6 



STRUCTURE OF VESSELS. 



curve. Figs, v, x, y, z, represent the most advan- 

 tageous forms of logs for cutting into plank. The 

 dotted lines shew the section of the saw in planking : 

 the straighter the log is in the plane of the saw, it 

 is the more suitable, as the planks bend sufficiently 

 side-waj by steaming ; Fig. v, of considerable bend 

 and taper, where the planks, when cut, have a bend 

 edge-wsij, is the most valuable : this form requires 

 to be very free of knots. In straight planks. Fig. z, 

 cleanness from knots is not such a desideratum. 



z 



r— 1 













1 



Figs, z, y, of any length — best long ; x, from 25 to 35 feet ; v, v, 

 from 12 to 24 feet. 



In the above cut, for distinctness, the saw is drawn enter- 

 ing the butt. In practice it enters the top. 



When planks are cut out where grown, they are 

 sawn from the round log immediately after it is fell- 



