The strength at maximum load is not so great with the most rapid-growing wood; it is maximum with from 14 to 20 rings per inch, and again becomes less as the wood becomes more closely ringed.

The natural deduction is that wood of first-class mechanical value shows from 5 to 20 rings per inch and that slower growth yields poorer stock.

Thus the inspector or buyer of hickory should discriminate against timber that has more than 20 rings per inch.

Exceptions exist, however, in the case of normal growth upon dry situations, in which the slow-growing material may be strong and tough."[20] [Footnote 20: Bul.

80: The commercial hickories, pp.