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420
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may safely wash them in melted lead. He adds, that by washinghis hands in the juice of onions, he could bear a hot shovel on themwhile it melted lead.
Fire-Cocks, are contrivances for admitting water into pipes orreservoirs ; churchwardens in London , and within the bills ofmortality, are enjoined to lix them at proper distances in streets,together with painted characters on the opposite wall, pointing outsuch distance. They are also ordered to deposit in every housethus marked, an instrument or key for opening a plug, and like-wise a large engine, and an hand-engine, under the penalty of tenpounds.
h ire-Engine. See Steam-Engine .
Fire-Escape, a contrivance for the purpose of rescuing per-sons in imminent danger from fire. In the Annual Register for1775, an account is given of a machine for saving persons and ef-fects from the flames. It consists, l. Of a pole of fir, which maybe of any convenient length, being about live inches in diameterat the bottom, and at the top or smallest end, about three inches.At the distance of three feet from the top, is a mortice through thepole, to which a pulley is fixed, that is nearly of the same diame-ter as that part of the pole. 2. A rope about three-fourths of aninch in diameter, and twice the length of the pole, at one end ofwhich is a spring-hook, to pass through the handle of the basket,when used ; it is put through the mortice over the pulley, anddrawn tight on each side, nearly to the bottom of the pole, whereit is secured till wanted. 3. A basket which ought to be of strongwicker-work, three and a half feet long, two and half feet wide,rounded off at the corners ; and four feet deep, rounding every"’ay at the bottom. To the top of the basket is fixed a strong ironcurve, or handle, with an eve or ring in the middle : a small cordabout the length of the pole, is likewise fastened to one side of thebasket, near the top. These being the principal parts, there arealso several straps, &c. tor securing the poles from sliding; ofwhich the reader will find a minute account in the volume beforequoted. This contrivance can be raised, and two or more per-sons may be taken out of the upper windows of a house, and letdown safely in the street, within the space of thirty-five seconds,or in little more than half a minute. \Ve cannot on this occasion,omit to point out the great utility of those fringed ropes whichshould be fastened lo the foot of a bedstead, and extend to a suf-ficient length, to descend by them, in case of fire, through a win-dow : they are sold by several rope-manufacturers in town, gene-rally at two shillings per yard.
FIRE-PLACE, a .contrivance for communicating heat torooms, and also for answering various purposes of art and manu-facture. See Furnace and Stove . In the construction of fire-places for domestic purposes, the chief object is the saving offuel ; vvith this intention, several ingenious artists have inventeddifferent kinds of grates, more or less adapted to that useful end.i he fire-places in general use are, 1. The large open ones, whichWere commonly adopted in former times, and are still retained inflic country, and in kitchens: they require a wide funnel, con-s ume a great quantity of fuel, and generally smoke, unless thedoor, or a window, he left open. 2. The modern fire-places ge-nerally adopted in towns, are constructed with low breasts andhearths^ narrowed by jambs. These being more contracted than*l>e antiquated chimnies, easily keep the room free from smoke ;hut the funnel necessarily occasions a considerable draught of air,which rushing in at every crevice, renders the situation of those''up are exposed to it very uncomfortable, and even dangerous:or it is unquestionable, that most of the diseases that proceed fromoolds may he justly attributed to the strong draught of cliim-rues, by which, in severe weather, persons are scorched before,while they are freezing behind. Such fire-places, therefore, areof I'Wc service in heating rooms, as the surrounding air, which is"’armed by the direct rays of the fire, does not remain in die apart-eient, but is continually collected in the chimney, by the current0 c pid air which surrounds it, and by which it is in a short timeparried off. Nor is this the only inconvenience attendant on such'^'proper contrivances; for the greatest part of the lire is lost, inconsequence of its being absorbed by the back, jambs, and hearth,which are dark and obscure, and reflect very little, so that theleat flips directly up the chimney. 3. To remedy this inconve-Ience , an ingenious Frenchman, named Gauger, in the year 1709,proposed seven different constructions of a new kind of chimnies,11 wluoh there are hollow cavities, formed by means of iron plates
v ol. II— K0 . $4
