Page:Cyclopaedia, Chambers - Volume 1.djvu/936

 GRI ( 1 86 ) GRI

We find mention of the Griffon in Holy Scripture ; but Poli/h • for this Reafon Huygcn recommends thofe a h't- are not to underlland theText of that chimerical Animal juft tie yellcwifh, reddifh, or greenifh ; M eveliiiS the blueifli. defcribed, which no Eody ever faw but in Painting and Ar- A Glafs is found to be free from Bubbles, Sands, Veins, mories, notwithstanding what Servius, in his Comment on Knots, and Spires, by holding it to the Sun, and receiving the 8 ,h Eclogue of Virgil and Ifidore, fay of it. — The Grif- the Rays through it on a white Paper; for the flaws above- fon in Scripture, is that Species of Eagle, called in Latin mentioned, will each project a Shadow thereon, OJJifraga, and in Hebrew D13, 'Peres, of the Verb D")3> If inilead of Lenticular, or at lead Spherical GlafTes, you Tares, to break. make ufe of Plate Glafs ; it mufl be divided, and cut with

God prohibited the Jews to eat divers Kinds of a Diamond, into Squares ; and if it be too thick to break Birds of Prey, as the Kne, Vulture, iSc. And the divers othcrwile, you may do it by laying it on a Table covered Species of Eaples, which are diftinguilhed in Latin by the with a Cloth, in fuch manner, as that the Side or Part to Names of AqSila, Gryfs, Ililu-tus. — 'Panfanias, in Area- be fever'd, hang over the Edge; for being (truck with an dicis, fays the Griffon has his Skin fpotted like a Leopard. Iron Inftrumenr, in this Situation it eafily breaks in the

The Griffon, we mean the fabulous one, is frequently Direction of the line drawn by the Diamond. Having feen on antient Medals ; and is ftill bore in Coat-Armour. thus got a fquare Piece, defcribc two concentric Circles

Or, a Griffon Rampant, with Wings difplay'd, Sable, is thereon, with a Pair of Compaffcs, one of whofe Legs car- born by the Family of Morgan in Monmotithjbire, &c. Gail- ries a Diamond ; the Diameter of the inner Circle, to be Aim blazons it Rampant; aliedging that any very fierce equal to the Breadth of the intended Lens, and that of the Animal may be fo blazoned, as well as a Lyon. outer fomewhat more ; and break off the Corners, as above

Sylveftcr, .Morgan, and others, ufe the Term Segrei- directed ; and 'the leffer Inequalities take off on a Grind- ant inflead of Rampant. See Rampant and Secreiant. Stone, or the like. Examine now whether the Piece of

GRILLADE, in Cookery, a Dim of Meat broiled on Glafs be every where equally thick ; if it be not, reduce it the Grid-Iron ; thus called from the French Griller, to broii. to fuch Equality by grinding it on an Iron Plate with Sand

The Word is alfo ufed for the browning of any Difh, by and Water. Laftlyjglue or cement the Glafs thus prepared rubbing a hot Iron over it. to a wooden Handle N M O, Fig. 3 I. with a Cement made

To Grill Oyfters, is to put them into Scollop Shells, fca- of Pitch, with a fourth part of Rofin ; or one Part of Wax, fon them witn Silt, Pepper, and Parfley (bred, and pour their and eleven of Colophony. Care to be taken that the Bali, own Liquor to them ; covering them with grated Bread ; or bottom of the Handle N O, be equal to the Glafs ; and flowing them half an Hour on the Fire, and browning them that the Centre of the Glafs and Handle meet to<*e- with a red-hot Iron. ther. Smaller Lens's, as thofe ufed for Microfcopes, are

Shrimps zvo^rrU'd after the fame Manner. fix'd on with Sealing-Wax.

GR-iKDING, trituration, the Ail of breaking, or com- Now^ to grind the Glafs, and bring it to the Convexity minuting a folia Body, and reducing it into a Powder, required; fmear over the Difh eq'taily with fine lifted Dull, Flower, Farina, or the like; particularly, by means Sand moiften'd with Water : Then taking the Handle with of a Mill. See Mill. the Glafs thereon, work the Bafon fometimes his way, and

Grinding is one of the Species of Diffolving. See Dis- fometimes that, to prevent the Form of the Bafon from be- solution. ing diilurb'd ; never leaning too hard therecn. When the

The Painters Colours are ground on a Marble, or Porphy- Glafs has get the Figure of the Bafon, clean it well of all ry, either with Oil or Gum Water; fee Painting and the Sand, and Filth adhering; and fprinkle the Ba'bn over Colour. _ with Emery moiften'd in'Water ; grinding the Glafs'tnere-

Some late Phyficians have contended, that Digefticn is on, till all the Rougbneffes and Inequalities are taken away. perform'd by grinding the Food in the Stomach : Some After this, the fine Sand ufed in Hour GlafTes may be of even maintain that every Part in the Body, is a Veffel Service, applied and ufed as before; remembring to take or Veffels; that all the VefTels have a Motion of Syflole ai i out the Sand when too much worn, and fubftitute new in Diallole ; and that all the Operations of the Body confiii in its ftead. Some in lieu hereof, chufe feveral Sorts of Emery, the Attrition or grinding of the Humours or Matters con- each finer than other, or even the Powder of Flints calcined tained in fuch Vefleis. See Digestion and Tritura- and pounded. Lafily, grind the fame Glafs in another tion. Bafon, or Dilh which is a Segment of a lefler Sphere,

