338 | Capt. Koschkull on the Caucasus, 
of new wells in the vicinity of old ones seems not to affect the 
yield of the latter, so that the productiveness of a given area 
depends directly on the number of wells which it. contains 
This fact has determined the method pursued in the collection 
of petroleum on the island of Tschelaken and on the eastera 
shore of the Caspian, where to obtain a. large quantity of oll — 
20,000 wells have been sunk, but none to any great depth — 
The Persians, who were the first to collect the oil of the penin- _ 
sula of Abscheron, seem to have followed the same system of 
exploitation. 1 
The number of wells dug there is very great, and they ae 
very closely approximated. In 1863, a new well was sunk 
the side of one which had for centuries yielded about ], 
ilograms of petroleum per day. The new one now produces 
19,200 kilograms every twenty-four hours without affecting ™ 
the least the yield of the old well. ; 
In 1865, the method pursued with so much success 
America in the exploitation of petroleum was introduced into 
the Caucasus and with complete success, In a locality let 
by myself, near some oil springs in the valley of one of 
tributaries of the Kuban, a well was commenced in the abot 
mentioned year. At the depth of 40 feet encouraging mate 
met with, and in Feb., 1866, when the boring had reac : 
At first the production of this fountain well was 32,000 kl o 
ey per day, but the yield gradually diminished to about one 
alf that amount. There have since been periods = na 
flow was entirely arrested, but apparently in consequenc® “a 
clogging of the well, as when cleaned out, the normal flow ¥ 
resumed. this 
During 57 days in 1866 during which the flow from ilo 
well was carefully measured, the production was 880, + yale 
grams of petroleum, with one-tenth of that quantity * rodced : 
2,160,000 196 days of service this well hae: a 
160, ograms of oil. . i : 
The tariipstatate of the oil as it flows from this well 67 
Reaumur, that is to say, 3° less than it should be acco ; 
the geothermic law for a liquid drawn from a depth of 5 
low the surface. Can this depression of temperatm’ iy 
tributed to the absorption of heat in the conversio? of a : 
of the petroleum into cas ? that 
learn by a letter recently received from the Canary oilf | 
a new well sunk in the vicinity of that just described, ‘ 
reached in November last the depth of 258 feet, eemajet : 
fissure from which the oil issued with such force 4 oe ee 
60 feet in height, and yielding 64,800 kilograms of oil pet 
