NO. 17.] 



CLOUD. 



523 



cumulus and stratus. The Tables give the sums of cases of each of the 

 16 points for the whole year and for the sunny season. In the dark season 

 and in the night, the observation of the form of clouds is very difficult and 

 sometimes impossible. The figures for this season and for the equinoctial 

 months are therefore not to be considered as altogether trustworthy. It is only 

 for the sunny season that they are likely to give results of scientific interest. 



CIRRUS. 



