Page images
PDF
EPUB
[merged small][merged small][merged small][merged small][graphic][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][subsumed][ocr errors][ocr errors][merged small][ocr errors][ocr errors][merged small][graphic][subsumed][subsumed][ocr errors][subsumed][subsumed][subsumed][ocr errors][subsumed][subsumed][merged small][ocr errors][merged small]

son.

of the ring-handles on the sides, it may be there. A furnace of this kind will fuse 30 cwt. moved along a floor without difficulty. A of pig iron in about three hours; the furnace great variety of operations, and on a tolerably being previously heated red before the charge large scale, may be performed in this useful of metal is introduced. The Auid metal runs furnace, which is very durable, and from its down the foor F, and accumulates below; weight and solidity not liable to be damaged when it is laded out through the door L, which by external blows, or easily displaced. is then opened; or it is suffered to run out

The Portable Chamber Furnace is of a through a hole at K, which was before stopmuch smaller size, and generally employed in ped with sand. The floor of the furnace is lecture roums; it is usually fitted for a great composed of sand, which in some degree vivariety of purposes. Its upper part often con- trifies without running; and every time before sists of a rounded dome terminated by a per- the furnace is used, the stoker rakes the sand pendicular iron fue.

into such a form as will suit best for the quanThe best Muffle Furnace for a very intense tity of metal to be fused. When the reverbeheat is that first employed by Pott, and after- rating furnace is used for heating iron or other wards by Darcet in experiments on the habi- matter without melting, its Aoor is made level; tudes of earths and storesin long continued and but its operation is exactly the same. The violent heat. The construction is simple; the brick-work of the furnace is surrounded with body is the form of an oblong coffer bulging iron plates, and kept together by long bolts, as out in the middle, the hole for the muftle is shewn in the plan. An air or wind furnace also in the middle; and the draught is raised for crucibles is described in BrASS POUNby a long perpendicular chimney.

DERY; but the shape of its body is adapted to The Reverberating Furnace is used for the number of crucibles it is to contain. roasting and smelumg ores: and in this the Refining Furnace. This consists of the fol. substance to be heated is not in actual contact lowing parts. 1. Masonry of the pillars and with the fuel, but strewed on a separate foor walls surrounding the furnace. 2. Channels or hearth placed between the fuel and the for carrying off the moisture. 3. Other sınall chimney, and is heated by the flame in its channels which join in the middle of the bapassage through.

4. Bason made of bricks. 5. Bed of The reverberating furnace is shewn in fig. ashes. 6. A hollow or bason in which the 2 and 3, Plate 80. The fuel, which is raw metal is melted and refined. 7. Great flamepit coal

