HELIUM, THE NEW BALLOON GAS 



441 



gion is allowed to pass into the hands of 

 commercial industries, the people of the 

 State of Indiana and of the entire conn- 

 try will lose for all time their free access 

 to Lake Michigan. 



The importance of prompt action can- 

 not be urged too strongly, as the demand 

 for large tracts of land with railway and 

 water facilities would soon result in the 



destruction of the natural advantages of 

 this remnant of scenic beauty and fasci- 

 nating forest and plant life. 



Under commercial occupancy the 

 growth of centuries could be destroyed 

 in a short time. It would be a catastro- 

 phe if this opportunity for preserving an 

 incomparable breathing spot on Lake 

 Michigan should be neglected. 



HELIUM, THE NEW 7 BALLOON GAS 



By G. Sherburne Rogers, Ph. D. 



Of the United States Geological Survey 



HELIUM, the new incombustible 

 gas which promises to revolution- 

 ize the science of ballooning, ap- 

 pears to be the latest addition to the long 

 list of natural products with which the 

 United States is bounteously endowed. 

 In fact, the only workable supplies of 

 the gas that have yet been discovered 

 anywhere in the world are found in the 

 Lnited States, and this country thus has 

 a powerful advantage in the competition 

 for supremacy in the air which the next 

 decade is bound to witness. 



The history of helium, which derives 

 its name from the fact that it was first 

 discovered in the sun — almost 30 years 

 before it was identified on earth — and 

 which was later found to be related to 

 that most precious and wonderful of all 

 elements, radium, is in itself of interest; 

 but the discovery of the supposedly rare 

 helium in ordinary natural gas by one 

 scientist, the conception of another that 

 helium would be ideal for inflating bal- 

 loons, and the labors of still others in de- 

 vising methods for extracting it from 

 natural gas and in locating supplies ade- 

 quate for this country and its allies, form 

 an interesting chapter in the account of 

 America's contribution to the war. 



The qualities of helium that make it so 

 valuable for use in balloons are its light- 

 ness and its incombustibility. Helium is 

 the lightest of the so-called inert gases, 

 which do not combine with oxygen or 



any other substance and therefore can- 

 not explode or burn. 



Hydrogen, the gas commonly used in 

 filling balloons, is, on the other hand, 

 highly inflammable. Many a great bal- 

 loon, or rigid airship, costing thousands 

 or hundreds of thousands of dollars to 

 construct, has been destroyed by fire in 

 a few minutes — some by lightning, some 

 by sparks from the motor, and others by 

 any one of the numerous accidents that 

 may happen even when the craft is in 

 its hangar. 



WEAKNESS OF HYDROGEN-FILLED 

 BALLOONS 



In military balloons or airships the fire 

 hazard is, of course, greatly increased, a 

 single well placed incendiary bullet be- 

 ing sufficient to transform the whole 

 costly structure into a mass of flames ; 

 and in this event the fate of the crew is 

 practically sealed. This weakness, in- 

 herent in all hydrogen-filled balloons, was 

 not only a potent factor in the practical 

 failure of the German Zeppelin program, 

 but has always been a drawback to the 

 development of lighter-than-air craft. 



With the fire hazard completely elimi- 

 nated by the use of helium, however, the 

 risks of ballooning are greatly decreased 

 and many new possibilities open up. The 

 power plant of the airship may be placed 

 as close as desired to the great gas bag 

 without fear of sparks, and by thus mak- 

 ing the design more compact, and so re- 



