IMPROVED GAS BURNER. FIG. 3.--Section through C D.
When the gas is lighted at the burner, and the glass closed, the burner begins to act at once, although some minutes are necessarily required to elapse before its full brilliancy is gained. The cold air passes in through the tubes provided for it, and when these are heated to the fullest extent on their outside, by the hot fumes from the burner, they so readily part with their heat to the air that a temperature of 1,000° to 1,200° Fahr. is easily obtained in the air when it arrives inside, and commences in turn to heat the burner-tubes. The air-tubes are placed so as to intercept the hot gases as completely as possible; and also, of course, obtain heat by conduction from the sides of the annular body. It is evident that the number and dimensions of these tubes might be increased so as to abstract almost all the heat from the escaping fumes, but for the limitations imposed, first, by a consideration of the actual quantity of air required to support combustion, and, secondly, by the obligation to let sufficient ascensional power remain in the gases which are left to pass out through the upper chimney. If the gases are cooled too much, they will either fall back into the lamp and extinguish the flame, or will be removable only by the draught of a long chimney. It will probably be the aim of the inventor to balance these requirements, and so to produce burners with very short or longer chimneys, according as appearance is to be consulted or the highest possible effect produced. The burner is a ring of brass tubes of considerable diameter, in proportion to the quantity of gas consumed, and thus provides for the delivery of gas expanded by heat. In connection with this device an explanation may be found of the failure of the British Association Committee on Gas Burners to find any advantage from previously heating the air and gas consumed. The Committee did not make the necessary provision for the increased bulk of the combustible and its air supply, caused by their heightened temperature; and the same quantity of gas measured cold (at the meter) could only be driven through the ordinary small burner holes at a velocity destructive of good results. Herr Frederick Siemens perceived this in his early experiments, and not only increased the orifices of his burners, but provided for the closer contact of the more rarefied gas and air by the use of notched deflectors, which are now an essential part of his apparatus. Mr. Grimston also uses separate tubes of large area for his hot gas, but dispenses with deflectors, save in so far as the same duty may be performed by the plain lower edge of the inner cylinder of the lamp body, and the indentation of the glass beneath, which, as will be noticed, is made to follow the shape of the flame. It only remains now to speak of the flame and its qualities. It is, in the first place, a flame of hot gas, burning at an extremly small velocity of flow, and wholly exposed to view from the exact point which it is required to light. In this latter respect it differs materially, and with advantage, from the Siemens burner, which, while presenting an extremely brilliant and beautiful ball of flame outside its central tube of porcelain, may yet be tailing smokily downward inside this opaque screen, and thereby causing unperceived waste. The flame of the Grimston burner, on the other hand, is quite exposed, and all its light, from the ends of the burner-tubes to the point where visible combustion ceases, is made available for use. As a perfect Argand flame in the usual position has been likened in form to a tulip flower, so the flame of this burner presents the appearance of an inverted convolvulus. So far as he has already gone, Mr. Grimston prefers to keep the tubes of the burner at such a distance from each other that the several jets part at the point where they turn upward, so that the convolvulus figure is not maintained to the edge of the flame. From its peculiar position the light is, of course, completely shadowless as regards the lamp which affords it; and this, of itself, is no small recommendation for a pendant. It shows well for the simplicity and effectiveness of the perfected burners that Mr. Grimston's experimental example, although necessarily imperfect In many ways, burns with a remarkably steady light, of great brilliancy, which is assured by the fact that the products of combustion are robbed of all their heat to magnify the useful effect, so that the hand may be borne with ease over the outlet of the chimney. With respect to the endurance of the apparatus, it will be sufficient to remark that there is nothing in the gas or air heating arrangements to get out of order, and they are all easily accessible while the burner is in action. The glass is not liable to breakage, although it is in close proximity to the flame, as may be gathered from the testimony of the inventor, who has never broken one, notwithstanding the severity of some of his experimental studies upon his first lamp. The consumption of gas in the first working-model burner made by Mr. Grimston was 10 cubic feet per hour, and its illuminating power averaged 60 candles. The diameter of this burner was 1¼ inches across the tubes. It is scarcely necessary to state that if this high duty, which was obtained with the ordinary 16-candle gas of the Gaslight and Coke Company, can be maintained, to say nothing of being exceeded, in the commercial article, the Grimston burner, with its other advantages over all existing methods of obtaining equal results, has a great future before it. For example, it does not require a separate air supply under high pressure, or any extra material to render incandescent, and it may be turned on full immediately upon lighting. It throws a shadowless light, and lends itself to ventilating arrangements; and it is not by any means cumbersome, delicate in construction, or costly in manufacture. One of the greatest advantages to which it lays claim is, however, the power of yielding almost as good results in a small burner as in a large one. This is a consideration of great moment, when it is remembered that the tendency of most of the high power burners hitherto introduced is to benefit the lighting of streets, large interiors, and, generally speaking, points of great consumption. Meanwhile, the private user of burners, consuming from 3 to 5 cubic feet of gas per hour, has been left to attain as best he might, by the use of burners excellent of their kind, to the maximum effect of the standard Argand. Now, however, Mr. Grimston seeks to make the small consumer partake of the advantages erstwhile reserved for the wholesale user of large and costly Siemens and other lamps, and he even looks to this class of patrons with particular care. The example which we now illustrate, in Fig. 1, is a sectional presentment precisely half the actual size of a 5-foot burner, which it is intended to prepare for the market before all others. Another simple form of the burner, with vertical tubes, will, we understand, be introduced as soon as possible. It will be readily understood that the principle is capable of being embodied in many shapes; and it is satisfactory to learn that the inventor is quite alive to the necessity of producing a cheap as well as a good burner.
Gas companies, as Mr. Livesey has expressed it, will be well content with a slower relative growth of consumption, if their consumers are at the same time making their gas go as far again as formerly, by the use of burners which turn nominal 16-candle gas into gas of 30-candle actual illuminating power. How far Mr. Grimston's invention may succeed in this work it is not for us to say. It is sufficient for the present that he has done excellently well in showing how Herr Frederick Siemens' scientific principles of regenerative gas burner construction may be carried out yet in another way. There is nothing more common in industrial annals than for one man to begin a work which another is destined to bring to greater perfection. Whether this natural process is to be repeated in the present instance must be left for the future to decide. In any case, Mr. Grimston's success, if success is to be his reward, though it will be well merited by his ingenuity and perseverance in solving a difficult problem, will never cause us to forget the prior claims of Herr Frederick Siemens, of Dresden, to the palm of the discoverer. Mr. Grimston may or may not be the happy inventor of the best gas-burner of the day; but there is the consolation of knowing that in the same field in which he will find his recompense there is room for any number and variety of useful improvements of a like character and object.--Journal of Gas Lighting.
DEFTY'S IMPROVEMENTS IN GAS BURNERS AND HEATERS.
Among other inventors who have turned their attention to gas consumption is to be found Mr. H. Defty, who has made several forms both of heating and lighting burners. Mr. Defty has sought in the latter to apply the principle of heating the air and gas in a simple manner, with the object of obtaining improved photometrical results. The double-chimney Argand, as tried many years since by Dr. Frankland and others, makes a reappearance in one of Mr. Defty's models, illustrated in the accompanying diagram (Fig. 1).
Fig. 1.