erwards proceeded to Edinburgh and took the degree of M.D. in 1821.
He then settled for some years as a medical practitioner at Penzance;
there geology engaged his particular attention, and he became secretary
of the Royal Geological Society of Cornwall. The results of his
observations were embodied in his _Treatise on Primary Geology_ (1834),
a work of considerable merit in regard to the older crystalline and
igneous rocks and the subject of mineral veins. In 1837 he removed to
London, where he remained for about a year, being elected F.R.S. In 1838
he became partner in a firm of bleachers at Dundee. He retired in 1871,
and died on the 5th of May 1883.

BOAT (O. Eng. _bat_; the true etymological connexion with Dutch and Ger.
_boot_, Fr. _bateau_, Ital. _battello_ presents great difficulties;
Celtic forms are from O. Eng.), a comparatively small open craft for
conveyance on water, usually propelled by some form of oar or sail.

The origin of the word "boat" is probably to be looked for in the A.S.
_bat_ = a stem, a stick, a piece of wood. If this be so, the term in its
inception referred to the material of which the primitive vessel was
constructed, and in this respect may well be contrasted with the word
"ship," of which the primary idea was the _process_ by which the
material was fashioned and adapted for the use of man.

We may assume that primitive man, in his earliest efforts to achieve the
feat of conveying himself and his belongings by water, succeeded in
doing so--(1) by fastening together a quantity of material of sufficient
buoyancy to float and carry him above the level of the water; (2) by
scooping out a fallen tree so as to obtain buoyancy enough for the same
purpose. In these two processes is to be found the genesis of both boat
and ship, of which, though often used as convertible terms, the former
is generally restricted to the smaller type of vessel such as is dealt
with in this article. For the larger type the reader is referred to
SHIP.

Great must have been the triumph of the man who first discovered that
the rushes or the trunks he had managed to tie together would, propelled
by a stick or a branch (cf. _ramus_ and _remus_) used as pole or paddle,
convey him safely across the river or lake, which had hitherto been his
barrier. But use multiplies wants, discovers deficiencies, suggests
improvements. Man soon found out that he wanted to go faster than the
raft would move, that the water washed