72 THE ABOARD BURNER. 



The air within the chimney, being heated, is light and buoy- 

 ant, and, of course, the taller the chimney, the more buoy- 

 ancy there is, and the greater the draft that is, the faster 

 the air is " drawn in," as we usually express it, though the 

 real mode of operation is that the pressure of the atmos- 

 phere above the fire being taken off, in part, by the buoy- 

 ancy of the hot air in the chimney, the air is forced in to 

 the fire by the atmospheric pressure which acts on the or- 

 ifice below. 



Now Argand's plan was to furnish the increased supply 

 of oxygen to the fire in the flame of the lamp or candle by 

 " drawing it in" from below by means of a chimney, and 

 he also conceived the thought of bringing in the current in 

 the middle of the flame instead of around the outside of it. 



Argand, as has already been said, was a Swiss. He was 

 of quite humble origin, but he received a scientific educa- 

 tion, and in the earlier part of his life he was engaged very 

 successfully in the southern part of France in connection 

 with industrial occupations, in which his scientific knowl- 

 edge, and especially his knowledge of chemistry, were of 

 great service. 



His attention was called, while thus employed, to the 

 subject of light, especially for use in manufacturing and 

 other such establishments; for in those days near the 

 close of the last century there was nothing in use for ar- 

 tificial light but such naked, smoking, and flickering flames 

 as are given out by common lamps, torches, and flambeaux. 

 His knowledge of chemistry showed him that the reason 

 why the flames were not bright was the scantiness of the 

 supply of air, which could only reach the flame on the out- 

 side. It had been discovered some time previously that 

 an ordinary flame was hollow being bright only on the 

 outer surface of it as, of course, it must be, as in the case 

 of such a flame there is no access to the air within. 



