ELECTRICAL ENGINEERING PROBLEMS 625 



Newark, Paterson, New Haven, Hartford, Providence, or any other 

 populated centre within a radius of about two hundred and fifty miles 

 of New York City, and get just as quick and just as good service 

 as he gets with any subscriber in his own town. The solution of 

 this problem would mean that all these populated centres within 

 a radius of two hundred and fifty miles, covering a territory of a 

 large empire, would form, telephonically, one town, where within 

 a time interval of a few minutes one could call up anybody that 

 is of any account and have a pleasant chat or any other kind of a 

 conversation. A few years ago the solution of this problem would 

 have been impossible, to-day it is, and the engineers of the Amer- 

 ican Telephone and Telegraph Company are actually working upon 

 it with all the vigor of their young and well-trained intelligence. 

 A similar problem occupies the attention of the engineers of the 

 Siemens and Halske Company of Berlin. 



The new method of high potential transmission of electrical 

 waves by conductors of suitably increased inductance has given 

 them a new weapon for attacking the problem, and they are wield- 

 ing it with extraordinary force and skill. The telephonic union of 

 the thickly populated centres just mentioned into one community 

 covering the area of a large empire means, of course, the stretch- 

 ing of thousands of wires between such towns as New York, Boston, 

 Philadelphia, Baltimore, and Washington, and that means the 

 employment of cables in underground conduits. No pole line could 

 support anything like that multiplicity of wires. Transmission over 

 underground cables over such distances was an impossibility a 

 few years ago, when a distance of twenty miles was considered 

 quite a serious matter. To-day there is a high-tension telephonic 

 transmission cable containing a large number of wires supplying 

 a most satisfactory telephonic transmission between Boston and 

 Worcester, Massachusetts, a distance of over forty miles, and the 

 experimental results obtained with this cable by connecting several 

 circuits in series back and forth between Boston and Worcester 

 justify the confidence of the engineers of the American Telephone 

 and Telegraph Company that they will certainly solve, in the near 

 future, the grand problem of the telephonic union of the great cen- 

 tres of the Atlantic coast. The same confidence is expressed by 

 the engineers of the Siemens and Halske Company of Berlin in 

 their work on the problem of telephonic communication between 

 Berlin and London through a cable over 400 miles under the North 

 Sea. 



A side issue of this problem is the problem of establishing a satis- 

 factory telephonic communication between any two important 

 centres of a continent. The new principle of high-tension telephonic 

 transmission, mentioned above, affords a satisfactory solution, 



