Page:Timber and Timber Trees, Native and Foreign.djvu/61

From Wikisource
Jump to navigation Jump to search
This page has been proofread, but needs to be validated.

VII.]
EXPERIMENTS ON TIMBER.
41

France, Prussia, Asia Minor, and European Turkey, and also in the royal forests in England, and later on as Timber Inspector of a dockyard, and Timber Inspector to the Admiralty, every effort has been made to acquire a knowledge of the capabilities and characteristic properties of the several varieties of timber which came under notice.

Many of the experiments to which I shall have to refer were made at Woolwich Dockyard, where it was necessary, as a part of the duty of my office, to ascertain the specific gravities, strength, and measurement, and attend to the receipt of the timber coming in under contract with the Admiralty.

Especial care was taken to carry out the experiments upon wood brought to a well-seasoned condition and fit for appropriation to works of construction; and in many instances we have tried not only a number of pieces taken from different trees, but a series of pieces from the same tree, with a view to find, if possible, in what part the maximum of strength lay.

Formerly, I believe, it was the practice to carry out these experiments upon exceedingly small pieces of wood, and I have seen it stated that some were no bigger than a French line, =.0888-inch measurement, and varying in size from that to about one quarter of an inch of English measure, the result per square inch being obtained by subsequent calculations. This was probably done in consequence of the great difficulty there is in securely holding, and bringing a sufficient strain to bear upon and break the larger scantlings. I should not, however, be disposed to place much reliance in the results so worked out, as it would seem to be impossible to reduce pieces of wood to such small dimensions without cutting across some of the fibres, and thus