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Building and Bush work for
Selector y Squatters, and Others.
WHITTEN SOIL I"3B TOWN AND COUNTRY JOURNAL BY FBH HARRISONS ARCHITECT, DENILIQUIN.
WOOD ÍB a moat valuable material for con-
structivo purposes, and a short notice of its value and propertied will be useful. Tho woods of different trees differ much in strength, hard- ness, durability, and beauty; and consequently in their fitness for the various purposes to which they are applied. If the stem of a troo bo cut acrosB, the wood is found to bo nmde up of numerous concentric layers or rings; very distinct in some trees, but IOBS SO in others. Ono of theEe layers is usually formed every j'ear; consequently their number corresponds nearly with the age of the tree. Each layer consists in general of two parts; the ono solid, hard, heavy, and dark .coloured; tho other of a lighter colour, porous and soft; which renders the lino of separation be- tween tho annual layers distinct. The outer rings contain more sap than those round the pith or centre, which form what is called heart wood. These rings are also traversed by rays extending from tho centro of the stem to tho bark, called medullard rays.' These are . very distinctly marked in tho sheoak, which split more readily in their direction or off the quarter as it is termed by bushmen ; in distinction to others which cleave more readily the opposite way, technically termed breaking off.
In trees, as the leaves expand tho sap ceases to flow, and the bark adheres to the wood; from January to March there appears to be a pause in vegetation; but after this period tho sap again begins to flow, and tho bark which adhered so | closely in the preceding months may be stripped j
almost as easily as in the spring.
In proparing timber for the use of the builder there are three principal things to be attended to, viz., tho ago of tho tree, tho time of falling, and the seasoning for use.
Jf a treo be felled before it is of full ago, whilst the heart wood is scarcely perfected, the timber will bo of inferior quality, nnd, from the quantity of sap contained in it, will bo very liable to decay. But, if tho treo bo allowed to stand until tho heart wood begins to decay, the timber will be weak and brittle'; the beet timber comes from trees that have nearly done growing, as there is then but littlo sapwood, and the heart wood is in the
The be3t time for falling trees is either in midwinter when the sap has ceased to flow, or in midsummer when the sap is temporarily ex- panded in the production of leaves. It is a good plan to bark the timber in the spring and fell it in winter, by which means tho sap wood is dried up and hardened.
The seasoning of timber consists in the extrac- tion or evaporation of the fluid parts, which aro liable to decomposition when the treo ceases to grow. This is usually effected at home by steeping the green timber in water to dilute and wash out the sap ns much as possible, and then drying it thoroughly by exposure to tho air in an airy situation. Tho common practico of usinjr timber that was crowing in the forest perhaps a few days beforo is objectionable, for the reasons stated, and Btill more is painting green timber. Still, at times tho exigencies of Australian life necessitate this being done, and another important reason is, that colonial hardwood becomes ^so excessively hard when dry as to cost double for sawing or working.
Pine, cedar, and other soft woods, aro not opon
to this objection ; and for Joinery purposes it is indispensable that the timber sawn be g woll seasoned. Tho best thing to do in the other case is to see that flooring boards, lintels, and so on, are dried as much ns practicable.
The durability of timber varies tinder different circumstances. In a wot state, the piles under tho piers of old London Bridge may bo instanced. They had been driven about GOO years, were of elm timber, and in 174G woro sound enough to support tho bridge. When buried in tho ground, timber is very durable. In digging around the foundation of old Savoy Palace, London, which was built 700 years ago, Trodgold says tho wholo of tho piles were perfoctly sound.^Soiuo wore oak
and olui, others beach and chestnut. Bclzoni, in opening ono of tho tombs at Thebes, discovered two statuettes, a littlo larger than lifo, in good preservation. The wood of these statues is pro- bably tho oldosfc in existonco that bears tho traeos of human labour. The durability of framed timbers is also very considerable. Tho trusses of tho old part of tho roof of tho basilica of St. Paul's at Romo, woro frauiod in 81G, and woro sound and good in 1814, a space of nearly 1000 yoars. Theao trusses nro of lir.
Paint, tar, pitch, or charring contributes much to tho durability of woll seasoned timber, but hastous tho decay of grcon timber.
Warmth and mois turo aro tho most prolific causes of dry rot. Building tiuibor into now walls io often a eauso of docay.
Ono of tho most doatruotiYo insoota to '-winch
timfeer la eSpoaed In Auatralia is the -white ant. It is very diiloront from tho carpenter or true ant, being a nasty looking insect about a quarter of an inch long, having a body about four-fifths of the full length, of a cream colour, very soft and fatty in substance. It has a head of a dark brown colour, pointed and protected by a thin shell or hard covering, with two short mandibles. The body is supported on short, dark coloured logB, which movo very rapidly, while the insect ad- vances about two inches in a second. The white ant destroys tho timber work of a honso without noise ; and frequently, as they so'.dom destroy the sut'taco of tho wood, their destructive work goes on without any indication of the mischief they are doing. They will eat out tho whole of tho interior wood, leaving a thin shell of tho surfaco untouched, and aomotimes only the paint supported hore and there by a thin splinter. In a week they will eat a large box full of paper, reducing tho whole to a mass of dark brown dirt. Their attacks are not confined to Boft wood, but every kind except Jarrah and teak are liable to hem. Deal weather-boards, skirtings, and archi- traves aro Very subject to their ravages. Gum timber and other hardwoods aro less seldom at- tacked. It may bo said thoro is no remedy. Timber has been saturated with corrosive sub- limate, chloride of zinc, creosote, salts of lead, and even carbolic acid, but with little or no advantage. These substances all tend to preservo wood in various degrees. Kyar*s patent was cor- rosivo sublimate, and Kyanising has many ad I vooates. Sir William Burnett's patent was
chloride of zinc, but the most succeasful means yet tried of preserving timber, whether from the effects of exposure to tho weather, dry rot, or the attacks of worms and insects, is by impregnating its substance with the oil of tar called creosote.
