Chap. XXII.

TIMBER AND ITS PROPERTIES.

1285

Cedar ( Cedrus pinusj grows to a great size; the timber is resinous, of a reddish whitecolour, light ami spongy in its texture, easily worked, but apt to shrink and warp, if greatattention be not paid to the seasoning ; the annual rings are distinctly marked, and appa-rently consist of two layers, one narrow and hard, the other three or four times its thick-ness, and softer: it was exceedingly valued by the ancients for its durability and otherproperties.

Pliny asserts that the beams of the Temple of Apollo at Utica , which were of Xumidiancedar, had endured 1178 years: its resin or gum was considered to possess the quality ofpreserving any matter from decay that had been steeped in it; the leaves of the papyrus,rubbed with it, Vitruvius says, were never attacked by insects. The wood is odoriferous,and admirably adapted for joiners’ work : it is the lightest of resinous woods, and con-taining but a small quantity of resin : its weight is said to be 29 lbs. 4 oz. per cube foot,according to one authority; 42 lbs. 14 oz., and 57 lbs. by others: as a mean, it may,perhaps, be taken in a dry state at 42 lbs., or a little more.

Cedar , Indian ( C. Deodara ), a native of the Indo-Tartaric mountains, grows to a verylarge size, and is a very compact wood, strongly impregnated with resin : the hardness andthe fineness of its grain occasion it to be much used by the Hindoos for the purposes ofbuilding, and when constantly exposed to the weather, its durability is considerable :bridges constructed of it, though occasionally exposed to the action of the torrent, haveendured for .500 years.

Chestnut (Castanea ) _This timber, when found in old buildings, has been frequently

mistaken for oak, but the pores in the alburnum of the latter are generally much larger,more numerous, and very distinguishable, whilst those of the chestnut are irregular, andscarcely discernible to the naked eye ; there is also an absence of the tranverse septa, whichdistinguishes ihe oak : there is, however, a species of oak, much used in the middle agesfor the carpentry and roofs of halls and chapter-houses, which in colour and texture beara close resemblance to chestnut; this species has a smooth bark, large leaves, and its woodrather softer than that of the ordinary oak, which might occasion it to be preferred forcarved work, or where delicacy of execution was required ; but whichever material wasselected, great care was taken to admit the air freely, as well as to protect it from theweather, precautions as important as the proper selection and requisite seasoning of thetimber. The cohesive force of the chestnut varies from 9G70 to 12,000 lbs. per squareinch when dry.

lbs. oz.

The weight of the chestnut when green is - - 68 9 per cube foot.

Ditto dry - - 41 2 —

Horse Chestnut is a soft wood, and not applicable to any purposes where strength isrequired ; in the open air it has little durability : it has been employed for water-pipes,when it can constantly be covered with earth.

lbs. oz.

The wood, when newly cut, weighs - - - 60 4 per cube foot.

Ditto dry - - - - - 37 7 —

Cypress is remarkable for its fine grain and durability, and by some is supposed to be theGopher wood used in the construction of the ark : this evergreen tree grows with a straighttrunk, and its wood is harder than that of the pine, the colour partaking of a yellowishred with dark veins : in consequence of its not being subject to injuries from the worm,it was said to be incorruptible, and was much employed by the ancients for statues,in the construction of temples, and the gates of their public buildings : those removed fromSt. Peter’s, when the bronze gates were introduced, had previously served to adorn thebasilica of Constantine. In Egypt this wood was used for mummy cases; it is lessaffected by exposure to the atmosphere than cedar.

Elder. —The wood of this tree, when old, is very hard and adhesive, of a fine yellow-colour, and susceptible of a high polish ; in a dry state a cubic foot weighs 42 lbs. 3 oz.

Elm (Ulmus ) —The campestris is the most durable and the hardest of the fiveEnglish species ; the suherosa not so valuable ; the montana , or broad-leaved, is that mostcommonly produced in Europe ; the glabra , or wych elm, is used by wheelwrights ; andthe major , or Dutch elm, is of an inferior quality. The elm, either in a perfectly wet ordry state, is very durable, and is admirably suited for planking or piling under water,enduring six or seven centuries. The wood is porous, cross-grained, has no large septa,shrinks in drying, both in length and breadth, is difficult to work, but will not readilysplit when nails or bolts are driven into it.

lb'.

The wood of the campestris, when green, weighs - 70 per cube foot.

ditto dry - - 48J —

Tire cohesive force of a square inch varies from 6070 to 13,200 pounds : it is rich in alkalinesalts, occupying a tenth place out of 73 woods experimented upon.

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