This invention relates to lighting by mixing air or other gaseous supporter of combustion with illuminating or other hydrocarbon gas or vapor, and burning the mixture (at a suitable pressure) in a burner of special construction, shown in the accompanying illustrations.
The burner is constructed as shown in Figs 1 and 2. It consists of a central tube, i, screwing upon the pipe by which the gaseous mixture is supplied. Upon this tube is screwed a cup, k, of metal or refractory material which supports a cap, l, of fire-clay in the shape of a thimble (or of other form, according to the intended use of the burner). The flanged base of this cap is perforated with a ring of holes, m, as small and numerous as possible, and the sides of the cap are pierced with oblique perforations, n. The top of the tube, i, is provided with four small projections, upon which rests a copper cone, o, soldered to the tube at a point below the perforations in the base of the thimble. The cone is perforated at its lower end with small holes, p, the sum of whose areas is at least equal to the area of the tube. The thimble, l, is surrounded by an envelope, q, of platinum wire netting or other refractory material of the same form. The gaseous mixture arriving by the pipe, i, escapes at the upper orifices, r, and passes down against the interior surface of the cone, o, out at the orifices, p, and escapes through the orifices in the cap, l, at which it is burned. The cap is thereby raised to a high temperature; and the platinum wire sheath becoming incandescent radiates the light. The gaseous mixture, by coming first in contact with the copper cone and then with the refractory cap, becomes raised to an exceedingly high temperature before it is consumed.
In the modified burner represented in Fig. 3, the metal cone and the fire-cap are truncated. The tube, i, is provided with a number of small perforations, r, at its upper end, the sum of whose areas is at least equal to the area of the tube, and by which the gaseous mixture is distributed within the chamber, k. Upon the upper closed end of the tube is fixed a cup or inverted thimble, o, of fire-clay. A refractory cone, l, surrounds this cup and rests by its base upon the cup. This flanged base is perforated with small vertical holes, m, and upon it is fixed a platinum wire cage or envelope, q. An annular space is left between the cone and cup for the passage of the gaseous mixture, which, on escaping from the orifices, r, passes over the exterior surface of o, the interior of which is already heated by the flame which has not passed through the wire gauze, and has been forced by the pressure of the mixture into the interior of o. The gaseous mixture before passing through the annular space thus attains such a temperature that on escaping from the orifice its combustion is greatly promoted.
PREVENTING IRON FROM RUSTING.
In the present state of civilization the use of iron has reached a very wide extension, and in a great number of cases iron is used where wood or stone was formerly used. It is certainly an important question how this metal can be protected under all circumstances against rust or oxidation, so that the many costly iron structures may retain their usefulness and strength, and be handed down uninjured to posterity.
Wherever bright iron comes into contact with air and moisture it immediately begins to rust, and this rust is not content to continually rob it of its substance in its persistent progress by scaling off the surface, but at the same time it injures the remainder of the iron by making it brittle. Attempts have hitherto been made to protect the iron by covering it with other and less easily oxidizable metals. For this purpose tin was first selected, then lead and zinc, and recently nickel. Furthermore, earthy glazings and enamels, such as are used on stone ware, have been applied to iron vessels, and they have already found extensive use in the household. In most cases these coatings, either metallic or vitreous, are inapplicable, either because they cannot be applied or are too expensive, so that on a large scale recourse must be had to paints made by mixing oils with metallic oxides, earths, etc., for protecting the surface of the iron from air and moisture.
It has been observed that iron does not rust in dry air, not even in dry oxygen. In like manner it frequently happens that unpainted iron, such as weather vanes, fences, etc., is exposed to the air for a century with very little injury, being covered with a thin coating of the magnetic oxide (proto-sesquioxide), which acts as a protection and prevents farther action. Hence it has been proposed to produce a layer of this magnetic oxide on the surface artificially, and it was found that superheated steam furnished the means for doing this. But it is not to be supposed that such a process would find use on a large scale, and besides this protection could only serve for iron tolerably exposed to the open air and not for that in direct contact with carbonic acid and water.