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320 © Proceedings of the British Association. 
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fluence of the stars. Under the head of pressure, the barometer, 
its construction and proper use, came under consideration. He 
pointed out the use of curves in recording and comparing its indi- 
cations,—the great variety of its oscillations in the several parts 
of the-earth, and the importance of accurate registers of its indi- 
cations being kept,—alluding to the value of the hourly observa- 
tions recorded, for so many years, under the inspection of Mr. 
- Snow Harris, at Plymouth, and those at Leith and other places " 
in Scotland, under the inspection of Sir D. Brewster. He next 
referred to a fact which seems to lead to the inference, that we 
must repose less confidence in the barometer as a means of meas- 
uring heights than has been heretofore supposed. It has been 
found by actually leveling between the Black Sea and the Cas- 
pian, that the latter is only 82 feet below the level of the former; 
whereas barometric measurements, founded on previous deter- 
minations, since carefully repeated, gave, in consequence of 
wignown anomaly, the difference of 320 feet. The hu 
f the atmosphere was the next topic discussed. As to 
the andount of vapor in the air, at any one instant, he considered 
that by the researches of Dr. Apjohn, begun at the suggestion of 
the Association, the important problem of the wet-bulb thermom- 
eter had been completely solved, and meteorologists thus put in 
possession of a simple and most effective instrument. The distri- 
bution of humidity in the atmosphere was next noticed. Under 
the head of wind, he alluded to the theory of Dove, which he 
said was comparatively unknown in these countries ; and briefly 
spoke of the researches of Lieut. Col. Reid, Mr. Redfield, and 
Mr. Espy. Passing over the topics of clouds and rain, he prom 
ised to bring forward on a future day, some facts connected with 
extraordinary falls of rain which had been observed; but which, 
as stated by him, in one instance in his former report, had been 
in his absence called in question. Regarding electricity, he ob- 
served that little had been added either to our instrumental re 
sources, or to our knowledge of the subject, since his former Té- 
port. On the subject of meteors, the report contained all the re- 
cent information concerning the unusually numerous appe 
of those which had been seen for some. years, on the 12th and 
13th of November, and 10th of August ; and concluded by point 
ing out the advantages of public meteorological observations for 
the purpose of, Ist. determining laws: 2d. keeping, and. under 
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