ARTESIAN WELLS. AUT 
currents which are seen to pour into chasms opened, as it were, 
expressly for their reception ; and in others, where no apertures 
in the crust of the earth have been detected, their existence is 
proved by the fact that artesian wells sometimes bring up 
from great depths seeds, leaves, and even living fish, which 
must have been carried down through channels large enough 
pose in Piedmont, with complete success. See the interesting pamphlet, Sulla 
Estrazione delle Acque Sotterranee, by C. CALANDRA. Torino, 1867. 
The most remarkable case of infiltration known to me by personal observa- 
tion is the occurrence of fresh water in the beach-sand on the eastern side of 
the Gulf of Akaba, the eastern arm of the Red Sea. If you dig a cavity in the 
beach near the sea-level, it soon fills with water so fresh as not to be undrink- 
able, though the sea-water two or three yards from it contains even more than 
the average quantity of salt. It cannot be maintained that this is sea-water 
freshened by filtration through a few feet or inches of sand, for salt-water 
cannot be deprived of its salt by that process. It can only come from the 
highlands of Arabia, and it would seem that there must exist some large reser- 
voir in the interior to furnish a supply which, in spite of evaporation, holds 
out for months after the last rains of winter, and perhaps even through the 
year. I observed the fact in the month of June. See Rosinson, Lidlical 
Researches, 1857, voli., p. 167. 
The precipitation in the mountains that border the Red Sea is not known by 
pluviometric measurement, but the mass of débris bronght down the ravines 
by the torrents proves that their volume must be large. The proportion of 
surface covered by sand and absorbent earth, in Arabia Petreea and the neigh- 
boring countries, is small, and the mountains drain themselves rapidly into 
the wadies or ravines where the torrents are formed ; but the beds of earth 
and disintegrated rock at the bottom of the valleys are of so loose and porous 
texture, that a great quantity of water is absorbed in saturating them before 
a visible current is formed on their surface. In a heavy thunder-storm, 
accompanied by a deluging rain, which I witnessed at Mount Sinai in the 
month of May, a large stream of water poured, in an almost continuous cas- 
cade, down the steep ravine north of the convent, by which travellers some- 
times descend from the plateau between the two peaks, but after reaching 
the foot of the mountain, it flowed but a few yards before it was swallowed 
up in the sands. 
Fresh-water wells are not unfrequently found upon the borders of ocean 
beaches. In the dry summer of 1870, drinkable water was procured in many 
places on the coast of Liguria by digging to the depth of a yard in the beach- 
sands. Tubular wells reach fresh water at twelve or fifteen feet below the 
surface on the sandy plains of Cape Cod. In this latter case, the supply is 
more probably derived directly from precipitation than from lateral infiltra- 
tion. 
