WIRELESS TELEGRAPHY 



the earth. One remembers how, with only two 

 sets of instruments, during the yacht races each 

 pair picked up the other's signals, to the confusion 

 of both. One is led to surmise that not much good 

 can come from such a muddle as that. 



Now that Marconi has erased distance, this is 

 the great problem. Happily, there is hardly any 

 nation without its corps of experimenters, and 

 both Professor Slaby and Marconi, to say nothing 

 of scores of others, already believe they see their 

 way out. Indeed, a single mast, if such be needed, 

 may perhaps serve as the receiver for an indefi- 

 nite number of messages, coming from every point 

 of the compass. And here again the arrangement 

 would be simple. 



The first electric - waves measured by Hertz 

 vibrated back and forth transversely, of course, 

 to their path through space at the rate of about 

 fifty million times per second. Their wave-length 

 that is, the distance between two ridges and 

 two hollows was about twenty feet. The waves 

 used by Marconi to signal Newfoundland, Professor 

 Fleming estimates at about one thousand feet long. 

 Professor Bose, of Calcutta, has with his tiny os- 

 cillators produced others of but a tenth of an 

 inch. There is a corresponding difference in the 

 number of vibrations per second. This is a wide 

 range. 



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