I' I Si F C|or«eU InioerBita Sthrary 3ti!aca, S^ew fartt Charles H. Hull Cornell University Library arV18590 History, theory, and practice of tlie eie 3 1924 031 307 196 olin.anx The original of tliis book is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31 924031 3071 96 HISTORY, THEORY, AND PRACTICE OP THE ELECTKIC TELEGEAPH, ft BY GEOEGE B. PRESCOTT, gUPERUtTENDENT OF ELECTBIC TELEOKAPH LINES. FOCETH EDITION, REVISED AND ENIAKGED. BOSTON: TIOKNOR AND FIELDS. : Entered according to Act of Congress, in the year 1860, by TICKNOK AND FIELDS, in tlie Clerk's OiBce of tlie Distijct Court of tlie District of Massacliusetts. tTniversity Press, Cambridge Electrotyped and Printed by Welch, Bigelow, & Co. PEEFACE. Theee is no subject upon which the American public should be better informed, and none, perhaps, in which it should feel greater pride, than in that of the foremost invention of the age, the Electric Telegraph ; for aside from the fact that three of the best systems in use are American inventions, and that to our countrymen is due the credit of producing the first successful recording elec- tric telegraph, it is more generally used in this country than in any other, and probably more than in all others combined, for the common convenience of mankind. In Europe, with the exception of Great Britain, the use of the telegraph is almost wholly under the control of the governments, and its use restricted by the high rates of tolls to the wealthier classes, while in this coun- try it is alike open to all, and telegraphic despatches are " household words " among the poorer as well as the wealthier citizens. The wires extend, not only through every State in the Union, from Maine to Texas, and from Massachusetts to Kansas, but already they are creeping over the Rocky yi PREFACE. Mountains, and erelong we shall have momentary advices from the Pacific States. We have endeavored in this volume to explain the principles and operations of the various systems of elec- tric telegraph in such a manner as to be readily com- prehended by every reader. In order to accomplish this, we have in the first three chapters given a brief treatise upon electricity in theory and practice. As there has been much controversy between rival claimants to the discovery of the principles of the elec- tric telegraph, we have devoted much time to the full consideration of the claims of each, and present the facts so obtained to the impartial judgment of the reader. CONTENTS. PAQS INTBODUCTION 1 PART I. PRELIMINARY NOTIONS. CHAPTER I. ELECTRICAL MANIFESTATIONS. Derivation of the Word Electricity. — Electricity developed by Friction. — Positive and Negative Conditions of Electricity. — Electric Conduc- tibility. — Conductors and Non-Conduotors. — Causes which influence Electric Conduotibility. — Tables of Conducting and Insulating Bodies. — Electricity by Communication. — Distinction betweSn the two Elec- tricities. — Neutralization of the two Electricities. — The Earth the Common Reservoir. — Static and Dynamic State of Electricity. — Theo- ries on the Nature of Electricity 11 CHAPTER H. PROPAGATION OF ELECTRICITY. The Electrical Machine. — Electricity developed by Chemical Action. — Galvani's Experiment. — Volta's Column Pile. — The Discovery of the Electric Current. — Various Forms of Volta's Pile. — Daniell's Constant Battery. — Smee's Constant Battery. — Chester's Telegraph Battery. — Electricity in Animals. —The Raia Torpedo. — The Gymnotus Electri- cus, or Electric Eel 19 CHAPTER in. MAGNETISM. Derivation of the Word Magnet. — Loadstone and its Properties. — Direc- tive Properties of the Magnetic Needle. — Analogy existing between Electric and Magnetic Phenomena. — Oersted's Discovery of 'Electro- Magnetism. — Mutual Action of Magnetism and Electric Currents. — Mutual Action of Two Electric Currents. — Ampere's Theory of the Con- stitution of Magnets. — Investigations to determine the Conditions most favorable for the Development of powerful Magnetftm in Electro-Mag- nets. — Electro-Magnetic Galvanometers. — Induced Currents. — Mag- neto-Electric Machines. — Induction Coils. — Rumkorifs Induction Ap- paratus. — Electro-Static Effects of Electro-Dynamic Induction. 