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manntr of laying the ftones, and even the quality of the 

 ftones; as wlicn the walls were built of rude, unequal 

 ftones. In reality, the ftones were cut for fuch work, but 

 not fquared or uniform ; fo that amenta ftood oppofed lo 

 quadrUt lap'ides. 



C«MENT is particularly ufed in Arch'tk^urc, for a ftrong 

 binduig fort of mortar, ufed to bind or unite bricks or 

 ftones to^xcther, for fomc kind of mouldings ; or to 

 make a bfock of bricks, for the car\ing of fcrolls, capi- 

 tals, &c. 



It is of two forts : the hot cement, which is the ruoft com- 

 mon, is made of rcfiu, bees-wax, brick-duft, and chalk, 

 boiled together. The bricks to be cxmented are heated, and 

 rubbed one upon another, with cxment between. 



The cold eminent is lels ufed; and is made of Che(hire- 

 cheife, milk, quick-lime, and whites of eggs. 



Mortar, folder, glue, &c. arc cements. The bitumen 

 brought from the Levant is faid to have been the ctcment 

 ufed in the walls of Bal)ylon. 



Equal quantities of powdtred glafs, fea-fak, and iron 

 filings, mixed with loam, made a very hard and durable 

 ctment. 



Mr. Boyle informs us, that the bed method to clofe and 

 repair pipes of fuhtenaneous aqueducts is with tobacco- 

 pipe clay pvilveri/.ed. and mixed with a large quantity of 

 pulverized flocks, and carefully beat up with liiifeed oil 

 into a ftitf palle. See Mortar and Tarras. 



CLEMENT is alfo ufed among Golafmiths, Engravers, 

 Jewellers, &c. for a compofition of fine brick-dull, well 

 lifted, refin, and bees-wax ; in ufe among thofe artificers 

 to keep the metals to be engraven, or wrought on, firm 

 to the block, &c. as alfo to fill up what is to be chil- 

 felled. 



The receiver of an air pump may be fattened to a metal- 

 line plate by means of a c:cment of bees-wax and turpentine, 

 made with equal parts, for the winter ; and three parts of 

 the former to two of tlie latter, for the fummer. We have 

 various receipts for making cxments to mend broken china 

 and glaffes : one of the fincft, and at the fame time (Irongtll 

 cxments for this purpofe, is the juice of garlick, ftamped in 

 a ftone mortar ; this, if applied with care, will leave little 

 or no mark. Another csment for broken glafles, china, or 

 earthen ware, may be prepared by beating the white of an 

 egg very clear, and mixing it with fine powdered quick- 

 lime ; or ifinglafs ; powdered chalk and a little lime may be 

 mixed together, and diffolved in fair water ; with which the 

 glafles, Sec. are to be cxmented, and then fet in the Ihade lo 

 dry. 



Drying oil with white lead is alfo frequently ufed for 

 this purpofe ; but where the veffels are not expofed to heat 

 or moillure, ifinglafs glue, with a fmall quantity of tripoli, 

 or chalk, is better. 



Some have recommended a cxmcnt made by tempering 

 quick-lime with the curd of milk, till it become of a proper 

 confidence for ufe ; but as cheefe has a greater degree of 

 tenacity than milk, the following compofition will be pre- 

 ferable. Let the thin fliavings of fweet cheefe be ftirred 

 with boiling water ; and when the tenacious (lime has been 

 Avorktd with other hot water, let it be mixed on a hot ftone, 

 vith a proper quantity of unflaked lime, into the confidence 

 ef a pafte, and it will prove a ftrong and durable cxment for 

 wood, ftone, earthen-ware, and glafs ; and it has this 

 advantage, that when it is thoroughly dry, it will receive 

 no injury from water. C. Pajot, of Charmes, lately tranf • 

 mitted to the Philomathic Society and the National Inftitute 

 of France, fmall bits of glafs, which he had joined and 

 foldcred fo firmly that the glafs would rather break clofe 

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to the junftion than in the fradlure ; but he concealed hi* 