, is placed upon the fire-grate AA, si- hole. 8. Two openings for the entry of the tuated over an arch, 'having free communica- tuveres of the bellows. 9. Vault or dome of tion with the open air. The coals are introduced the furnace. 10. Fire-place. 11. Grate. 12. through the hole BB: this has no fire dioor, but Draught-hole. 13. A hole in the vault, in lieu, the aperture is closed up with fresh which, being opened, serves to cool the furcoals; and when the fire requires a supply of nace. coals, the stoker shoves some of the coals into The Blast Furnace, or, as it is sometimes the fire, and stops up the hole with fresh coals. térmed, Cupola, is constructed within a castThis forins an effectual stoppage to the air, and iron cylinder AA, fig. 1, Plate 80, by lining it obliges it to pass through the grate and the with glass-grinder's sand; which being interAaming fuel laid upon it. The grate is covered mixed with small particles of glass, vitrifies over with a dome of fire-brick, DD; and upon with the first heating, and forms an excellent one side of the grate a wall EE of fire-brick is lining. The internal cavity is of a cylindric raised, which is called the bridge. Behind shape, and has a tap-hole B at the botiom, to this is the floor of the furnace FF, an inclined let out the melted matter; at D is the blowing plane leading from the top of the bridge to the hole, or tuire, through which the blast of air bottom of the chimney HH, which is lined is introduced by the nose F, of the bellows with fire-brick, and carried up about 30 feet FGH, which are double. The lower part GH above the fire-grate. K, is the door to introduce is moved up and down by the lever IK, which the iron or matter to be heated, which is placed a labourer works and forces the air into the upon the inclined floor of the furnace, oppo- upper part FG; from whence it is expressed site, or rather a little higher up, than the door, by the weight a into the furnace. By means which is now closed, and the fire lighted, upon of the double bellows the streain of air is conthe grate AA. The smoke and heated air from stantly supplied without any material interthe hire proceeds along the body of the furnace mission. For the fusion of iron, the fuel is up the chimney, and heating the air contained coke or charcoal, which is put in at the top, therein, the draught takes place by a column and the iron in fragments at the same time: 30 feet high of rarefied air in the chimney; the coke is lighted by first putting down a few which being lighter than the cold air, the hot coals, and blowing the bellows. In the flame is forced up the chimney by the weight course of half an hour the metal begins to drop of the atmosphere pressing upwards through down through the cokes, and accumulates in the fire-grate in a rapid stream, which parts the bottom of the furnace until the whole with its oxygen to the fire, while the remain- quantity follows. It is then let out by removder passes up the chimney in a rarefied state. ing the sand with which the tap-hole B was When the fire burns fiercely, its flame rises up rammed up:, For experiments, or for melting against the dome D, and is thereby reflected more valuable metals, a crucible is let down down upon the floor with exceeding great into the furnace with tongs, as described in force, and quickly heats ang matter placed Brass POUNDERY.

Many of our practical chemists of the pre- pipe, will carry that air along with it, and sent day have their laboratories stocked with a part with it again as soon as it comes out variety of furnaces, conmunicating very inge- of the pipe; and if the air is then collected niously where it is necessary with one common by a proper apparatus, it may with success be chimney, and are thus coinpetent to make any used for exciting the most violent degrees of experiments with the greatest case and least heat. expence. One of the best of this kind is that Thus, with very little expence, where there belonging to Mr. Pepys, which exhibits ele- is a sufficient quantity of water, as strong a gance as well as convenience. The set of fur- blast of air as can be desired may be readily ob. naces in this laboratory consists of a still with tained; for several machines may be constructits worm-tub; a furge-hearth; a muffle-fur- ed, and joined together in a manner somewhat nace; a strong drauglit-furnace for melting; similar to that above-mentioned, until all the a furnace for naked distillation; a square sande quantity of water is employed. It is proper to bath for digestions; and a round sand-bath observe, however, that as by this method the for distillations.

air is loaded with moisture, it is proper to Machines for blowing. Air into Furnaces. make the condensing vessel as high as correThe earliest method of animating large fires in niently may be, that the air may arrive at the the furnaces where ores were smelted seems to furnace in as dry a state as possible. The long have been by exposing them to the wind. slender pipes in the left-hand machines repreSuch was the practice of the Peruvians before sent a gage filled with mercury or water, by the arrival of the Spaniards among them. which the strength of the blast may be deterAlonso Barba relates, ihat their furnaces, call. mined. ed guairas, were built on eminences, where the In the large iron founderies another method air was freest; that they were perforated on is used for blowing up the fires by means of a all sides with holes, through which the air was kind of air-pumps. These consist of cast-iron driven in when the wind blew, which was the cylinders of about three feet diameter, exactly only time when the work could be carried fitted with a piston moved up and down by on; that under each hole was made a pro- means of a water-wheel. In the bottom of jection of the stone work, on which were the cylinder is a large valve like that of a bel, laid burning coals, to heat the air before it lows, which rises as the piston is lifted up, and entered the furnace. Sonje authors speak thus admits the air into the cavity of the cylinof several thousands of these guairas burning der from below. Immediately above the borat once on the sides and tops of the hills tom is a tube which goes to the furnace ; and of Potosi; and several remains of this practice as it proceeds from the cylinder is furnished are to be found in different parts of Great with a vaive opening outward. Thus, when Britain.

