The gauge has also a movable joint upon its stalk, or handle, by which means it can be placed square to any limb or branch, so as to gauge them; but it requires to be seen, before any conception can be given of it. The one I have long used has this motion regulated by means of a semicircular piece of ironwork bracing the scale, and fixed tangent arms about 3 in. beyond their point of junction, which hence prevents it gauging timber below that diameter.

The same motion can be given by means of a ball and socket, which is both more elegant and universal. The other, however, is more useful, as it strengthens the gauge at a point much wanted. Mr. Cary, in the Strand, has one now in hand for me, with all the improvements which my experience of the defects, and his knowledge of construction, could suggest.

On this it is proposed to have decimal multipliers stamped upon the fixed tangent arm, so as to be always at hand when any calculations are wanted on the spot; and the same brasswork is to be made to fit different sets of wooden arms, so as to be suitable for large or small-sized timber; it being inconvenient to use a large gauge for the latter. I may also notice that, instead of a regular gauge thus constructed, I have frequently used one of a more ordinary description, being merely a flat piece of wood, 3 in. or so in breadth, for the scale arm; on the under side of which the divisions for the quarter girt are marked with strong black lines right across it, and having a fixed tangent arm nailed upon one end of it, down into a round short rod fitted for a tin tube, by which it can be sent up to any height by means of other rods. By applying it to the tree, and the observer standing so as to look square past it, the division which cuts the opposite side from the fixed tangent arm can be ascertained, and read off, although not so correctly as when the perfect instrument is used.

I have them also made in a rough manner, with all the scales on them, and the slipping arm to move by the hand, which are useful for gauging timber when lying on its side, being so much quicker than the ordinary way; and such a mode will be found useful by all artificers who work with rough or unsquared timber, as their common rectangular square might be readily fitted for this purpose.

The divisions for the quarter girt scale, allowing for the bark, are found by dividing one foot in the ratio of 8.64 equal parts, each division being 1.388 in.; and such divisions, when the gauge is applied to a tree, are representatives of the real inches of its quarter girt when rectified, as formerly noticed, for the allowance for the bark; butit will be obvious that this scale can be so varied as to make any other allowance which may be

37

customary in different districts; and, when 1.388 is subdivided into four equal parts, the half and quarter inches are shown.

The quarter girt scale, without allowance for the bark, requires one foot to be divided in the ratio of 9.425 equal parts, each part representative of an inch being 1.273 in.

The circumference scale requires one foot to be divided in the ratio of 37.698 equal parts, each part representative of one inch, being 0.318 parts of an inch.

The diameter scale is divided into real inches and parts.

In making valuations of growing timber, the hedgerows and standard trees are usually all gauged tree by tree; but in large woodlands they are usually numbered in successive portions, enclosed within a white cord line, and classed under their respective heads, and some average trees then gauged.

Timber intended to be exposed for sale, when not cut down by the exposer, is usually gauged tree by tree, and a prepared list of the measurement and value put into the auctioneer's hands to assist in guiding him. London, May 30. 1837.

Explanation of References in Figs. 37. and 38.

Fig. 37. shows a side view of the gauge.

a a, Scale arm of box, lance, or any kind of elastic wood, defended on the edges with slips of thin brass plate, to make the tangent arm move more easily.

b, The fixed tangent arm.

c, The movable tangent arm. d, A sheave over which the cord ee is drawn, to move the tangent arm (c). There is a double sheave placed on the side. of the movable joint f, over which the cord is also drawn. e e, Cord for drawing the tangent arm (c) close upon the f, Movable joint. gg, Semicircular guide of iron or brass, to fix the scale and tangent arms square, to gauge branch wood.

tree.

h, Socket of iron or brass, with a screw cut on the inside, for infixing a rod of any length required.

Fig. 38. shows a horizontal view of the gauge, on which the scale arm (a a) is divided on its under side for the quarter girts; also the tangent arms (b and c) are shown at full length, and the sheaves (d and ƒ), over which

38

the cords are drawn; also a cross spring (ii) at the neck of the movable tangent arm, to keep it steady and erect; and a screw (k) for fastening the arms of the gauge either square or at any angular position required.

Fig. 39. shows a different horizontal view of some of the parts as above described.

ART. II. Valuation of the Woodlands upon the Estates of Drummawhance and Culdees, situated between Auchterarder and Crieff, Perthshire. BY WILLIAM BLACKADDER.

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GENERAL Remarks on Drummawhance Estate. The woodlands of this property extend to 41 Scotch acres, with the addition of numerous hedgerows, and some scattered timber in the middle of the fields. The trees are chiefly from 40 to 50 years of age, but a few are from 20 to 30, and very few of the oldest exceed 50. The plantations consist principally of larch, with a mixture of spruce and Scotch fir, and in a few cases some oak. The belts around the mansion are chiefly beech, with a few other varieties of hard wood; and the rows round the fields are generally oak, beech, and elm. None of these trees, except a few of the oldest hard-wood kinds, are of large size; but, as they are of vigorous growth, they will in time become fine timber, particularly the oak and beech, wherever the soil is of sufficient depth.

The larch, spruce, and Scotch fir are generally on soils which will not produce timber beyond the ordinary sizes for roofing, and other country purposes. Most of these being now arrived at maturity, are ready to be cut down. In some cases, as on the banks of the Machany, where there is a sufficiency of oak, it should be converted into coppice; and other places, wherever the soil is suitable, should be replanted with oak for a similar purpose. The soil, in general, is more adapted for oak and beech than any of the other varieties of hard wood: but beech is not a species of timber worth planting to any considerable extent.

Valuation of the Woodlands upon the Estate of Drummawhance.

Drummawhance Farm, No. 8. on the Plan, Wood at the Toll-house, 5.551 Scotch Acres.

data upon which they are founded is in every other respect correct. lower than the market rate, they may readily be recalculated: the be a fair average rate for the district; but, if they are higher or ment constructed for the purpose. The prices are considered to under different average sizes, and then measured by an instruthe trees on the estate were accurately numbered, and classed In making the survey for the following valuation, the whole of

This wood is about fifty years old; and the soil a drained marsh, made into raised beds. The
timber is very tall, but does not square on the side in the same proportion. The root-cuts for
12 ft. average a few inches more on the side than what the full timber length of the tree
does, as above set down; a remark which is also applicable to all the rest which follow. The
timber is of fair quality, and much in want of being thinned. There being so little oak, it has
been considered unnecessary to state the bark separately, as its value has been taken into account
with that of the timber.

558

0 6

13 19

0

31

688

0 4

11

9 4

10

0 6

0

5 0

12182