Sylva Florifera; the Shrubbery Historically and Botanically Treated: With Observations on the Formation of Ornamental Plantations, and Picturesque Sce

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1823 edition. Excerpt: ... Results of Experiments, on the transverse Strength of Timber, made at Mr. Atkinson's, Grove End, St. John's Wood, on Thursday, March 12th, 1818. The pieces were each an inch square, except No. 3., which was only 8-10ths of an inch in breadth. The numbers in the Table show the weights it would have borne if it had been an inch square; the pieces were supported at each.end, and were loaded by putting 5 lbs. at a time into a scale suspended from the middle; -- the distance between the supports 30 inches. As the strength of small pieces depends much on the position of the annual rings, the pieces were placed as nearly alike in this respect as possible. When the pieces were in the position in which they were broke, the dark lines or portions of the annual rings that appear in the section of a piece were vertical. -- From the results exhibited in the preceding Table, it appears very clearly, that Larch is best adapted to resist the force of a body in motion; -- but to leave no doubts in this respect the following experiments were made, Experiments on the Resilience of Timber. The pieces were each an inch in depth, and laid upon supports thirty inches apart. The weight fell between two vertical guides (similar to a pile engine), upon the middle of the piece. No. 11 was a dark-coloured and apparently very strong piece of wood; specific gravity 0.872 or 54J lbs. per cubic foot. * On the whole, then, it appears, that Larch is superior to oak in stiffness, in strength, and in the power of resisting a body in motion (called resilience): and it is inferior to Memel or Riga timber in stiffness only. I am, Sir, yours, &c. THOMAS TREDGOLD. Grove End, March 16, 1818. * These experiments were made in the presence of His Grace the Duke of At hoi I, Lord...