226 NINTH ANNUAL REPORT OF 



■continued higher than the lower cloud, and was rising and whirling, 

 while I was in the margin of the storm, during twenty-five minutes. 



"6th. The storm was much wider below than above and divero;ino: at 

 least twenty-five degrees from a perpendicular line. 



"7lh. The deposition of rain and hail was thicker about the centre 

 of the storm. 



" 8th. Under the shadow of the upper cloud it is very cold, and in 

 the lower cloud quite warm. The upper cloud was moved by the cur- 

 rent which always moves from west to east." 



To these allegations Mr. Wise might have added tlie following, as 

 they are merely a repetition of facts alleged in his narration: 



9th. A balloon, instead of being borne ahead by the current of air in 

 which it floats, may be so approximated to the cloud as to be involved 

 in the "outskirts of its rain," and be made to "rock by its whirling 

 motion." 



10th. A third cloud may be formed by the rusliing together of two 

 •others, seen previously in opposite quarters, and remote from each 

 •other. 



11th. Tfie gas in a balloon may be so acted upon by the electric 

 medium around it, as to acquire an augmentation of volume equivalent 

 to calorific expansion. 



10. The existence of two "plates," or strata, of clouds, as stated in 

 paragrapli 1st of the above synopsis, I have iov some time considered 

 as the usual concomitant of rainy weather. When, agreeabl}'' to the 

 observations of Dalton, on which Espy founded his theory of storms, 

 the vapor in an ascending mass ot" air is condensed, b}' the rarifaction 

 and consequent increase of calorific capacity, which the air acquires on 

 attaining the elevated region usually occupied b}^ the clouds, this in- 

 crease of capacity enables it to rob the aqueous vapor associated with 

 it of heat; but by these means becoming warmer than if this vapor 

 were not present, it consequentl}' acquires an ascensional power ; but by 

 admixture with a larger portion of air,. the warmth and moisture are 

 again absorbed in the state of vapor, so that the clouds thus created be- 

 low a certain level are reabsorbed at a higher level, producing a cold 

 proportionally as great as the heat resulting from its condensation. 

 This may be called the level of absorption, while the level at which 

 they are created may be called tfie level of condensation. Between 

 these levels the clouds, in fine weather, seem to float as if they were 

 persistent, when, in reality, they^ are no more of this character than 

 the fog which surmounts the escape-pipe of a steam-boiler when letting 

 off steam. 



IJ. Yet the moisture which escapes from permanent condensation at 

 the first level at wliich this process takes place, b}' reaching a higher 

 level, may be a second time condensed, by which a second stratum of 

 clouds, as much colder as the associated air is rarer, may be generated. 

 The process of reabsorption which had previously taken place imme- 

 diately above the lower stratum, can now only take place immediately 

 above the upper stratum, and, in consequence of the greater refrigera- 

 tion, must proceed with proportionall>^ less rapidity. Consequently the 



