63 G REPORT OF NATIONAL MUSEUM, 1891. 



latlier flat, slightly concave floor, and becanse of tlieir moderate draft^ 

 they could venture into shallow water or easily land upon the shore. 



The keel was generally of oak, and at its slightly upward beut ends 

 the stem and stern posts were attached, and the connection strength- 

 ened by the insertion of a crooked timber. In the Nydam boat the 

 connection is made by means of wooden pegs; in the Tune ship a close 

 joint is made, while in the Gokstad ship a jieculiar jnece is inserted, 

 bound to the keel by a scarfing and two rows of spikes. 



In the Greek and Konian ships the ribs, were seldom made of one 

 piece, but were generally formed of three layers of timber securely 

 bound together .2 



The same process occurs in nearly all the northern ships that have 

 become known to us. While in the Nydam boat the ribs which give 

 the boat its shape are mostly in their natural crooked and irregularly 

 bent sha])e, those of the Tune and Gokstad ships were built up of three 

 different layers of wood, one above the other, joined together partly 

 by wooden and partly by iron nails, the middle piece projecting. The 

 same construction occurs in the beams, which rest on the top of the 

 frames, where they are fastened to the overlying lower limbs of the 

 knees and its continuation, and the ledge formed by the j)rojection of 

 the central piece is employed as sui)port lor the deck boards. 



The ribs were not nailed to the keel, but lay loose above it, but vari- 

 ous devices were adopted to keep them in their proper places. In the 

 Greek and Roman ships they were fitted to the keel by notches cut in 

 them, and were further held in place by the keelson, which, by means 

 of notches cut in its under side, fits upon the ribs and prevents their 

 lateral displacement. In the Gokstad ship this is in a measure effected 

 by the fish-tail-shaped blocks which, straddling the frame timbers 

 amidships across the .3 to 4, G to 12, 14 to IG ribs, are held in jilace by 

 the l)eams connecting them Avith the short ribs of the superstructure. 



A further support is given to the ribs by the planking, which in the 

 Greek and Eoman ships was nailed to them, but in the i^ydam. Tune, 

 and Gokstad ships iron spikes were used only to nail the bottom plank 

 to the keel and trenails to fix the to]) plank to the knees; tlie other 

 IDlanks, while riveted to each other, were tied to the frames through 

 clami^s left in the solid wood and corresponding holes in i]m ribs. 



The Greek and Roman s]ii])S were additionally strengthened l)y sup- 

 plemental external and internal phinks at certain intervals, and inter- 

 nal perpendicular bolts. In the northern ships this is attained by 

 double thickness allowed to certain strakes at points subjected to 

 greater strain and by short frames or timbers going down from the 

 gunwale of the Gokstad ship between each alternate i)air of knees. 



^ Lemaitre : Revue ArclieoL, p. 146; Asainann: Seewesen, p. 1616, 1626; also iii Ber- 

 lin, Pliil. Wocheusclirift, 1888, r, p. 28, estimate a greatest draft of 1.25 meters 

 (4 feet). 



' BrcHs'iny : Nautik dor Alteii, ]>. o3. 



