 of the atmosphere, and higher than which a common atmosphere pump will not 

 raise that fluid. Then 344 feetdivided by 138 as before is =r .25 of a foot, therefore 

 34.5 feet height of water : 14.75 lbs. pressure on the square inch ', * 34.5 +.25, (or 

 height of water plus its 138th part = 34.75 lbs.) : 14.856,876 lbs. pressure on a 

 f.quare inch, only exceeding the former 14.856,884,072 by the .000,008,072nd part 

 of a lb. and proving the result of the former calculation to be correct. 



In the above investigation, the specific gravities of air and water are taken as 

 equal, but as they differ much*, and as I have no other data, let the height of the 

 atmosphere be considered uniform, for 5^ miles only, as before explained ; the 

 calculations will, on the foregoing principle, make the height, gained by the baro- 

 meter, equal to only ^gth part of an inch, which is almost an inperceptible quan- 

 tify, and shews, that that instrument cannot sensibly indicate the difference of 

 altitude of the atmosphere, due to the attraction of the sun and moon, as sup- 

 posed by the Burmese Prince ; for ^i~ 138 miles=r. 003, 804,347, 8th part of a mile, 

 when the atmosphere is uniform, and 5^ miles high, therefore, as 5.25 miles : 

 14.75 lbs. I*. 5. 25+.003, 804,347,8 miles:*. 14.760,688,405,7 lbs; and again, Hiflbs. 

 -.30 inches :: 14.760,688,405,7 lbs.: 30.021,739,125 inches, or .021,739,125 - s ' 5 th 

 part only of an inch gained in height by the barometer as above stated. 



I subjoin a table of the heights of the barometer, in order that the differences, 

 which I have shewn, for every month, may be observed, at the times of spring 

 and neap tides, in Calcutta, for the satisfaction of the Burmese philosopher, should 

 he think it necessary, to prosecute his inquiries any further into this subject. 

 Barometer at Sunrise, {reduced to 32° F.J , at the Surveyor General's Office, Cal- 

 cutta, taken from the As. Sjc. Journal, vol. I, for the year 1832. 



1832. 



January, . . 

 February, 

 March, . . 

 April, 



May 



June, 



July, . . . . 

 August, . . 

 September, 

 October, . . 

 November, 

 December, 



Means. In. 



Monthly 

 Ditf. 



30.051 ~) 



29.943 



29.865 



29.760 



29.664 



29.515 



29.489 



29.468 



29.650 



29.837 



29.997 



30.998 J 



Temperature 



of Air. 



54.6 

 61.2 

 66.3 

 74.9 

 79.5 

 80.8 

 80.1 

 80.0 

 79.3 

 74.7 

 64.9 

 55.8 



Monthly 

 Difference. 



* Viz. o 22 to 1000. 