It may be desirable to notice Borne of the most valuable trees indigenous to Australia, but local experience will generally have taught the value and quality of the timber, peculiar to various
Iron Bark.-This ia a rugged looking tree, which frequently attains a height of 100 or 150 foet, with a diameter from 2 to 5 feet. The wood is very dense and hard; the colour is dark red ; it is very strong and durable, but is difficult to work. The weight of a cubic foot when dry is G4'¡jlb. Crushing force in the direction of the fibres, of a cube 1 inch square and 1 inch high, 99211b. Breaking load on the middle of a specimen 1 foot long and 1 inch square, is
Blue Gum.-(Eucalyptus globulus).-This tree grows to a height of 100 to 150 feet, with an average diameter of 3 to 6 feet. The wood is of a light reddish colour, hard and compact, and I rather difficult to work. The weicrht of a cubic
foot dry is about 53lb. The crushing force of a piece 1 inch square and 1 inch high is 88001b; and the transverse strength of a specimen 1 inch square and 1 foot long between the supports, loaded in tho middle, is 8381b. Another variety of tho blue gum grows in Tasmania, to a height of from 250 to over 300 feet, with a diameter of 8 to 10 feet. The colour of the wood is a yellowish
White Gum.-(Eucalyptus obliqua).-This treo is found in most of the colonies. It attains a height of 150 to 200 feet, with a diameter of nearly 8 feet at about 3 feet from the ground. The bark of tho tree is perfectly white, hence the name ; and so thin that above the butt it can be easily cut round with a sharp knife. I have seen sheets taken off whole (as the tree lay across a gulley) 15 and 20 feet wide; and six or eight large sheets from tho one beautiful straight stem. The weight and strength are about the same as blue gum, or rather less. The wood is much softer, of a lighter coloxir, and more easily
Stringy Bark.- (Eucalyptus gigantea).-This is considered ono of tho best trees for building purposes. It is very straight in tho grain. The colour is a light brown. On tho average in a forest tho stems run from 20 to 30 feet, and 2 to 3 feet diameter, and very straight. Occa- sional trees are much larger and longer. Clumps of young timber yiold splendid spars, of all sizes, great length, and straight as an arrow. Theso are useful for a variety of purposes. Tho weight of a cubio foot when dry is aboub 541b. Like other hard wood it is hard to work when dry. The bark is in great favour for roofing, and is the description most commonly used. 1 havo seen the roof of a hut that I was credibly informed was a quarter of a century old. It waB quito im- pervious to rain, but crumbled to dust under tho hand in lifting it.
Jarrah, or Australian Mahogany.-This is one of tho gum trees chiefly found in Western Australia, where it grows to a heicht of 200 feet. Tho colour is much darker than tho blue gum, and very much resembles mahogany. It is used for all ordinary purposes, as woll as hydraulic works, such ns piers, jetties, &c, and for snip building. It has tho most valuable property of resisting tho sea worm, and tho whito ant seldom penetrates moro than tho sap wood.
Oak (Fenns casuarina).-Thia is another hard- wood tree. It grows from 30 to 50 feet high and 12 to 30 inohes diamotor. Tho two species moat used aro tho forest oak, or sheoaks; - G. Forulosa; and tho swamp oak, O. Padnlosa. lt was formerly adopted by tho Oovornmont for shiuglos, but as it only oloaves iu radiating linos from tho centre (on the quarter), tho shiuglos bocomo foathor edged. A cubic foot weighs 421b. Tho crushing weight of an inch cubo is about 55001b, and the transverso strength about 8001b.
Codar.-(Oedrela Australis).- Tho Australian rod cedar ia supposed to bo tho samo species ns tho Ccdrcda toona ol India. It somewhat re- sembles thu Havannah codar, but is of a coaraor grain and darker colour, not unliko Honduras mahogany. It ia chiefly used for joiners' work and boat building. Tho weight of a cubic foot dry is 351b, and tho tranavorse strength of a specimen 1 foot long botwoon tho Biipporto and 1 inch square, loaded in tho middle, is about I
4711b. In former times tho wast o in this valuablo timber was vory groat, being so abun- dant on tho llichmond, Macloay, Claronco, and othor rivers north o£ Sydnoy m to ho UB:CI for
I firewood. It is now only to be attained farther
back, and is much more valuable
I Norfolk Island Pine (Araucaria excelsa).
J:¿is tree is a native of Norfolk Island and Australia. In tho former place it is found growing 200 leet high and 10 foot diameter, and has been known to reach the height of 267 feet, with a diameter of 12 feet for nearly SO feet of its length. Tho wood is white, tough, and close grained, containing a largo quantity of
Moroton Bay Pino (Araucaria Cunninghame). This tree is still plentiful in Queensland, growing to a height of 150 feet and 5 feet diameter. The wood is straight grained, tough, and tolerably free from knots. The colour is similar to that of tho yollow pine used in England. It is not so durable as Baltic pino, and is very liable to the attacks of sea worms and white ants. The weight of a cubic foot when dry is about 451b.
There are a vaBt number of other timber trees of almost equal importance, some possessing very peculiar properties, of which space will not permit any further notice. Among these may be named mountain ash, blackbutt, mess mate, peppermint, box, blackwood, light wood, Murray pine, bellah, tedgee, beef wood, &c; in fact, timber grows in rich profusion in all parts of this favoured land, excepting tho vast plains in the interior. _