manent appointment in the service, and, consequently, of experience and information in its concerns; and who are alike responsible with the head of the department.* One of the fruits of this improved organization is offered to us in the report mentioned at the head of this article: in which, among other things, the best method of managing ship timber, with reference to its durability, is ably discussed.

At this period, when ships of war are considered by all maritime nations so important a means of defence-when navigation is so widely extended, and the bounds of knowledge so wonderfully enlarged by the progress of science, it is somewhat extraordinary that the subject of the durability of timber should be so little understood. We know what kind of trees afford the most lasting materials; but it is yet problematical what is the best method of managing the timber they furnish, so as to give it the greatest degree of durability of which nature has made it susceptible. The most solid timber often, in a very short time, becomes decayed, and that which is open and porous sometimes endures in a surprising degree: numberless instances of this fact have existed both in vessels of war and merchant ships: but the circumstances associated with such premature decay or unexpected durability are so imperfectly set forth, as to furnish no satisfactory solution of the phenomenon. We know what

are the causes of corruption, and we are sure that the same causes uniformly produce the same effects upon vegetable sub

We are much gratified to see an approach to the same improvement, in the military department of the government-as effected by the late change in the organization of the army. It is, in this case, much more sur. prising that the command of the army, involving duties purely professional, should so long have devolved upon the civil head of the department-leaving the general officers and Etat-Major of the army, with no other employment than, as clerks in the several districts, to copy, to record, and to distribute, the rules and directions (sometimes of a subordinate agent) of the war office.

It is, now, to be presumed that the military chief, stationed at Washington, will have the management of the military departments of the army, with the assistance of the Staff officers appointed to each-the contracting and disbursing departments continuing under the immediate direction of the Secretarywho will hold communication with the others, but never issue an order to any portion of the army, except through the medium of the commanding General. The ministerial duties of the Secretary, and his general arrangement for the service of the army, both external and internal, will thus be kept distinct from the military execution and supervision of the service in detail. There can be no advancement in the discipline of the army, and the execution of its service must be unmilitary, irregular, and discordant, without the office of a permanent Commander, whose authority shall be carefully supported by the government, and recognized by all who are subordinate in command.

stances; and yet the most skilful and enlightened men differ about the best modes of preparing timber for ship building. Some recommend particular periods for felling the trees, as connected with the season of the year, or the age of the moon: some season their timber under sheds, others in the open air: some cure it with artificial heat, kept up uniformly to a certain degree of the thermometer: some saturato it with chemical mixtures: some char the wood by burning, and others again immerse it for a time in water, either salt or fresh, in order to expel the sap. This latter mode of treating timber has for some time past been more especially practised; and immersion in salt water, particularly, has hitherto been deemed, by experienced men, as salutary. The opinion of the Commissioners is decidedly opposed to this method of treating timber; and the arguments for and against it are set forth with much ability and precision. While, on the one hand, it is fully admitted that the sap juices exert a powerful and deleterious influence upon wood, and that their removal is essentially produced by immersion; yet they observe

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It is contended, on the other hand, that their expulsion may be produced by other and more advisable means; less sudden, but more salutary in their operation, and unattended with any of the ills arising from immersion; that a succession of wet and dry devests the fibres of the wood of their natural tenacity, adhesiveness, and organization, when exposed in the open air; the wet, swelling, and the dry separating, the soft fibres; that one of the tendencies of immersion is to render the wood porous, and subject it peculiarly to the action of the atmosphere; that in this porous state timber, confined as it must be when brought into use, where there cannot be a free circulation of air, and where a greater or less degree of humidity must prevail, the interstices become filled with putrid, corroding matter, and decay ensues; that timber exposed to intense frosts, after immersion, by which it becomes water soaked, or saturated with water, the pores of the wood become over distended, and in that state remaining fixed, the elastic adhesiveness of its fibres, and their power of contraction, are destroyed; that a firm, adhesive consolidated state of fibre is essential to great durability; that this state never can be produced after the timber shall have been saturated with water, and its pores once distended; that, if the timber be not cut while in a vegetative state, and be kept under shelter, exposed neither to rain, to the heat of the sun, nor to piercing winds, yet having a free circulation of dry air, nature will expel the sap juices, without the aid of any artificial

means.

It is further contended, that timber of close texture, such as live oak, or the best white oak, when once saturated with water, cannot be dispossessed of its moisture, in any reasonable time: that, when put into a ship, it imparts to the surrounding atmosphere a degree of

humidity which damages the provisions and stores, and generates diseases among the crew; that timber, in a dry state, is not subject to the destructive effects of frost, one of the most insinuating and irresistible of all, operating on the texture of bodies.'

.. The report then proceeds to state, that

The

With respect to other materials of wood, the result of the experiments made many years since, would seem to indicate the inefficacy of covering as a means of preservation. The white oak and pine, collected under the act of 1799, and placed under sheds, was in a few years found in such a state of decay as to be unfit for use. Commissioners know but little of the history of the oak and pine collected at that period. Whether the trees had attained their full growth-whether they were not cut in a vegetative state-whether, when stowed, the timber was properly stuck, so as to admit a free circulation of air-whether the sheds were of a sufficient width and height to protect it against the sun, or sufficiently tight to secure it against rains and piercing winds-whether the timber had not been water soaked, prior to its being placed under sheds, are points upon which the Commissioners possess no positive information. Since, however, universal experience affirms the inefficacy of this method of preserving ship timber, the Commissioners are persuaded that these causes of decay must have existed in a greater or less degree; and that the result of experiments so partial and unsatisfactory, should by no means deter us from adopting it as far as circumstances may render it expedient to do so.'

