164 Proceedings of Indiana Academy of Science 
weak, nearly uniform glow extending only 4 or 5 mm. from the wire 
before it tends to break into a spark. With No. 24 wire, fine streamers 
or brushes are noticeable which become the chief characteristic of the 
discharge around a No. 18 wire. A No. 12 wire was tried, but the 
effect was to reduce the radius of curvature so much that sparks were 
the only form of discharge which could be produced.” A No. 16 wire 
gave the same effect, but, remembering Vosmaer’s experiments on space 
distribution,“ a number of small points were filed on this wire from 
which magnificent brushes would be thrown out sometimes to distances 
estimated as half of the radius. The resonance range under these 
conditions is narrow and easily overstepped, so that while ‘the dis- 
charges most brilliant optically and most effective chemically occurred 
around a No. 16 wire with points, yet very small surges of power 
tended to throw them over into sparks with greatly diminished yields. 
Better total yields are obtained with smaller wires, thus sacrificing 
erratic for more reliable, although less intense, effects. 
Under the best conditions ozone was produced at an efficiency of 
from 15 to 17 g. per kilowatt hour calculated on a basis of gross 
power input. No attempt was made to determine the efficiency of the 
process on a basis of the power delivered from the secondary of the 
transformer because of the uncertainty in obtaining the tare of the 
transformer. However, certain considerations indicate that it had a 
rather large tare, so that with a properly designed transformer the 
efficiency would have been doubled, or possibly trebled. The loss of 
energy in the spark gap varied, of course, with conditions. To deter- 
mine the value the spark gap was enclosed within a water-tight con- 
tainer and immersed in a large calorimeter which had been calibrated 
with electrical energy. The results at 80 and 110 watts gross input 
indicated a loss of the total energy supplied to the transformer of 12 
and 15%. ; 
The concentration of oxides of nitrogen produced in the corona 
discharge was 0.005-7% by volume. For every molecule of nitric oxide 
formed there were produced from 70 to 90 molecules of ozone. When, 
however (as around a No. 16 wire), a spark played more or less inter- 
mittently, the concentration of oxides of nitrogen as well as their ratio 
to ozone was materially increased. Two runs were made with a dis- 
charge in which almost continuous sparking predominated, accompanied 
by some corona. With a gross input of 120 watts, 41 mg. of nitric 
acid was obtained in 20 minutes at a flow rate of 95 cc. per minute, 
so that the concentration was about 0.8% by volume (21 mg. per 
liter). A 40-minute run at a flow rate of 200 cc. per minute pro- 
duced 90 mg., reducing the concentration nearly half. The efficiency 
in each case was a little more than 1 g. nitric acid per kilowatt 
hour. This method offers little promise as a means of nitrogen fixation 
under these conditions but might be effective at high temperatures. 
19The larger wire increases the capacity and tends to throw the cireuit out of 
resonance. With the reduction in radius of curvature of the smaller electrode, the 
condition of parallel plates is approached. 
11 Vosmaer, Ozone, Van Nostrand, 1916, pp. 56-64. Incidentally, this question of 
space distribution has resulted in a very larger variety of possible modifications, many 
of which have been patented. 
