LINE CAPACITY 105 



Future progress rests so much on greater perfec- 

 tion being obtained in the line pictures that I have 

 dwelt at some length on these points. The present 

 systems are good and practicable ; it is perfection 

 of detail that is required. M. Chatenet is a par- 

 ticularly clever photo -engraver, and has rendered 

 much assistance in finding the best means of the 

 preparation of the half-tone pictures. A consider- 

 able time elapsed at Manchester before the photo - 

 engravers there were able to make really suit- 

 able line prints ; but, having once found out the 

 " right way/' the work proceeds quite smoothly. 

 But what I would like to point out is that, 

 although telegraphed pictures are now to be seen 

 so regularly in the Daily Mirror that they occa- 

 sion no surprise, they have only become what 

 they are through the attention from start to finish 

 given to minute details. 



By means of the apparatus described in 

 Chapter VI. it has become possible to make a great 

 variety of experiments, transmitting pictures over 

 an artificial telephone line in which resistance, self- 

 induction, leakance, and capacity can be varied 

 at will. By examining oscillographic records of 

 these transmissions, various arrangements for over- 

 coming line faults can be tested, and their practical 

 utility estimated. The problem, of photo -tele- 

 graphy over telephone lines is closely allied in many 

 respects to ordinary telephone work, only that the 



