.^^ 



300 



METEOROLOGY. 



[Sect. IX, 



formsj definitely terminated above, indicating saturation in 

 the upper clear region of the air^ and a rising supply of 

 vapour from below. Stratus is an extended continuous 

 level sheet, which must not be confounded with the flat 

 base of the cumulus, where it simply reposes on the 

 vapour plane. The cumulo-stratus, or anvii-shaped 

 cloud, is said to forerun heavy gales of wind. Peculiar 

 aspects of cloud, preceding gales, squalls, or hurricanes, 

 should be specially described in the sheet of remarks, or 



in a jonrnal. Nimbu 



int<» a crown of cirrus above, and passing beneath into a 



;h< 



snower 



Under the heading I will stand a note of the general 



state of the weather, according to Admiral Beaufort' 



s 



system of abbreviations, which is as follows :— Numbers 

 from 1 to 12 denote the force of the wind : thus, denotes 

 calm ; 1, ligld air, just perceptible ; 2, light breeze, in 

 which a ship, clean full, in smooth water, would go from 



one to two knot 



s : 



5 



aentl 





e oreeze 



f^ 



') : 4^ Tnoderate breeze (fi 



c 



royals, &c, ; o 



(from two to four 

 tm four to six knots) ; 5, 

 ould just carry on a wind 



n 



? 



c 



topgallant-sails) : 7, moderate gale (double-reefed, &c.) ; 

 8, fresh gale (triple-reefed and courses) ; 9, stormy gale 



(close-reefed^ 



O 



etc.; ; 



10, 



( 



mam- 



1) I 11, storm (storm-staysails) 



12, hurricam (no canvas can etand). These numbers, in 

 the absence of an anemometer, may be entered in column 



Gh. The follow] 

 weatlier : 



Q 



a 



bbreviations denote the state of the 



I 



*' 



■* 



*. 



