AMSTUTZ AND BELIN g 



ceived at the distant station in an engraved manner 

 ready for printing." 



" Theoretically/' he says, " the half-tone system 

 encounters no difficulties whatever. From a prac- 

 tical point it is not available for commercial work." 

 He describes the troubles that would arise from 

 interference effects, owing to the lack of correspon- 

 dence that there would be between the mesh of the 

 half-tone screen and the path travelled by the stylus 

 over the cylinder, and claims that by using the 

 single-line pictures referred to these troubles could 

 be avoided. 



In all the half-tone photo -telegraphic work 

 single -line pictures are solely used, but at present 

 no satisfactory method has been obtained of 

 engraving the block direct during the reception. 



Amstutz's idea of using a photographic image in 

 relief, and making the actual relief mechanically 

 vary an electrical resistance, has been successfully 

 followed up by a French inventor named Belin, but 

 he again cannot obtain direct engraving at the 

 receiving end. 



Direct photo - engraving by telegraphy may 

 "come" some day, but not until that much desired 

 thing has been discovered, the variable relay. The 

 resistance of a telephone line two hundred miles 

 long may be, perhaps, 2,000 ohms. We cannot 

 employ very high voltages, 100 volts being con- 

 sidered very high ; if we divide i oo by 2,000, we 



