92 HEIGHT OP CLOUDS. CHAP. 2. 17- 



a bed of cirrocumuli lower down to be smaller 

 than those of one more elevated. This was 

 noticed among the abundance of cirrocumulus, 

 cirrus, and other clouds, which appeared on 

 21st Oct. 1811 : the night succeeding was 

 cloudy, with a gale from South and distant 

 lightning. The long lines of cirrus extending 

 across the sky have been found to be very high, 

 by geographical observation. By the same mode 

 of mensuration, I found that I was frequently 

 much deceived in my opinion as to the height 

 of clouds at first view of them. Saussure 

 writes of the very great height of clouds, 

 which from the description must be a kind 

 of cirrostratus in mottled beds, and Dalton 

 mentions, that the clouds of the Mackerelback 

 Sky, as he calls it, have appeared almost as di- 

 stant from the top of high mountains, as from the 

 ground.* That clouds are sometimes very high, 

 there can be no doubt : and their height may 

 be easily taken with quadrants at different 

 stations. Aeronauts have generally ascended 

 much beyond the cumuli ; but I question if 

 there be not clouds much higher up than 

 any balloons have ever ascended. M. Sadler 



* Dalton's Meteorological Essays. 



