The Age of the Earth’ 
By ARTHUR Ho.mes, Regius Professor of Geology, University of Edinburgh 
[With 2 plates] 
Long before it became a scientific 
aspiration to estimate the age of the 
earth, many elaborate systems of 
world chronology had been devised 
by the sages of antiquity. The most 
remarkable of these occult time scales 
is that of the ancient Hindus, whose 
astonishing concept of the earth’s 
duration has been traced back to the 
Manusmitri, a sacred book that was 
probably completed in its present 
form about 150-120 B. C. According 
to this venerable compilation of law 
and wisdom, the whole past and future 
of the world is but a “day” in the 
eternal life of Brahma—a Day of 4,320 
million years, throughout which finite 
things are being created out of the 
infinite. The Day of Brahma is di- 
vided into 14 great cycles, each lasting 
308,448,000 years, together with a final 
“twilight”? period of 1,728,000 years, 
at the close of which, when Brahma’s 
Night begins, the finite is destined once 
more to merge into the Infinite. At 
present the world is in the seventh of 
these cycles and, according to the 
Hindu calendar recorded in the 
Vishnu Purana, it is now (A. D. 1947) 
1,972,949,048 years since the earth 
came into existence. By a curious 
coincidence this characteristically pre- 
cise assessment is of the same order as 
the 2,000 million years which has 
recently been the most widely favored 
1 Reprinted by permission from Endeavour, 
vol. 6, No. 23, July 1947. In this reprinting, 
several passages in the manuscript as origi- 
nally written, which were omitted in Endeay- 
our, have been restored. 
estimate for the age of the expanding 
universe. 
If geological concepts had developed 
in a community endowed in advance 
with so generous a concept of the 
past, much confusion and bitter con- 
troversy might have been avoided. 
But in western Europe the age of the 
earth had long been identified—to 
within a few days—with the few 
thousand years of mankind’s history 
as recorded in the narratives of the 
Old Testament. On the interpretation 
of Archbishop Ussher (1581-1656) 
the creation of the world took place in 
the year 4004 B. C., and pioneer geolo- 
gists whose observations suggested 
that the Mosaic traditions might not 
be scientifically reliable were branded 
as dangerous heretics. 
A mild though significant instance 
of the prejudicial influence of this 
cramping limitation of time is afforded 
by a remark made by the celebrated 
astronomer Edmund Halley (1656- 
1742), in the course of a communica- 
tion to the Royal Society of a ‘‘Pro- 
posal... to Discover the Age of the 
World” (1715). Halley realized that 
the sea had become salt because of the 
accumulation of saline material con- 
tributed by inflowing rivers, and he 
suggested that the total amount of salt 
in the sea might therefore provide a 
measure of the age of the oceans. 
At that time the necessary data for 
making the calculation were not avail- 
able, and Halley lamented that the 
ancient Greek and Latin authors had 
not ‘“‘delivered down to us the degree 
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