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NATURE AND PROPERTIES OF TIMBER.
[sect. X.
There is another species called the Durmast oak, which is a native of France and thesouth of England; its wood is not so strong nor of so firm a texture as the English oak,and it retains its foliage much later.
The Austrian oak is a taller tree than the English oak; but the wood is whiter, softer, andless valuable.
Of the American species the chesnut-leaved oak is a tall tree, remarkable for the beautyof its form: the wood is coarse grained, but is very serviceable, and is much used for wheelcarriages.
The mountain red oak (Quercus rubra ) is a native of Canada , and the country west ofthe AUegany Mountains; it is called the red oak, from the leaves changing to a red or pur-ple colour before they fall off. It is a large and fine tree , of 90 or 100 feet in height, andof rapid growth; the wood is useful for many purposes, but it is light, spongy, and not verydurable.
Tire white oak (Quercus alba ) so called from the whiteness of its bark, is a native of thewoods from New England to Carolina, and acquires an immense size in some of the middlestates. Its wood is tough and pliable, and it is preferred to all others in America for bothhouse and ship carpentry, being much more durable than most of the species. It is lessdurable than British oak, but it is of quicker growth.
The blunt-lobed iron oak (Quercus obtusiloba) is another of the American species thatproduces very valuable ship-timber; the wood is hard, and not liable to decay, and is pre-ferred for fencing. It is found in most of the upland forests from Canada to Florida , andis a tree of 60 or 70 feet in height.
But the live oak (Quercus virens) is esteemed the best of the American kinds for ship-timber ; it grows to the height of 40 or 50 feet with wide spreading branches, and the woodis very durable : Mr. Knowles states that out of 507 pieces, which had been in the Essexfrigate 12 years, only 6 were found to be defective.
The species of the Riga oak, so valuable on account of the straightness of its grain andfreedom from knots, does not appear to have been determined: neither have we been ableto find from what species the Dutch wainscot is obtained; it is grown in the forests of Ger many , and floated down the Rhine . •
According to Ilassenfratz, the mean size of the trunk of the
Common oak is. 45 feet in length and 32 inches diameter.
Oak of a good quality is more durable than any other wood that attains a like size. Vi truvius says, it is of eternal duration when driven into the earth; and it is well known tobe extremely durable in water; and in a dry state it has been known to last nearly 1000years. The more compact it is, and the smaller the pores are, the longer it will last;