HOW TO KNOW THE CLOUDS 



117 



and these are generally cumulo-nimbi or 

 cumuli, the deduction is somewhat logical. 

 Most picturesque photographs of these 

 rays and clouds can be easily secured, 

 but lack of space prevents one from 

 being reproduced here. 



type. The cumulo-nimbus is always asso- 

 ciated with rain or snow or hail. 



In the lower illustration on page 118 

 the shower cloud form of cumulo-nimbus 

 is illustrated. The shower cloud is usually 

 somewhat larger than the ordinary sum- 



CUMULUS CLOUDS. 

 From a Photograph taken at Tunbridge Wells, May 18th, 1907. at 10.15 a.m. 



On some days cumuli appear as if 

 partially broken up by strong winds, 

 the detached portions undergoing con- 

 tinual changes. They are then termed 

 fracto-cmmili. An example of this type 

 is shown on page ii8, which is from a 

 photograph taken at South Kensington. 



We now come to another form of 

 cumulus, termed cnmido-niinhiis. This is 

 the thunder or shower cloud. It consists 

 of heavy masses of clouds towering up 

 in the form of mountains, turrets, or 

 anvils. They are generally accompanied 

 by a sheet of thin, streaky cloud above 

 them, termed " false cirrus," while under- 

 neath is a mass of cloud of the nimbus 



mer cumuhis, l)ut much smaller than the 

 thunder cloud. The well-known saying : 



" A round-topped cloud, with flattened base, 

 Carries rainfall in its face," 



verv well describes this type of cloud and 

 its rainy character. The particular one 

 here shown droj)ped rain heavily as it 

 passed over the ]iositi(m of the camera, 

 thus proving its nimbus character ; while 

 its dome-shaped top renders it a cumulo- 

 nimbus. The photograph was taken at 

 Tunbridge Wells on ^lay iSth, 1907, at 

 II o'clock. 



The ne.xt illustration will give the 

 reader some idea of the enormous dimen- 



