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massy columns, let them be bored through from end to end.It is an excellent preservative from splitting, and not unphi-losophical; though, to cure the accident, painter’s putty isrecommended; also, the rubbing them over with a wax-clothis good ; or before it be converted, the smearing the timberover with cow-dung, which prevents the effects both of sunand air upon it, if, of necessity, it must lie exposed. But,besides the former remedies, I find this for the closing of thechops and clefts of green timber, to anoint and supple it withthe fat of powdered beef-broth, with which it must be wellsoaked, and the chasms filled with sponges dipt into it. Thisto be twice done over.

“ Some carpenters make use of grease and sawdust min-gled ; but the first is so good alway,” says my author, “ thatI have seen wind-shock timber so exquisitely closed, as notto be discerned where the defects were. This must be usedwhen the timber is green.

“ We spake before of squaring ; and I would now recom-mend the quartering of such trees as will allow useful andcompetent scantlings, to be of much more durableness andeffect for strength, than where (as custom is, and for wantof observation) whole beams and timbers are applied in shipsor houses, with slab and all about them, upon false supposi-tions of strength beyond these quarters. For there is in alltrees an evident interstice or separation between the heartand the rest of the body, which renders it much moreobnoxious to decay and miscarry, than when they are treatedand converted as I have described it; and it would likewisesave a world of materials in the building of great ships,where so much excellent timber is hewed away to spoil, wereit more in practice. Finally,

“ I must not omit to take notice of the coating of timberin work used by the Hollanders, for the preservation of theirgates, portcullises, draw-bridges, sluices, and other hugebeams and contignations of timber, exposed to the sun andperpetual injuries of the weather, by a certain mixture ofpitch and tar, upon which they strew small pieces of cockleand other shells, beaten almost to powder, and mingled withsea-sand, or the scales of iron, beaten small and sifted, whichencrusts, and arms it, after an incredible manner, against allthese assaults and foreign invaders; but if this should bedeemed more obnoxious to firing, I have heard that a washmade of alum has wonderfully protected it against the assaulteven of that devouring element; and that so a wooden toweror fort at the Piraeum, the port of Athens, was defended byArchelaus, a commander of Mithridates , against the greatSylla.

“ Timber that you have occasion to lay in mortar, or whichis 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 effects of thelime ; but it has since been found rather to heat and decaythem, by hindering the transudation which those partsrequire: better supplied with loam, or strewings of brick-dust, or pieces of boards ; some leave a small hole for the air.But though lime be so destructive whilst timber lies thusdry, it seems they mingle it with hair, to keep the worm outof ships, which they sheathe for southern voyages, though itis held much to retard their course. 'Wherefore, the Por-tuguese scorch them with fire, which often proves verydangerous ; and, indeed, their timber being harder, is not soeasily penetrable.

“ For all uses, that timber is esteemed the best which isthe most ponderous, and which, lying long, makes deepestimpression in the earth, or in the water, being floated; also,what is without knots, yet firm, and free from sap, which is

that fatty, whiter, and softer part, called by the anci®alburnum, which you are diligently to hew away. , fl

“My Lord Bacon , Exper. 658, recommends for trial osound or knotty piece of timber, to cause one to speak atof the extremes, to his companion listening at the otnfor if it be knotty, the sound, says he, will come abrupt. .

“ For the place of growth, that timber is esteemed ^which grows most in the sun, and on a dry and hale g raUl Vfor those trees which suck and drink little, are most ha ^robust, and longer-lived instances of sobriety. The cli®contributes much to its quality ; and the northern situais preferred to the rest of the quarters ; so as that "' a ggrew in Tuscany was, of old, thought better than that otVenetian side ; and yet the Biscay timber is esteemed be ^than what they have from colder countries ; and trees ot ,wilder kind and barren, than the over-much cultivated agreat bearers.” 0 f

Dr. Parry published an excellent paper on the causesthe decay of wood, and the means of preventing it, athough written many years ago, is worth a careful p erby those who wish for further information on the subject-Wood, Dr. Parry supposes to be subject to destruc 1 ^from two causes—rotting, and the depredations of insects-rot there are two supposed kinds : the first takes placeopen air ; the second under cover.

When perfectly dry, and in a certain degree of temp® j gture, both animal and vegetable matters seem scarcely c a P a ^ rof spontaneous decay. On this principle, fish and 0animal matter is often preserved. ^ , eI j

“ Similar causes produce the same effect on wood.^ ^ n0 (j

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under less rigid circumstances of this kind, as inand other timber of large buildings, it continues —astonishing length of time unchanged. ■ Witness the tir* ^of that noble edifice, Westminster-hall, built by Bicharin 1397 ; and the more extraordinary instance quoted by .Darwin, in his ingenious work, the Phytologia, of theof the old St. Peter’s Church in Borne, which were sa' a ))0have continued without rotting, from the time °Emperor Constantine to that of Pope Eugene IV., a P e ^;llof eleven hundred years. On the other hand, wooremain for ages, with little change, when continually ^mersed in water, or even when deeply buried in the earin the piles and buttresses of bridges, and in various mor* 1 ,,These latter facts seem to show, that if the access oi a a tpherical air is not necessary to the decay of wood, itleast highly conducive to it.” . js

Putrefaction is the cause of rotting ; and putrefac* 1 0 foccasioned by stagnant air and moisture. The moi= tl,I ^ I . e)the air, coming in contact with wood of a lower tempe( a oll ris condensed in the same manner, as is more visible

glass windows. In order to prevent the bad effects ,condensation, currents of dry air ought to be made to P‘ t j,econtact with the timber. Of the advantages of TfVit' 1Gothic architects seemed aware ; for it was commo ^j)them to leave openings for this purpose ; a practicewe would strongly recommend in cellars, &c. cld®^

“ It appears that the contact of water and air are the ^causes of the decay of wood. If, therefore, any h? ea , in b ebe devised by which the access of moisture and air -0)i3prevented, the wood is so far secure against decay- ^ j,yprinciple may be illustrated, by supposing a cylinder " a(jt ]ywood to be placed in a glass tube or case which it gti-fills, and the two ends of which are, as it is called, ^glte®cally sealed, that is, entirely closed, by uniting the j, »sides of each end of the tub. Who will doubt tha ^ Qipiece of wood might remain in the open air unchange t j,gtlet us take a little more apposite illustration of this t a ’