19 



The specific gravity and temperature of seven main stations 

 upon the lake, taken during August 1908, were as follows : — 



From the above table it is seen that the specific gravity for 

 some distance from the bar is that of normal sea water for the 

 temperature registered. 



As distance from the bar increases, the specific gravity 

 mounts higher with marked regularity — 1,031, 1,033 } aud 

 1,039— the last and highest reading being at Tada at the north- 

 west extremity of the lake, a place adjacent to a large series 

 of salt marshes and salt pans. Inshore at the north end of 

 Irakam, another high reading was obtained, J ,035*50, higher 

 indeed than that in mid-channel further north, 1,033, between 

 Venadu and Tada. This is due probably to mid- channel water 

 being subject to greater tidal influence than the inshore body 

 of water. The relatively great Motional resistance offered by 

 the bottom in the marginal shallows tends still more to render 

 the inshore body of water considerably more inert than that in 

 mid-channel. 



Much greater density than the highest now recorded must 

 prevail during the hot season whenever the bar is closed ; no 

 records taken during such period appear to be in existence and 

 we must wait till the next recurrence of these conditions to 

 obtain the needful data. Conversely, when floods are on, 

 especially with the bar shut, the density must be greatly 

 reduced in ratio according to the amount of dilution of the 

 normally somewhat super-saline water of the lake. 



Never was there any marked difference in temperature be- 

 tween the lake water and the air in shade. As will be noticed 

 the temperature ran fairly high ; August 27th was an abnor- 

 mally hot day, the air temperature being 96° F. in the shade 

 while the water was but one degree lower (95 c F.j, the highest 

 salt-water temperature I have ever recorded. 