 procefs lor this purpofe. However, it is not difficult to be 

 alccrtained. By intcrpofing between the broken parts a 

 glafs ground like a pigment, but more eafily fufible than 

 the pieces to be joined, and then expofing tluni to fuch a 

 heat as will fufe the cementing ingredient, the pieces will 

 be made to agglutinate without being themfelves fufed. A 

 glafs fit for the purpofe of cxmenting broken pieces of flint 

 glafs may be made by fufing fome of the fame kind of glafs, 

 previoufly reduced to a powder, along with a little red lead 

 and borax, or with the borax only. 



A cxment may be prepared for chemical glafles that will 

 bear the fire, by mixing equal quantities of wheat-flour, 

 fine powdered Venice glafs, pulverized chalk, with half 

 the quantity of fine brick-duil, and a little fcraped lint, 

 in the whites of eggs: this mixture is to be fpread upon 

 a linen cloth, and applied to the cracks of the glafles, 

 and ftiould be well dried before they are put into the fire. 



Old varnifli will likewife anfwcr the fame purpofe. A 

 very ufeful cxment for joining alabaHer, maible, poiphyry, 

 and other ftones, may be prepared in the following n!anner. 

 Melt two pounds of bees-wax, and one pound of refin ; add a 

 pound and a half of the fame kind of matter pulverized 

 as the body to be cxmented is compofed of, and ftir them 

 Well together ; let the mafs be kneaded in water, and heated 

 when applied to the heated parts of the body to be cx- 

 mented. The colour of this mafs may be adapted to that 

 of the body on which it is employed, by vai-ying the pro- 

 portion of the powdered matter added to the mafs of bees- 

 wax and refin. 



Jewellers, in joining pieces of precious ftone that are ac- 

 cidentally broken in the operation of letting, employ a 

 fmall piece of gum-maftich applied between the fragments, 

 previoufly heated fo as to melt the interpofed gum. They 

 are then prefled together fo as to force out the redundant 

 quantity of it. The Turkey cxment for joining metals, 

 glafs, &c. is prepared by diflulving five or fix pieces of 

 m.aftich of the fize of peas in a fufficient quantity of 

 fpiiits of wine, and diflblving as much ifinglafs (previoufly 

 fottened in water) in brandy or rum, as will make two 

 ounces by meafure of ftrong glue ; and adding two fmall 

 bits of gum-galbanum, or ammoniacum, rubbed or ground 

 till tbcy are diffolved ; let the whole be mixed with fuffi- 

 cient heat, kept in a llopped phial, and when ufed let in hot 

 water. 



Kafttllyn recommends a cxment for filling up cracks and 

 fiflures in iron veffels, which confifts of fix parts of yellow 

 potter's clay, one part of the filings of iron, and a quantity of 

 linfeed oil fufficient to form the whole into a pafte of the con- 

 fidence of putty. A durable cement for joining the flanches 

 of iron cylinders, and other parts of hydraulic and fteam 

 engines, n;ay be formed by boiling linfeed oil, litharge, red 

 or white lead, duly mixed, and applied on each fide of a 

 flannel filling the joint, which fliouid be put between the 

 pieces before they are clofely united by fcrews or other 

 faftenings. Another cxmer.t that will (land the aftion of 

 boiling water and fteam, may be prepared by rubbing in a 

 mortar and thus mixing together two oinccs of fal-ammoniac, 

 one ounce of flowers of fulphur, and i6 ounces of call iron 

 filings or borings. When this cxment is wanted for ufe, 

 one part of the above powder, and 20 parts of clean iron 

 borings or filings, fiiould be ir.timately blended by grinding 

 them in a mortar, and when uied, moiiUncd with water, and 

 applied to the joints wiih a wi,oden or blunt iron fpatula. 



Copper-fmiths often apply to the rivets and edges of 

 fheets of copper in large boilers, and in order to fecure 

 cocks from leaking, &c. a mixture of pounded quick- 

 lime 



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