ASTRONOMY AND METEOROLOGY. 



indications may, perhaps, be worthy of notice in future physical 

 investigations. 



INTERESTING METEOROLOGICAL OBSERVATIONS. 



The account of the meteorological observations made during the 

 scientific balloon ascents last year, by Mr. Welsh, of the Kew Obser- 

 vatory, have recently been published under the direction of the Royal 

 Society. 



The principal results deduced from the experiments described 

 are thus stated. The temperature of the air decreases uniformly 

 with the height above the earth's surface, until at a certain elevation, 

 varying on different days,"the decrease is arrested, and for a space of 

 from 2000 to 3000 feet, the temperature remains nearly constant, or 

 even increases by a small amount ; the regular diminution being after- 

 wards resumed, and generally maintained, at a rate slightly less 

 rapid than in the lower part of the atmosphere, and commencing 

 from a higher temperature than would have existed but for the inter- 

 ruption noticed. This interruption in the decrease of temperature is 

 accompanied by a large and abrupt fall in the temperature of the 

 dew-point, or by actual condensation of vapor, from which it may be 

 inferred that the disturbance in the progression of temperature arises 

 from a development of heat in the neighborhood of the plane of con- 

 densation. The subsequent falls in the temperature of the dew-point 

 are generally of an abrupt character, and corresponding interruptions 

 in the decreasing progression of temperature are sometimes distin- 

 guishable, but in a less degree, as might be expected from the fact, 

 that at lower temperatures the variations in the absolute amount of 

 aqueous vapor are necessarily smaller, and their thermic effects con- 

 sequently diminished. The analysis of the portions of air collected in 

 the ascents is reported by Professor Miller, of King's College. The 

 proportions of oxygen and nitrogen were determined by detonation 

 with hydrogen in Regnault's endiometer. The volumes of oxygen in 

 the air from different heights are given in the following table : 



Altitude. Volume of Oiygen. 



Air collected at King's College, 20-920 



Tube 2, " . . . 13,460 feet. . . 20 883 



Tube 3 18.000 feet . . 20-747 



Tube (G 1) Torricellian vacuum, . . 23,630 feet. . . 18-888 



These results confirm the statement made long ago by Gay Lussac, 

 at a time when gaseous analysis was less perfect than at present, that 

 there is no sensible difference in the composition of the atmosphere 

 on the surface and at the greatest heights accessible to man, so far as 

 the proportions of oxygen and nitrogen are concerned. The quantities 

 of air submitted to Professor Miller were too small to admit of the 

 proportion of carbonic acid being determined, but its presence seems 

 to have been shown in all by the formation of a film of carbonate of 

 lead upon a solution of the subacetate, which was introduced to a por- 

 tion of the air confined over mercury. 



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