398 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



cities of the empire. The successful completion of the line 

 laid down between Berlin and Halle (a distance of about 

 one hundred and five miles), which went into operation tow- 

 ards the close of 1876, appears to have given great impetus 

 to the system in that country. The following lines have 

 been decided upon, and at the time of this writing several 

 have been either completed or have been well advanced, viz. : 

 Halle-Leipsic, Halle-Cassel-Frankfort-Mayence, Berlin-Ham- 

 burg, and Hamburg-Kiel. The practical working of these 

 lines will be watched with very general interest, since they 

 are expected to definitely decide the question of the prac- 

 ticability of the underground system, not simply for cities, 

 where its utility has long since been demonstrated by gen- 

 eral use abroad, but as a substitute for the aerial system in 

 general. Up to the present time the Berlin-Halle cable, the 

 only branch of which any report has appeared, has given en- 

 tire satisfaction. 



THE ARTICULATING TELEPHONE, 



Although first presented to the world in crude form at the 

 Centennial Exhibition in 1876, was so greatly improved and 

 simplified during the past year that w r e may date its intro- 

 duction as a practical telegraphic apparatus from the 4th of 

 May, 1877, when Professor Grfcham Bell exhibited to an au- 

 dience in the Boston Music Hall a speaking telephone in op- 

 eration between that place and Providence, forty-three miles 

 distant. The apparatus, since this first public demonstra- 

 tion, from its great novelty and possible utility, attracted 

 almost universal attention, and was described and exhibit- 

 ed before scientific societies and public lectures with great 

 eclat y and at the time of present writing has been largely 

 introduced both at home and abroad as a means of commu- 

 nication in a great variety of situations. The longest line 

 in actual operation at the present is that between Boston 

 and New York, a distance of two hundred and fifty miles. 

 The first practical application of the instrument was made 

 by the Board of Water Commissioners of Cambridge, Mass., 

 between the central office and the water-works under their 

 control. Up to the close of the year, it is safe to say that 

 several thousand of these instruments are in practical use 

 in the United States, in verv various situations ; and their 



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