s kept up his friendship with
men of letters, especially the Lake Poets and Scott (who was a
connection of his wife's), and he was no very small man of letters
himself.

A contemporary (though very much longer lived) of Davy's and the most
famous Englishwoman who has ever written on scientific subjects, was
Mary Fairfax, better known from the name of her second husband as Mrs.
Somerville. She was born at Jedburgh on 26th December 1780, and when
twenty-four married her cousin, Captain Greig, a member of a family of
Scotchmen who had settled in the Russian navy. Her first husband died
two years afterwards, and six years later she married Dr. William
Somerville, also her cousin. She had already devoted much attention,
especially during her widowhood, to mathematics and astronomy; and after
her second marriage she had no difficulty in pursuing these studies. She
adapted Laplace's _Mecanique Celeste_ in 1823, and followed it up by
more original work on physics, astronomy, and physical geography. Her
life was prolonged till 1872, and an interesting autobiography appeared
a year later. It is possible that Mrs. Somerville profited somewhat in
reputation by her coincidence with the period of "diffusion of useful
knowledge." But she had real scientific knowledge and real literary
gifts; and she made good use of both.

Of at least respectable literary merit, though hardly of enough to
justify the devoting of much space to them here, were Sir David
Brewster (1781-1868), Sir John Herschel (1792-1871), Sir Charles Lyell
(1797-1875), Sir Roderick Murchison (1792-1871), the first a
mathematician and physicist, the second an astronomer, the third and
fourth geologists, and all more or less copious writers on their several
subjects. John Tyndall (1820-1893), a younger man than any of these, had
perhaps a more distinctly literary talent. Born in Ireland, and for some
time a railway engineer, he gave himself up about 1847 to the study and
teaching of physics, was remarkable for the effect of his lecturing, and
held several Government appointments. His Presidential Address to the
British Association at Belfast in 1874 was not less noteworthy for
materialism in substance than for a brilliant if somewhat brassy style.

But the chief Englishmen of science who were men of letters during our
period were Charles Darwin and Thomas Huxley. The opinions of the first
of these, their origin, the circumstances of their first expression, and
the prob