the piston is drawn up, the valve in the bottom This method of supplying air being sound rises and admits the air that way into the cylingenerally ineffectual and precarious, the in- der ; while the lateral valve shuts, and prevents strunients called bellows succeeded. These any air from getting into it through the pipe. were at first worked by the strength of men; When the piston is thrust down, the valve in but as this was found io be very laborious and the bottom shuts, while the air being compressa expensive, the force of running water was em- ed in the cavily of the cylinder is violently forced ployed to give motion to these machines. out through the lateral tube into the furnace. Thus a much greater quantity of metal could ju the great foundery at Carron, four of these be procured than formerly, and the separation large cylinders were a few years ago employed was likewise more complete ; insomnch, that at their principal furnace, and so contrived in many places the slags or cinders froin which that the strokes of the pistons, being made althe iron had formerly been extracted were ternately, produced an almost uninterrupted again used as fresh ore, and yielded plenty of blast. Some little intermission might indeed metal.

be perceived by the air, but it was too trifling But though this method was found to be to produce any sensible effect on the heat of preferable to the others, yet great improve- the furnace. Even this could have been pre inents were still wanted. In order to melt vented by means of a large reservoir into which very large quantities of ore at a time, it was all the four cylinders might discharge their necessary to use bellows of an immense size; blast. This should be furnished with a heavy and in proportion to their size they stood in piston; whose weight, being supported by the need of the more frequent and expensive re- air of the cylinder alone, would force it out pairs. The oil also,' which the bellows re- through its lateral tube in a manner perfectly quired in large quantity, becoming rancid, was equable, without any of that puffing or interfound to generate a kind of inflammable va- ruption in the blast, perceptible though but in pour, which sometimes burst the bellows with a small degree in the other, explosion, and thus rendered them totally use- To FU'RNACE. v. a. To throw out as sparks less. A new method, therefore, of blowing from a furnace : not used (Shakspeare). up fires, altogether free from the abovemen- FURNES, a town of Flanders, seated tioned inconveniences, was fallen upon by near the German Ocean, on the canal from means of water. It depends on the follow- Bruges to Dunkirk. Lat. 51. 4 N. Lon. 2. ing principle, viz. That a stream of water, 45 E. running through a pipe, if by any means it TO FU'RNISH. v. a. (fournir, French.) is mixed with air at its entrance into the 1. To supply with what is necessary (Knolles). 2. To give; to supply (Addison). 3. To fit goods, all kinds of the coarser hardware, cotup; to fit with appendages (Bucon). 4. To ton, hats, and stockings. equip; to fit out for any undertaking (IVatts). Furrs, in heraldry, a bearing which repre5. To decorate; to supply with ornamental sents the skins of certain beasts, used as well household stuff (IXalifax).

in the doublings of the mantles belonging to FU'RNISHER. š. (fournisseur, French.) the coat-armours, as in the coat-armour themOne who supplies or fits out.

selves. FU'RNITURE, s. (fourniture, French.) FU'RRIER. s. (from fur.) A dealer in furs. 1. Moveables; goods pui in a bouse for use or FU'RROW.s. (purh, Saxon.) 1. A small ornament (South). 2. Appendages (Tillol- trench made by the plough for the reception of son). 3. Equipage; embellishments; deco. seed (Dryden). 2. Any long trench or hollow rations—in this sense the word is chiefly ap- (Dryden). plied to the extra lines and curves drawn upon

FU'RROW-WEED. $.

A weed that grows a dial; as the ecliptic, parallels of declination, in furrowed land (Shakspeare). &c.

