Unlike most, if not all, of the early writers who set out to explain the new science and technology of electrical communications to lay audiences, the author of this book, Dionysius Lardner, never had any professional involvement with the telegraph. Readers of this book therefore, might well be astonished at the breadth and depth of knowledge about the subject that he reveals in this treatise. He discusses the theory and technology of the electric telegraph authoritatively, he describes in detail the uses to which it was put and the costs of doing so. He surveys the operation of telegraphs in Great Britain, the United States of America, Russia and in most of the European countries. He does not omit to explain, in a separate chapter, the somewhat specialised subject of railway telegraphy. We can only be amazed at the diligence and dedication required to amass this amount of material, to study and master its purport, and then present it in a highly readable form. As an important mediator of the culture of the new technologies of his time, Lardner's influence should not be underestimated, and his writings are a key source for understanding nineteenth-century popular ideas about progress and its relation to technological development. Although the day of the electric telegraph is now long past, supplanted by modern versions of the telegram and cablegram such as text messaging and e-mail, we can still enjoy and be enlightened by the writings of this remarkable man on a fascinating if obsolete technology.