HYDROGEN HARMONICON. 



191 



hydrogen being supplied to the central tap from a generator or 

 gas bag, and thence to the four burners ; the lengths of the tubes are 

 so proportioned as to give the 3d, 5th, 

 and octave of the note yielded by the 

 longest tube. 



Expt. 210. To render the Flame 

 of Hydrogen Luminous. Down the 

 thistle funnel of a gas generator pro- 

 ducing hydrogen pour a teaspoonful of 

 ether, or, better still, benzoline; these 

 substances will be partly volatilised, 

 and their vapours mixing with the 

 hydrogen will yield a gas that will 

 burn with a much more luminous flame 

 than pure hydrogen. If the generator 

 has become somewhat warm with 

 action, oil of turpentine will produce 

 the same result. 



This method of " carburising" a gas 

 which of itself will not give a very 

 luminous flame, is extensively practised 

 on the large scale. A current of 

 ordinary air passed through a vessel 

 containing a highly volatile suitable 

 fluid (extracted from petroleum) will 

 take up sufficient vapour to burn at a 

 jet like ordinary gas. The "albo- 

 carbon" gas burner acts similarly. 

 The gas supply is connected with a 

 chamber containing the substance 

 known as naphthalene (a pretty readily 



Fig. 82. Hydrogen Harmoni- 

 con (4 Pipes). 



volatile solid obtained from coal tar), so arranged that this chamber 

 becomes heated when the gas burns ; the heat melts and partly 

 volatilises the naphthalene, so that its vapour becomes mixed with 

 the coal gas, and enables the latter to give out much more light 

 whilst burning. 



Expt. 211. To produce an Oxyhydrogen Flame. A much 

 greater brightness of flame may be produced by burning hydrogen 

 and supplying the flame with a current of oxygen gas blown ink) 

 the flame from a narrow orifice, so as to blow the flame out in a 

 sloping nearly horizontal direction (fig. 83), like the " dart " or 

 flame produced by a plumber by means of a lamp and "blowpipe." 

 To produce the current of oxygen a gasholder like that represented 

 in fig. 74 may be used, so that by pouring water into the upper 



