Page:Palestine Exploration Fund - Quarterly Statement for 1894.djvu/259

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.
DEPTH AND TEMPERATURE OF THE LAKE OF TIBERIAS.
219

Lastly, a final table will enable us to compare the figures for a surface temperature nearly equal in two places.

Tiberias = 137 feet.
May.
Leman = 1,095 feet.
August.
o o o
7·34 Fah. 71·60 Fah.
32·81 feet 68·54 64·40
65·62 " 59·00 54·86
98·43 " 59·00 50·90
131·24 " 58·10 45·68

It is evident—what we have said of the Lake of Morat is enough to show it—that the difference in depth between the two basins is not sufficient to explain the divergence of nearly 7 degrees, which we ascertained between the temperature of the waters of the Lake of Tiberias and that of the waters of Lake Leman at a level of 40 metres.

A certain number of factors come into play to promote this divergence:—

1st The latitude, which is much further south at Tiberias, which causes its average temperature to be much higher than that of Geneva for example.

2nd. The altitude: Lake Leman is at + 1,230 feet, the Lake of Gennesaret at—682 feet; we know the stifling heat which prevails in the deep valley of the Ghôr, not only at Tiberias, but even more perhaps at Huleh, the altitude of which is, however, greater. M. Deshays, chief of the cultivation of the Jewish colony of Jessod-Hamaila, recently installed on the eastern shore of the Lake of Huleh, has assured me that in summer the thermometer frequently rises above 50 degrees, and that several times he had noted temperatures of 55 degrees. Also the water of the Jordan, after having been much heated in this superficial reservoir (5 to 6 metres in depth at the most) arrives in the Lake of Tiberias with a much higher temperature than that of the Rhone at its entrance into the Leman.[1]

3rd. The continuous flow into the Lake of Tiberias of a series of thermal springs, the principal of which are—

Hammâm d'Emmaus at 143° Fah. (Anderson);
'Ain-Tâbghah at 89° Fah. (Lortet);
'Ain-et-Tineh at 77º Fah. (Barrois).

Others must certainly have their source in the lake itself: it is thus that about 2 or 3 kilometres oft' 'Ain-Tâbghah, on the imaginary line which joins this latter locality to Tiberias, the captain of my boat, an old fisher-

  1. According to Forel (loc. cit., p. 30, in the note), the waters of the Rhone have in summer a temperature which varies from 6 to 11 degrees, while the upper bed of the lake is between 15 and 25 degrees.