Portugal 3 1 1 



Originally the subscribers' sets consisted of Gower-Bell instru- 

 ments, combined with magnetos and battery-boxes on a common 

 back-board (fig. 105) ; later, the Gower-Bell receiver and tubes 

 were replaced by Bell receivers, the transmitter being retained 

 (fig. 1 06) ; later still, the Blake transmitter succeeded the Gower, 

 and the instrument assumed the aspect which was so long 

 familiar in Great Britain (fig. .107). All the instruments have 

 been manufactured by the Consolidated Telephone Construction 

 and Maintenance Company. The most recent form of trans- 

 mitter supplied by this company is a Runnings of the construc- 

 tion shown in fig. 108, in which A is an ebonite mouthpiece, 

 which directs the sound waves to a ferrotype diaphragm F, having 



D 



I) 



FIG. 108 



behind, and in true contact with it, a thin carbon disc G. B is 

 a rigidly fixed carbon block furnished with a conical pocket, which 

 is nearly filled with truly-spherical carbon balls. The electrodes 

 are the carbon disc and carbon block respectively, and form their 

 connections through the screws D, which also serve to clamp the 

 transmitter to the magneto. When used with two or three cells 

 and a good receiver, the loudness of the transmission obtained is 

 very remarkable, while its clearness leaves nothing to be desired. 



HOURS OF SERVICE 



The Portuguese exchanges enjoy a perpetual day and night 

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