商品簡介
This book 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 organisation, 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 - 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 routes in the techniques of the telegraph pioneers. "When I first paged through this book, I was startled. I was myself gradually beginning to prepare to write another book after my Classics of Communication. But History of Telegraphy was exactly the book that I had imagined I would write. And then I very soon saw that I would never have reached the level Ken Beauchamp has achieved. So I put my own plans away." 405 Alive, January 2002
