Manchester Memoirs, Vol. xliv. (1900), No. \\\, 3 



A choking coil with an adjustable core was also 

 included in the primary circuit of the transformer, so that 

 out of 100 volts available at the mains, only 30 volts were 

 taken. The current amounted to 40 amperes. 



With the flame thus produced, working in a spherical 

 glass vessel of 50 litres capacity containing an alkali 

 fountain and having a continuous supply of a mixture of 

 1 1 parts of oxygen and 9 parts of air, or in the theoretical 

 proportion for the formation of NOo, Lord Rayleigh 

 obtained an absorption of 21 litres per hour. This is 

 equivalent to the production of 393 grms. of nitric acid. 

 The power expended amounted to 800 watts, or rather 

 more than a horse-power, per hour. 



To make a further study of the oxidation of nitrogen 

 by means of electricity, and more particularly of the rate 

 of oxidation when atmospheric air, unmixed with oxygen 

 is used, the following experiments were carried out. 



The electrical apparatus consisted of a Siemen's alter- 

 nator, frequency 60, with two armature circuits, one capable 

 of generating 12 amperes at 400 volts, and the other 24 

 amperes at 200 volts. The current from this machine was 

 used to feed the primary circuit of a transformer, trans- 

 forming upwards in the ratio of i : 40. It was therefore 

 possible to obtain a potential of 16,000 volts or 8,000 volts 

 — according to the alternator circuit used — at the terminals 

 of the secondary of the transformer. By varying the 

 strength of the current feeding the primary circuit, any 

 voltage between 8,000 and 16,000, or lower than 8,000, 

 could be obtained as desired. 



The primary current was directly measured by means 

 of an amperemeter. A voltmeter gave the voltage at the 

 alternator terminals, and, in addition, a wattmeter was 

 included in the circuit, by means of which a correct reading 

 of the power consumed by the flame could be obtained. 



