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decimal place, the scale not admitting of any more. Andnote, when the second decimal is 5, or more, the lirst decimalis made one more.

In the first quadrant, take the length of the middle radius,viz. 18.3: set one foot of the compasses in 20, then describean arc near to the centre ; with the same radius set the footof the compasses in 16.7, and describe an arc cutting theformer ; then, from the point of intersection, as a centre,describe an arc through all the three points 20, 18.3, 16.7.Proceed in the same manner with every quadrant, by takingthe middle radius ; and from the extremity of each outerradius, describe two arcs intersecting each other ; and fromthe point of intersection, as a centre, with the same radiusdescribe an arc through the two extremities, until you arriveat 2.4 ; then with the radius 2.4 describe a circle for theeye, and the whole spiral will be completed. >

Should it be required to describe a spiral through anygiven point, so as to form a fillet, divide the distance fromthe centre to that point into twenty equal parts, form a newscale, and proceed in the manner already described.

The foregoing Table contains the lengths of all the radii,to three places of decimals, and will be of use for volutesupon a large scale. And instead of constructing a scale forevery different spiral, the sector may be used, which is anUniversal scale to any distance within its reach.

But no instrument can be more easily or more accuratelyapplied, than the proportional compasses ; for if the sliderbe so shifted, that the two long legs may be to the two shortlegs in the ratio of the two first radii, then all the remainingradii may be found by extending the points of the long legsto the shortest radius, which will give the length of the nextshorter radius between the points of the short legs ; and byproceeding in this manner till all the points are found, thecurve may be drawn as before directed.

Plate II.—A volute drawn according to the precedingprinciples, consisting of three spirals : the numbers affixedfound the outer spiral are supposed to be minutes, and con-sequently no other scale will be required than that of theOrder itself; but in drawing the two interior spirals, two newscales must be formed ; or the scale of the order might beUtade to answer the purpose, by setting the proportional com-passes in the ratio of the two radii, then taking the length ofthe radii from the scale with the long legs, and transferringthe distances between the short legs to the spiral, and draw-ing the curve ; so that the whole may be completed as before.

The volute in this Plate is similar to that of the Ionic temple at Athens, the temple of Bacchus at Teos, and that ofMinerva Polias at Priene in Ionia.

j Plate III. Figure 1.—A volute in imitation of that of thetemple of Erechtheus, at Athens, drawn according to thepreceding principles. It consists of eleven spirals, whichmay be all drawn from the scale of the order by the assist-ance of a pair of proportional compasses. But if this usefulinstrument is not in the hands of the delineator, the elevenscales are here exhibited at Figure 2, for drawing the samenumber of spirals.

An universal scale may be made, as in Figure 3, thus :describe an equilateral triangle, cab, upon C b, equal to thegreatest radius; divide CB into twenty equal parts, anddraw straight lines from the points of division to A ; produceC b to b, and make B b equal to one of the equal parts ; divideB b into ten equal parts, and draw lines to A ; then make A dand ae each equal to the first radius, and draw the line ed,which produce to meet A b at d; then e d d will give thescale for drawing the spiral required: e d being the scale ofunits, and n d that of tenths ; and flhus any other radius maybe divided at once.

Figure 4, is another method of obtaining an universalscale, hy means of a right-angled triangle, ABC, right-angledat C, making C b and c A equal to each other : but there is nomethod so exact and expeditious as the proportional com-passes, and one scale, which may either be that of theorder or not, and consequently any scale divided, into unitsand tenths will answer the purpose, if this instrument beused.

Plate IY. shows a design for the capital and base of anIonic column, with the details of capital and..volute.

Figure 1 .—Front view of the capital*

Figure 2.—Plan of the same.

Figure 3.—-Profile or section through the front.

Figure 4. — Section through the flank.

Figures 5, 6, and 7.—Parts of the capital enlarged.

Figure 5 .—Half of the front, showing the sections throughthe volute and through the front.

Figure 6.—Elevation of the flank.

Figure 7.—Section through the front.

Figure 8.—Elevation of the base of the column to thesame scale as Figure 1.

VOUSSOIRS, the wedge-shaped stones forming the cur-vature or intrados of an arch.

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WAGGON-HEADED ceiling, a semi-cylindrical, orbarrel-ceiling, not uncommon in churches of the Gothic

style.

WAINSCOT, (from the Dutch wayschot,) in joinery,^ le linin'- of walls, constructed of wood, and most generally

Panelled.

The term wainscoting , as applied to the lining of walls,paginated in a species of foreign oak of the same name, used, or that purpose ; and although that has long been supersededby the introduction of fir-timber, the term has been con-ned notwithstanding the change of the material.Wainscoting is generally used for the lining of walls to the

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height of about 5 or 6 feet ; and when it does not reach thewhole height, it is called dwarf wainscoting.

To prevent the joints of panels from opening in conse-quence of the glue being softened'or consumed by dampsfrom the walls, the back of the wainscot ought to be primedover at the joint with white lead, or Spanish brown, andlinseed oil.

The method of measuring wainscot is, to multiply thelength by the breadth, and find the number of square yards ;the price is adjusted according to the difficulty of the workor the time required to perform it. See Carpentry andJoinery.