16 
In the Little Belt there is only a small difference between the salinity at 
the surface and in deep water; it is about 20° or a little less. The temperature 
at the surface is comparatively low in summer (during 1902—1906 on an average 
13.7° in June, in July 15,2°, in Aug. 15,1°), comparatively high in winter (during 
the same period 2,5° in January, 1,7° in Febr.). There is generally a strong cur- 
rent, especially in the narrowest part of the Belt. 
In the Sound a salt bottom layer is found as far as Saltholm Tærskel, some- 
times however passing it. The salinity greatly deereases southward in the upper 
layers. The salinity of the bottom-layer also deereases southward; north of Hveen 
it is 25—28%Y% at a depth of 20M. In deep hollows the salinity may be 30—32° 0 
and here the temperature in winter is constant for a long time. The following 
numbers found at the lightship on Lappegrunden are very instructive. 
Average of 1883—94 (Meteorol. Aarbog): 
Temperature Salinity 
Min. Max. Min. Max. 
OM. 2225226552 1,0° (Febr.) 17,0° (July) 12,0 %/00 16,7 “/00 
1 1 En RE ET 3.1° (March) 15,7° (Aug.) 21,0 - 26,2 - 
AO ee EEE 4,1° (March) 11,5° (Sept.) 28,3 - 32,8 - 
DE ie Wea ater 2 3,5° (April) 11,3° (Oct.) Day alee Dies 
North of Saltholm (1880 — 1907): 
Salinity 0 M. 10—13"/00, 10 M. 13—16 oo. 
In the western Baltic there is also, at any rate in the summer, a contrast 
between the surface-water and the salt bottom-water, but as a considerable mixing 
occurs the surface-water west of Fehmarn is comparatively salt, 11—18°o, and 
has a somewhat lower temperature in summer than in the true Baltic. The salt 
bottom-water has its maximal salinity in July and August, when it is ca. 20° 00 at 
a depth of 20M. In the area between Fehmarn and Gjedser—Dars—Terskelen the 
salinity decreases considerably in the upper water-layers eastwards. The salinity 
also decreases somewhat in the bottom-water (ca. 15—20° 0 at a depth of 20 M.). 
At the lightship on Gjedser Reef the average salinity was in 1880—94: 
OM. ...... 8,7—12,8%o0 
Bie ee 98—136 - 
its RE ag 
In the Baltic round Møen, from Gjedser to Sweden, the salinity and tem- 
perature are fairly uniform from surface to bottom. At Moen the salinity at the 
surface is on an average ca. 8°00, at a depth of 20 M. 8—10°%oo. From this place 
the salinity increases both at the surface and at the bottom towards the two en- 
trances, the Gjedser—Dars—Terskel and the Drogden Tærskel. 
To illustrate the hydrography of the Baltic round Bornholm it may be 
mentioned that the salinity of the surface-water at Christiansø in 1902—1906 was on 
