-^ ^* 



138 



GEOGRAPHY. 



[Sect. V. 



which they issue ; how they are affected hy diiFercnt sea- 

 sons ; whether they are of ordinary temperature or ther- 

 mal, and if the latter, it is desirable to ascertain the 

 degree of heat by means of a thermometer : the touch 

 alone is a very vague and uncertain guide. It is also 



when it can be done conveniently, to procure 

 specimoRs, in closely sealed bottles, of the water of such 

 springs as appear to possess mineral properties, or to 

 contain salts in solution, for the purpose of analysis at 

 home. Naval officers whose ships are at hand have in 

 this respect great advantages over those whose only means 

 of transport is on horseback or on camels. 



5. Lakes. — These sheets of water varying greatly in 

 size, form very important features in the geographical 

 description of a country, and the traveller should care- 

 fully remark their connexion with the other hydrogra- 

 phical features of tlie district. AVhether they constitute 

 the sources of rivers, or are their ultimate recipients, 

 whether they are or are not connected with the ocean or 

 other great seas, their levels with regard to the ocean, 

 particularly when at a lower level, what rivers flow into 

 or out of them, and whether they are fresh water or salt. 



I 



than 



marks from Colonel Jackson's work, who says 



a 



J 



re 



With 

 ard to lakes in general, the observations to be made 



upon them may be comprehended under the following 

 heads : 



" Name ; geographical and topographical situation ; 

 height above the level of the sea, and as compared to 

 oilier neighbouring lakes ; subterranean communication ; 

 form, length, breadth, circumference, su^-face, and depth : 



( 



t 



i 



I 



r 



I 



X 





tliei 



renc; 



a 



the* 

 the 



cilia 



poll- 

 tion 



yet ^ 



and 

 fairl 



C 



less 



SF'' 



mar 

 com 



be 



C( 



peril 



mail 



feat 

 be i 



1 



6. 



I 



the 

 one 

 subd: 



