W .Mr. Gilbert Burnett on the Decay 



which, previous to using them, their probable durability may 

 be determined, — a subject of at least equal, if not greater, 

 importance ; and to some rudimentary trials on this point I 

 beg shortly to call your attention. 



The experiments by which the hardness, gravity, stiffness, 

 elasticity, toughness, tenacity, &c., of different kinds of wood, 

 and of differently treated specimens of the same kind, may be 

 computed, are so simple and so easily performed, that almost 

 every work on carpentry teems therewith ; hence it would be 

 foolish here to repeat in detail such as but confirm previous 

 observations, and increase the number, rather than add to the 

 extent, of facts already known and published. Suffice it, then, 

 to generaHze these points in the words of Tredgold, who ob- 

 serves, that ** the oak is universally allowed to be the best of 

 woods ;" not that it is either the hardest, the heaviest, or the 

 toughest — in single qualities it yields to many ; it is in their 

 conjunction that its superiority consists: thus many kinds of 

 wood are heavier, as guiacum and teak ; many harder, as 

 ebony and box ; many tougher, as yew and ash ; many easier 

 to work, as fir and poplar ; but none other as yet is known in 

 which the several most important properties are combined in 

 so great a degree, or so apportioned to be useful, as in the oak, 

 and no oak is equal to British oak, *' No nation," (said Bacon 

 long ago, in his advice to Villiers,) " no nation doth equal Eng-. 

 land for oaken timber, wherewith to build ships." 



The experience, however, of the last fifty years would lead 

 almost to the denial of this boasted, this so long cherished 

 superiority : when we find on record, that some of our ships 

 have rotted on the stocks, needing repairs even before they 

 have been launched ; that others, more fortunate, have, never- 

 theless, in three, five, seven, or ten years, proved not sea- 

 worthy; and that, of the best modern-built ships, the average 

 duration seldom exceeds twelve or fifteen years. Much discredit 

 has consequently attached to oaken timber, and especially, 

 though most injudiciously, to British oak ; it having once been 

 given in evidence by some ship-builders (but on very insufficient 

 grounds) that it is less durable than that of foreign growth. 

 It has also been disparagingly compared to locust and other^ 

 woods, which have been found, in some cases, to outlast oak as 

 posts and spurs, not considering the other qualities in which. 



