18 



STKUCTUllE OF VESSELS. 



Fig. a, Flat floor, from 9^ to 18 feet long (that is, 9^ for a vessel 

 of 50 tons, and 18 for one of 500)j and from 9 to 16 inches 

 deep at middle ; thickness ^th less than depth, the diameter 

 increasing in proportion to the length. When fillings such 

 as s are used, flat floors are cut from straight logs. 



h, Rising floor shorter, and same depth and thickness as former. 



c, c. High rising floors, from 4 to 8 feet in length of wing, and 



a little deeper, and same thickness as former. From the 

 difficidty of procuring this bend, the wings are often used of 

 unequal length, according as the timber turns out, the shorter 

 wing to exceed 3 feet, and more when of considerable dia- 

 meter. Floors are of every rise from a to c, being flattest 

 at midships, and rising gradually as they approach the bow 

 and stern. In all timbers, it is necessary, for strength, that 

 the fibre of the wood extend from one end to the other with- 

 out much cross grain. See lines on high rising floor, c. 



d, First foot-hook, from 7 to 13 feet long, and from 7 to 14? 

 inches deep ; thickness jth less than depth. 



e, Second foot-hook, from 6 to 10 feet long, and from 6 to 



13 inches deep, thickness ^th less than depth. This 

 curve, when of great size, is valuable as^ breast-hooks — 

 curved timbers stretching horizontally -^^^Pj and at right 

 " angles to the bow-timbers, to support the bow. 



j')f'>f', Knees, the one wing nearly at right angles to the other ; 

 from 2 to 9 feet in length of wing ; depth at middle as much 

 as possible ; thickne^^s from 4 to 12 inches, — generally re- 

 quired about 3^ feet;^o»g, and from 6 to 8 inches thick. 

 Knees, when large, suit for high rising floors. 



Fig. li is a valuable piece, and easily procured by bending the 

 young plant ; when cut, it forms two second foot-hooks. 



Figs, fi, c, d, e, ai'e suitable, though the part cut ojff by the 

 dotted line be awanting. In good work, this plan is often 

 followed, and a cross-chock put on. (Vid. s, left side of the 

 cross-section of a vessel thus timbered, page 20). By this 



