Arizona republican., 1901-05-08
TO TELEPHONE TO LONDON.
Prof Pupin Explains His Recent Elec-
 trical Discovery.

Prof. Michael I. Pupin of Columbia university lectured in Carnegie Lyceum laat evening on the subject of "Electri- cal Wave Transmission" leading up through a series of interesting illus trative experiments to the theory which. applied to submarine telephony, will in his opinion. and in the opinion of practical electrical experts, enable us to call up London. Paris and Rome as we now call up Chicago, Cleveland or St. Louis, and talk with persons in those remote itiea with perfect ease over the telephone.
 The lecture last evening was deliv- cred for the benefit of the scientific de- partment of Columbia college, and Prof Pupln was introduced by President Seth Low cf Columbia university, who in speaking of Prof. Pupin's discoveries and his application thereof, said that he. President Low, was like the old lady in Buffalo who said she had heard of Niagara Falls bat had never aeen them He had heard Of Prof Pupins achieve ment, but had never seen 1t demon- strated.
 The stage oc the Yyceum was filtered with apparatus like the class room of professor of physics. and close up by the footlights was small braos weight suspended ov cord. and this. was the pendulum on which Prof. Pupin hung the beginning of his talk The ewing of the pendulum. he said. from the point where it received its initial impulse back to that point was period and 1t would be found that during the en- tire time the .enGulum was in motion 1t covered an equal number of periods in any given interval of time.
 If the character of the impetus were changed, the motion of the pendulum varied and rcvolved fin an orbit as the earth does. the earth being In fact noth- ing but Jig pendulum revolving about the sun, just as the moon Is another pendulum revolving about the earth. and just as the Initial energy which set the pendulum in motion was being con stantly diseipated by air resistance and friction. so were counter forces dissipat- ing the earth's swing and the moons swing and the earth was slowly falling into the sun just as the moon was fall ing into the earth.
 The ITDtlOn or tne penuululn was wave motion. and wave motion Is de- pendent upon the nature of the force back of 1t and the medium through which it is transmitted. Electric wave motion is dependent upon the magnetic density of the medium through which fl Is transmitted. just as the wave mo- tion transmitted to cord Is dependent upon the heavlness of the cord. Prof Pupin demonstrated this proposition by an apparatus which. under the impetus of swift motor, gave quick. sharp wave motion to two cords each about ten feet long and each resting upon a canvas uptited on the stage SO the au- dience could see plainly.
 Prof Pupin pointed out that the lighter of the two cords only carried the wave motion to about one-half the length of the canvas, whereas in the heavier cord 1t was transmitted the en- tire length
 He then showed that by attaching weights or sinkers to the smaller cord it could be made to transmit the wave motions to greater distance. He first placed the weights eighteen inches. then twelve inches, and finally two inches apart. diminishing the size of the weights as the distances were di-