Page:Timber and Timber Trees, Native and Foreign.djvu/140

120 is against the specimens tried in England, but this may be attributed mainly to the more seasoned state of the pieces, and, perhaps, in part, to better appliances for testing.

The mean deflections of the twelve pieces referred to, were, when weighted to 390 lbs., 1.791 inch, and with the breaking weight of 878 lbs., 5.916 inches. From these results it appears, by the application of the formulae used by Professor Barlow, that the strength is represented by 2303, and the elasticity by 530970. The same pieces being tested for tensile strength, took a strain nearly equal to 6 tons to overcome the direct cohesion, or about 3,301 lbs. to the square inch.

A number of cubes of this timber were subjected to a crushing force in the direction of the fibres, and these generally gave way under a pressure of about 2 tons per superficial inch of base. Altogether, some fifty-three experiments of this kind were made upon Teak, four being on pieces 2 × 2 of various lengths, others were 3 × 3, varying by 1 inch from 8 to 18 inches in length, the piece of 16 inches proving to be the strongest, and taking 28.75 tons to crush it; then there were pieces 4 × 4, and severally varying by 1 inch from 15 to 24 inches in length, the piece of 20 inches proving to be the strongest, and taking 42 tons to crush it. Again, there were pieces 6 × 6, and severally varying by 3 inches from 12 to 30 inches in length, the piece 18 inches in length taking 174 tons to crush it; and finally, there were other pieces 9 × 9¼, varying by 3 to 6 inches from 12 to 30 inches in length, the strongest of which, 21 inches in length, took 368.6 tons to cripple it; the details of these will, however, appear in Tables XLVIII. and XLIX.

The following experiments were made in order to