562 



GAS, COAL 



1017 



minating power of a given volume of the gas. Fig. 1017 shows the burner contrived 

 by Dr. Frankland for this purpose, a is a. common argand burner, or bettor, a Leslie's 

 argand, furnished with the usual gallery and glass chimney b, c; 

 the latter must bo 4 to 6 inches longer than usual, dd is a circular 

 disc of plate glass, perforated in the centre, and fixed upon tho stem 

 of the burner, about l inch below tho gallery, by tho collar and 

 screw e. ff is a second glass chimney, somewhat conical, ground 

 at its lower edge so as to rest air-tight, or nearly so, upon tho 

 plate dd; and of such a diameter as to leave an annular space 

 inch broad between the two cylinders at g g. The cylinder / 

 should bo of such a length as to reach tho level of the apex of tho 

 flame. The action of this burner will now be sufficiently evident. 

 When lighted, atmospheric air can only reach tho flamo by passing 

 downwards through the space between tho cylinders / and c ; it 

 thus comes into contact with the intensely-heated walls of c, and 

 has its temperature raised to about 500 or 600 before it reaches 

 the gas flame. The passage of this heated air over the upper por- 

 ^ tion of the argand burner also raises the temperature of the gas 

 considerably before it issues from tho burner. Thus the gases 

 taking part in the combustion are highly heated before inflamma- 

 tion, and the temperature of the flame is consequently elevated in 

 a corresponding degree. Experiments with this burner prove a 

 great increase in light, due chiefly to the higher temperature of tho 

 radiating particles of carbon ; but, no doubt, partly also to the 

 heat being sufficiently high to cause a deposition of carbon from 

 the light carburetted hydrogen ; thus rendering this latter gas a 

 contributor to the total illuminating effect, whilst, when burnt in 

 the ordinary manner, it merely performs the functions of a diluent. 

 The following are the results of Dr. Frankland's experiments with 

 this burner : 



Bate of Consumption 

 per Hour. 



I. Argand burner without fjj'3 cubic feet 



external cylinder. | ,. 

 2-2 



II. Same burner with ex- 



ternal cylinder. 



Light in Sperm Candles, each 

 burning 120 grs. per Hour. 

 13-0 candles. 

 15-5 

 17-0 

 13-0 

 15-5 

 167 

 19-7 

 217 



1018 



These results show that the new burner, 

 when compared with tho ordinary argand, 

 Saves on an average 49 per cent, of pas, 

 when yielding an equal amount of light ; 

 and also that it produces a gain of 67 per 

 cent, in light for equal consumptions. 



Faraday's ventilating Burner. This ad- 

 mirable contrivance, tho invention of the 

 late Prof. Faraday, completely removes all 

 tho products of combustion, and prevents 

 their admixture with the atmosphere of the 

 apartments in which the gas is consumed. 

 Tho burner consists of an ordinary arpnml, 

 jig. 1018, a, fitted with the usual gallery 

 and chimney, b b. A second wider and 

 taller cylinder, cc, rests upon tho outer 

 edge of the gallery which closes at bottom 

 tho annular space, d d, between the two 

 glass cylinders, cc, is closed at top with 

 a double mica cap, e. f is tho tube con- 

 veying the pis to tin- argand; gg is a wider 

 lulic 1 \ inch in diameter, communicating at 

 one extremity with the annular space between tho two glass cylinders, and at them ln-r. 

 either with a flue or the open air. Tho products of combustion from the gas llaniu 

 are thus compelled to take the direction indicated by tho arrows, and are therefore 

 prevented from contaminating the air of the apartment in which tho gas is consumed. 



