RET
365
E O A
\H
lr ° n ’ ^ inches diameter, were to lift a quarter ofettle weight that they would support, thenThe fir would bear ... 8£ c? 2 hundred weight.
Thei
rope
22 d 2 ditto.
^ iron . 6f d? tons.
' nVe stii^ e resu lts we may add, from the experiments and^rble 10as °f Professor Eobison, that a prism of whiteinch square, and a foot long, bears about 5001b.tS'sLt om ' he various authors he has collected, the0,0001, or ce °f a square inch of gold, when cast, is about*° ®0>00ful s *i ver > 40,0001b.; cast-iron from 40,000jo ni?' ’ wrought iron from 60,000 to 90,0001b.; soft. dir’ 9°lb.; razor steel, 15,0001b.; oak and beech, in;o° n °f their fibres, from 8,000 to 17,0001b. ;6 '0°4 ’ 0001b -; cedar, 5,0001b.; fir, 8,0001b. ; ivory,^ ' a ch j’ b ? ne > 5,0001b.; rope, 20,0001b. And a cylinder,S h’on "? d * ar aeter, loaded to one - fourth, will carry, if8f > 9 n..’. n5cwt.; of rope, 22cwt.; oak, 14cwt. ; and
0 pera? 1Stance some metals is doubled, or tripled, byla ' Ve H as‘T for gi n g and wire-drawing ; and the cohesive,j, e ratg ttle re pnlsive force of wood, is often increased bye ’ but „ Cotn pression. Oak will suspend much more than* 8 su F W ' b su Pport twice as much as oak ; which differ-th ’ yet , 0sed t0 arise from the curvature of the fibres ofr 8 two t baa keen known to support, with safety, moreN 250 f t0ns fo r every square inch. Stone will support^ 8oja eti ° ®50,000 pounds, on a foot square ; brick, 3001b.;s ^Uch. t ^ ea they are practically made to support one-sixthw p - , 011 ® is said to be capable of bearing a much* ®*ry, . in that position in which it is found in the
in, ^OrTJ," an y ot her position.
t\y 0 u ft ON OF FORCES, the division of a forcebe b sli a p e ^ arate forces, acting in different directions,e ^° HcEs - llaVe an e 4 u ‘ va ' ent e fi" ec t to the original force.
^>Vt a half pillar or pier attached to or abutting
atl 0 ^cts ) bT, (French ) the effect of a body, which either
Tiir ! s ° r ls back> *’ 6 '
, . stands either more out or in than
'“S term aS to be out of the line, or range, with it.J>l® f eq u *, S . little used in English ; though the want of aC^W^ m P° rt pi eads f° r its naturalization.
eu r !^ WALL , a wall erected for the purpose ofof j,. § slics ’ ° r ot k er loose or shifting material, and pre-8nd similar accidents ; such are the wing-walls
Wtwilto^'^’TED, a term applied to any plane surface,fyjj 11 is t 0 'f? ares by chequered lines. The use of reticu-hu a St Marine 6 e draw ‘ n " similar to a given original, in the
• p ‘ o ' ~ ” o- ■ ^ o w ~ 7 —*
tl ' • * P ur P ose > t ^ ie original is divided into
u . le size of the drawing, required to be copied,
SS. through * 6 ' lame num t >er °f squares ; then tracing‘nSig® S( i Ua ‘«
all the squares as they appear in theres of the original will give the outline of
. ’ f°ruiefi WORK, a kind of masonry ■
° s fflall square stones or bricks, set
.^Pr eS(
.*4
or brick-
f . Hre . - square stones or bricks, set lozenge-
01 Va ^ENo tbe appearance of net-work on the face.
tr y, °f r e ^MENT, (from the French , retranchment,Sn.^'iis v, ’ and trancher, to cut) in architecture, carpen-Vy Se i. 6(1 not fml„f-1... . -me. -•-■
Vn>£
m v ’ u 1 not only for what is cut off from a piece whenV,, a Vc e °f der to better proportioning it, or some otherb nt also for
ic
the projectures taken out ofys> &c., to render them more even, and in
5 A
Retrenchment, in war, denotes any kind of work castup to strengthen or defend a post against the enemy.Such are ditches, with parapets, gabions, fascines, &c. fora covering, &c.
Retrenchment, (in fortification) is more particularlyused for a simple retirade made on a hornwork, or bastion,when it is intended to dispute the ground inch by inch.
RETURN, in building, denotes a side, or part that fallsaway from the front of any straight work.
RETURN BEAD, a bead which appears on the face andedge of a piece of stuff in the same manner, forming a doublequirk.
REVELS, (pronounced reveals, from the Latin , revello, toretract or draw back) the vertical retreating surface of anaperture, or, the two vertical sides of the aperture, betweenthe front of the wall and the windows, or door-frame, mostcommonly posited at right angles to the upright surface.
The revels of windows, in common brick buildings, aregenerally 4£ inches in breadth, receding from the face of thewall to the sash-frame; but, in massy stone buildings, theyought to be of greater thickness, according to the magnitudeor dimensions of the aperture.
REVOLUTION, (from the Latin, revolvo ) in geometry,the motion of any figure quite round a fixed line as an axis.Thus, a right-angled triangle, revolving round one of its legsas an axis, generates by that revolution, a cone. See Cone .
RHOMBOIDES, (Greek) a quadrilateral figure, whoseopposite sides and angles are equal, but which is neitherequilateral nor equiangular; or, it is an oblique - angledparallelogram.
RHOMBUS, or Rhomb , (from the Greek, pep/Sw, toencompass, or turn round ) an equilateral rhomboid ; or aquadrilateral figure, whose sides are equal and parallel, butthe angles unequal ; two of the opposite ones being obtuse,and the other two acute.
RIB, (Saxon) an arch-formed piece of timber. Also theprojecting moulding on the soffit of a vaulted roof, whichdivides the vault into severies or compartments ; and servesto conduct the thrust of the vault to the pier erected for itssupport.
RIBBING, the whole of the timber-work for sustaininga vaulted or coved ceiling.
RIBET, a term used in Scotland for the recess made inthe sides of apertures of stone or brick work, to admit of dooror window-frames.
RIBS, arch-formed timbers for sustaining the plaster-workof a vault, or coved ceiling.
RIDGE, (from the Saxon, hrigg ) the highest part of theroof, or covering of a house. The term is particularly usedfor a piece of wood in which the rafters meet.
Ridge-Tile. See Tile.
RIGGEN, a provincial term for the ridge of a roof.
RIGHT ANGLE, an angle which subtends a quadrant orquarter of a circle, containing 90 out of the 360 degrees intowhich the circumference is divided.
ROADS , as regards the history of road-making, the firststeps towards the construction of permanent and durableroadways are said to have been taken by the Greeks, andalso that this people expended considerable care and labourin their construction. But more noted than the Greeks inthis matter, were the Carthaginians, from whom the Romansare by some reported to have derived their success in similarworks. The first Roman road was constructed during thecensorship of Appius Claudius , about 309, B.c. ; it was firstcarried to Capua, and afterwards extended to Brundusium ,a length of 350 miles ; its breadth is about 14 feet, and its