CHAP. 1. 5. OP CLOUDS. 15 



SECTION V. 



Of the Cirrocumulus or Sondercloud. PI. III. 



Fig. 1. 



CIRROCVMVLVS. Def. NYBECVLAE DENSIORES SVBRO- 



TVNDAE, ET QUASI IN AGMINE ADPOSITAE. 



AFTER the cirrus has ceased to conduct the 

 electric fluid, it probably either disappears by 

 dispersion or evaporation, or it changes into the 

 cirrocumulus or cirrostratus. Its change to the 

 cirrocumulus is frequently marked by the fol- 

 lowing circumstances : it loses its cirriform 

 and fibrous structure, descends lower in the 

 atmosphere, and assumes the form of a number 

 of well defined and roundish little clouds, lying 

 in close horizontal arrangement: the change is 

 more or less rapid on different occasions, and 

 sometimes takes place in part of the cloud, 

 while the other part remains cirriform, or ap- 

 proaches to the nature of cirrostratus. 



When the cirrus ceases to conduct, it pro- 

 bably becomes electrified either plus or minus, 

 and its conversion to cirrocumulus seems to 

 indicate that it has acquired a strong positive 



