480 ARTESIAN WELLS IN THE DESERT. 
for the water rises to the surface and flows over it as from a 
spring.* 
* See a very interesting account of these wells, and of the workmen who 
clean them out when obstructed by sand brought up with the water, in 
Laurent’s memoir on the artesian wells recently bored by the French Govern- 
ment in the Algerian desert, Mémoire sur le Sahara Oriental, etc., pp. 19 e 
segg. Some of the men remained under water from two minutes to two min- 
utes and forty seconds. Several officers are quoted as having observed im- 
mersions of three minutes’ duration, and M. Berbrugger witnessed one of six 
minutes and five seconds and another of five minutes and fifty-five seconds. 
The shortest of these periods is longer than the best pearl-diver can remain 
below the surface of salt-water. The wells of the Sahara are from twenty to 
eighty métres deep.—DrEsor, Die Sahara, Basel, 1871, p. 43. 
The ancient Egyptians were acquainted with the art of boring artesian 
wells. Ayme, a French engineer in the service of the Pacha of Egypt, found 
several of these old wells, a few years ago, in the oases, They differed little from 
modern artesian wells, but were provided with pear-shaped valves of stone for 
closing them when water was not needed. When freed from the sand and 
rubbish with which they were choked, they flowed freely and threw up fish 
large enough for the table. The fish were not blind, as cave-fish often are, but 
were provided with eyes, and belonged to species common in the Nile The 
sand, too, brought up with them resembled that of the bed of that river. 
Hence it is probable that they were carried to the oases by subterranean chan- 
nels from the Nile.—DrEsor, Die Sahara, Basel, 1871, p. 28; Stoppant, Corso 
di Geologia, i., p. 281. Barth speaks of common wells in Northern Africa 
from 200 to 360 feet deep.—Weisen in Africa, ii., p. 180. 
Ti is certain that artesian wells have been common in China from a very 
remote antiquity, and the simple method used by the Chinese—where the 
drill is raised and let fall by a rope, instead of a rigid rod—has lately been em- 
ployed in Europe with advantage. Some of the Chinese wells are said to be 
3,000 feet deep ; that of Neusalzwerk in Silesia is 2,500. A well was bored at 
St. Louis, in Missouri, a few years ago, to supply a sugar refinery, to the depth 
of 2,199 feet. This was executed by a private firm in three years, at the 
expense of only $10,000. Four years since the boring was recommenced in 
this well and reached a depth of 3,150 feet, but without a satisfactory result. 
Another artesian well was sunk at Columbus, in Ohio, to the depth of 2,500 
feet, but without obtaining the desired supply of water. Perhaps, however, 
the artesian well of the greatest depth ever executed until very recently, is that 
bored within the last six or seven years, for the use of an Insane Asylum near 
St. Louis. This well descends to the depth of three thousand eight hundred 
and forty-three feet, but the water which it furnishes is small in quantity and 
of a quality that cannot be used for ordinary domestic purposes. The bore 
has a diameter of six inches tothe depth of 425 feet, and after that itis re- 
duced to four inches. For about three thousand feet the strata penetrated 