Grinding is alfo ufed for the rubbing or wearing off, making ufe of the like Sand as before; till it have got a the irregular or otherwife redundant Parts of the Surface pretry high Rim or Margin all around, of a Body, and of reducing it to the deftined Figure, whe- In regard the Preffion is not here determined accurate- ther that be flat, concave, or the like. See Figure. ly enough upon the Middle of the Glafs, by the mere Gui-

The grinding of GlafTes is a confiderable Art, and as fuch, dance of the Hand ; fome have chofe to make Ufe of the neceffarily requires to be here infilled on ; efpecially that following Machine, efpecially for grinding of Objeft-Glaffes. of Optic Glaffes. See Glass, Optic Glass, £?c. Fix the Dilh H I, Fig. 14. on a horizontal Table : exactly

over its Centre let the Aperture D be, through which pafs Method of Grinding Optic Glaffes. an Iron Arm five or fix Inches long, faften'd to the Staff

A B. Let the other Extreme of the Staff be fitted into a

For Convex-Glaffes, the firft Step is to provide a Difh Hole cut in the Dilh, and faften'd therein. Now to «rind or Bafon, within whofe Cavity the Glafs is to be form'd. the Glafs, inftead of the Difh, take hold of the faid Staff

In order to this, they take a piece of Brals, Copper, Iron, an d work with Sand, tgc. as before, or Wood, and form it into a Segment of a Circle, with the Huygens tells us, that he firft ufed coarfe Emery, then a Radius of the Bafon or Dilh intended. This done, a Ba- finer Powder of the fame, which would be 50 Seconds in fon js made by a Smith, either of Iron or Copper; having finking to the bottom of a Veffel of Water, putting in fre/h its Cavity exactly fitting or correlponding to the Segment every half or quarter of an Hour. Sometimes too, he u- above mentioned : tho' fometimes they chufe to have- the fed Emery of 50 Seconds, for £ of an Hour; then Emerv Bafon call; in which Cafe, the Rules above delivered for of 400 Seconds, for J of an Hour; and lafily, Emery o'f concave Minors, are to be here obferved. See Mirrour. 45 Minutes-tor '4 of an Hour. The fame Effect is had from

The Figure of the Bafon thus roughly formed, is to be Powder of Flints, broke in an Iron Mortar, mix'd with finifhed in the Pewtercrs Lathe ; or on a Stone Mould A. Water, and ftirred fometime with a wooden Spatula, taking 1"a b. Mifeellany, Fig. 11. fixed to an Iron Axis, with a Pinion the Powder as it precipitates in fome certain Time to the BC, moveable by a Wheel D E, and that by a Winch or bottom of the Veffel, by decanting the Water. Handle F. The Bafon being ground on the Mould, till it What remains is, to polifh the Glafs ; -which fie under exactly fit in all Parts ; they take it off, and cementing it the Article Polishing.

to a wooden Block (loaden, if need be, with Lead) ftrew Grinding is alfo ufed for a coarfer, and lefsaccurate Me- it over with fine fitted. Sand, and thus grind it over again thod of fmoothing or polifhing the Surface of a Body; on the Mould, till all the Furrows or Scratches be quite particularly Glafs for Looking-Glaffes,e?c. See Looiunc- taken away. Glass, %$c.

Lallly, They grind large Pieces of Glafs in a Bafon, with In the new Method of working large Plates of Glafs for fine Sand between ; till fuch Time as its Surface being well Looking Glaffes, Coach-Glaffes, &c. by moulding, and, as fmoothed, there is no longer any Oppofition to the Motion, it were, calling them fomewhat after the manner of Me-

Note, the Difh is known to be perfectly finifhed, when a tals ; defcribed under the Article Glass : The Surface be- Hair being flrctched over ir, its Shadow projedled in the ing left uneven, it remains to be ground and polifhed. Cavity, particularly in a Camera obfeura, does not appear In order to this, the Plate of Glafs is laid horizontal, on a diftorted. Stone in Manner of a Table; and to fecure it the better,

The Bafon finijh'd, proceed to chufe Glaffes for the Pur- plafter'd down with Mortar, or Stuc, that the Effort of the pofe : In order to this, lay 'cm on clean Paper, and obferve Workman, or of the Machine ufed therein, may not make what Colours are projected thereon ;_ for the fame are the or difplace it. To fuftain it, there is a ftronp wooden Colours of the Glaffes. Always fct afide thofe of the darker Frame that furrounds it an Inch or two higher than the Colours, and chufe the brighter: But as the whiteft and Glafs.

brightell have ufually Veins ; and befide, in Tracl of Time, The Bottom or Bafe of the grinding Engine, is another by the Humidity of the Air, are apt to ruil, and lofe their rough G'afs, about half the Dimcnfions of the former : On

this