1854.] 



NEW SMOKE-CONSUMING AND FUEL-SAVING FIRE-PLACE. 



When the coal is heated to about 600 degrees Fahrenheit, the 

 bitumen or pitch evaporates as a thicli, visible smoke, which, 

 when it afterwards cools, assumes the form of a black dust or 

 flakes, called blacks, or smut, or soot. If that pitch, however, 

 or pitchy vapour, be heated still more, as it is in the red hot 

 iron retorts of a gas work, or in rising through a cert-ain thick- 

 ness of ignited coal in an ordinary fire, it is in great part 

 resolved into invisible carburetted hydrogen gas, such as we 

 burn in street lamps. 



Now, when fresh coal is thrown upon the top of a common 

 fire, part of it is soon heated to 600 degrees, and the bitumen 

 of it evaporates as the visible smoke, which immediately rises. 

 Of such matter the great cloud over London consists. If the 

 pitchy vapour, however, be heated to ignition by the contact 

 of a flame or of ignited coal near the surface, it suddenly be- 

 comes in a great part gas, and itself burns as flame. This is 

 the phenomenon seen in the flickering and burning which takes 

 place on the top of a common fire. 



But if fresh coal, instead of being placed on the top of a 

 fire, where it unavoidably must emit visible pitchy vapour or 

 smoke, be introduced beneath the burning, red-hot coal, so 

 that its pitch, in rising as vapour, must pass among the parts 

 of the burning mass, it will be partly resolved into the inflam- 

 mable coal gas, and will itself burn and inflame whatever else it 

 touches. Persons often amuse themselves by pushing a piece 

 of fresh coal into the centre of the fire in this way, and then 

 observing the blaze of the newly-formed gas'. 



Various attempts, beginning, perhaps, with Dr. Franklin's, 

 have been made to feed fires always from below, and so to get 

 rid altogether of smoke. Another more recent one was made 

 about thirty years ago, by an ingenious manufacturer in 

 London, Mr. Cutler. He placed a box filled with coal under 

 the fire, with its open mouth occupying the place of the re- 

 moved bottom bars of the grate, and in the box was a move- 

 able bottom, supporting the coal, by raising which the coal 

 was lifted gradually into the grate to be consumed. The ap- 

 paratus for lifting, however, was complicated, and liable to get 

 out of order, which, with other reasons, caused the stove to be 

 little used. The moveable bottom rested on a cross-bar of iron, 

 which in moving was guided by slits in the side of the coal-box, 

 and was lifted by chains at each end, drawn up by a windlass, 

 and this windlass was turned by bevel wheels, of which one 

 had to be moved by a winch in the hands of au attendant. 

 Mr. Cutler was not aware that others had been ensaaed in the 

 same pursuit, and took out a patent for his apparatus. A trial 

 at law, however, afterwards decided that he had no patent 

 right. 



In the new fire-grate which I am now to describe, I have 

 sought in every part the greatest possible simplicity which 

 could give complete efficiency. The combination is repre- 

 sented in the wood-cut. — (in next number. — I'M.) The charge 

 of coal for the day is placed in a box immediately beneath the 

 grate, as shown in the diagram at the letters c f // h, and is 

 borne upwards, as wanted, by a piston in the box, raised 

 simply by the poker used as a lever, and as readily as the wick 

 of an argand lamp is raised by its screw; the fire is thus 

 under command, as to its intensity, almost as completely as 

 the flame of a lamp. There are notches in the piston. rod for 

 the point of the pokw-, and a ratchet catch to support the 

 piston when the lever is withdrawn. 



The coal-box of an ordinary fire may have a depth of seven 

 or eight inches, which will receive from twenty to thirty pounds 



of coal, according to the area. In winter an inch or two more 

 depth of coal ma}' be placed over the mouth of the box before 

 the fire is lighted, and in warmer weather the box will not 

 require to be quite filled, tliat is to say, the piston at the time 

 of charging needs not to be lowered quite to the bottom. If it 

 become desirable on any account, as will happen with kitchen 

 fires, to replenish the coal-box in thecour.se of the day, it may 

 be done almost as ea-sily as to put coal on a common tire ; thus, 

 when the piston has been fully raised, so as to have its flat 

 surface flush with the bottom bar of the gi'ute, e f, a broad 

 fiat .shovel or spade, of the shape of the bottom of the grate, 

 is pushed in upon the piston, and it becomes at once a tem- 

 porary bottom to the grate and a lid to the coal-box. The 

 piston being then allowed to sink down to the bottom of the 

 coal-box, the .spade or lid is raised in front by its handle, and 

 opens the bo.x, so that a new charge of coal can be shot in. 

 The .spade being then withdrawn, the combustion goes on again 

 just as in the morning. That the opening of this lid may be 

 wider, the second bar of the giate is hinged, and yields to the 

 upward pressure of the spade. 



This fire is lighted with singular ease and speed. The wood 

 is laid on the upper surface of the fresh coal tilling the coal-box, 

 and a thickness of three or four inches of cinder or coked coal 

 leit from the fire of the preceding day is placed over it. The 

 wood being then lighted, instantly ignites the cinder above, 

 and at the same time the pitchy vapour from the fresh coal 

 below rises through the wood-flame and cinders, and becomes 

 heated sufliciently to inflame itself, and so to augment the 

 blaze. When the cinder is once fairly ignited, all tlie bitumen 

 rising through it afterwards becomes gas, and the fire remains 

 quite smokeless ever afterwards. A fire-place supplied with 

 coal fi'om below was used by a distinguished engineer in town 

 for ten years, and the fact that his chimney had not to be 

 swept in the whole of that time, proved that no soot was 

 formed. 



In the new grate, because no air is allowed to enter at the 

 bottom of the coal-box, — I'or the piston-rod fits its opening 

 pretty accurately- — there is no combustion below, but only be- 

 tween the bars of the grate, where the fuel is completely 

 exposed to the air, and near the mouth or top of the coal-box. 

 The unsatisfactory result of some other attempts to make such 

 a fire have been owing, in part, to the combustion extending 

 downwards in the coal-box, because of air having been admitted 

 below, and then consequent melting and coking of the mass 

 of coal, so as to make it swell and stick, impede the rising of 

 the piston. 



A remarkable and most valuable quality of this fire is, its 

 tenacity of life, or its little tendency to go out or be extin- 

 guished. Even after nearly all the coal in the grate, sur- 

 rounded by the fire bars, has been consumed, the air will dive 

 into the coal-box and keep the fire there gently alight, like a 

 torch burning from the top downwards, until nearly the whole 

 contents of the box are consumed, and thus the tire will remain 

 burning for a whole day or night, without stirring or attend- 

 ance, and yet at any moment it is ready to burn up actively 

 when the piston is raised. 



In certain cases, as during long nights, it may be desirable 

 to ensure the maintenance of conibu.stion with rather more 

 activity, and for this purpo.^e there is a slide in a small door 

 at the front bottom of the coul-box, by which a graduated ad- 

 mission of air may be allowed. That dour itself is ojien before 



