POL
318
POL
wdre the inventors of the pointed arch, and not of pointedarchitecture. Now, there is a vast difference between the twoquestions, for the former embraces but a fractional part ofthe latter : a pointed arch is but a component part, and doesnot of itself constitute absolute Gothic architecture, althoughit is one and a very important characteristic of it. At the sametime there are other peculiarities little less important ; sucliare its principle of verticality ; its lofty towers and spires;its cross-vaulting; its light and clustered pillars, with theirslender shafts ; its tracery, mullions, &c. ; these are all neces-sary to make up a complete whole, and each and all ought tobe considered in determining the origin of the style.
With such conflicting opinions as to the origin of thestyle, it is not to be expected that there should be any agree-ment as to what European country was the first to adopt it.The honour has been claimed for England, France, and Ger-many : the claim has been made for England by Sir HenryEnglefield and Horace Walpole ; but although the buildingsof the style are to be found in this country in great numberand variety, and are, on the whole, of greater purity, and, inour opinion, of superior excellence, to those on the continent,still more satisfactory evidence has been elicited in favour ofthe latter. The late Mr. Hope, in his Historical Essay onArchitecture, has produced much able argument in favour ofGermany ; whilst Wetter, a writer of that country, contendsthat priority of date, as regards the adoption and developmentof the style, properly belongs to France . The claim has beenmade for Italy , but there seems to be little evidence to favoursuch an opinion; and Mr. Gaily Knight, in his elaboratework on the ecclesiastical architecture of that country, givesgood reason for disregarding it.
Notwithstanding the variety and antagonism of the opinionswhich have been started upon the subject, it is possible thatmore than one of them may be partially correct, because avariety of circumstances may have contributed more or lesstowards the same end; but we must confess that the change ofstyle has not as yet been sufficiently accounted for. Whether thequestion will ever be determined beyond dispute, may fairlybe questioned ; nor do we know that any substantial advan-tage would be gained thereby. It is true, we are every dayadvancing to a more perfect knowledge of the style, and, inthe course of our inquiries, some unexpected light may bethrown upon the subject; but be this as it may, it is certainthat it will be much more advantageous to continue our jpractical study of the style, than to turn aside for the merepurpose of speculating on its origin.
POINTS, Proportion of Mathematical. It is a currentmaxim, that all infinities, whether infinitely great or infinitelysmall, are equal ; yet is the maxim false in both cases. Dr.Halley shows several infinite quantities, which are in a finiteproportion to each other ; and some infinitely greater thanothers.
The like, the honourable Mr. Roberts shows of infinitelysmall quantities, viz., mathematical points. He demonstrates,for instance, that the points of contact between circles andtheir tangents, are in a subduplicate proportion to the diame-ters of the circles ; that the point of contact between a sphereand a plane is infinitely greater than that between a circleand a tangent ; and that the point of contact in spheres ofdifferent magnitudes are to each other as the diameters of thespheres.
POLISHING, the art of giving a gloss or lustre to athing ; particularly a precious stone, marble, glass, a mirror,or the like.
For grinding and polishingsteel, the grindstones used aremade to revolve, either vertically or horizontally, with a velo-city so great as to describe sometimes as much as sixty feet
in a second. The steel is also, in some cases, dra' v, ‘ fl ndwards and forwards horizontally on a circular surfs ’gli-in order that the action may be equally distributed j„e;ii |jout the surface, it is allowed to revolve on an axis g t joii Wfof the friction : its motion being confined to one duthe action of a catch. Various substances, chiefly 0origin, are also used, on account of their hardness, ,^ e semediate materials, for grinding and polishing others- gj a ss,are diamond-dust, corundum, emery, tripoli, P utt ^’ re piU jsand, flint, red oxyde of iron, or crocus rnartis, and P , a iidchalk. These are sometimes applied in loose l’°'J fi9 iisometimes fixed on wood, leather, or paper. Cuttle- _ a i)0and seal-skin are furnished by the animal king 00 c iiicfl/Dutch rushes by the vegetable ; these are employ* hv t^‘
in polishing wood or ivory.
afl 1
d
the polishing-blocks are sometimes caused tomachinery in a trough, in which the marble is P a fjy to ()water, and are drawn at the same time gradua j , v hi c 'from the centre ; or the slab itself, with the frame ^jjgtl' 6it rests, is drawn slowly backwards and forwards, j ( ir 0 * 1blocks are working in it. Granite is polished f jt is
but
teb
it
rubbers, by means of sand, emery, and putty >necessary to take care, during the operation, that ^ wi“- jwhich trickles down from the rubbers, and carr . n)r , 3 , aj’jsome of the iron, may not collect below the c ° avoWstain them ; an inconvenience which may be who j ^ ^by employing rubbers of glass. that
POLLARD, in planting, a term applied to a
been frequently polled or .opped, and its topi—,i..u u __ nt
tree 'take»
j r - -- -rr- , ,■
headed down to the stem, for the purpose oi "' ge9j assmall poles for hurdle-wood, and other simila r u seas for hop-poles, &c. It is a term most commonthe southern and eastern districts of the k> bthough much wood of this small sort may be pt t
only »> u >ttill 3
ov ided 0 piystet 0
llivugu UlUOll I? WU VI bllil} QUiUil OVit J-*-* I* J - * ,
way, the practice has been highly reprobate >* ug g y~being destructive of good timber, but as a bat ' c ouOwhich disfigures, and renders the appearance o 9
disagreeable. f an tiq ll,t ^rf<t
POLYCLETUS , a celebrated sculptor V .C-
native of Sicyon , wbo flourished about the yea y„hest jj e S e ,was supposed to have carried the art to t e ofsihS le ^d ° fof perfection, at least as far as the excellence jjfg.gua * }could go. One of his figures, representing prop? r aS athe king of Persia , was executed in such exa ^ u jy it ^ e &that it was called the rule, and artists came 0 g esdV tjP e ‘model. He made the statue of a boy, wine i 'ppe * ,,d,at a hundred talents (nearly 20,0001 sterling^ ^y In 3 g j,e-ror Titus had two naked boys playing at a S iB It " 9 or te^which was considered as a perfect perform* 1 ’® sUpPculiar to him, that he formed almost all l* 13 jn vaf l tl‘ eon one thigh, which made them appear de c ‘ col 0 ! 11 '’, of" and XP^ l cnrfl' ceS
POLYCIIROMY (Greek ttoXvc
-. . "flat sunv^-g ii>
art of painting in positive colours, either on j;gyP tl!1 jcC®It was much used by "' lfl
•, he saW e E0 T}off iafl9 fsuch ornament. The Greeks adopted t , t ],e t of
it; as also r flDp lica tia
th® c „ tl>' 3
sculptured figures. Jt was muon u,™their edifices, and they were probably the^ ^ ^
decoration .. , .
There are still eSnJ^ Up ° n 11 ; as aisu — , cu .-
fins art in the ruins „e S ii amy s P e(: ‘ , neiis of the fPPf’^Lloar 1
st, H retaining the! i p f ercu l ;in eum and Fompeiu th . t ui$
V>. as 1® evIdenZ b , nlIi ^y. The Arabs excelled * gStheir peculiar bps *• by their edifices, which owe ! , er ioi' 3
f their ediflceAt 68 ( ° t,le aid ^ ^ ilS^
decoration, such r, com Ptetely covered with pol/ e , tV jtbactual painting 3 tPe W:, hs as were not ° oie j tH eS ',
^hrotne JJZ" 8 Uaed with aad S
US also m general use amongst our