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included the unlikely pairing of Alexander von Humboldt (1769-1859)
and Archduke John of Austria (1782-1859), the youngest brother of
Emperor Francis I. John Baptist Joseph Fabian Sebastian vonHabsburg,
to give himhis full name, apparently promoted geological and minera-
logical studies of the Austro-Hungarian Empire and was 'always happy
to welcome the English visitor who carried a hammer and sketch-
book.' He would not have afforded such a cordial welcome to French
geologists in the year before his death: that year the two Empires
clashed and the Austrian army partially under his command was
first defeated at Montebello on 20May and soon afterwards elsewhere.
On 6 July 1859 Austria surrendered to the French.
Phillips then got to the core of his address, which was partly a
review of recent geological work, but also an account of some of his
own ideas. Of interest to us now are the sections headed 'Geological
Time' and the immediately following 'Conversion of Geological into
Historical Time'. In the first he stated that the thickness of the sedi-
mentary pile as seen in the various strata amounted to 72,584 feet. The
Palaeozoic was 57,154 feet thick, the Mesozoic 13,190 feet thick, and
the Cenozoic 2,240 feet thick. These thicknesses he converted to the
percentage of geological time that they represented: 79% Palaeozoic,
18% Mesozoic and 3% Cenozoic. He stated: 'It is possible by some
hypothesis of the annual waste of the surface of land, or the annual
deposition of sediment, as now observed in the sea, at the mouths of
rivers or in lakes, to transform the unit of geological time above
suggested into an equivalent term of years.' Tantalisingly he did not
state what his figure was.
As an example he looked at the denudation of the rocks that
formerly covered the rocks of the Weald of Sussex, an area of 3,000
square miles that includes Sussex, much of Kent and some of Surrey
and Hampshire. Geologically the district is underlain with a variety of
terrestrial sediments 1,000 feet thick of muds and sands, generally
termed the 'Wealden', but including distinct horizons such as the
Weald Clay, the Tunbridge Wells Sands and the Gault (Figure
10.2
).
Phillips could have taken any geographical region for his example but
