1182 



METEOROLOGY. 



[OLAISHEK'S 



ASCENTS. 



feat thick, was passed through. This was o dome that 

 the balloon was uot visible from the car." 



.Mr. (Jlttishor propami Uie folluwiog table, which 

 show* the mean temperature of the air at each 6,000 feet 

 above the level of the sea, on the date* named, selecting 

 those in which the highett ascent* were made. 



On these facts Mr. Glauber remarks "The results of 

 July 17 aro perfectly anomalous. Up to 10,000 feet the 

 decrease accords with the other days of experiments ; 

 but from 10,000 feet, the results are perfectly surprising, 

 and continue so up to more than 20,000 feet. Above 



25,000 foot, thoy are again accordant If we suppose 

 that up to 10,000, and a- "00 feet, the results 



are not abnormal, by continuing the curvu joining these 

 two portions, and then reading, we should have the 

 following readings : vis. 



"At feet, mean temperature 



feet, 



6,000 



10,000 



16,000 



19,000 

 20,000 

 85,000 



Cl c -2 



27" -5 

 22 7 



jo ,, 

 !.' ;, 

 - 16 -3 



' ' Then the measure of disturbance would be as follows : 



viz. 



"At 10,000 feet 



15,000 



19,500 



20,000 



J.-,. i KiO 



. = 0'5 in excess. 

 . - 8-3 

 . = 22-2 

 . - 13 -6 

 . = 3 -3 in defect. 



"The numbers, in the last column of the table, show 

 that the average decrease of temperature, in the lh.-t 

 5,000 feet, exceeds 20, and, in the next 5,000 feet, in but 

 little more than 10. The numbers, in the lowest line of 

 the table, show that the average decrease of temperature 

 for 25,000 feet, is 51 nearly. From these numbers, it 

 seems that two-fifths of the whole decrease of tem- 

 perature, in five miles, takes place in the first inil> : 

 and, therefore, that the decrement is not uniform with 

 the increment of elevation." 



So far, our attention has been confined to the results 

 which Mr. Glaisher obtained during the highest ascents 

 he effected. In the following table the t. m] .T.iUire is 

 given for each 1,000 feet of elevation, between the 

 and 5,000 above it, for each ascent made during the 

 summer of 1862. It will be seen that the temperature 

 decreases 21 in the 5,000 feet, and that the rate is uot 

 uniform. (See also Tables at pp. 1215 and 1210). 



With respect to other objects of inquiry, it was found, 

 that tho electricity of the air was generally positive, 

 diminishing in amount as tho elevation increased ; that 

 ozone was present in large quantities ; that the vibration 

 of the magnet was longer at high elevations than on tho 

 earth ; and that sounds -varied, in the distance at which 

 they could be heard tho barking of a dog being noticed 

 at a height of two miles, whilst the shouting of a multi- 

 tude wu not heard at one mile high. 



The general results deduced wore 



1. Tint tho temperature of the air does not decrease 

 uniformly with an increasing elevation above the surface 

 of the earth j a fact bearing strongly on the refractive 

 powers of the atmosphere, in relation to astronomical 

 observations. 



'ITiat an aneroid barometer may be correctly read 

 to one, and probably to two, places of decimals, when 

 indicating a pressure equal to live inches of mercury in 

 the barometer. (See Table at page 1214.) 



3. That the atmospheric humidity decreases rapidly 

 to a height of five miles, where its amount is extremely 



:.. ... 



4. That tho readily accepted theory, as to the prevalence 

 of a settled west or north-west wind, was not confirmed. 



6. That the opinion of the clouds assuming a counter- 



part of the earth's surface, and that they rise and fall 

 like hills and dales, was not countenanced by the 

 appearance of their upper surface. 



The following interesting description of the appear- 

 ance of the clouds, as observed on the date named, is 

 quoted from the Atliciunim, to which periodical wo 

 are indebted for many of tho facts wo have adduced. 

 The balloon had descended on the previous evening at 

 II' iidon, and had been anchored for tho night, prepara- 

 tory to an ascent on tho following morning. 



"Before sunrise, on August 21, all tlio instruments 

 were replaced, and the balloon left tho earth : it was a 

 warm, dull, cloud}-, morning; clouds were reached at tho 

 height of 5,000 feet ; tho light rapidly increased, and 

 gradually the balloon emerged from dense clouds into a 

 basin surrounded by immense black mountain,* of cloud, 

 rising far above. Shortly afterwards there v>< TO dn-p 

 ravines of grand proportions below, bounded with 

 beautiful curved lines. The sky was blue, with cirri. 

 The tops of the mountain-like clouds became silver and 

 golden : at tho height of 8,000 feet we wero on their 

 level, and the sun appeared, flooding, with golden light, 

 all space for many degrees both right and left, tinting 

 with orange and silver all tho remaining space. It was a 

 glorious sight. As the sun's rays fell on tho balloon we 