To FU'RROW. v. a. (from the noun.) To FUROR UTERINUS. (furor.) See cut in furrows (Milton). 2. To divide in long NYMPHOMANIA.

hollows (Suckling). 3. To make by cutting FURR, in commerce, signifies the skin of (Wotton). sejeral wild beasts, dressed in alum with the FU'RROWED, in botany, futed or grooveck hair on, and used as part of dress, by magis- stem. Caulis sulcatus, Marked with deep trates and others. The kinds mostly made use broad channels longitudinally. Applied someof are those of the ermine, sable, castor, hare, times to the leaf. rabbit, &c. It was not till the later ages that FURRUCKABAD, a district of Hindustan the furrs of beasts became an article of luxury. Proper, contiguous to the W. bank of the GanThe more refined nations of ancient times ne- ges, and surrounded by Oude. The chief town ver used them; those alone who were stigma- is of the same name.' Lat. 27. 28 N. Lou. tised as barbarians were clothed in the skins of 79. 30 W. animals. During captain Cook's last voyage FU'RRY. a. (from fur.) 1. Covered with to the Pacific Ocean, besides various adrantages fur; dressed in fur (Felton). 2. Consisting of derived from it as enlarging the boundaries of fur (Dryden). science, a new source of wealth was laid open FURSTENFIELD, a town of Lower Sti. lu the exchange of European commodities for ria, in Germany, 50 miles S. of Vienna. Lat. furrs of the most valuable and important kind 47. 23 N. Lov. 16. 5 E. on the north-west of America. Previously to FURSTENWALD, a town of the middle this, a similar tracle had been carried on, though Marche of Brandenburg, in Germany. It is on a much narrower scale, in Canada. It was 20 miles W. of Frankfort. Lat. 52. 23 N. begun by the French almost two centuries back, Lon. 14.8 E. and in time Montreal was the grand mart of FU'RTHER. a. (from forth ; forth,

further, this species of commerce. The number of In- furthest. See Forth and FARTHER.) . dians who resorted thither increased as the name At a great distance. 2. Beyond this (Matof the Europeans was more known. Whenever thew). 3. Further has the force of a substanthe natives returned with a new supply of furrs, tive in the phrase no further, for nothing furthey usually brought with them a new and ther. more distant tribe; thus a kind of market or FU'RTHER. ad. (from forth.) To a greater fair was opened, to which the several Indian distance (Numbers). nations of the new continent resorted. Our To FU'RTHER. v. a. (rorðrian, Saxon.) To own countrymen were not long easy without put onward; to forward; to promote ; to counsharing in this trade, and the colony at New tenance ; to assist ; to help (Hooker). York soon found means to divert the stream of FU'RTHERANCE. s. (from further.) Prothis great circulation. The Hudson's bay motion ; advancemnent; help (Tillotson). trade, carried on by a company designated as FUʻRTHERER. s. (from further.) Promo. the Hudson's Bay Company, was at one time ter; advancer (Ascham). almost the only trade in this article from Great FU'RTHERMORE. ad. ( further and Britain ; there have, however, been other per- more.) Moreover ; besides (Shakspeare). sons of late years engaged in it. About twenty FU'RTIVE. a. (furtive, French.) Stolen; years ago a commercial establishment of this gotten by theft (Prior). kind was formed under the title of the North- FU'RUNCLE. (fúrunculis, from furo, to West Company. It was an association of rage; so named from its heat and inflammaabout twenty persons, agreeing among them- tion before it suppurates.) A boil. An inflamselves to carry on the furr trade. Their capital ination of a subcutaneous gland, known by an was divided into twenty shares; of these a cer- inflammatory tumour that does not exceed the tain proportion was held by the people who size of a pigeon's egg. managed the business in Canada, who were FU'RY. s. (furor, Latin.) 1. Madness. 2. stiled agents, and paid as such independently Rage ; passion of anger ; tumult of mind apof the profits of the trade. The articles manu- proaching to madness (Shakspeare). 3. En. factured here that are used in this traffic, are thusiasm; exaltation of fancy (Dryden). coarse woollen cloths of different kinds, blan- 4. A stormy, turbulent, raging woman (Adkets, arms and aimunition, Manchester dison).

« PreviousContinue »