inserted in the back, jambs, and hearth ; through these the heatpasses and warms the air in those cavities, which is thus continu-ally communicated to the room. Although many advantagesarise from this arrangement, yet the expence necessarily incurred,must ever be an insuperable obstacle to its general adoption. 4.Another kind of fire-place is the Holland iron-stove, which has aflue proceeding from the top, and a small iron door that opens intothe apartment. They serve to warm a room, lessen the consump-tion of fuel, and to produce a constant change of air; but, as thelire is too much confined, it is neither sufficiently cheerful, norcalculated for culinary purposes, and is therefore employedchiefly in work-shops. 5. The German stove consists of ti'*e ironplates, which are screwed closely together in such a manner, thatthe fuel may be put into it from another room, and even from theoutside of the house. This stove warms rooms with little fuel,and is not attended with anv danger from the irruption of coldair ; but it admits of no change or draught of airm the room, andthe fire is likewise concealed. Such are the inconveniencies at-tending tiie fire-places in general use ; and, though we by nomeans wish to depreciate the inventions of Count Rumford , yetwe are of opinion that the Pennsylvania fire-place, which was origi-nally contrived by Dr. Franklin, is eminently adapted to domes-tic purposes, both for its economy in the consumption of fuel,and on account of its efficacious mode of imparting heat. Fromthese considerations, we have been induced to present the readerwith some account of this machine, which consists : 1. Of a bot-tom plate or hearth-piece, as shewn in the figure, with a risingmoulding in front, for a fender. See Plate L\X. fig. 5. At thesides are attached two perforated ears, F. G, for receiving twoscrew-rods; a long air-hole u a, through which the outwardair passes into the air-box ; and three smoke-holes represented bythe dark squares in BC, through which the smoke descends andpasses away ; besides, double ledges for receiving between themthe lower edges of the other plates. 2. A back plate withoutholes, and furnished with a pair of ledges to receive. 3. The twoside plates, each of which iias a pair of ledges to receive tile side-edges of the front plate, with a shoulder on which it rests two pairof ledges to receive the side edges of the two middle plates whichform the air-box, and an oblong air-hole near the lop, throughwhich the air warmed in the box is discharged into the room, anda wing or bracket as II, and a small hole as R, for the axis of theregister to turn in. See fig. 6, which represents one of theseplates. 4. An air-box, conSposed of the two middle plates DEand FG, fig. 7 and S. The first has five thin ledges or partitionscast on it, the edges of whicli are received into so many pair ofledges cast in the other - , the tops of all the cavities formed bythese tlvn deep ledges are also covered by a ledge of the sameform and depth cast with them ; so that when the plates are put to-gether, and the joints luted, there is no communication betweenthe air-box and the smoke. In the winding passages of this box,fresh air is warmed as it passes into the room. 5. A front plate,whicli is archyd on the under side, and ornamented with foliages.Sic. 6. Atop plate, with a pair of ears M, N, fig. 9, answerableto those in the bottom plate, and perforated for the same purpose.It has also a pair of ledges running round the under side to re-ceive the top edges of the front, back, and side plates.. The air-boxdoes not reach up to the top plate by 2| inches. All these platesare of cast iron ; and when they are all in their proper places, theyare bound firmly together bv a pair of slender rods of wroughtiron with screws, and the machine appears as in tig 9. There arealso two thin plates of wrought iron, viz, 7. Tlie shutter, whichis of such a length and breadth as to dose well the opening of thetire-place, and serves to blow up the fire, and to secure it in thenight. It is raised or depressed by means of two brass knobs, anilslides in a groove left between the foremost ledge of the side platesand the face of the front plate. 8. The register, which is placedbetween the back plate and air box, and furnished with a key ; sothat it may be turned on its axis, and made to lie in any positionbetween level and upright. The operation of this machine, andthe method of fixing it, may be understood by observing the pro-file of the chimney and fire-places in fig. 10. M is the mantlepiece or breast of the chimney ; C the funnel; B the false back,made of brick work in the chimney, four inches or more from thetrue back, from the lop of which a closing is made over to thebreast of the chimney, that no air may pass into the chimney ex-cept that which goes under the false back, and up behind it; T5 11 tie