706 



Popular Science Monthly 



of the air manifests itself more and more as 

 speed is increased, so that each additional 

 mile-an-hour of speed is purchased at addi- 

 tional waste of energy. Gravitation is con- 

 stant. It pulls a moving object down to 

 the earth, and sooner or later stops it. 



How You Can Travel for Nothing 



It is apparent that if we are to attain 

 and maintain anything like the speed of a 

 bullet we must remove the air and we must 

 neutralize the attraction of gravitation, 

 since it cannot be 

 destroyed. If 

 this is attained 

 you need not ex- 

 pend energy to 

 maintain the 

 value of the ve- 

 locity of the car — 

 the principal 

 waste of energy 

 in all usual sys- 

 tems of locomo- 

 tion — and you 

 could travel in- 

 definitely for 

 nothing. 



A considera- 

 tion of the sub- 

 ject led me to 

 conduct labora- 

 tory experiments 

 which show that it is possible to move a 

 car at high speed in a tube from which the 

 air has been partially exhausted — thus 

 overcoming the obstacle opposed by air 

 resistance — and to support that car, not 

 on the usual rails but literally in space by 

 means of electromagnets — thus neutralizing 

 gravitation. 



In these laboratory experiments I used a 

 copper tube ten inches in diameter curved 

 so that it returned into itself. The straight 

 portion was wrapped with a long coil of 

 insulated wire divided into sections to 

 constitute as many solenoids — electromag- 

 nets without iron cores. By manipulating 

 a system of switches I could send the cur- 

 rent through these solenoids in rapid suc- 

 cession. The "car" was an iron cylinder 

 running on wheels. It was magnetically 

 sucked into the influence of the first solenoid, 

 then into the next and in this waysuccessively 

 passed from one coil to the next. When 

 the car had attained a velocity of four 

 miles an hour in my experiments and was 

 passing out of the influence of the last 

 solenoid the current began to flow through 



In his laboratory experiments, Prof. Weinberg used 

 a copper tube ten inches in diameter, curved so 

 that it returned into itself. The "car" is shown 

 here — an iron cylinder running on wheels 



the first. All the solenoids were placed 

 on top of the copper tube and served 

 to raise the car from the bottom of the tube. 

 When this current was too weak the car 

 would jump just slightly from the bottom 

 of the tube; when it was too powerful the 

 car would actually scrape the top of the 

 tube and run touching, not the bottom but 

 the "ceiling" of the tube; and when the 

 current was of just the proper strength the 

 car rose from the ground without touching 

 the top wall and sped on to another 



electromagnet 

 which, in the 

 same way, kept 

 it thus suspended 

 in space. Every 

 electromagnet 

 was energized 

 only during the 

 time that the 

 front of the car 

 began to ap- 

 proach it and 

 until the rear of 

 the car had passed 

 it. In this way the 

 electromagnet 

 merely lifted the 

 car but did not 

 change its ve- 

 locity at all. The 

 tube was con- 

 nected with an air pump so that the air 

 could be practically exhausted. 



You Are the Only Passenger in the Car 



In imagining this principle applied, I 

 must ask my readers to divorce them- 

 selves from all current conceptions of rail- 

 ways. The car of the vacuum electric 

 system would be a three hundred pound 

 iron cylinder three feet in diameter, with 

 conical ends hermetically sealed. You 

 enter that car and lie prone in it, its solitary 

 passenger. The sustaining electromagnets 

 are much bigger than those used in my ex- 

 periments shown in the photographs, and 

 they are spaced thirty feet apart and are 

 successively fed with a powerful current 

 for a fraction of a second. 



The direction of motion of such a high- 

 speed car cannot be easily changed. Im- 

 agine the difficulty of swerving a fifteen- 

 inch projectile as it leaves the mouth of a 

 naval gun! Like any railway the vacuum 

 tube would have its curves. How are they 

 to be rounded? I again utilize electromag- 

 nets. The distance between these electro- 



