454 Modification of Clouds 



•a 



Art. XL On the Modification of Clouds called Wind Reels, 

 By J. Rennie, A.m. 



The names which have been given to different species of 

 clouds by Mr. Luke Howard, are now pretty generally known 

 and adopted in meteorological journals ; but, though the author 

 (naturally enough, no doubt) deprecates the attempts which 

 have been made to substitute English terms for his Latin 

 ones, there can be little question that his learned nomenclature 

 has retarded the popularity of the science. If this be the fact, 

 as it, indeed, appears to be, it will be preferable to adopt such 

 English terms as may be more intelligible to the general reader. 



The species of cloud, therefore, which is called Cirrus by 

 Mr. Howard, may be conveniently termed the %icane-cloud, 

 being the thinnest, lightest, and highest of all the clouds : as 

 if the accumulated vapour which composes the lower and 

 denser clouds had wa7ied away, by its distance and elevation. 

 The different forms which the wane-cloud assumes, in conse« 

 quence of atmospheric changes, may be equally designated by 

 English as by Latin terms. The modification which falls to 

 be noticed at present, is called, by the peasants in Kent, >wind- 

 reels, from the notion that the streaks lie in the direction of 

 the wind. That the current of the wind may have some in- 

 fluence in the arrangement of those streaks of wane-cloud, is 

 not improbable : but that some portions of the cloud are not 

 influenced by the wind, is proved by the streaks which may 

 often be observed to cross the main lines at various angles ; in 

 some instances, indeed, so regularly, as to make a part of the 

 sky look like network. 



A very beautiful instance of the wind reel fell under my ob- 

 servation, on the 20th of May, 1828. The wind was N. W., 

 light, warm, and there bad been a succession of dry weather 

 for many days, a circumstance which is popularly supposed 

 to influence the formation of such clouds ; with some justice, 

 perhaps, as they seem to be frequently the forerunners of rain ; 

 the first nucleus, as it were, of the gathering rain-cloud. One 

 of the streaks spanned the entire visible horizon, from N. W. 

 to S. E., in an uninterrupted and nearly uniform arch, about 

 the usual dimensions of a rainbow, though not so well defined, 

 as I have endeavoured to represent in the following sketch. 

 {Jig, 198.) This arched cloud was accompanied by others, 

 conterminous with it, and nearly parallel with respect to the 

 direction of their component streaks. These appeared to verge 

 to a point ; but this was, probably, a common optical decep- 

 tion, depending on the laws of perspective ; at least, this is the 

 received opinion of meteorologists respecting arched clouds. I 

 am disposed, however, to think that the phenomenon cannot 



