98 On the ModlficatioMS of Clouds, an^ 



in order to form a judgment upon occasion, resides onhy Ii\ 

 the mind before which their relations have passed, though 

 perhaps imperceptibly, in review. In order to enable the 

 meteorologist to apply the key of analysis to the experience 

 pf others, as; well as to record his own with bjevitv and pre- 

 cision, it may perhaps be allowable to introduce a methodi- 

 cal nomenclature, applicable to the various forms of sus- 

 pended v/ater, or^, in other words, to the modifications of 

 <;loud. 



By modification is to be understood simply the structure 

 or manner of aggregation, not the precise form or magni- 

 tude, which indeed varies every moment in most clouds. 

 The principal modifications are commonly as distinguish-* 

 able from each other as a tree from a hill, or the latter froiT^ 

 a lake; although clouds in the same modification, considered 

 with respect to each other, have often only the commoi'^ 

 resemblances which exist among trees, hills, or lakes, taken 

 generally. 



The nomenclature is drawn from the Latin. The reasons 

 for having recourse to a dead language for terms to be 

 adopted by the learned of different nations are obvious. If 

 it should be asked why the Greek was not preferred, after 

 the example of chemistry, the author answers, that the ob- 

 jects being to be defined by visible characters, as in natural 

 history, it was desirable that the terms adopted should at 

 once convey the idea of these, and render a recourse to de- 

 finitions needless to such as understand the literal sense, 

 which many more would, it is concluded, in Latin than ii^ 

 Greek words, i 



There are three simple and distinct modifications, in any 

 one of which the aggregate of minute drops called a cloud 

 inay be formed, increase to its greatest extent, and finally 

 decrease and disappear. 



But the same ac-gregate which has been formed in one 

 rnGdi(ication,upon a change in the attendant circumstances, 

 niay pass into another. 



Or it msy continue a considerable time in an intermediate 

 ^tatc, partaking of the characters of two modificatioxis ; and 

 it mav also disappear m this stage, or return to the first mo- 

 dification. 



Lastly,^ aggregates separately formed in different modifi- 

 cations may unite and pass into one exhibiting different 

 characters in different parts, or a portion of a simple ag- 

 gregate may pass into another modification without sepa- 

 rating from the remainder of the mass. 



Hence, together with the pimple, it becomes necessary to 

 ' ' - . ■ admit 



A 



