124 Telephone Systems of the Continent of Europe 



HOURS OF SERVICE 



The Copenhagen central station is open day and night ; the 

 suburban ones from 6 or 8 A.M. till 8 or 10 P.M., which are also 

 about the hours of the provincial exchanges. 



SUBSCRIBERS' INSTRUMENTS 



Magneto ringers are employed, the instruments now put in 

 being made by the Great Northern Telegraph Company of 

 Copenhagen. Transmitters and double-pole receivers of Ericsson's 

 make are now exclusively used. A good many of the older sets 

 are by the Bell Manufacturing Company, Antwerp, and the 

 Norske Elektrisk Bureau, Christiania. A peculiarity is the use of 

 the Lorentz induction coil for the transmitters. It consists of a 

 ring, three inches in outside diameter, of soft-iron wire, on which 

 is wound a primary of "36 of an ohm and a secondary of 360 

 ohms resistance, the whole enclosed in a radially and closely- 

 wound layer of soft-iron wire of 9 mm. section. It is stated to 

 yield better results than the ordinary coil. Certainly the speaking 

 in Copenhagen is very good. 



OUTSIDE WORK (LOCAL) 



The wire used locally is 1*25 mm. bronze, supported on small 

 double-shed porcelain insulators. There are still, however, some 

 single-shed glass insulators, relics of the International Bell Tele- 

 phone Company, in use. The Macintyre tube joint (fig. 99, 

 Norwegian section) is employed, and is said, on the faith of many 

 years' experience, to be quite satisfactory. When well made, the 

 resistance of this joint is no more than that of the unjointed wire ; 

 the twisting brings the metal in contact at many points, and the 

 copper sheathing apparently is quite efficient in protecting these 

 points of contact from the weather, so that the metal remains un- 

 corroded and even bright after prolonged exposure of the joint. 

 Mechanically, the joint is stronger than the wire. Solder could 

 not produce better results than these, and the elimination of 

 the soldering bolt in any form is a decided gain. Of course the 



