"Sonic carpenters make use of grease and sawdust min gled; but the first is so good always" says toy author, "that I have seen wind-shock timber so exquisitely closed, as not to be discerned is here the defects were. This must be used Nyhen the timber is green.
"\\'e spake before of squaring; and I would now recom mend the quartering of such trees as will allow useful and competent scantlings, to be of much more durableness mid elket for strength, than where (as custom is, and fin. want of observation) whole beams and timbers are applied in ships or houses, with slab and all about them, upon fidse supposi tions of strength beyond these quarters. For there is in all trees an evident interstice or separation between the heart and the rest of the body, which renders it much more obnoxious to decay and miscarry, than when they are treated and converted as 1 have described it ; and it would likewise save a world of materials in the building of great ships, where so much excellent timber is hewed away to spoil, were it more in pi actice. Finally, "1 must not omit to take notice of the coating of timber in work used by the Hollanders, for the preservation of their gates, portcullises, draw-bridges, sluices, and other huge beams and contiguations of' timber, to the sun and perpetual injuries of the weather, by a certain mixture of pitch and tar, upon which they strew small pieces of cockle and other shells, beaten almost to powder, and mingled with sea-sand, or the scales of iron, beaten small and sifted, which encrusts, and arms it. after an incredible manner, against all these assaults and foreign invaders; but if this should be deemed more obnoxious to firing, 1 have heard that a wash made of alum has wonderfully protected it against the assault even of that devouring element ; and that so a wooden tower or fort at the Pirtcum, the port of Athens, was defended by Archelaus, a commander of Mithridates, against the great Sylla.
"Timber that you have occasion to lay in mortar, or which is in any part contiguous to lime, as doors, window-cases, groundsels, and the extremities of beams, &c., have some times been capped with molten pitch, as a marvellous pre server of it from the burning and destructive etfects of the lime ; but it has since been floind rather to heat and decay them, by hindering the transudation which those parts require : better supplied With loam, or strewings of brick of boards; some leave a small hole fill- the air.
But though lime be so destructive whilst timber lies thus dry, it seems they mingle it with hair, to keep the worm out of ships, which they sheath for southern voyages, though it is held much to retard their course. Wherefore. the Por luguese scorch them with fire, which often proves very dangerous; and, indeed, their timber being harder, is not so easily penetrable.
" For all uses, that timber is esteemed the best which is the most ponderous. and which, I:. Mg long, makes deepest on the earth. or in the water, being ; also, what is without kuots, yet firm, and free from sap, which is that fatty, whiter, and softer part, called by the ancients alburnum, which you are diligently to lice away.
"My Lord Bacon, Exper. 058, recommends for trial of a sound or knotty piece of timber, to cause one to speak at one of the extremes, to his companion listening at the other ; for if it be knOtty, the sound, says he, will come abrupt.
For the place of growth, that timber is esteemed best which grows most in the sun, and on a dry and hale ground; for those trees which suck and drink little, are most hard, robust, and longer-lived instances of sobriety. The climate contributes touch to its quality; and the northern situation is preferred to the rest of the quarters; so as that which grew in Tuscany was, of old, thought better than that of the Venetian side; and yet the Biscay timber is esteemed better than what they have from colder countries ; and trees of the wilder kind and barren, than the over-much cultivated and great bearers." Dr. Parry published an excellent paper on the causes of the decay of wood, and the means of preventing it, which, though written many years ago, is worth a earefid perusal by those who wish fbr further information on the subject.