Geoscience Reference
In-Depth Information
A Fortune Taken Wings
As we saw, in 1868 Archibald Geikie had endorsed Kelvin's 100-million-year
timescale. Over the decades, he watched as the fund of time available to geology
shrank until the science approached temporal bankruptcy. In his 1892 presidential
address to the British Association, Geikie defected. His erudite, eloquent, even ro-
mantic defense of the science of geology is one that every student of the subject
hindsight,wecanseehowitbridgedthedescriptive methodsofthenineteenth cen-
tury and the quantitative ones that were to arrive in the twentieth.
Geikie acknowledged the successes that uniformitarianism had brought to the
understanding of the Earth, yet, he said, “We must admit that the doctrine has been
to the ice ages, he said, “We recognise the catastrophe, while at the same time we
see in its progress the operation of those same natural processes which we know to
be integral parts of the machinery whereby the surface of the earth is continually
transformed” (17).
Hutton had been able to find no vestige of a beginning, but according to Geikie,
LordKelvin hadshownthattheremusthavebeenone.Kelvin, usingtheheatflow-
ing from the Earth, had estimated, as Geikie put it, that “the surface of the globe
could not have consolidated less than twenty millions of years ago, for the rate of
increase of temperature inwards would in that case have been higher than it actu-
ally is; nor more than 400 millions of years ago, for then there would have been no
sensible increase at all” (18).
Geikie wrote that Kelvin, when first dealing with the subject, was inclined to
believe that “100 millions of years would embrace the whole geological history of
the globe.” For the uniformitarian geologists who had accepted a limitless Earth,
“It was not a pleasant experience to discover that a fortune which one has uncon-
cernedly believed to be ample has somehow taken to itself wings and disappeared”
(18-19). When the physicist assured the geologist
that he had enormously overdrawn his account with past time, it was but natural under the cir-
cumstances that he should think the accountant to be mistaken, who thus returned to him dis-
honoured the large drafts he had made on eternity.
