The evening times., 1898-10-24
THE EARTH's AGE.

In the geological laboratory of Harvard
University an interesting series of expert
ments is being carried on to determine
the age of the earth. The question is an
old one and many guesses of more or less
scientific exactness have been made in
the past endeavors to solve it. These.
says the Pittsburg Dispatch, have
been based for the most part on the
situation and formation. of rock and earth
deposits, or the decay of vegetable mat
ter. Profs. b. o. Pierce and r. w. Will
son, who are carrying on the present
tests, are working by a new process.
which involves the use of mechanism for
testing the conductivity of different places,
including the deepest hole that has ever
been sunk into the earth. Incidentally the
process also involves interesting mining
problems, namely, the getting of gold
from very deep levels, and other ques-
tions of deep shafting. 1t will probably
settle the question of why certain parts
of the interior of the earth are hotter or
colder than other parts, laying down rules
of scientific accuracy.
The Investigations are being carried on
under the auspices of the Rumford fund.
and the professors who conducting
them are being supplied with material for
the research by Prof. Alexander Agassiz,
Prof. Agassiz Is chief owner of the Calu-
met and Hecla mine, the deepest in the
world. The upper levels of this mine
have been worked out. but as the shafts
have been driven deeper and deeper the
ore continues as plentiful as ever. I'M
mense fortunes have been taken out of
this great hole, and ii is of value TO SCI
entists because the shaft, being now
nearly a mile deep, has permitted exami-
nation of the interior of the earth such
as has not been had before.
1t has been agreed among scientists
generally that raging fires no longer eX-
ist in the interior of the earth. They b.
lieye that the center of the earth Is very
hot, but that this latent heat Is what
remains of the cooling process which has
been going on for millions OF years
Like a fallen cannon ball, the earth is
cooling off from the surface toward the
center, but the general pressure on all
sides prevents the confiagration from
raging within. According to this hypc tn
esis the Temperature ought TO Increase
gradually but surely as the earth is pen
etrated This has proved to be the case
in every deep hole which has been dug
in the earth except in the Calumet and
Hecla mine.
In a. well, which is over 5000 feet deep,
near Pittsburg Pa, Prof. Hailock. OF
Columbia College, found that the tenn
perature rose l degree for every % feet
the thermometer was lowered. AT o'lo9
feet the temperature was 1ound 10 pe
12O9 degrees Fahrenheit At 5.592 the
temperature was lbs degrees. In another
deep well near Wheeling. Pa, the tenn
| perature at 1850 feet is 10 degrees. In
| the Sperenberg salt well near Berlin.
Germany. the temperature at 4,l10 feet
is 1IO degrees The Schaladabdch sd. I
well. near Leipsic has temperature OF
| 1855 degrees at 5.740 feet. Yet these tenn
| peratures are surpassed. as far as rap-d
| rise is concerned, in holes bored In gey-
! ser regions In the Sutro tunnel, which
| does not go far beneath the surface, the
| heat is so intense that the men employ
| ed therein are compelled To work In y
minte shifts.
| Now. all this is directly in contradis-
| tinction to what has been found TO exist
| in the Calumet and Hecla mine. AT
| depth of a mile the laborers work ali day
| In a temperature of 10 degrees, which
| condition ii must be added, Is not
| brought about by any elaborate system
| of ventilation Seventy degrees is the
| natural temperature at the bottom OF the
| mine Prof. AgassiZ has made some eiab-
| crate experiments in testing the general
| temperature of the mine. he caused 10
| be placed at regular depths a number or
| thermometers. He had them walled up
! in inches in the rock and left them there
| months at A time. These thermometers
were self-registering. That is. the mer-
| cnry would ascend to the point of the
| highest temperature which acted upon
| them during their stay in the rock, but a
crook in the mercury tube prevented the
mercury from ever descending Ii could
| always rise, but it could never run back.
| So 1t was compelled TO stay at the point
| of greatest temperature. When Prot.
Agassiz unearthed his instruments, how
ever, he found great uniformity in the
general temperature of his mine. Evident
| " the gradual rise in temperature did not
| hold in the Lake Superior district, in
which the mine is located. as 1t did else
| where.
The question now arose: why was this
| so?' Did 1t not have a strong bearing
on the manner in which the earth cooled
! during geological ages? Gould not the
| condition be experimental upon and th5
results be utilized in some economic man.
| ner?" Clearly the condition surround
| ing the copper mines in Michigan wa:
| the result of the very low conductivity
| of the surrounding rock. Evidently this
| rock had not the power of conducting
| heat and cold to the degree manifested
| by rocks in other parts of the earth. The
| internal heat of the earth does not rise
up through it as easily. for instance. as
| il does in the rock surrounding the wei
! upon which Prof. Hallock expert
mented near Pittsburg. Pa Just wha
! is the difference. however. is not so easy
| to determine. and this really is what Pro,
| fessors Pierce and Wilson. of Harvard
| are trying to find out When they have
| done so they will have established 6
| basis of calculation from which some
new facts may be CLEANED. and upor
which some startling theories may bt
! built.