The insufficiency of immersion, or covering in the ordinary way, to preserve timber from rot, having thus been stated, the Commissioners then propose, as a substitute,

That the whole frame should be put together, and planked, bolted and stayed, so firmly that no piece could spring out of its place or shape, and covered so effectually as to be protected from the sun, moisture, and high piercing winds, yet to admit a free circulation of pure dry air.'

In favour of which mode of managing ship timber, they state, that

Many instances might be added of the great durability of ships thus built and preserved: one, if not inore, occurred at Venice. A ship built there remained on the stocks, under cover, for sixty years, when, on being examined, no mark of decay could be discovered in her timbers; they were somewhat shrunk, which was ascribed, no doubt justly, to their having been put in the ship in an unseasoned state. Escalier observes, "we perceive that wood used on land, kept dry and under shelter, will preserve itself for ages." Thus preserved, the wood acquires a close texture, a hard consolidated fibre, which prevents its imbibing moisture, and enables it to resist all the destructive effects thence arising.'

We readily acknowledge, that as far as they go, there is much

good sense and sound reasoning in the above extracts from the report but before entering fully upon the subject, we cannot omit to remark, that for every vessel thus built under cover, possessing superior qualities of durability, hundreds may be adduced in favour of such as are built in the open air; and it is questionable, as this system has been practised for some time past both in Europe and in this country, whether it does not furnish as many instances of premature decay, as of superior durability. The circumstance stated by Escalier, admits of no dispute; but its application, as well as that of the instance of the Venetian ship, only extends to vessels upon the stocks and in ordinary, since the moment they are at sea, new circumstances and combinations take place which must produce new consequences. From the best consideration which we have been able to give the subject, we cannot discover, that the plan proposed in this report amounts to any thing more in effect than an entire rejection of all the methods heretofore practised for the preservation of ship timber, except such as were in use centuries ago; and, in fact, notwithstanding the change of circumstances, it leaves us without any more knowledge than was possessed upon the subject in the time of Vitruvius. That a number of errors have existed in regard to the management of timber to prevent decay, and that a vast many of the schemes which have been proposed have proved visionary and chimerical, there cannot be a doubt; but it does appear to us that there are principles emanating from the present enlightened state of human knowledge, which, if properly applied, must be attended with salutary results; and until experience shall clearly prove them to be founded in error, it is the part of wisdom to attribute their want of efficacy rather to an imperfect application of them, than to any radical defects which they may possess in themselves.

In reasoning upon the causes of durability and of decay in ship timber-there are some facts, which, if properly appreciated, will, we think, assist us to form an opinion whether there be not some mode of preparation which shall prolong its existence. We know that live oak is more durable than hemlock and as the fibre of all wood is substantially composed of the same ingredients, and as it is known that neither of these possesses any peculiar oil or acid which can resist the effects of corrupting causes or can promote decay; it follows, therefore, that the strongly marked character of durability, in live oak or locust, is to be attributed entirely to the closeness of their textures, or, in other words, to their being more solid and compact than other timber. This being granted, it also follows that, to render live oak or locust as durable as possible, it should

be so managed that it shall acquire the greatest degree of compactness or solidity of which it is susceptible.

There is another point, to which the ingenuity of man has been more particularly directed,-viz: that as corruption is produced by the combined agency of heat, air, or moisture, if one or all of these be excluded by artificial means, the subject will be rendered more lasting :-thus wood, when immersed in water, will endure for centuries, because air is excluded;-when placed in dry houses, also, because moisture is excluded;-or, when kept in an atmosphere below thirty-two degrees of Fahrenheit, because that deleterious heat is excluded;-thus resisting the effects of the other two agents, which in each of those cases are left to exert their influence freely. Having thus stated the form in which we think this subject should be considered, and the particular points to which our inquiry ought to be directed, we will now offer a few remarks upon,

1st. The best mode of increasing the solidity of timber:

2d. The best method of seasoning ship timber, and of excluding from it, or preventing the deleterious effects of, either beat, air, or moisture, by artificial means.

And in the course of these remarks we shall take occasion to comment upon the usual mode of seasoning timber, the object of which is simply to expel the sap juices.

It appears to us that the experiments of Buffon are conclusive, in regard to the best mode of increasing the solidity of timber; which is to detach the bark from the tree, while standing, (this being the most readily effected in the spring, when the sap flows actively,) and suffer it to remain in that situation for one, two, three, or four years. Buffon found, from a number of experiments accurately made, that timber, thus treated, invariably possessed more strength and solidity than any that was differently treated; and particularly, he ascertained that the sap wood of a tree, deprived of its bark and left standing for four years, possessed more strength or solidity, than the heart of a tree felled and seasoned in the usual way. The rationale of this phenomenon apparently is, that the sap flows through the pores or vessels of the wood to the leaves-whence, after undergoing some preparation, it is transmitted between the bark and the wood, and there becoming indurated, it produces annual concentric layers or circles. These circles, or layers, possess different degrees of solidity, diminishing from the center to the circumference; the outer circle being always the most open and porous. The sap being thus transmitted through the cells or pores of these layers with different degrees of activity, increasing from the centre to the periphery-it follows that the