118 Mr. Green's Ohservatiom, &c. 



the tenipcrature agrees with this supposition, ^vhich also ac- 

 counts for the great height to which the balloon ascended with- 

 out entering the clouds ; thus the dryness would have decreased 

 from 10°, on the surface of the earth to 5°, and before the next 

 observation I should conjecture that the aeronaut must have 

 passed the point of precipitation through a bed of clouds. After 

 crossing this plane the temperature and the force of the vapour 

 rapidly decreased, and the degree of dryness increased with the 

 ascent. 



The condition of the atmosphere appears to have varied con- 

 siderably with the progress in-land, and in receding from the 

 sea the force of the vapour seems to have decreased, and the 

 temperature of the air still more rapidly. The point of deposi- 

 tion in the descent was passed in a shower of rain, at a 

 distance of not more than 3,(>30 feet above the surface of the 

 earth, the constituent temperature of the vapour having fallen 

 16°, and the temperature of the air not less than 24° in the 

 short space of thirty-five minutes. The increase of the density 

 of the vapour towards the surface of the earth, was much more 

 gradual during the descent over the land than during the as- 

 cent over the sea: was the difierence owing to a large body of 

 vapour rising from the sea ? The temperature of the water at 

 the time would have been a valuable addition to the observations. 



It is to be hoped that Mr. Green will be enabled to persevere 

 in his exertions, as a continuation of such observations cannot 

 fail to be of the utmost use to science. It would be desirable 

 also that he should be a little more particular in noticing the 

 different indications of the atmosphere, that is to say, the course 

 of the wind on the surface of the earth, and the direction of the 

 different currents — the height of the clouds and the temperature 

 when crossing them, and whether there is more than one stratum 

 at different heights. Now that he is aware of the tendency of 

 the different experiments, there are, no doubt, many particulars 

 which will readily suggest themselves to him, and he will not, 

 of course, neglect to make observations before his departure^ 

 and after his return, if circumstances will permit. 



