120 



THE NATURE BOOK 



nounced when the photograph was taken. 

 The reproduction on this page will serve 

 to render some idea of the peculiar ap- 

 pearance of the cloud. 



We come now to the last type of cloud 

 — namely, the stra/iis, a form with which 

 we are all very familiar, it being nothing 

 more than an ordinary fog lifted up from 

 the ground. Sometimes it is broken here 

 and there by the wind, and exposes the 

 blue skv overhead, or the summits of 

 mountains penetrate it. On these occa- 

 sions it may be distinguished by the name 

 of fracto-stratiis to differentiate it from 

 the unbroken sheet. 



Those who live in hilly districts can 

 often tell successfully the kind of weather 

 that will prevail by close observation of 

 the behaviour of these low clouds. When 

 hill-tops are shrouded in mist, this is 

 nearly always a sign of rain, and innumer- 

 able old sajangs, such as : 



" When Cheviot ye see put on his cap, 

 Of rain ye'U have a wee bit drap," 



tell us that this is very generally known. 

 One other old weather-lore saying is 



well worth quoting here, for it shows that 

 the rhyme must have been based on both 

 accurate and long-continued observation : 



" Mists dispersing on the plain 

 Scatter away the clouds and rain ; 

 But when they rise to the mountain tops, 

 They'll soon descend in copious drops." 



In bringing this article to a close the 

 writer hopes that even if he has not 

 imbued the reader with enthusiasm for 

 the study of cloud-land, he will never- 

 theless have wakened in him an interest 

 to observe more closely the sky over- 

 head. INlany a half-hour can be pleas- 

 antly spent by watching the happenings 

 in the upper air, and the more familiar 

 one becomes with such the more one is 

 fascinated and drawn to make a closer 

 study of them. 



"Thus when the changeful temper of the skies, 

 The rare condenses, the dense rarifies, 

 New motions on the altered air imprest 

 New images and passions fill the breast ; 

 Then the glad birds in tender concert join, 

 Then croaks the exulting rook, and sport the 



lustv kine." 



Virgil's "Georgicx. 



William J. S. Lockyer. 



MAMMATO- OK FESTOONED-CUMULUS CLOUD. 



