CIVIL ARCHITECTURE. 



593 



account of the bark of the oak being of great use in 

 tanning leather, that wood is always, in England, cut in 

 the spring, or rather from April to June, according to 

 the state of the season, and soon after the sap begins to 

 ascend and the leaf to appear ; if it is cut before the sap 

 rises, the bark adheres to the wood, and cannot be 

 stripped off, and if left until the leaf is quite expanded, 

 the bark is less valuable ; when the tree is felled and suf- 

 fered to lie in the trunk, it will shrink in size, but this 

 is probably from its discharging water, because, if a dry 

 tree be laid in a damp place, it will increase both in 

 weight and size. The part called the sap varies in quan- 

 tity in different trees; it is least in bad soils, where the 

 growth is slow ; it is of very little use. 



Oak, used in damp situations, appears to decay gra- 

 dually from the external surface to the centre of the 

 tree ; the outside ring or addition it received in the last 

 year of its growth decaying first, and afterwardi that 

 uext within it, and then the following one. This appears 

 to proceed from two causes ; first, from the outward ring 

 being, where whole trees are used, first exposed to the 

 action of the atmosphere, which cannot reach the second 

 until the first is destroyed ; secondly, from the centre 

 part of the tree having arrived at a greater degree of 

 maturity than the outward rings, which are many years 

 younger. But this must be understood only of trees 

 which are not past their prime before they are cut down; 

 for when a tree begins to decay from age, that part of 

 the tree which is oldest, namely the central part, de- 

 cays first ; to this succeeds the parts which are next 

 oldest, being the ring next the centre, and the other an- 

 nual rings in succession gradually approaching the bark. 

 A judicious builder will therefore, in the choice of his tim- 

 ber, always carefully examine the central part of the 

 tree, especially of that which is next the root, and more 

 particularly if the tree is large, and has the appearance 

 of great age. 



The best mode of seasoning oak is to put it in water. 

 This, if in the log, should be done /or a whole year or 

 more, but, if cut in planks, less time is necessary ; in 

 either case, alternate soaking and drying is to be prefer- 

 red. This, in planks, is very practicable ; but, in regard 

 to logs, one soaking and drying gradually in the shade, 

 is, on account of the great labour attending the opera- 

 tion, most generally practised. After the planks have 

 been soaked in water, they are dried by placing a strong 

 pole in a horizontal position, at such a height as will ad- 

 mit of one end of each plank being placed on the ground, 

 and the other resting against the pole edgewise, pla- 

 cing a plank first on one fide of the pole, and then ano- 

 ther on the other side alternately, thus leaving a space 

 for the air to pass freely and dry them, and being ex- 

 posed edgewise to the sun, they are net liable to split. 



In ash, there is little difference in the quality through 

 the whole thickness of the tree, the outside is rather the 

 toughest : it soon rots when exposed to the weather, but 

 will last long when protected. 



Of elm, some sort will decay sooner than the brown or 

 red. It is improper for roofs or floors, being generally 

 cross-grained, and very liable to warp ; it also shrinks 

 rery considerably, not only in breadth, but lengthwise. 

 It answers well when used under water ; it is not liable 

 to split, and bears the driving of bolts and nails better 

 than any other timber. 



fcecb. Beech is hard and close. There is a black or brown, 

 and a white kind : the brown is tough, and sometimes 

 used as a substitute for ash ; it is improper for beams, 

 because a small degree of dampness in the walls very 



VOL. VI. ART II. 



Aih. 



Elm. 



soon rots the ends ; it is fittest for furniture, or where Practice, 

 constantly under water. v - v ""- ' 



Poplar is of a very close quality, is liable to the same 

 objections as the beech in beams, but is well adapted for 

 floors and stairs, being not readily inflamed : it rots soon 

 when exposed to the weather. 



Asp resembles the poplar in appearance ; it is soft and Asp. 

 tough ; it lasts when exposed to the weather ; it is equally 

 good through the body of the tree. 



The Sycamore and Lime are subject to the same ob- Sycamorr. 

 jections, in roofing and flooring timbers, as the poplar 

 and beech. The lime is something like the ash, and, like 

 it, is greasy when worked smooth : It is suitable for 

 furniture. 



Birch is equal in quality quite across the body of the iji rc j,. 

 tree ; it is very tough, but does not last when exposed to 

 the weather ; it is also subject to be destroyed by the 

 worms. 



Chesnut, viz. the sweet, or Spanish, (not the horse- chesnuti 

 chesnut,) is frequently found in old buildings in Eng- 

 land ; and although difficult to be distinguished from oak, 

 differs from it in this, that wherever a nail or bolt has 

 been driven into oak before it was dry, a black substance 

 appears round the iron, which is not the case in chei- 

 nut. 



The Walnut-tree is, in Britain, now too valuable to be Walnut, 

 used iu the framings of roofs or floors, and in furniture it 

 has long been superseded by mahogany ; it is now used 

 chiefly in stocks of firelocks, fowling-pieces, pistols, &c. 



Mahogany is used chiefly in furniture, but also some- Mahogany, 

 times in doors and window sashes ; it ii sawn out and sea- 

 soned by perching out in the winter, and drying in the 

 open air, the use of fire is not advisable. This beautiful 

 timber was introduced into England about the beginning 

 of the last century : its first application was in a box for 

 holding candles, made by a Mr Wollaston for a Dr Gib- 

 bons, who had afterwards a bureau of it ; the Duchess of 

 Buckingham had the second bureau. It very soon came 

 into general use. It is divided chiefly into Jamaica and 

 Honduras j the former is by much the hardest and most 

 beautiful : they may be readily distinguished before 

 they are oiled ; the pores of the Honduras appear quite 

 dark, those of the Jamaica as if filled with chalk. 



Fir, being cheaper, and more easily wrought than oak, p t - n 

 and next to it in usefulness, is more used in Britain than 

 any other kind of timber. That most generally employed 

 in carpentry is distinguished by the name of Memel, 

 (which includes Dantzic and Riga) ; Norway, (which 

 also includes Swedish,) is much uoed for the smaller 

 timbers, and answers well either when exposed to the air, 

 or under ground. Dranton, or Dram, is suitable for 

 flooring. All these are very durable. American fir it 

 much softer, but suits inside joinery work, such as pan- 

 nelsand mouldings. What is termed itiEnglandi'A//ef/ro/, 

 and in t-cotland pine mood, that is, fir deprived of its re- 

 sinous part, being very durable when kept dry, is much 

 used by cabinet makers; but, as it will not stand the wea- 

 ther, it is little used in carpentry or joinery. 



Evelyn makes the following observation on the use of 

 fir : " That which comes from Bergen, Swinsund, 

 Mott, Longland, Dranton, (called Dram,) being long, 

 straight, and clear, of a yellow and more cedary colour, 

 is esteemed much before the white for flooring and 

 wainscot j for masts, those of Prussia, which we call 

 spruce, and Norway, especially from Gottenburgh, and 

 about Riga, are the best." 



The torulus, at Vitruvius terms it, and heart of deal 

 kept dry, rejecting the alburnum or white, is everlasting ; 

 4 F 



