The Sun.
London, England, 1844-12-26 00:00:00

ARTESIAN WELL OF GRENELLE

The most remarkable example of an Artesian well
is that recently formed at Grenelle, a suburb at the
south-west of Paris, where there was a great want
of water. It cost eight years of difficult labour
to perforate. The surface at Grenelle consists
of gravel, pebbles, and fragments of rock, which
have been deposited by the waters at some period
anterior to any historical record. Below this layer of
detritus, it was known to the engineer, by geological
induction, as well as previous experience, that at
Grenelle marl and clay would be found, instead of
the limestone which generally forms the immediately
subjacent stratum. He was aware that he had to bore
about 440 yards deep before he should arrive at the
sheet of water which flows in the gravel below the
limestone, and supplies the wells of St. Ouen, St.
Denis, and Stains. Underneath the marl and the clay
the boring rods had to perforate pure gravel, plastic
clay, and finally chalk, which forms the bottom of the
general tertiary basin, as we have seen. No calcula-
tion from geological data could determine the thick-
ness of this stratum of chalk, which, from its powers
of resistance, might present an almost insuperable ob-
stacle. The experience acquired in boring the wells
of Elbeuf, Rouen, and Tours, was in this respect but
a very imperfect guide. But supposing this obstacle
to be overcome, was he sure of finding a supply of
water below this mass of chalk ? In the first place, the
strata below the ohalk possessed, as we shall see, all the
necessary conditions for producing Artesian springs,
namely, successive layers of clay and gravel, or of
pervious and impervious beds. M. Malot confidently
relied on his former experience with Grenelle. M.
Arago had shown that the water of the spring here
would necessarily rise to the !surface, because in the
well at Elbeuf, which is nearly 9 yards above the
level of the sea, the water rises from 27 to 29 yards
above the level of the earth, and, consequently, from
36 to 38 yards above the ocean level. Now, as the
orifice of the bore at Grenelle is only 34 yards above
the same level, it follows, that if the identical spring
be met with, the water must rise above the earth's
surface at Grenelle.

But one other condition is requisite to ensure the
rising of the water in an Artesian well, namely,
that the feeding level of infiltration should be higher
than the orifice in the bore above which the water is
to ascend. This, however, turned out to be the case
en
andteEribehaudf'be
found 'below the chalk, between similar strata of clay
of the boringsw h where
e a
bouf n
d thean t wells
supplies
of w a
and gravel.
The necessary works were commenced with
boring rods 'about 9 yards long, attached to each
other, and which could be raised or lowered by
mechanical power, while an ingenious method
was adopted for giving them a rotary motion.
inches.
The diameter of the bore was about 6
The instrument affixed to the end of the lowest
boring-rod was changed according to the different
strata which were successively attacked ; the form
suited for passing through the softer materials near
the surface being unsuitable for boring through the
chalk and flint, as a hollow tube was used for the
former, while a chisel-shaped tool was employed to
penetrate the latter. The size of the rods was lessened
as the depth increased ; and, since the subterranean
water was not reached as soon as was expected, it be-
came requisite to enlarge five several times the dia-
meter of the bore, in order to permit the work to be
successfully prosecuted. Accidents occurred which
tried the patience of the projectors. In May, 1837,
when the boring had extended down to a depth of 418
yards, the hollow tube, with nearly 90 yards of the
long rods attached to it, broke, and fell to the bottom
of the hole, whence it became necessary to extract the
broken parts before any further progress could be
made. The difficulty of accomplishing this task may
be conceived; for the different fragments were not all
extracted until after the constant labour of 15 months.
Again, in April, 1840, in passing through the chalk, the
chisel attached to the boring rod got detached, and,
before it could be recovered, several months were
'pent in digging round about it. A similar occur-
rence created an obstacle which impeded the work
for three months; but, instead of withdrawing the
detached part, it was forcibly driven down among the
stratum of gravel. At length, in February, 1841,
after eight years' labour, the rods suddenly descended
several yards, having pierced into the vault of the
subterranean waters so long sought after by the in-
defatigable engineer. A few hours afterwards he
was rewarded for all his anxious toils ; for lo ! the
water rose to the surface, and discharged itself at the
rate of 600,000 gallons per hour !
The depth reached down was 602 yards, or about
three times the height of St. Paul's. The pipe by
which the water reaches the surface has been recently
carried to a height nearly level with the source of
supply. The portion of the pipe above the ground is
surrounded with a monumental pagoda of ornamental
carpentry, and it discharges a circular cascade of
clear water continually into a circular iron reservoir,
to be thence conveyed by a lateral pipe to the ground.
The water is well adapted for all domestic uses, and
it will be unfailing, being supplied from the infiltra-
tion of a surface of country nearly 200 miles in dia-
meter. The Artesian wells of Elbeuf, Rouen, and
Tours, which were formed many years ago, overflow
in never-varying streams ; and the ancient Artesian
well at Liners, in the Pas de Calais, has for about
seven centuries furnished a constant and equable
supply.
The opportunity of ascertaining the temperature of
the earth at different depths was not neglected during
the progress of the works at Grenelle. Thermometers
placed at a depth of 30 yards in the wells of the Paris
Observatory invariably stand at 53 deg. Fahrenheit.
In the well at Grenelle the thermometer indicated 74
deg. F. at a depth of 442 yards, and at 550 yards it
stood at 79 deg. At the depth finally arrived at of
602 yards, the temperature of the water which rose
to the surface was 81 leg., corroborating previous
calculations on the subject. For a descent of 572
yards there is an increase of temperature equal to 28
deg. F., which is 20'4 yards, or 6P2 feet for each de-
gree of that scale. Now that the skilful labour of so
many years is terminated, the Parisians regret that
the subterranean sheet of water had not lain 1,000
yards beneath the surface, that they might have had
an overflowing stream of water at 104 'deg., to fur-
nish a cheap supply to their numerous hot-bath esta-
blishments.—Dr. Ure's Supplement to his Dictionary
of Arts, Manufactures, and Mines.

Lord Thynne, Sir John Johnstone, Bart., Hon. B.
R. Lawly, George Lloyd, Esq., and the members of the
York and Ainsty Hunt, gave a sumptuous dinner on
Friday last, at the Black Swan, York, to Ralph Creyke,
Esq., on the retirement of that gentleman from the.mas-
tership of the hounds. •