CHARACTERISTICS AND DISTRIBUTION OF LAKES 587 
present in process of being divided into two parts in the same way. 
The tributary streams enter the main valley of the Inn at points well 
up on the valley sides, and their waters fall abruptly in cascades to 
the main stream below. Such " hanging " valleys are of common 
occurrence in Switzerland, and are regarded as a reliable indication of 
glacial erosion in the main valley.^ 
In Transylvania many small lakes owe their salinity to the presence 
of rock-salt in the district, and may contain as much as 525 per cent, 
of common salt. In the Medve Lake,'^ the largest of the group near 
Szovata, the area of which is 0*01 square mile, with a maximum depth 
of 34 metres (112 feet) and an average depth of 10 metres (33 feet), 
observations on the temperature gave the following results. At the 
surface, where there is a superficial layer of fresh water, the tempera- 
ture varies with that of the atmosphere, and in summer is 68° to 86" 
Fahr. (20° to 30° C.) ; below the surface the temperature rises gradu- 
ally, and at a depth of 1'32 metres (4 J feet) reaches its maximum of 
133° Fahr. (56' C). Below this it again falls, and is 86° Fahr. (30° C.) 
at a depth of 5*32 metres (17J feet). The conversion of the solar rays 
into heat in the salt layer depends on the fresh-water layer on the 
surface.^ This phenomenon also occurs in other Hungarian salt lakes, 
as well as in Wallachia and elsewhere, and in the lagoons found on 
parts of the shore in Norway (see p. 580). 
Scutari Lake (or Skader), situated half in Montenegro and half in I'^iver Bojana. 
Albania, at an elevation of 20 feet above sea-level, drains into the 
Adriatic by the River Bojana, which enters the sea at the boundary- 
1 Davis, " Glacial Erosion in France, Switzerland, and Norway," Froc. Boston 
Soc. Nat. Hist., vol. xxix. p. 273, 1901 ; Davis reviews the j^revious writings on 
hanging valleys on pp. 311 et seq. 
^ See Scot. Geogr. Mag., vol. xviii. p. 317, 1902 ; vol. xx. p. 216, 1904. 
^ In this connection Professor Kaleczinsky (see " Ueber die ungarischen 
warmen nnd heissen Kochsalzseen als natiirliche Warme- Accumulatoren, sowie 
iiher die Herstellung von warmen Salzseen und Warme-Accumulatoren," Foldtani 
Kodony, Bd. xxxi. p. 1 (sep.), 1902 ; " Ueber die Akknmnlation der Sonnenwarme 
in verschiedenen Fliissigkeiten," Math. u. naturw. Berichte aus Ungarn, Bd. xxi. 
p. 1 (sep.), 1904) conducted a series of observations on tubs sunk in the ground 
and filled with various saline solutions, each tub bearing a superficial layer of 
fresh water, while a tub of fresh water served as a control. In the latter it was 
found that the warmest layer of water was the superficial one, which never reached 
a higher temperature than 86° F. (30° C). In all the other cases the conditions 
were the same as in the salt lakes, i.e. the highest temperature was never observed 
at the surface, but in the lower layers. Kaleczinsky believes that similar con- 
ditions prevailed in geological times, and that the layers of salt obtained in salt- 
mines form as it were a kind of geological thermometer. Thus he believes that 
the rings of anhydrite well known in salt-mines have been deposited in summer 
when the temperature of the water was high, while the deposits of rock-salt took 
place in winter when the temperature of the water was low. 
