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409
scu
f 0l) ^OLLOP ED MOULDING, a moulding commonly
do, . ln Norman buildings, of which the title is sufficiently
S0r> tive ‘
UPAS > an eminent Grecian artist, of the isle of Paros ,eq 0 flourished in the year before Christ 430. He wasdistinguished as a statuary and sculptor, and was thethose man y works which placed his name on a level with“ °f Phidias and Praxiteles . One of the columns in the
fo u 7 l ? °f Ephesus was his performance; as was one of the8 evp Sl .^ es ^ le famous tomb of Mausoleus . Rome possessed7 fine works, the productions of Scopas ; among which,tw- 0s t admired were the great group of Neptune and otherHjgt e deities, in the Flaminian circus; which, of themselves,lif® ’ according to Pliny , have been the labour of a wholeSc 0 ' n ‘" e same writer speaks of a Venus, the work of§Cr!’ sur P ass ' n 8 ‘ha 1 of Praxiteles .t^UlcT HA, (from o-Korof, obscurity, or darkness ,) a recessedthe t 11 ?®’ °f an elliptical or circular section, placed between<)U en ? ri > in the bases of columns. The scotia is most fre-fent y formed by the junction of circular areas of two diffe-Oogijt^d'i ; but this is upon an erroneous principle, as ithi 0tI r ather to be a regular portion of an ellipsis. See
r °ati(j e Scot ' a has an effect just opposite to that of the quarter-h'ot^ .’ The workmen frequently call it the casement ; and,to ,. s form, it is sometimes termed the trochilus. AccordingIt> lv len ’ * he cavetto is a fourth part of the scotia.die Ur 11 e Ionic and Corinthian bases, there are two scotias,SORa 1 " which is the smallest.
°f h„: A TCH WORK, (from the Italian, sgraffuita,) a mode
it,
for
Paioti]
'aid ■
i8 h7j“ tln e in fresco, by preparing a black ground, on whichwhich white being taken off with an
°t) ^ white plaster ;
ior s , °nkin, the black appears through the holes, and servesdiUojj .7 s - This kind of work is lasting ; but being veryV* un Pi easant t0 l h e sight. It is chiefly used to em-fronts of palaces, and other magnificent buildings.
an
ediR c .„ , a-- '
ip 6 „; tfom another. Screens are very frequent in churches,
'•'ItUlv iV xi n • ....... .1 _. _ l. . _
EN, a partition, or means of separating one part of
d>ey * a hy in those of a more important character, wherer °ai Used to partition off chantry-chapels, and such like,
‘'at,
the ™ a * n building; to enclose the choir, and to sepa-
v ati 0 7 e chancel from the nave, &c. Such screens are offlw ttlate rials, but usually of
We are ‘
,fhe SCR:
ofSEEN.
wood or stone, and manyexcellent designs and workmanship. See
c don erni * a also applied to any means of shelter or pro-to ^ c ttE{f a, " nst heat, cold, light, &c.
(Siting 7 rom the French , escran,) an implement used in' f,ict an r r , Q 7 tai '’ consistin g °f t ' lr ee wooden ledges joined to^tUg u „ a f frame at the bottom ; the upper part of which
Of
Oil
'Hie hhed with reticulated wirework, for sifting sand
f "oal (from the Dutch , scroeve ,) one of the six media-
te, ^ ers > chiefly used in pressing or squeezing bodies^ The s ° U oh sometimes also in raising weights.
J 1 ) and revv * s a spiral thread, or groove, cut round a cylin-„ >t. Q e verywhere making the same angle with the length
Sl“» th *t,if,he,urr,o. ‘ ' ■
Si
hi 6 ien ... -- _r_,
Would be to its height, as the circumference of
i of the cylinder, with this spiraltj- - it> were unfolded and stretched into a plane, the, le ad would form the section of an inclined plane,
*0f,
N, hi
'r> Vv oTk s P' ra i rises along the cylinder the distance between
distance
by
between two threads of thethat in making one
considering,
'‘ der is to the.i S 18 evident‘i* spiral‘breads.
screw may be traced upon theace of a cylinder thus : cut a sheet of paper into5 M
"V^rf 6 threads of a
the form of a right-angled triangle, having its base to itsheight in the above proportion, viz., as the circumference ofthe cylinder of the screw is to the intended distance betweentwo threads ; then wrap this paper triangle about the cylin-der, and the hypothenuse of it will trace out the line of thespiral thread.
When the spiral thread is upon the outside of a cylinder,the screw is said to be a male one ; but if the thread be cutalong the inner surface of a hollow cylinder, or a round per-foration, it is said to be female ; and this latter is also some-times called the box or nut.
When motion is to be given, the male and female screware necessarily conjoined ; that is, whenever the screw is tobe used as a simple engine, or mechanical power. But whenjoined with an axis in peritrochio, there is no occasion for afemale ; but in that case it becomes part of a compoundengine.
The screw cannot properly be called a simple machine,because it is never used without the application of a lever, orwinch, to assist in turning it. The force of a power appliedto turn a screw round, is to the force with which it pressesupwards or downwards, setting aside the friction, as thedistance between two threads is to the circumference wherethe power is applied.
For the screw being only an inclined plane, or half wedge,whose height is the distance between two threads, and its basethe said circumference ; and the force, in horizontal direc-tion, being to that in the vertical one as the lines perpendi-cular to them, viz., as the height of the plane, or distance ofthe two threads, is to the base of the plane, or circumference,at the place where the power is applied ; therefore the poweris to the pressure, as the distance of two threads is to thatcircumference.
Hence, when the screw is put in motion ; then the poweris to the weight which would keep it in equilibrio, as the velo-city of the latter is to that of the former. And hence theirtwo momenta are equal, which are produced by multiplyingeach weight, or power, by its own velocity.
SCRIBING, a term applied to the edge of a board, whenfitted upon any surface.
Thus the skirting of a room is scribed to the floor, in themost ordinary cases ; and the method of doing it is as follows:—Lay the edge of the intended skirting upon the floor; thentake a pair of compasses, and extend the points so as to beequal to the greatest breadth of the hollow between the floorand the skirting-board, taken in a vertical direction ; beginat one end of the board, and, with one point upon the floor,and the other upon the wood, and both points in a line per-pendicular to the horizon, draw the compasses towards theother end, keeping both points always in a straight line,parallel to the floor, and in the surface of the board, or in thesurface of the board extended ; and the upper point will tracea line on the board, exactly similar to the surface of the floor;so that, if the superfluous part below the line be cut awaj',the board will fit close to the floor.
Scribing, in joinery, the act of fitting one piece of woodupon another, so that the fibres of both may be perpendicularto each other, and the end cut away across the fibres, so as tofit upon the side of the other.
This method is used in doors and sashes, when it canbe done ; but in quirked mouldings, recourse must be had tomitering.
SCROLL, see Volute.
SCULPTURE, (from the Latin sculptural) the art ofcarving in wood, stone, &c. The term is also used for thecarved work itself.
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