SILBER LIGHT 



779 



forms an air-jacket. D is the wick-ease, that is to say, an inner concentric, annular, 

 or tubular chamber, which holds the -wick and which receives oil or combustible 

 material from the chamber B, through the pipe E, which traverses the air-jacket c, and 

 forms the communication between the chamber B and the wick-case D. The lower 

 portion of the wick dips into the oil-supply through the pipe E from the chamber B. 

 G are air-tubes inserted concentrically within the chambers B, c, D. They consist 

 of tubes held by struts t. These tubes are preferably bell-mouthed at top. 



It will be observed that the air-jacket c is interposed between the oil-chamber B and 

 the wick-case D, so as to keep the oil and wick sufficiently cool and prevent the undue 

 or immature evaporation of the oil. 



Air is supplied to the air-jacket c and to the internal air-tubes G from a chamber H, 

 which is in a space within the case A, at tho foot of the lamp, which is supplied with 

 air through orifices of plain or ornamental shape k, k, k. i is the feed-hole for supply- 

 ing the chamber B with oil or combustible liquid ; j is a screw-cap which closes the 

 feed hole ; j* is an air-hole through the plug of the screw-cap J, forming a vent to the 

 chamber B ; k is a perforated conical cap surrounding the wick ; I is a conical annular 

 cap perforated only near the lower part, I* also surrounding the wick. There are in- 

 tervals for the passage of currents of air between the wick-case D, the cones k, I, and 

 the outer shell or case A x of the burner. M, M X , are the ordinary key and rack for 

 raising and lowering the wick. 



Tho next difficulty to be overcome was to produce a steady light, of a colour pleasing 

 to the eye, and, at the same time, to secure the complete combustion of the oil em- 

 ployed. In the ordinary circular or Argand burner, the current of air produced by 

 the flame passes so rapidly over the exposed part and surface of the wick, that it 

 carries off with it much partially -consumed oil ; and such a burner, if lighted for any 

 length of time in a close room, very perceptibly contaminates the atmosphere. In the 

 burners described, it will be observed that a tube or tubes are placed-within the wick- 

 case ; and these tubes divide the current of air in tho interior of the flame, and permit 

 the atmospheric oxygen to mix freely with the carbon, not only at the top of the wick, 

 but also higher up, about and above the centre of the flame. By this means a light 

 of uniform white colour is obtained, and 

 3 inches high. Moreover, the insertion 

 of tubes admits of an increase of the 

 diameter of the burner. In this inven- 

 tion, the patentee claims two things : 

 first, the conversion of the oil into vapour 

 before it reaches the top of the wick; 

 secondly, the admission of air by the 

 inner tube, specially to the upper part of 

 the flame, where it gives a fresh impulse 

 to, and completes the combustion of vola- 

 tilised matter that might otherwise be 

 carried off uuconsumed. The conversion 

 into vapour is effected by separating the 

 bulk of the oil from the wick-case, and 

 by admitting to the latter only a few 

 drops at a time. The heat generated by 

 the flame is imparted to tho metal at tho 

 top of the burner, and is thus commu- 

 nicated to the wick-case, where it at least 

 partially volatilises the small quantity 

 of oil contained therein. 



Another patent, dated December 19, 

 1870, refers to a roof-lamp for railway 

 carriages, in which the bulk of the oil 

 is kept not only outside the lamp, but 

 also outside the carriage, and thus nearly 

 at the temperature of the air. In all 

 previous roof-lamps the oil is contained 

 within the lamp, and soon becomes greatly heated. A x , A 2 , is the body of the lamp, 

 which consists of two main portions, one fitting on the other. The lower portion A* 

 is the glass, or as it is technically called ' globe,' though it is not precisely of a 

 globular form as ordinarily used. It is made of glass held in a metal frame a x . 

 The upper portion A 2 is of metal. Brackets are fixed to the body of the lamp, 

 and project outward from the same. On these brackets rests an annular receiver or 

 receptacle or oil-holder c, intended to receive the oil for supplying the burner of 

 the lamp. This receiver c is therefore on the outside of the lamp, and its outer surface 



