The Manitowoc pilot. [volume] (Manitowoc, Wis.) 1859-1932, 1892-09-22
DEEPEST HOLE EVER BORED.
Science Sinks Shaft More Than Mile
Into t.ie Earth.


Although mountains and cliffs have
indicated the formation of projections
of the eaFth's crust. and mines have
shown to some extent the formation
under ground, the very deepest mines
have not permitted the extensive and
minute researches that ge0logists and
scientists have desired. Boylngs are
limited, of course. by natural obsta-
cles, like exceedingly hard formations,
and BY the expense, unless the pur-
pose be TO ascertain the location of
minerals worth mining, or get sup
ply of water, AS in artesian wells.
Holes for geological research need not
be very large, says the \. I. SUa, but
they must be very deep, and it is nat
ural to suppose that interest has been
excited by the reports of observations
in the deepest hole in the world.
The hole is at Schladebach, near
Ketchan, Germany. 1t is 5,735 feet in
depth, and is for geological research
solely. Boring was begun in 1880 un-
der the direction of the royal mines
commission of Prussia. The work
was carried on under great difficulties,
and the accidents and delays would
have discouraged the engineers if it
had been a private enterprise, but it
being a state work the obstacles were
overcome, Notwithstanding the ex-
penses,and the boring was continued
for six years ut a cost of more than
sJ3, 900. 1T the depth of 5,735 feet,
howeveF, the engineers had so many
Inishaps that it was evident that for a
while and until the ingenuity of man
could devise better means operations
would have to he discontinued. Prog
ress was slow and the expenses had in
creased beyond expectation. The
drills were Withdrawn and the ther-
mometric measurements were contin-
ued down to the lowest depth.
The initial diameter of the hole is
11.2 inches. The first drilling appar-
atus was of the drop tool form, and o
casing was sent down as the drilling
progressed. AT depth Of 1S7 feet the
casing of that size would not 90 any
further and the drilling was continued
without 1t. Subsequently casing 90
inches in diameter had to be used
through Il layer of loose material. Be
yond Il depth of 574 feet the boring
was continued by means of diamond
drill 81 inches in diameter, that cut
core 1-2 inches in diameter. The
size of the hole had to be decreased
gradually as the depth increased. at
Il depth OF 3,5l0 feet the diameter was
l.62 inches and at 5,655 feet and be-
yOnd it Was 1872 inches. Owing to
two long interruptions and other de-
lays the average daily rate of boring
was about 4.59 feet.
The thermometric measurements
were begun after a depth of 1886 feet
had been marked, and were repeated
at every 100 feet The latest observa-
tions have been noted with great care
and during considerable periods of
time. The thermometers were fixed
in a water chamber that was inclosed
in q Wrought-iron casing to prevent
brcakage of the instruments under the
pressure at the great depths, water be-
ING used to clear out the hole Three
Thermometers were used for each read
ING, and the mean of their indications
was taken as the result of the meas
urement. For each observation the
thermometers were left in the hole
about sixteen hours. The observa-
tions showed that the temperature in
creased regularly and constantly with
the Increase Of depth. According to
the German method of reading the
temperature at 5,62S feet was 1873 de-
grces Reaumur (133S degrees Fahren-
heit), and the increase was | degree
Beaumur for every 1900 meters (about
15l feet1.