Digital Libraries as Information Source on the Evolution of Telegraph
The century before last saw revolutionary changes in the transmission of information. For the functioning of the optical telegraph, which appeared at the end of the 18th century, cumbersome towers were necessary for the line of sight of the semaphore signals. One hundred years later, telegraph lines were hundreds of thousands of kilometers long; at the turn of the century, the first experiments with the use of a wireless telegraph began. This is reflected in numerous brochures, books, periodicals of that time. A hundred years later, many of these materials became publicly available thanks to the development of the Internet and electronic libraries, which made the appearance of this work possible. Its goal is to trace the evolution of technologies and processes of information transfer in the 19th century using a wide variety of electronic libraries - from the grandiose projects of the Library of Congress and Google Books with their millions of digitized books to modest private collections dedicated to local topics. Used materials from 20+ electronic libraries.