443. "It should be," says the venerable Evelyn, "in the vigour and perfection of trees that a felling should be celebrated." * When a tree is felled too soon, the greater part of it is sap-wood, and in a young tree even the heart-wood has not acquired its proper degree of hardness; indeed the whole tree must partake so much of the nature of sap-wood, that it cannot be expected to be durable. And when a tree is not felled till it be on the decline, the wood is brittle and devoid of elasticity, tainted, discoloured, and soon decays. But in trees that have arrived at a mature age, the proportion of sap-wood is small, and the heart-wood is nearly uniform, and is hard, compact, and durable. Hence" it is important that Evelyn's precept should be carefully attended to. It is true that the proper age for felling each species has not been satisfactorily determined, but it is a point where great accuracy is not necessary; for half-a-dozen years in the age of a tree will not make much difference, provided it be not cut too soon. Trees increase slowly in size after they arrive at a certain age, therefore it becomes the interest of the timber grower to fell them before they arrive at maturity; because it is his object to obtain the greatest possible quantity of timber, without regard to the quality. But the carpenter who is aware of the inferior quality of young timber in respect to duration, should endeavour to check this growing evil, by giving a better price for timber that has acquired its proper degree of density and hardness.

* ' Silva, or a Discourse on Forest Trees,' vol. ii.. p. 205.

The period generally allowed for an oak-tree to arrive at maturity is 100 years, and the average quantity of timber produced by a tree of that age is about 1 1/2 load, or 75 cubic feet. In some instances oak-trees arrive at maturity in less time than 100 years, and in others not until after that period.*

The age of an oak-tree, according to Daviller, should never exceed 200 years, nor should it be felled at a less age than 60.† Belidor states about 100 to be the best age for the oak.‡ It is much to be regretted that in districts where the oak flourishes it is seldom suffered to attain a mature age; being often cut before the trees will produce 50 feet of timber each.§

The ash, larch, and elm should be cut when the trees are between 50 and 100 years old; and between 30 and 50 is a proper age for poplars.

The Norway spruce and Scotch pine are generally cut when between 70 and 100 years old in Norway.

444. In order that timber may be durable it is also necessary to attend to the proper season of the year for felling. But on this point there is much difference in opinion, and the question is only to be decided by attending to the state of trees at different seasons of the year. The best period for felling timber is undoubtedly that in which it is most free from extraneous vegetable matter, or such matter as is intended to be expended in leaves and buds, and which is in a more fluid state and of a more saccharine and fermentable nature than the proper juices, or such as form the wood. A tree deposits in the sap-wood a portion of matter to be dissolved by the rising sap,* and at the period when the leaves are putting forth, the wood must be filled with matter in a state ready for germination; consequently the timber cut at that period must be easily acted upon by heat and moisture, and subject to rapid decay, or to be destroyed by worms. Now, there are two periods in the year, the spring and the autumn, when trees are in a state of vegetation; therefore, at these times it is desirable to avoid felling timber for any other than temporary purposes. Of the two periods the spring must be the worst, because trees then contain the greatest quantity of matter in a state fit for germination.

* ' First Report of the Commissioners of Woods and Forests,' pp. 24 and 25, 1812. † 'Cours d'Architecture.' ‡' Science des Ingenieurs,' liv. iv., chap. i. § See Marshall's ' Southern Counties,' vol. ii., p. 127.

On the other hand, the best time for felling timber is in mid-winter or mid-summer, as at these times the vegetative powers are at rest, or have expended all the most changeable parts in producing leaves, etc. In some kinds of trees, a little after mid-summer appears to be decidedly the best time for felling. Alder felled at that time is found to be much more durable; and Ellis says that beech, when cut in the middle of summer, is better and less liable to worm-eat; particularly if a gash be cut to let out the sap some time before felling, † Mr. Knowles states that "about Naples, and in other parts of Italy, oaks have been felled in summer, and are said to have been very durable." ‡ And as summer felling is an advantage in some species, it seems reasonable to conclude that it will be so in all.

* ' Philosophical Transactions,' 1805. † Ellis's 'Timber Tree Improved,' p. 35.

‡ 'Inquiry into the Means which have been taken to Preserve the British Navy, "p. 20, 4to, 1821.

445. But in oak-trees the bark is too valuable to be lost; and as the best period for the timber is the worst for the bark, an ingenious method has been long partially praetised, which not only secures the bark at the best season, but also materially improves the timber. This method consists in taking the bark off the standing tree early in the spring, and not felling it until after the new foliage has put forth and died. For by the production of new buds the fermentable matter is expended, and the sap-wood becomes nearly as hard and durable as the heart-wood, being both less liable to decay and to be destroyed by worms.

Buffon has ascertained by experiment that the wood is materially improved by this method of barking the trees standing in the spring, and felling them about the end of October.* Duhamel, whose extensive knowledge of the nature and qualities of woods is well known, recommends the same method; and Evelyn states that "to make excellent boards and planks, it is the advice of some that you should bark your trees in a fit season, and so let them stand naked a full year before felling." † But a tree will not be benefited by standing so long; and the best time for felling appears to be when the new foliage has put forth and died, as Mr. S. Pepys observes in his paper on the subject: ‡ and Mr. T. A. Knight, to whom we are indebted for many interesting as well as important facts respecting timber, has made some experiments and observations, from whence he concludes that in all cases where it is essential to give durability to the sap-wood of oak, the trees should be barked in the spring, and felled in the ensuing winter; § also that winter-felled heart-wood is less affected by moisture and is likely to be the best and most durable.

* " Moyen facile d'augmenter la Solidite, la Force, et la Dure'e du Bois;" 'Memoires de l'Academie des Sciences,' Paris, 1738, pp. 169-184. † ' Silva,' Dr. Hunter's edition, vol. ii., p. 214. ‡ ' Philosophical Transactions,' vol. xvii., p. 455. § ' Annals of Philosophy,' vol. xiv., p. 52, or 'Phil. Trans.,' 1826.

When the bark of a tree is not of sufficient value to defray the expense of stripping, the timber should be felled during the months of December, January, and February, in the winter; or during the month of July in the summer. Winter felling is recommended by most writers, chiefly in consequence of the timber drying more slowly, which renders it less liable to split or twist in seasoning. According to Vitruvius, the proper time for felling is between October and February; and he directs that the trees should be cut to the pith, and then suffered to remain till the sap be drained out. The effusion of the sap prevents the decay of the timber, and when it is all drained out, and the wood becomes dry, the trees are to be cut down; the wood will then be excellent for use.*

A similar effect might be produced by placing the timber on its end as soon as it is felled, and it would no doubt compensate for the extra expense by its increased durability.

In France, so long ago as 1669, a royal ordinance limited the felling of naval timber from the 1st of October to the 15th of April. Buonaparte directed that the time for felling naval timber should be from the 1st of November to the 15th of March, in order to render it more durable.†

Seasoning Timber.