The lamp, as patented to Reichmann, was one of a large number of attempts made about the time to utilize petroleum and its various products for purposes of illumination. The old lamps adapted to sperm oil, lard, and other gross and sluggish oils were unfitted for the use of so volatile and dangerous a substance. In them the flame was set close to the lamp, and the tube holding the wick was projected downward into the oil, so that the heat of the flame might be communicated thereto in order to render it more fluid and susceptible to the capillary attraction of the wick. Such an arrangement as this with petroleum would have produced a
speedy explosion. This article required that the flame should be elevated as far as possible above the lamp and that the metallic wick tube should not communicate any heat to the fluid. This was one object to be attained in the burners required for the use of the new illuminator. Another was some contrivance for concentrating a current of air upon the flame itself, so as to consume as perfectly as possible all the rapidly escaping volatile gases, both as a saving of light and as a preventive of the disagreeable odors-which they would otherwise diffuse.
Reichmann's burner, illustrated in Figure 1, was intended to accomplish these main objects as well as some subsidiary ones, which will hereafter appear. It consisted of several distinct parts, combined and arranged in a particular manner. First, a flat wick-tube (indicated in the figure by the letter c) attached to the cap or stopper of the lamp, and rising above the same one or two inches, more or less, according to the size of the burner, but not projecting into the lamp below. Secondly, ratchet-wheels attached to the side of the wick-tube on a small shaft (g), for raising and lowering the wick. Thirdly, a slide or sleeve (i) fitted to slip up and down over the wick-tube, and sufficiently tight to stay in any position thereon, and furnished with arms (o, ), two or more, for supporting above the wick-tube a dome or deflector (m). Fourthly, the dome aforesaid, having an oval or oblong slot for the flame to pass through, so that part of the flame might be above the dome and part below it. The object of this dome was to collect and concentrate the air upon the flame, in order to make it burn more brightly and consume they hydro-carbon and other gases which emanated from the petroleum. It also acted as a deflector of the light proceeding from the lower part of the flame, whereby it was thrown downward towards and around the lamp, whereas the light from that part of the flame above the dome was all thrown upward or horizontally about the room. Fifthly, around the periphery of the dome several narrow slips of the metal (k) were turned up, to act as arms or supports to the glass chimney of the lamp, and between these arms spaces were cut out of the edge of the dome, to allow air to pass up between the dome and chimney for the purpose of guiding the flame and feeding it with additional oxygen. Sixthly, the chimney itself (p), which was placed inside of and upon the said arms or supports, and held in its position thereby.
This was the combination of elements of which Reichmann's burner consisted, and it will be perceived that the chimney was so elevated that the flame of the lamp below the dome was exposed on every side, and a current of air or a rapid movement of the lamp would extinguish it. This was the great defect of the burner, which prevented its introduction into general use, and rendered it of little value. The principal advantage which Reichmann in his patent claimed for it was that it allowed the light from the under side of the deflector to be reflected or thrown downward upon the table or lamp. This was effected by the use of upright, slender arms to support the dome, so that the space around and underneath the dome was left open and uninclosed. He also claimed some less important advantages in his arrangement of the ratchet-wheels for raising the wick, and one or two other things of no importance in this controversy.
The patent had but one claim and that amounted to the general combination of elements referred to and their peculiar arrangement. It was in these words:
'What I claim as new and desire to secure by letters-patent is, in combination with the lamp, the slotted, open, bell-shaped cap (i. e., the dome) when so constructed, arranged, and operating as to allow light to be deflected downwards, substantially in the manner and for the purpose herein set forth and explained.'