OAJIPHIXB LAMP!!.] 



UNDULATORY FORCES. LIGHT. 



113 



. 117 



names given to the lamps which are constructed to burn 

 the highly rectified oil of turpentine a liquid which 

 Tig. 116. Mr. English originally prepared and 

 patented under the name of camphine. 

 Air. Young, of Queen-street, Cheapside, 

 has devoted great attention to the manu- 

 facture of these lamps, which he calls 

 Vesta spirit lamps. The reservoir for 

 holding the camphine is made of glass, 

 in order that the Leat from the burner 

 may not be communicated to it : in fact, 

 every precaution is taken to guard against 

 such a result; fur the wick, instead of 

 being supported oil a long metal tube, 

 which passes down into the body of the 

 oil, as is the case with the common Ar- 

 gand lamps, is merely held at the top 

 by a narrow ring, while the remaining 

 portion floats freely in the spirit ; besides wliich, the 

 burner is insulated from the lamp by a collar of wood. 

 The next point of importance in their construction is 

 that which ensures an abundant supply of atmospheric 

 air ; for if this is not attended to, the turpentine burns 

 with a remarkably sooty flame, and evolves a large quan- 

 tity of black smoke. This is eflected by having a slit in 

 the side of the wick so as to allow the atmosphere to 

 pass freely into its interior ; and the nipple, or cap, of 

 the solar lamp is used to break the outer current of air, 

 and blow it into the flame ; besides 

 which, the chimney is very tall, and it 

 is bulged in, or contracted, at the point 

 where it reaches the flame. In the 

 larger kinds of camphine lamps, the 

 button of Mr. Roberta is also intro- 

 duced into the interior of the flame, so 

 as to break the inner current of atmo- 

 spheric air (Fig. 117). And then, in 

 addition to all this, a cylinder of per- 

 forated brass is put around tli> 

 holes of the burner, so as to prevent 

 the ill effects of extreme draughts. 

 The principles, therefore, which are 

 kept in view in the construction of 

 these, are 1st, to prevent the heating 

 of the liquid ; 2nd, to ensure a large 

 supply of atmospheric air ; and 3rd, to 

 guard against the influence, of external 

 draughts. One of the great advantages 

 of the Vesta lamp, is the intensity and 

 purity of the flame. Dr. Ure says, that a lamp which 

 consumes two ounces of camphine in an hour, gives the 

 light of nearly twelve sperm or wax candles of three or 

 four to the pound. Our own experiments show, that 

 the smaller lamp, which has no button, consumes about 

 140 grains per hour, and gives the light of two-and-a- 

 half sperm candles, each burning at the rate of 120 grains 

 per hour ; while the larger lamp, which has the button. 

 consumes about 640 grains of camphine per hour, and 

 gives the light of Sevan sperm candles. 



Among the disadvantages of the Vesta lamp, are its 

 liability to smoke, and its disagreeable smell The for- 

 mer may arise from bad management, or from a resinifi- 

 cation of the camphine a circumstance that is sure to 

 occur if the tin-can containing the liquid is not kept well 

 corked, or if too much liquid is put 

 into the lamp for an evening's con- 

 sumption. 



1. Naphtha Lamps. Of these there 

 are two kinds viz. , the Argand naph- 

 tha, which is constructed exactly 

 like the preceding ; and the flat- wicked 

 Limp, which is represented in Fig. 118. 

 In the hitter, the air is directed upon 

 tho exterior of the flame by means of 

 two lateral pieces of tin, which incline 

 inwards as they ascend to the wick ; 

 and the supply of air is regulated by 

 an external opening or valve, which 

 may be shut up to any extent When naphtha is burnt 



. us. 



in a small Vesta lamp, it is consumed at the rate of about 

 136 grains per hour, and it gives the light of two 

 standard sperm candles; when burnt in the large one, 

 its consumption is 486 grains per hour, and its light is 

 equal to nine sperm candles. The disadvantages of these 

 lamps are, the unpleasant smell of the naphtha, the lia- 

 bility to smoke, and the danger of explosion ; for naph- 

 tha, being much more volatile than camphine, is likely 

 to give off vapour, which, with the air, forms an explo- 

 sive mixture. Great caution is therefore necessary in 

 managing these lamps. 



8. Gas or Vapour Lamps. Several attempts have been 

 made at various times to burn inflammable liquids with- 

 out a wick. The earliest and simplest of these is 



(a.) The Common Floating Night-lamp, which is no- 

 thing more than a small cup of metal pierced in the 

 middle with a small glass tube. The oil rises by capillary 

 attraction in the tube, and may be ignited. 



(6.J Another form of self-geiierating lamp is represented 

 in Fig. 119, where two tubes, a a, bring the oil down 

 Fig. 119. 



Fig. 111. 



from the annular reservoir, and convey it into a cistern, 

 whence it rises by the tube 6 into a cup which has a 

 cylinder filled with it, pierced with a number of small 

 holes that serve for jets. When the lamp is trimmed, 

 alcohol is poured into the cup, and set fire to. This, in 

 the act of burning, makes the cylinder so hot that the oil 

 within it is converted into gas ; and this escaping through 

 the hole or jets, is fired, and burns with a brilliant light. 

 The heat produced by the combustion of the gas, keeps 

 up the supply. A glass is placed around the burner to 

 protect it from external currents, and to prevent the 

 flame from smoking. 



(c.) A mixture of camphine or highly rectified spirits 

 of turpentine with al- rig. 120. 

 cohol, is burnt on the 

 continent in a lamp 

 that was originally de- 

 signed by Ludersdorff, 

 but which has been pa- 

 tented in France, by 

 Ribot, under the name 

 of "Eclairage au Gaz 

 Liquide." The French 

 lamp is represented in 

 Fig. 120. It is an ele- 

 gant-looking arrange- 

 ment, the body and 

 stem of which are com- 

 posed of cut glass. Fig. 

 121 exhibits the me- 

 chanism by which the 

 spirit and turpentine 

 are converted into va- 

 pour, a is the wick 

 which floats in the 

 liquid, and conveys it 

 up through the tube 6 

 into c, which is the va- 

 pour chamber; d is a cap of brass, which, when heated 



q 



