CONTENTS 



PAGE 



PREFACE . . . . . . . . . . v 



LIST OF ILLUSTRATIONS . . ix 



CHAPTER I. 



Attempts at the Solution of the Telegraphic Transmission of 

 Photographs and Pictures p. i 



CHAPTER II. 



Professor Korn's Selenium Process Early Work with his 

 Original Receiver The String Galvanometer Syn- 

 chronism First Experiments The Early History of 

 Commercial Photo-Telegraphy . . . . p. 2,2, 



CHAPTER III. 



The Korn Telautograph Principles of Working Advantages 

 over Selenium Early Work with Line Pictures Experi- 

 ments with Telephone and Telegraph Cables Recent 

 Progress with the Telautograph . . . . p. 61 



CHAPTER IV. 



The Thorne- Baker System Differences between the Telectro- 

 graph and Earlier Chemical Systems Electrolytic 

 Records of Currents Transmitted through Long Cables 

 The Thome-Baker Line-balance Work with the Electro- 

 lytic Telectrograph p. 88 



