178 TREUBIA VOL. II, 2—4. 
higher than that of the sea-water near the coast, it was only in the ponds 
near Heemraad Oost that on October 22nd 1918 salinities were still to be 
found of 11.5; 13.5 and 15.4 °/,, respectively, and that on the 24th of December 
following a salinity of 20.2 °/,, was observed. This is a consequence of the 
fact that the water of the ponds of Heemraad Oost can be drained away to 
the mouth of the Gunung Sahari canal, from which mouth water of a 
low salinity can then be made to flow into the pond again. 
| The columns of Table VI further demonstrate that in this respect the ponds 
of Heemraad Oost are not unique. For on putting together the monthly 
salinity averages mentioned in Table VI, we obtain the following survey: 
NCB Fluit Pegan- |pekulitan, Lat Jaagpad nes | Neem Antjol. 
Karang tungan Batang raad [raad Oost 
2181 DSO 05 SI Ol ln OT Oop 21 0 AUD 
218 | 46.0 °/,,/ 58.1 Joo) M38) YW 28.050 SSO) an 12400005 
19 | 39.0 Joo | 24:2 0j, 
719 33.9 Um 
’19| I 
719 SON 576 Oates) ag 
2197 OE eal UGE Olan 13.332 Zen, ES ne Oan 
19 ,10.5 9/0 Soll an 207.00 10.89, 20.52 
719 TEAM NES IG 
719 On MOT aa WAAS Ol 18006 
719 22/50) OSL 
719 See) Yan NOs os 
The above sets forth the fact that in November and December 1918 
the salinity of the pond water was everywhere higher, even considerably 
so than the salinity of the sea-water on the coast, excepting in the ponds 
of Heemraad Oost and those of Luar Batang. As regards the ponds 
of Heemraad Oost this phenomenon has already been accounted for by 
the possibility of admitting water of a low salinity from the mouth ofthe 
Gunung Sahari canal. In the same manner also in the ponds of Luar 
Batang water can be let in not only from the sea, but also from the Old 
Harbour Canal of Batavia, which communicates by a lock with the Muara 
(— River mouth) Baru, and from the Muara Baru itself. Finally I also saw at 
Tjilintjing how the large fish-ponds there (cf. photos 8 and 9, Plates XIV 
and XV) do not communicate directly with the sea, but with the Kali 
(= River) Tjilintjing from which more or less brackish water can be admitted. 
In the little statistics just given, setting forth the monthly averages of 
the salinity, there is a large and striking difference between the averages 
for the ponds situated near Kampong Jaagpad, for the periods of, on the 
one hand, January and the first 4 days of February, and on the other hand 
of the rest of February 1919. 
