OAS-BURSEKS.] 



UNDULATORY FORCES. LIGHT. 



129 



7. The Gaumont Burner is a bat's-wing burner with 

 two or tliree slits, instead of one. By means of this 



contrivance there are two or tliree flames amalgamated 

 into one ; and, as is always the case under these circum- 

 stances, the total amount of light is increased. A Gau- 

 inont, which consumes three cubic feet per hour, gives 

 the light of seven sperm candles. 



8. The Sun Burner is a cluster of fish-tail burners, 

 usually nine in number, placed round a common axis, 

 and spreading out in a horizontal direction, so as to pro- 

 duce the figure of a flower or of the sun. This burner 

 ia so constructed, that the products of combustion are 

 carried out of the room by means of a ventilating funnel 

 and tube placed immediately over it ; and the air which 

 supplies the name is made to descend through the ven- 

 tilating tube, and thus to become very hot before it 

 reaches the burner. By this arrangement there is a 

 great saving of gas. In most cases the sun-burner con- 

 sists of seven clusters of nine fish-tails each. The burners 

 are supplied with gas by a descending-pipe, which branches 

 to each cluster ; and, surrounding the whole, is a sheet- 

 iron cone, with a tube attached to the top, for carrying 

 off the products of combustion. In this tube there is 

 placed a butterfly- valve, for the purpose of regulating 

 the current of air, so that the draught may not be too 

 great, and the lights may burn in a horizontal direction. 

 Around the cone are placed three other sheet-iron cases, 

 hii:h not only serve for ventilation and for the supply 

 of air to the burners, but also insulate the inner cone, 

 and by their cooling effect, prevent the intense heat of 

 the latt,-r from being communicated to the woodwork of 

 the ceiling. These cylinders are not connected with 

 each other, or the cone, and, therefore, distinct currents 

 of air pass between each of them ; and auch is the cooling 

 effect of these currents, that, while the cone is red-hot, 

 the two outside (rises are of the same temperature as the 

 atmosphere of the room. On the upper part of these 

 cylinders there is an inverted cone, with a pipe passing 

 tliroii/n the ceiling and roof, and protected on the outside 

 by a wind-guard, which allows the hot air and products 

 of combustion to escape. By this contrivance the gas is 

 consumed in a very heated atmosphere, and thus there 

 is less necessity for combustion in order to obtain a given 

 amount of light ; for, in the generality of cases, a large 

 portion of the gas consumed is employed in raising the 

 air to the temperature necessary for sustaining the igni- 

 tion of the small particles of carbon contained in the 

 flame. It has been stated by Mr. Edwards, of Liverpool, 

 that the burners, in this position, do not consume more 

 than half the usual amount of gas ; besides which, the 

 intensity of the light is very great. 



9. The Common Argand Burner produces a flame 

 which is exactly like that of an ordinary Argand oil- 

 lamp. The burner consists of a circular disc of iron, 

 pierced with a number of holes. It is hollow in the 

 middle, for the purpose of allowing a supply of air to the 

 interior of the flame ; and the jets of gas coalesce, so as 

 to form a hollow cylindrical flame. A glass chimney is 

 placed around the burner, in order that the supply of 

 atmospheric air may be copious and steady. The number 

 of holes or jets varies from ten to thirty for ordinary gas, 

 and from thirty to ninety for cannel. In the former 

 case the holes are comparatively large, and in the latter 

 they are very small. When common gas is consumed 

 from an Argand burner, the chimney ought not to be 

 above seven inches in height ; but, when cannel gas is 

 burnt, it may be increased to nine or ten inches. If the 

 chimney be too high, the supply of atmospheric air is 

 too great, and the gas is overbtunt ; whereas, if it be too 

 low, the supply is not sufficient, and then the gas smokes : 

 in either case the intensity of the light is diminished. 

 For ordinary London gas, a burner with fifteen holes, 

 and a seven-inch chimney, is considered to be the best. 

 Such a burner will consume about five cubic feet of gas 

 per hour, and will give the light of fifteen sperm candles. 



Several patents have been taken out, during the last 

 few years, for irnfrrovements in this form of burner : they 

 have chiefly been directed to the lessening of the shadow 

 which is cast by the ring and body of the apparatus. 



TOt. I. 



10. The Argand with a Button or Deflecting Disc. 

 This form of burner has received various names, 

 according as it has been modified by different patentees. 

 It is called the Wiufield burner, Young's burner, Guize's 

 burner, and the Aberdeen burner. The button or disc 

 is composed of copper or iron, and it is placed in the 

 centre of the flame, a little above the level Fig. 130. 

 of the burner. It acts as a break to the 

 inner current of air, and deflects it out- 

 wards so as to enlarge the upper part of 

 the flame, and to give it the form of a 

 tulip (Fig. 130). This kind of burner is 

 only suited for the richer kinds of gas, as 

 cannel gas and naphthalised gas. In some 

 cases the air is deflected to the outside as 

 well as inside of the flame. This is the 

 principle of Guize's burner, and the deflec- 

 tion is effected below the button by means 

 of a bend or constriction in the glass 

 chimney, or else by the aid of a metal 

 cone like that of the solar lamp. In 

 Young's burner there is a series of discs 

 placed one above the other, the discs being successively 

 larger and larger from below upwards ; by this means 

 the air suffers a series of deflections, and causes the flame 

 to be most vivid. A burner of this description is par- 

 ticularly well suited for the combustion of very rich 

 cannel gas. 



11. The Argand Burner with two or more Kings of 

 Flame, one within the other. This is the principle of the 

 Boccius burner; and, from the circumstance that one 

 flame always assists in promoting the combustion of 

 another, the light from this burner is very considerable. 

 Mr. Carter has obtained a patent for a burner of this 

 description, modified somewhat in its form, so as to pro- 

 vide for a due supply of atmospheric air, and also to 

 carry off the products of combustion. The burner con- 

 sists of a series of Argand flames concentric to each 

 other, with only just so much space between the rings 

 as will serve for the transmission of the necessary 

 quantity of atmospheric air ; and over the flames there 

 is placed a conical chimney, which carries away the pro- 

 ducts of combustion. In the concentric burners hitherto 

 used, the object has been simply to obtain the effect of 

 two or more concentric flames, without having due regard 

 to the proper and uniform supply of air to each flame. 

 The consequence of this is, that great and unnecessary 

 quantities of air enter such burners; and the flame is 

 thereby cooled much below the temperature requisite for 

 the perfect combustion of the gas. On this account the 

 intensity of the light is very much below what it ought 

 to be. In Mr. Carter's burners this 



objection is overcome ; for the space 

 between the rings is properly gra- 

 duated, and the current of air is 

 made to compress the flame, and blow 

 in upon it by means of a contraction 

 in the glass chimney the point of 

 contraction being at such a height 

 above the burner as to produce a 

 bright and steady flame (Fig. 131). 

 The vcutilating-shaft is placed over 

 the burner, and communicates above 

 the ceiling with the chimney. It 

 consists of a funnel, and a tube, which 

 may be either of metal or glass. These 

 are arranged so as to regulate the 

 supply of air to the flames, and they 

 are enclosed in a chandelier of glass 

 pendants. 



12. An Argand with a Jet of Gas within it. This 

 form of burner has been patented by Mr. Billows, who 

 describes it as an ordinary Argaud, having a central 

 tube with a single jet, which burns within the hollow of 

 the flame : and, instead of the ring being perforated 

 with a number of holes for the issue of gas, as is usually 

 the case, the ring is contrived with a circular slit, so 

 that there is a continuous sheet of flame in a cylindrical 

 form. 



Fig. 131. 



