The century before last saw revolutionary changes in the transmission of information. For the functioning of the optical telegraph, which appeared in the late 18th century, cumbersome towers were necessary for the line of sight of semaphore signals. A hundred years later, the length of telegraph lines was hundreds of thousands of kilometers. At the turn of the century, the first experiments with the use of wireless telegraph began. This is reflected in numerous brochures, books, periodicals of that time. After another hundred years, many of these materials have become publicly available thanks to the development of the Internet and electronic libraries; they are intensively viewed and posted online. The rapid growth in the number of digital libraries and their content made this paper possible. Its goal is to trace the evolution of technologies and processes of information transfer reflected in literature, using a wide variety of electronic libraries - from the ambitious projects of the Library of Congress or Google Books with their millions of digitized books to modest private collections. dedicated to local topics. Materials from more than 20 electronic libraries have been used.