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SEDGWICK, ADAM (b. Dent, Yorkshire, England,
22 March 1785; d. Cambridge, England, 27
January 1873), geology.
and he had a direct and informal manner that made
him accessible to and popular with students. But
he found the formal composition of scientific papers
irksome, and their completion repeatedly was
delayed by recurrent ill health (dating from a serious
breakdown in 1813) and by his political activities
and administrative responsibilities within the
college and the university. His published works,
therefore, hardly reflect the full extent of his
achievement.
Sedgwick inherited a geological collection somewhat
enlarged from Woodward's original bequest;
but he himself expanded it during his long tenure
of the chair into one of the finest geological museums
in the world, partly through his own and his
students' collecting activities, and partly through
purchasing fine specimens and collections with his
own resources or with funds raised from public
appeals. In 1841 a new museum building was
opened to accommodate this rapidly growing
collection; by the end of his life this in turn was
inadequate, and the present Sedgwick Museum
was erected as a memorial to him.
Sedgwick was president of the Geological Society
of London from 1829 to 1831, and of the British
Association at its first visit to Cambridge in
1833. In 1834 his appointment as a prebendary of
Norwich gave him greater financial independence
(the stipend of his chair was very small), but at the
cost of requiring his residence at Norwich for part
of every year for the rest of his life.
In politics Sedgwick was one of the most prominent
Liberals at Cambridge, and was in the forefront
of the movement for university reform;
Prince Albert, on becoming chancellor of the university
in 1847, chose him to act as his “secretary”
at Cambridge, and Sedgwick was later (1850-1852)
a member of the royal commission on the
reform of the university.
Sedgwick began his geological work under the
influence of William Conybeare, and his earliest
major studies were on the stratigraphy of the problematical
and poorly fossiliferous deposits of the
New Red Sandstone. In a monograph published in
1829 he successfully used the distinctive Magnesian
Limestone of northeastern England as a key
to these strata, and was able to correlate them with
the classic successions in Germany. This work
showed Sedgwick to be a field geologist with an
exceptional flair for grasping the regional significance
of local details. The wider relevance of its
conclusions lay in his interpretation of the strata as
the products of long-continued processes, and in
his emphasis on the strata as conformable “connecting
links” from the Coal Measures below to
the Lias (Jurassic) above. The same emphasis on
stratigraphical continuity is evident in his joint
work with Roderick Murchison on the eastern
Alps at about the same period, in which he clearly
was concerned to bridge the apparent faunal break
between “Secondary” and Tertiary strata.
Sedgwick therefore naturally welcomed some
aspects of Charles Lyell's work: in his presidential
addresses to the Geological Society in 1830 and
1831 he agreed with Lyell that incalculably vast
periods of time must be inferred for many geological
events, and he retracted his earlier view
(derived from William Buckland) that a single paroxysmal
episode could account for all the “diluvial”
deposits. But in reviewing the first volume of
Lyell's Principles of Geology he sharply criticized
Lyell's confusion of different meanings of “uniformity.”
He agreed that the “primary laws of matter”
were “immutable,” but he felt it was “a
merely gratuitous hypothesis” to assume that the
geological processes based on those laws must
have been rigidly uniform in their intensity
throughout earth-history: uniformity in the latter
sense had to be tested by empirical observation,
not assumed a priori.
In conformity with this empiricist program,
Sedgwick approved Élie de Beaumont's theory of
occasional paroxysmal elevation of mountain
ranges, because it made explicable many common
phenomena (local folding of strata and local unconformities)
in terms of events that, although abrupt
and uncommon in occurrence, were perfectly natural
in their mechanism. Similarly, he rejected
Lyell's assertion of steady-state uniformity in the
organic realm, because the facts of the fossil record
seemed to indicate unequivocally a gradual
approach to the “present system of things.” Above
all, Sedgwick felt that the geologically recent appearance
of man was “absolutely subversive” of
Lyell's Huttonian conclusion.
Sedgwick's most important geological work,
which led to the foundation of the Cambrian system,
seems to have been motivated by a desire to
penetrate the fossil record back to its farthest limits,
and to demonstrate that life had indeed had a
beginning in time. Some of his earliest fieldwork
was an attempt to unravel the complex structure of
the old rocks of Devon and Cornwall, and later he
studied in detail those of the Lake District (where
for many years he enjoyed the friendship of William
Wordsworth). In the classic paper “Remarks
on the Structure of Large Mineral Masses” (1835)
he combined his mathematical training with his
