126 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1918. 



The cost of producing helium at the outbreak of the war was 

 about $1,600 per cubic foot, and Zeppelin balloons would require 

 many hundreds of thousands of cubic feet. Apparently the sugges- 

 tion was merely a wild dream absolutely incapable of realization. 

 However, there are in Texas and Oklahoma certain gas wells which 

 yield as much as nine-tenths of 1 per cent of helium. Plants were 

 constructed to recover helium from the natural gas by means of 

 liquefaction. As the temperature and pressure are properly adjusted 

 and the temperature reduced, the natural gas first liquefies and runs 

 away ; after this the nitrogen and oxygen which may be present, and 

 so on, one after another of the various gases of which the mixture is 

 composed, until at length helium stands alone. In this way it was 

 found possible to recover about 60 per cent of the helium in the mix- 

 ture, so that a yield of about one-half per cent was obtained from the 

 original natural gas. Of course, no waste of the natural gas itself for 

 combustion occurred, for the liquefied gas could be warmed and could 

 be quite as useful as before for purposes of combustion. 



Several large plants were operated by the Government in Texas 

 for the recovery of helium. The matter was, however, kept a well- 

 guarded sceret. Even the name was hidden. Photographs of the 

 plant taken, were labeled " argon " manuf acturies. The idea was 

 spread that the purpose of the experiments was to produce a new va- 

 riety of poisonous gas for warfare, or perhaps a special variety of 

 gasoline for use in airplanes. All sorts of camouflage were adopted 

 to prevent the enemy from learning the true purpose of the experi- 

 ments. So far had the work progressed that at the time the armis- 

 tice was signed a consignment of 150,000 cubic feet of helium was 

 on the dock at New York, waiting to be sent to France to be used 

 by the Allies for their balloons. Plans were on foot for increasing 

 the output of helium enormously, so that it is probable that had the 

 war lasted until the summer of 1919 the Allies could have employed 

 helium gas for observation balloons and for Zeppelins with entire 

 immunity from all possibility that they could be shot down with 

 incendiary bullets. 



It seems a far cry from the peaceful sun, 90,000,000 miles away, 

 and the still more peaceful stars that dot the summer night, at more 

 immeasureable distances, to the horrible war which has just been 

 ended upon our little earth, but yet who knows when he goes about 

 an investigation to increase the bounds of knowledge, however re- 

 mote his subject may be from the ordinary walks of life, what appli- 

 cations the future may have in store for the results he gains ? 



