This book, number 26 in the Institution of Electrical Engineers' History of Technology series, records the growth of telegraphy over two centuries, depicting the discoveries and ingenuity of the experimenters and engineers involved, the equipment they designed and built, and the organization, applications and effects on society. The two main phases - cable-based techniques that began in the early 19th century and then wireless transmission in the 20th century - parallel the changes in voice and information communications seen recently. Modern methods of data compaction, coding and encryption in today's communications all have their roots in the techniques of the telegraph pioneers. The book provides an excellent overview of telegraphy from the earliest mechanical systems to the beginnings of the Internet.
The history of submarine cables is well-covered in its own chapter of 47 pages; the bibliography in this chapter includes some useful references to more obscure sources. This chapter also includes information on early technology of submarine cables, the discovery of gutta percha insulation, the first cable to cross the English Channel and other short cables, the first oceanic cables, theory and techniques of transmission, Thomson's mirror galvanometer, cable-laying technology, the cables to North America, India, China and Japan, Africa, and Australia. Like the rest of the book, the submarine cable chapter contains many illustrations and diagrams from contemporary publications.
The book gives a comprehensive overview of the history of telegraphy; the extensive bibliographies at the end of each chapter provide ample resources for more detailed research. Recommended.