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 forward of the mast, rises vertically out of it. This piece is fastened to a huge log of oak, 16 ft. long, 38 in. broad, and 14 in. deep in the middle, marked _f_ (Figs. 25 and 26), which rests on a sole-piece about 4 in. thick. The sole-piece is countersunk over the beams. The large log is called by Mr. Colin Archer the "fish," partly because its ends are fashioned to represent the tails of two whales, and partly because the mast partners of modern ships, which take the place of this heavy piece, are to this day called _Fisken_ in Norway. The fish contains a slot (_h_) nearly 6 ft. long, and the same width as the mast, 12-1/2 in. The mast goes through the forward end of the slot, and when it is in use the slot is filled up with a heavy slab. When the mast is lowered for going into action, or when going against a head-wind, the slab is removed, and the fore-stay slacked off, thus permitting the mast to fall aft. The sail used was a solitary square one. The rudder resembles a short oar. It is hung by a rope passing through a perforated conical chock on the starboard side of the ship. There is an iron eyebolt near the bottom edge, through which a rope probably passed for the purpose of raising the rudder when not in use.