, and cross pieces to _yoke_ or _key_ (cf. [Greek: zugon,
klaeis]) them together. These thwarts once fixed naturally suggested
seats for those that plied the paddle or the oar. The ends of the vessel
were shaped into bow or stern, either turned up, or with the side
planking convergent in stem or stern post, or joined together fore and
aft by bulkheads fitted in, while interstices were made water-tight by
caulking, and by smearing with bitumen or some resinous material.

The evolution of the boat as distinct from the punt, or flat-bottomed
type, and following the configuration of the dug-out in its length and
rounded bottom, must have taxed the inventive art and skill of
constructors much more severely than that of the raft. It is possible
that the coracle or the canoe may have suggested the construction of a
framework of sufficient stiffness to carry a water-tight wooden skin,
such as would successfully resist the pressure of wind and water. And in
this regard two methods were open to the builder, both of which have
survived to the present day: (1) the construction first of the shell of
the boat, into which the stiffening ribs and cross ties were
subsequently fitted; (2) the construction first of a framework of
requisite size and shape, on to which the outer skin of the boat was
subsequently attached.

Further, besides the primitive mode of tying the parts together, two
main types of build must be noticed, in accordance with which a boat is
said to be either carvel-built or clinker-built. (1) A boat is
carvel-built when the planks are laid edge to edge so that they present
a smooth surface without. (2) A boat is clinker-built when each plank is
laid on so as to overlap the one below it, thus presenting a series of
ledges running longitudinally.

The former method is said to be of Mediterranean, or perhaps of Eastern
origin. The latter was probably invented by the old Scandinavian
builders, and from them handed down through the fishing boats of the
northern nations to our own time.

Ancient boats.

The accounts of vessels used by the Egyptians and Phoenicians generally
refer to larger craft which naturally fall under the head of SHIP
(q.v.). The Nile boats, however, described by Herodotus (ii. 60),
built of acacia wood, were no doubt of various sizes, some of them quite
small, but all following the same type of construction, built up brick
fashion, the blocks being fastened internally to long poles secured by
c