90 



Treubia Vol. \\\, i. 



break over the land 

 connection. 



Between the 

 lake and the ocean 

 is a narrow neck of 

 land consisting of 

 nearly barren dunes. 

 The deepest place 

 of the lake is afthe 

 western end ; the 

 soundings which 

 Dr. SUNIER, Chief 

 of the Laboratory 

 for Marine Investi- 

 gations, took here 

 in April 1919 gave 

 a depth of 5,7 M. 

 (19 feet). 



At the eastern 

 end the water is 

 very shallow and it 

 seemed to me that 

 the shore at this 

 place is moving for- 

 ward and becoming 

 more and more 

 Fig. 2. Map of Verlaten Island North, Scale 1: 30.000. overgrown by small 



a, brackish-water lake; b, brackish pool. The dotted lines indicate ^ . 



the coast-line of 1908; at c begins the hilly land; hereabouts Casuanna trees. 



was the coast-line shortly after the eruption. jj-jg greatest length 



of the lake is about 800 M. Dr. ESCHER is of opinion that the lake will 

 disappear in the end, the dunes at the west end moving inwards and the 

 whole land shifting in an easterly direction. 



The level of the lake changes a little in different seasons, also the 

 salinity of the water undergoes seasonal changes (see table below), but is 

 always less than that of pure sea-water. 



Dr. SUNIER has been kind enough to take the following analyses for me. 



Salinity. 



Lake a. Pool b. 



22.8 %o 22.5 «/oo 



25.3 „ — 



20.6 „ 12.85 „ 



23.3 „ 24.6 „ 



21.4 „ 16.4 „ 

 29.0 „ 27.9 „ 



April 



1919 . . 



Dec. 



1919 . . 



April 



1920 . . 



Sept. 



1920 . , 



April 



1921 . . 



Oct. 



1921 . . 



