SLA
431
SLA
Si\’ GI ‘ E " J0ist Floor, a floor without binding-joists.
Gle Joists, those which are employed singly in a floor,on Measure, a term applied to a door that is square
Uinni 1 s ' deS- stands opposed to double measure, orsi ( j e ' ec ^ on both sides. When doors are moulded on ones< l uare on l * ie other, they are accounted measure
of the situation or locality of a building, &c.; the plotSl 3»*d °n which it stands.
tvitjj ARCH, an arch, the face of which stands obliquelycrip t . rt ** er once to the inner faces of the piers. See a des-a Skew Bridge in the article Stone Bridge.to car ^'TABLE, a stone I’nMt at the bottom of a gable,tfonhtp^ l * le raking coping above. The term is of ratherCopi ntt . application ; and is employed also to signify theinto t? Use ^'> consisting of either slabs or solid blocks, toothed«ppl' ' e ntasonry of the walls. It may be, perhaps, furtherSeen ** to tPe sloping projecting rib of masonry frequentlyticni ° Ver gable-ends of roofs, where they abut against ver-' V ^en't^ S 0p S reater height than the apex of the roof; asof. ne roof of the nave of a church abuts against the side4 tower.
Sir 1
STINGS, or Skirting Boards, the narrow boards
ti ’ 7’ -- - -’ — - --
•he (j„ j 1 le niargin of a floor, forming a plinth for the base of
be noj 0 ’ or simply a plinth for the room itself, should there
°t l et . at '°" The skirting is either scribed close to the floor,
0 t the 7 o it by a groove ; in the former case, a fillet is put
SlflD k of the skirting, to keep it firm.
f°ies j,. (from the Swedish skiorle,) one or moresuper-
‘«a V i
in»
in piano, but which would cover a body without
an y interstice, or without any one part lapping upon
^ner’
^ann^!' p he f° ur sides of a room, when laid out in this
out liv,' ’ are called skirts ; as are also the sides of a roof laid
S fe a Plane ‘
, FEN, (from the French escraii) the instrument1>l0l 'tar^ ^bearers in sifting earth, lime, &c., for making
tri or e RIGHTS, glass frames placed in a roof with one orWang c nned planes of glass. Skylights are either in one!')■< *« when placed in the inclined side of a roof, orfbfiy ap a ‘> conical, conoidal, spherical, or ellipsoidal, whenls pe rt) e traced above the roof; in which last cases the axis
6 ^liui f n ^'cular, with the vertex, of course, above. Plane41 vur '
s > the most common of all, are sometimes made to slide:?H r T uidal Ilave a more grand appearance ; but the mostv 18 tPe conical and conoidal, particularly when thet Pe less fdow forms a dome. The spherical and ellipsoidalgraced than the conical or conoidal, and much moreI joint"]? 6 to execute. In all skylights, it is necessary thatli Old b aetvveen the bottom and the curb on which they rest,i * at >e 8 t, e ,. so Secured as to prevent water running through.
rr latl ^ 'gl'ts, not intended to open, are fixed in the follow-^irtcl th Qer: tPu u PP er side of the skylight is bevelled all0 U Oqi 8 e< ige of the frame ; a row of slates is fixed at thea er aperture ; the skylight is then fixed, and the
a ^AR 66 s ' des covered in the process of slating.
^ber t an outs '^ e plank, or board, sawn from the sides of^ fh e vv ree > and frequently of very unequal thickness.
a, 'blp 1( t is also employed to express a thin piece of
' '
ing of right angles and plane surfaces,a bluish fossil stone, very soft when dug outr*es, t 0 ’ an J thereby easily cut or sawed into long thin^in™’. . serve instead of tiles for the covering of houses,
SQtaU.,, te.
. Pri„,. is
b^' ; . is employed, in architecture, in sundry ways,
' Jiag s | °f which refers to the covering of the roofs of’ bt such lias been lately the perfection of working
in slate, that it is now wrought and fitted into many usefulutensils, as well as made up into balconies, chimney-pieces,casings to walls, skirtings, staircases, &c.
The slate principally used in London is brought from Wales ,taken from quarries on Lord Penrhyn’s estate at Bangor, Caer-narvonshire, whence it is forwarded to all parts of the UnitedKingdom . There are also some other kinds of slate in use,the best sort of which is brought from Kendal, in Westmore-land, and is called Westmoreland slate. These are of a finepale bluish-green colour, and are most esteemed by archi-tects. They are not of a large size, but of good substance,and well calculated to give a neat appearance to a roof. TheScottish slate is nearly similar in size and quality to a slatefrom Wales , called ladies, but they are very little soughtafter.
French slates, which were very much in use many yearssince, are small in size, most commonly not larger than theWelsh doubles, extremely thin, and, consequently, light ;but their composition has been found to be not well adaptedto this climate, where the atmosphere contains an excess ofmoisture. By analysis, this slate is ascertained to contain& of manganese, besides other matters, such as iron, &c., theexcessive affinity of which for oxygen soon shivers the stonyportion of the slate, when employed as a covering, in thiscountry.
Slaters class the Welsh slates after the following orderand designations, viz.
Ft. Inch. Ft. Inch.
Doubles, average size . 1 1 by 0 6
Ladies. 1 3 by 0 8
Countesses. 1 8 by 0 ib
Duchesses . 2 0 by 0 12
Queens . 3 0 by 2 0
Imperials . 2 6 by 2 0
Patent slate . 2 6 by 2 0
The doubles, so called from the smallness of their size,are made from fragments of the larger qualities as theyare sorted.
The ladies are similarly obtained, but in pieces that willsquare up to the size of such a description of slate.
Countesses are a gradation above ladies; and duchessesstill larger.
The slate is extracted from the quarries, as other stonysubstances usually are, that is, by making perforationsbetween its beds, into which gunpowder is placed and fused.This opens and divides the beds of the slate, which thequarrymen remove in blocks of very considersble size. Theseblocks are afterwards split by driving iron wedges betweentheir layers, which separates them into scantlings of fromfour to nine inches in thickness, and as long and wide as maybe required. Such of the scantling as is intended for expor-tation is sawn to the sizes ordered.
For the purpose of sawing the slate, the works in Wales are provided with abundance of ingenious machines, someof which are put in motion by steam, and others by water,which keep in action a vast number of saws, all cutting thescantlings into pieces adapted to their several purposes.
The imperial slating for roofs is uncommonly neat ; andis known by having its lower edge sawn, whereas all theother slates, used for covering, are chipped square on theiredges only.
The patent slate is so called, among the slaters, from the
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