| Balks | 12 in. by 12 inches | to 18 in. by 18 inches |
| Whole timber | 9 in. by 9 inches | to 15 in. by 15 inches |
| Half timber | 9 in. by 41⁄2 inches | to 18 in. by 9 inches |
| Quartering | 2 in. by 2 inches | to 6 in. by 6 inches |
| Planks | 11 in. to 18 inches | by 3 in. to 6 inches |
| Deals | 9 inches | by 2 in. to 41⁄2 inches |
| Battens | 41⁄2 in. to 7 inches | by 3⁄4 in. to 3 inches |
When of equal sides they are termed die square. In conversion the pith should be avoided, as it is liable to dry rot.
When the logs are to be converted to whole timbers for use in that size, consideration has to be given as to whether the stiffest or the strongest balk is required. The stiffest beam is that which gives most resistance to deflection or bending. The strongest beam is that which resists the greatest breaking strain. The determination of either can be made by graphic methods.
Fig. 57
To cut the stiffest rectangular beam out of a log, divide the diameter of the cross section into four parts (see [fig. 57]). From each outside point, A and B, at right angles to and on different sides of the diameter, draw a line to the outer edge of the log. The four points thus gained on the circumferential edge, C, D, E, F, if joined together, will give the stiffest possible rectangular beam that can be gained from the log.
Fig. 58
To cut the strongest beam:—In this case the diameter is divided into three parts. From the two points A and B thus marked again carry the lines to the outer edge as before. Join the four points C, D, E, F, together, and the outline of the strongest possible rectangular beam will result (see [fig. 58]).
Boards—a term which embraces planks, deals, and battens—should be cut out of the log in such a manner that the annual rings run parallel to the width of the board. This method of conversion allows the knots, which are a source of weakness, to pass directly through the board, as A, [fig. 59], and not run transversely across as other sections (B) allow.