440 



Marvels of tlie Universe 



dome-shaped masses of condensation willi flat bases. ^^■hcn they pass over the sun thcj' appear 

 as dark masses with briglit edges. The average heiglit of their base level is about four thousand feet, 

 and that of their summits about six thousand feet. They are quite plentiful during summer, and 

 are a fine-weather type. 



Unfortunately this last remark cannot be applied to the Cumulo-nimbus clouds, for they appear 

 at their best during thunderstorms, and likewise give rise to the sharp hail- and rain-showers of 

 springtime. These clouds are really an over-development of the Cumulus type and have a similar 

 base level ; but they continue to heap up mass upon mass of cloud, till their summits reach almost 



as high as the Cirrus. 

 Imagine a pile of 

 cloud three or four 

 miles high, and con- 

 taining twenty or more 

 cubic miles of con- 

 densed vapour ! It 

 is fascinating to watch 

 the growth of their 

 fantastic forms, which 

 continues until con- 

 ditions become un- 

 stable, when the whole 

 huge " fabric collapses 

 in a torrential " thun- 

 der-shower." 



The Nimbus, or 

 rain-cloud, is a mass 

 of cloud without de- 

 finite form, from which 

 steady rain falls. It 

 is sometimes accom- 

 panied 'by small de- 

 tached pieces of cloud 

 which float below the 

 main mass, and to 

 which ■ sailors have 

 given^; the name of 

 flying scud." Its 

 height is six thousand 

 feet or thereby. 



Stratus, the lowest of aU clouds, is simply a sheet of lifted fog, found anywhere up to about three 

 thousand feet ; and, like the Alto-stratus, does not lend itself to photography because of its 

 uniformity. •^ '■' 



THE TELEGRAPH PLANT 



The two small leaflets, at the base of the large leaflet, are 

 their stalks. The large leaflet moves up and down only 



[/•;. ./. Wiiiih 



n constant movement, revolving on 

 like the arm of a railway signal. 



THE TELEGRAPH PLANT 



The telegraph referred to in the name of this plant is the old semaphore apparatus with which, 

 before the application of electricity, messages were signalled from hill to hill. .. It survives in the 

 signal-posts and arms of the railways by which sections of the line are indicated to be free^r blocked 

 according to whether the arm is depressed or horizontal. The suitability of the name will be 



