The Barre daily times. (Barre, Vt.) 1897-1959, 1922-08-30
AGE OF THE EARTH
STILL UNDECIDED
The Latest Figures Put 1t at a
Thousand Million
Years.

1 AT the meeting Of the British Asso
citation in Edinburgh in September las
Joint discussion on the age Of TIL
! earth took place under the auspices 81
the sections for mathematics. geology
zoology and botany. The inadequacv Of
Lord kelyin's original estimate OF 20
100000 or 30,O0o000 years has lone
been admitted. The more recent esti.
mates are for a much greater age.
| Lord Rayieigh considered that the
most accurate estimate Of the age OF
the earth can be derived from the rate
of radioactive disintegration Urani-
um passes through series of success
sive stages during its disintegration
which terminate in an isotope of lead,
having an atomic weight less than that
of ordinary" lead, but chemically in.
distingrishable from it. The order and
rate Of this disintegration through sue
cessive stages are known with d high
degree 81 accuracy so that a deter
mlnation OF the amount Of isotope Of
lead present in minerals containing
uranium enables the time when disin
tepration commenced to be assigned
without very great uncertainty In this
way an age OF about l,000.000,O00 wears
is derived from pre- Cambrian rocks.
Prof. Gregory dealt with the geologi
cal estimate of the age Of the earth.
based upon the salinity of the sea. Es-
Inmates obtained in this way varied
from 70000,000 TO l50000.0O0 wears.
He pointed out that the argument sui.
fered from three fundamental obiec-
tons II was assumed that the sea
was originally fresh, although the old
est fauna, the Cambrian had marine
characteristics, and the contrast be
tween the fresh water and marine
fauna in Palaeozoic times was as sharp
as il is to day There was also no al
lowance for the large supplies of sodi-
um chloride raised from beneath the
earth's surface by magmatic waters.
Further, a uniform rate of denuda tion
was postulated, whereas, there have
been alternating periods quick and slow
crystal movements; the earth il now
under the influence Of time Of quick
movement, with consequently denuda
ton faster than the average Taking
these three causes separately, Prof.
Gregory estimated that, to allow for
them. the age Of the earth dednced from
the salinity argument should be multi
piled two fold, three or four-fold and
five fold, respectively. He concluded by
stating that the best known geological
estimates Of the age Of the earth re
qnires 70 be multiplied ten or twenty
fold in order to agree with the physical
estimates, and that this increase is
consistent with the geological evidence.
Z Or. Jeffreys stated that, from eonsid-
of the temperature distribu-
ton downwards in the earth's crust,
for the radioactive content, |
and also from the tidal theory of the
origin Of the solar system. he had sep
arately devised concordant estimates Of /
about 2,o00,00o,o00 years since the so.
lidification of the earth's crust Thus
with revised data. two Of Lord Kelvin's /
of reasoning have been
brought into agreement with the re.
suits derived from other physical meth.
IDS Lord kelvin's third method the
contraction hypothesis not valid on
recount Of the existence of other
ourees Of stellar energy.
II will have been gathered that, on
he whole, there is now a satisfactory
Igreement between the results Of argu-
nents based upon astronomical, physi>
al and geological considerations These
Indicate an age Of the earth since solid
Iication. II i.000.0OOooo years Scien.
fife American.