ihc-lr Production, Suspension, and Destrnction, 345 



mencement of wet weather, the latter in the twihght of the 

 evening, when dew was falling : the smaller ones show it5 

 appearance in the distance, c, c, the mixed and the distinct 

 cumulo-stratus ; the latter in its most regular staie, as some- 

 times seen at the approach of thunder storms and after 

 showers. 



Plate Vlf. A distant shower coming from behind an ele- 

 vated point of land, in which are represented the superior 

 sheet stretching in different parts to windward, and cumuli 

 advancing towards and entering the mass^ the whole of 

 which constitutes the nimbus. 



As the establishina; distinctive characters for clouds has 

 been heretofore deemed a desirable object^ and it is conse- 

 <}uenlly probable that the author's modifications will begin. 

 to be noted in meteorological registers a« tliey occur, a 

 practice which may be productive of considerable advan- 

 tage to science, the following system of abbreviations may, 

 perhaps, be found of some use m this respect. The}' will 

 save room and the labour of writing, and types may be 

 easily formed for printing them. These are advantag&s not 

 lo be despised, when observations are to be noted once or 

 oftener in the day. It is only necessary that thev be in- 

 serted in a column headed Clouds ; that the laodirications 

 which appear together be placed side by side, and those 

 which succeed to each other in the usual succession of the 

 column, but separated by a line or space from, the preced- 

 ing and succeeding day's notations. 



\ Cirrus. 



f~\ Cumulus. 



— Stratus. 



^'~> Cirro-cumulus. 



^— Cirro-stratus. 



''^'— Cumulo-stratus. 



"^n— Cirro-cunuilo-stratus, or Nimbus. 



In tracing the various appearances of clouds, we have 

 only adverted to their connection with the dificrent states 

 of the atmosphere (on which, indeed, their diversity in a 

 great measure depends), having purposely avoided mixing 

 difficult and doubtful explanation with a simple descriptive 

 arrangement. 



Of Evaporation. 

 On the remote and universal origin of clouds there can 

 be but one opinion — that the water of which they consist 

 has been tamed into the atmosphere by evaporation. It 



is 



