e two upper strakes are only 3/4 in. thick, and inside the
top one is placed the gunwale, which is 3 x 4-1/2. The planks are
fastened together by iron rivets spaced from 6 in. to 8 in. apart. The
heads of the rivets are 1 in. in diameter, and the riveting plates 1/2
in. square. The planks are worked down from thicker slabs, and a ledge 1
in. in height is left on the inboard surface of the middle of each
plank. The planks bear against each floor at two points, viz. the upper
edge and the projecting ledge. Fig. 24 shows a section of a floor and of
the plank, with its projecting ledge. The fastenings of the planking to
the floors are very peculiar. Two holes are bored transversely in the
ledge, one on either side of each floor. There is a corresponding hole
running fore and aft through the floor, and through these holes are
passed ties made of the tough roots of trees barely 1/4 in. in diameter,
crossed on the ledge and passing once through each hole. The only iron
fastening between the planking and the floors is at the extreme ends of
the latter, where a single nail is driven through each, and riveted at
the ends of the floors. The beams rest on the shelf strake and on the
tops of the floor-ends. They are 7 in. deep and 4 in. wide. They are
connected with the planking by knees (see the section, Fig. 23),
fastened to their upper faces and to the side of the ship as far up as
the oar-strake, or "mainwale," by means of oak trenails. The knees are
not so wide as the beams, and consequently a ledge, or landing, is left
on each side of the latter which supports the flooring, or bottom
boards. The top strakes are connected to the body of the vessel by short
timbers, shown in the section, Fig. 23. These are placed in the spaces
between the knees. The beams are supported in the middle by short
pillars resting on the throats of the floors.

[Illustration: FIG. 22.

FIG. 25.

FIG. 26.

FIG. 24.

FIG. 23.

Viking ship.]

The vessel was propelled by sails as well as oars. It was fitted with a
single mast; the arrangements for stepping and raising and lowering the
latter were peculiar. A beam of oak, 11 ft. long, 19 in. wide, and 14
in. deep, formed the step. A side elevation of this is shown at _s_, in
the longitudinal section, Fig. 25, and a cross-section in Fig. 23. The
step, as may be seen, is countersunk over the throats of the floors; it
is tapered towards the ends, and a piece (_c_) nearly 12 in. thick,
immediately for