I:
; !
i i
the plaster shall form the surface of a sphere. See Plas-tering.
The form of the bracketing depends upon the planes inwhich they are disposed, within the surface of a sphere: but,in all cases, the edges are circular, because the section of asphere is a circle, according to any position of the cuttingplane: the edges of the bracketing will be equal circles, whentheir planes intersect each other in the centre of the sphere;in this case, the edges require no bevelling: but if the planesof the brackets are disposed in a parallel way, the edges areall unequal circles, and the edges, which receive the lath, willbe more oblique, as the planes of the circles are more remotefrom the centre of the sphere : therefore, the quantity oflabour, and the waste of timber, will entirely depend on thedisposition of the planes of the bracketing.
SPHEROIDAL BRACKETING, the bracketing pre-pared for a plaster-ceiling, whose surface is to form that ofa spheroid.
As all the sections of a spheroid are either circles orellipses, the edges of the bracketing are either circles orellipses.
As a spheroid may be supposed to be generated by therevolution of a semi-ellipsis upon one of its axes; therefore,if the planes of the bracketing be disposed in parallel planes,perpendicular to the axis of the generating circle, the edgesof the bracketing must be circles.
If the planes of the bracket be disposed in planes passingthrough the axis of rotation, the edges of the bracketing will• be portions of an ellipsis, equal and similar to the generatingsemi-ellipsis.
If the planes of the bracketing be so disposed as to passthrough a diameter of the great circle of the spheroid, viz.,that circle perpendicular to and bisecting the generating axis;then all the ribs of the bracketing will be elliptic quadrants,bounded by two semi-axes and the quadrantal curve ; oneof the semi-axes will be equal to the radius of the greatcircle, and the other will be found upon the plane of the gene-rating ellipsis.
SPHINX, a sculptured figure frequently found in Egyp-tian temples, and their approaches, representing a monsterwith the head and breasts of a woman, the wings of a bird,the claws of a lion, and the other parts of the body likea dog.
SPIRAL, (from the Latin , spira, involved,) a curve whichmakes one or more revolutions round a fixed point, and whichdoes not return to itself. See Volute.
SPIRE, a pyramidal acutely-pointed lofty termination ofa tower, of which some of our cathedrals and churches pre-sent fine examples. Spires are built of stoneor of wood coveredwith lead,slate,or oak shingles. They were probably not intro-duced into England till some time after the Norman conquest .Tn the earliest examples, they are usually of the same plan asthe tower, either square, circular, or octagonal, and are ofno very great height. In early English examples of laterdate, they are sometimes of the same plans, but more fre-quently octagonal, and also of much loftier proportions;where an octagonal spire stands on a square tower, the angu-lar spaces left unoccupied are covered by pinnacles, or bysemi-pyramidal masses of masonry sloping against the spire.The outline is frequently broken by one or more tiers ofsmall open windows, termed spire-lights, the faces of whichare vertical, and therefore project out at the top from thesloping face of the spire ; they are usually covered with ga-blets or sharp pediments, which, in the later and more orna-mented styles, are often enriched with crockets, finials, pin-nacles, &c. Spire-lights are frequently placed on the alternatefaces of the spire in alternate tiers. Early English spires
'g tO
are usually what are termed broach-spires; that j t thethey spring directly from the edge of the tower, W . g> th 0intervention of a parapet, whereas, in the later ® •p^peO'parapet is seldom omitted. In the Decorated an j iaV in^dicular styles, the spire is more enriched, usua 1 tL® P’”"angular pinnacles, and often flying-buttresses * roU ^j eg of t*' enacle to the spire; crockets sometimes adorn the ang ^ stage*spire, and ornamental bands divide it into sevei ot
Spires are terminated at the apex either with a ^ of 8metal cross or vane, the latter being frequently w - reg ojcock, as an emblem of prayer and watchfulness. Jjueiib 1open work are not unfrequent in the larger cchurches.
to sphas
SPLAYED, (from the old French , disployer,abioad,) a term, in architecture, applied to whatever 1side making an oblique angle with the other: thus, t"?ing-joints of a boarded floor are frequently splay ed 1
ire»°
ou e
head'
thei!
WL 14 wuttiucu 11UU1 Uio ncnuui^v ' 1 n ■ in '■
thickness, as are also the jambs, or sides, of a
the
■eatest
■ture
latter case, the room may be lighted to the g 1L ~^ a peritage. The word fining is sometimes applied toin the same sense as splayed. de by * f
SPRING BEVEL OF A RAIL, the angle^ ends ottop of the plank, with a vertical plane touchingthe rail-piece, which terminates the concave s 1 • t (Jng * 1SPR1NGED, in boarding a roof, the art °‘ ut the ra'“ gboards together with bevel-joints, so as to keep 0 0 fSPRINGING COURSE, the horizontal coum ^ ^from which an arch begins to spring ; or the r ^
upon which the first arch stones are laid. . the c °P' n °
The term is also applied to the bottom stoneof a gable. • „ four
SQUARE, (from the Latin , quadratus, haV ^° er ial,ners,) a term, among workmen, applied to any j n join® Ltwo of the sides stand perpendicular to each ot \‘ ua re, vVthe work is said to be square-framed, or frame rn 0ljl
the framing has all the angles of its styles, i al ’ _ a
ings, square, without being moulded. , - an a»g' e j. g ,
Square , an instrument for trying whet! ^ j nrl er sfl u j g3)right angle, generally consisting of an outer ^ I1 j nter ior aU ^parallel to each other ; the former for tryingthe latter for exterior ones.
Square-Shoot. See Water-Shoot. fortify' 1 ’*’
Square -Staff, a piece of wood, used lor ^ a
angles of plaster-work intended to be paper® c utti sSQUARING HAND-RAILS , the metho^ ^ ti.e^
■ing , is *>*
■v ~~ -— ;1 • as th e •* flCC 1 *
the execution of hand-rai », r or ® ^gjgei
and finishing must be regulated by it. -*- 0 “ j^el, ° r Justrately, the plank must be shot to the propel li" e jjed>then, supposing it to be set to the pitch, a v ^ gt be "Djay
plank to the form of a rail for a staircase, s0 ; s thetical sections may be rectangles. The squeidifficult part in
tnen, supposing it to tie set to me pi“.»> gt bebe drawn on the edge, and the faee-mould^^ p 0
first on one side of the plank, so
that
of tlw®
ini 3 .’
co" 1
come close to the edge that is shot, and, n by ^ >e fr 11j:_ it _a:_ 1 r. _tn be O ia
ding with the vertical face, lines are to be * ^ jjp.
of the mould on the surface of the plank. Iin er, aI1 t oto be applied to the other side, in the same ^ be c ^jugdrawn as before; after which, the plan ^-eat c8 , r6 e d£ ei
he
of the mould on the surface of the plank.
£
lank
between the lines thus drawn on both yi a r. 1* 10 o f d‘ e
taken to keep the teeth of the saw perpen ^ bottom g e ewill then only want smoothing, and the *°P „ jjj n n- m 011rail-piece will be brought to a level by th e
Hand-Railing.
the
ottt
SQUARING OF A PIECE OF STUFF,ing it up by the square, in order to makeangles.