38 viii CONTENTS. PART II. GENERAL PRINCIPLES OE THE ELECTRIC TELEGRAPH. CHAPTER IV. Principal Requisites for ap Eleotrip Telegraph. — The Metallic Conductors. — Discovery of the Conducting Power of the Earth. — Earh^ Experiments of Messrs. Wheatstone and Bain. — Application of the Electro-Magnet for actuating an Alarm. — M. Vorselmann de Heer's Electro-Physiological Telegraph. — Three Grand Divisions in the Manifestations of the Electric Current. — Steinheil's the First Eecordiug Telegraph. — Controversy re- garding the Originality of Morse's Telegraph. — Morse's Telegraph uni- versally adopted^ — Various Manifestations of the Electric Fluid. — High Tension Electric Telegraphs of Lesage, Lomond, Betanoourt, Eeizen, Cavallo, Konalds, and Dyar. — Electro-Gnemioal Telegraphs of Soemmer- ing and Coxe. — Electro-Magnetic Telegraphs of Ampere, Schilling, Gauss and Weber, Steinheil, and Morse. — Masson's Magneto-Electric Tele- g-aph. — Bain's Electro-Chemical Telegraph. — Home's Electro-Thermal Telegraph. — Familiar Nature of Electricity. — Conditions upon which the Practical Utility of the Electric Telewaph depend. — High Tension and Low Tension Electricity, compared. — Bate of Travel of the Electric Current. — Mode of obtaining it. — Transmission of Signals by Electri- city. — Intensity of Electric Currents upon Telegraph Lmes. — PouUlet's Experiment's in Electro-Motive Forces. — Explanation of the Maimer in which the Earth serves as a Telegraphic Conductor. — The Null Resist- ance of the Earth to Electric Couductibihty 53 PART III. ELECTRIC TELEGRAPH APPARATUS. CHAPTER V. THE MORSE SYSTEM. The Relay Magnet. — The Register or Recording Apparatus. — The Key, or Transmitting Instrument. —^^The Combination of Circuits. — Descrip- tion of the Receiving Magnet. — Resistance Coils, or Rheostats. — Alpha- bet of Dots and Lines. — The Division of Time. — Reading by Sound. — Description of the Sounder. — Repeaters, or Transferrers. — Switches, Thumb-Screws, Screw-Cups, etc. — The Manipulator. — Galvanometer attached to an Electro- Magnet 73 CHAPTER VI. THE NEEDLE SYSTEM. The MiUtiplier. — The Alphabet. — The Needle. — The Commutator.— The Alarum. — The Complete Vocabulary. — Mode of Corresponduig. 100 CHAPTER VII. HOUSE'S PRINTING TELEGRAPH. Invention of the Instrument. — Supposed Infringement upon Morse's. Comparison of Speed with other Systems. — Its Wonderftil Accomplish- ments. — English Opmions regarding it. — Its Introduction in 1848 — Description of the Various Parts of the Machine. — DiflSculty in Working upon Long Circuits, owing to the great Resistance of the Helices — Operator's Attachment for the Instrument m — CONTENTS. ix CHAPTER Vin. BAIN'S ELECTRO-CHEMICAL TELEGRAPH. Mr. jBain's Arrival in the United States. — Eefased a Patent by the Com'- missioner. — His Decision overruled by Judge Cranch, and a Patent issued, — Construction of Bain Lines. — Morse Patentees commence Suits for an Injunction. — Description, of the Bain Instrument. — The Alphabet of Dots and Lines. — Electro-Chemical Deconipositions Instantaneous. Abmty to work through Storms. — Bain's Fast Method. — Bakewell's Copymg Telegraph — CaseUi's Pantographio Telegraph. — Remarkable Telegraphic Feat. 127 eHAPTER IX. THE HUGHES SYSTEM. Combination of the Natural and Electro-Mamets. — The Vibrating Spring and Adjusting Bar. — The Type-Wheel, Printing-Cam, and Detent. — Neutralization of the Natural Magnet by Electro-Magnetism. — Only one Impulse required to make a Letter. — Small Amount of Electro- Motive Force required. — Ability to work over Long Circuits. — Working both Ways over the same Wire at the same Moment 139 CHAPTER X. THE AMERICAN PRINTING TELEGRAPH, OR THE COMBINATION SYSTEM. Imperfections of the Hughes Instruments. — Effects of Magnetic Storms and Escapes. — Parts of House and Hughes's Instruments combined with Phelps's Magnetic Governor. — The Result. — Description of the Com- bination. — Bate of Speed of the Combination Instrument. — Superiority of Printing Instruments. — Phelps Patent. — Valuable Auxiliary dtevised by Mr. WT T. Eddy. — Experiments in working over Escapes. 144 CHAPTER XI. HORNE'S ELECTRO-THERMAL TELEGRAPH. Application to the Telegraph of the Heating Power of the Electric Current. — Description of the Apparatus Farmer and Batohelder's Telegraph. — Zooke and Barnes's Columbian Telegraph. — Its Introduction upon the Western Lines. — Injunction granted against it for Infringement upon Morse's Patent. — Modification of Bain's Telegraph by Henry J. Rogers. 156 CHAPTER Xn. THE DIAL TELEGRAPHS. Description of Wheatstone'a Instrument. — Bri'.guet's Dial Telegraph. — Froment's Dial Telegraph Siemens's Dial Telegraph 160 PAET IV. SUBTERRANEAN AND SUBMARINE LINES. CHAPTER XIII. Early Experiments in Subterranean Insulation. — Discovery of Gutta- percha. — Prussian Subterranean Lines. — English and American Sub- terranean Lines. — Submarine Cables. — Cables between Dover and Calais. — Cables uniting England and Holland 169 — ^ CONTENTS. CHAPTER XIV. THE ATLANTIC CABLE. Plateau. —Its Regular Depth. Lieut. Maury's Discovery of the Telegraph Cable and Return of the Fleet. -The First Expedition. - Parting Sf the of the Fleet. - Overtaken by _ Experimental Trip. - Second Departure then: Appomted Rendez- a Feaiful