PREFACE. THE favourable reception with which this work has been met by the public, and the kindly expressions of encouragement and approval accorded to it by the press, not in England alone, have determined the publishers to reprint it, with some additions, in this smaller and cheaper form. The edition in one volume is divided into two parts: the first containing a history of the rise and progress of the art of telegraphy, with descriptions of most of the apparatus in use at the present day; the second being devoted exclusively to the more scientific part of the subject, dealing particularly with matter having an immediate relation to submarine work. It has now been decided to separate these parts into distinct volumes, it being thought that there are many who, whilst interested in the history and apparatus, may not care for the scientific part; whilst others, and especially those connected with telegraphic engineering, may find only the information collected in the second part useful to them. For carrying out these objects there could be no better channel than "Weale's Rudimentary Series," the high character of which has rendered it deservedly celebrated. Following the issue of the first edition of this work, there have appeared new and improved editions of Mr. Culley's excellent handbook for operators; of Lardner's work, edited by Mr. Bright-a work of great interest to the reader for general information; and a new work, with useful tables, by Mr. Clark-a valuable contribution to the desk of the telegraph engineer. We see, therefore, that telegraph literature, which slumbered in England during so long a period, is not only awake and active, but, as the result has proved, is welcomed by the reading public; and ere long we hope to see each of our friends follow us in the endeavour to make this interesting branch of civil engineering still more widely familiar, in putting their books within the reach of all by reducing them, as far as possible, to cheaper editions. But ample room is still left for a more comprehensive, elaborate, and able treatise on telegraphy than this, and any of these, are or can be. And it is much to be desired that the history, the practice, and the science of the subject may be treated of separately and exhaustively. As far as the history goes, the author has done his best, with the scanty materials and limited space at his command, to give a short and truthful sketch of the origin, rise, and progress of an art grown to an importance sufficient in itself to immortalise its century. Where individual claims to a part of this immortality prominently occurred, they have been dealt with according to the author's lights. But the arrogance of any individual claim to the title of "the inventor of the electric telegraph" has not been recognised, for the reasons stated; and if a further reason be required, it may be given by the fact that those men who deserve the most credit happen to be those who advance the least claim to it. Some means of rapid communication is, and probably always has been, not only a necessity, but an accomplished fact, in some form or other. It is difficult to understand that the mere knowledge of the attractive and repulsive forces of magnets was not in itself sufficient to suggest to an imaginative mind its application to the communication of intelligible signals. It is also no less difficult to conclude that an employment of frictional electricity to this purpose did not occur to Grey, Watson, Franklin, and others, but, from its apparently chimerical nature, it may, perhaps, have been dismissed, from time to time, from their minds as impracticable. It is not in the first conception of this idea that so much credit lies, as in its gradual development into the proportions of a reality. How long a way to attain this may not have been struggling for birth in the thinking minds of past centuries it is now impossible even to imagine. Mr. Bellamy has kindly called the author's attention to the fact that Galileo was fully alive to the importance which would attach to the employment of magnets for transmitting intelligence to a distance, but failed to see his way to the attainment of that object. In one of his dialogues on the two great rival astronomical systems, written in 1632, he makes |