Mr. Barlow's patent provided for exhausting the air from one end of the log while one or more atmospheres press upon the other end. This artificial aerial circulation through the wood is prolonged at pleasure. However excellent in theory, this process is not practicable.

In October, 1844, M. Tissier proposed to place wood in a close vessel, and subject it to a current of hot dry air; and in 1847, Mr. Miller proposed to inject hot air through beams of wood to drive out the

sap.

In 1851, M. Meyer d'Uslaw proposed to first dilate the pores of the wood with steam, and then place it in a hermetically closed chamber, and make a vacuum there.

The following system of preparing timber for the Navy was, not many years since, adopted in South Russia. A full account of the practice will be found in Oliphant's Russian Shores of the Black Sea,' 1853. The only name we can give it is

"SEASONING' BY BRIBES."

A certain quantity of well-seasoned oak being required, Government issues tenders for the supply of the requisite amount. A number of contractors submit their tenders to a board appointed for the purpose of receiving them, who are regulated in the choice of a contractor not by the amount of his tender, but of his bribe. The fortunate individual selected immediately sub-contracts upon a somewhat similar principle. Arranging to be supplied with the timber for half the amount of his tender, the sub-contractor carries on the game, and perhaps the eighth link in this contracting chain is the man who, for an

absurdly low figure, undertakes to produce the seasoned wood.

His agents in the central provinces accordingly float a quantity of green pines and firs down the Dnieper and Bog to Nicholaeff, which are duly handed up to the head contractor, each man pocketing the difference between his contract and that of his neighbour. When the wood is produced before the board appointed to inspect it, another bribe seasons it; and the Government, after paying the price of well-seasoned oak, is surprised that the 120-gun ship, which it has been built of it, is unfit for service in five years.

Mark but my fall, and that that ruin'd me,
Corruption."-SHAKSPEARE.

A few words can only be given to a most important matter, viz., the second seasoning, which many woods require. If floor-boards are only laid down at first on the joists of a building, and at the expiration of one year wedged tight and nailed down, those unsightly openings caused by shrinkage, which form a harbour for dirt and vermin, will be avoided, as the wood will have had an opportunity of shrinking. Doors, sashes, architraves in long lengths, will also be better if made up some time before they are required for use. Many Indian woods require a second seasoning-kara mardá, for instance, a favourite wood with Indian railway engineers. Even sál and teak are not exempt. Teak shrinks sideways least of all woods. In the Tortoise,' store ship, when fifty years old, no openings were found to exist between the boards; yet Colonel Lloyd says he found the teak timbers used by

him in constructing a large room in the Mauritius to have shrunk of an inch in 38 feet. Thus a space of of an 3 inch must have been left at each end of the beam, where moisture could lodge and fungi exist, obtaining their nourishment from the wood. If unseasoned teak is used for ships, dry rot will in time find a place. place. It may be said that teak is a very hard wood, and very durable; yet "the mills of the gods," says an ancient philosopher, grind slow, very slow, but they grind to powder;" and so do the fungi mills.

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CHAPTER V.

ON SEASONING TIMBER BY PATENT PROCESSES, ETC.

LONG years of practical experience has shown that timber, however prone to dry or wet rot, may be preserved from both by the use of certain metallic solutions, or other suitable protective matters.

All the various processes may be said somewhat to reduce the transverse strength of the timber when dry, and the metallic salts are affected at the iron bolts or fastenings. The natural juices of some woods do this; and bolts which have united beams of elm and pitch pine will often corrode entirely away at the junction.

The processes adopted for resisting the chemical changes in the tissues of the wood are all founded on the principle that it is essential to inject some material which shall at once precipitate the coaguable portion of the albumen retained in the tissues of the wood in a permanent insoluble form, so that it will not hereafter be susceptible of putrefactive decomposition. For this purpose, many substances, many solutions, have been employed with variable success, but materials have been sometimes introduced for this purpose which produced an effect just the opposite to what was anticipated.

Experience has shown that timber is permeable, at least by aqueous solutions, only so long as the sap channels are free from incrustation.

Such in general is the case with beech, elm, poplar, and hornbeam, the capillary tubes of which are always open, or, at least, close very slowly. At the same time it may be said that there must remain ever in these species some parts impervious to injection, whilst it is almost impossible but that a certain portion of the fibres will be more or less incrusted. The sap woods, on the other hand, of every species appear quite pervious.

Very little is known of any preservative process adopted in ancient times. Pliny observes that the ancients used garlic boiled in vinegar with considerable success, especially with reference to preserving timber from worms: he also states that the oil of cedar will protect any timber anointed with it from worm and rottenness. Oil of cedar was used by the ancient Egyptians for preserving their mummies. Tar and linseed oil were also recommended by him. The image of the goddess Diana, at Ephesus, was saturated with olive and cedar oils; also the image of Jupiter, at Rome; and the statues of Minerva and Bacchus were impregnated with oil of spikenard.

The idea of preserving wood by the action of oil is therefore by no means new; but it is somewhat curious that the earliest modern processes should also be by means of oil. The oils most proper to be used are linseed, rapeseed, or almost any of the vegetable fixed oils. Oak wood, rendered entirely free from moisture, and then immersed in linseed oil, is said to be thus prevented from splitting: the time of immersion depending on the size, &c. Palm oil is preferable to whale oil, because impregnation with the latter, although in many instances eligible, causes