T H E THE TELEGRAP MAFNUAL: A COMPLETE HISTORY AND DESCRIPTION OF THE lmnaipotki, flctridt an0i agildet Cdegrap s OF EUROPE, ASIA, AFRICA, AND AMERICA, ANCIENT AND MODERN. WITH SIX HUNDRED AND TWENTY-FIVE ILLUSTRATIONS, Et non " eripuit caclofulmen," Fulguri mentemnfudit, et orbem lumzie cinxit.-PIRTLE. BY TALE. P. SHAFFNER, OF KENTUCKY. NEW-YORK: PUDNEY & RUSSELL, PUBLISHERS, 79 JOHN-STREET, LONDON: EDWARD STANFORD, No. 6 CHARING CROSS. BERLIN: JULIUS SPRINGER, 3 PLACE BIONTBIJOU. PARIS: LACROIX & BAUDRY, 15 QUAI MIALAQUAIS. 1859. Entered, according to Act of Congress, in the year 1859, BY TALIAFERRO P. SHAFFNER, In the Clerk's Office of the District Court of the United States, for the District of Kentucky. PUDNEY & RUSSELL, PRINTERS, 79 John-Street, New- York. -ZE~~~~~~~~~~~~~~~~-- ---------- ~ ~ ~ ~ ~ ~ ~ -: -:~~ --- ---- -- ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ -- -- --------- PREFACE. IN the preparation of this volume, the author has not advanced theories, other than those which are founded upon demonstrated philosophy. It is to be understood, however, that many of the views expressed concerning questions in the sciences may, from time to time, be modified by new developments. In every instance, the opinions given are based upon the known sciences as manifested through the medium of the arts, and more particularly the electric telegraph. I have reviewed the early semaphore telegraphs, and explained their respective modes of operation. These visual systems have, however, ceased to be employed by civilized nations, except for the marine service. As preliminary to the consideration of the electric telegraph, I have introduced a few chapters explanatory of the sciences immediately blended in that art; such, for example, as static and voltaic electricities, magnetism, and electro-magnetism. These questions of philosophy the telegrapher should most carefully study. The data given are from the most reliable authorities. In the collection of materials for this work I have spared neither labor nor expense. For nearly fifteen years I have made the subject-matter of this volume my most careful study. For the greater part of that time, practical telegraphing has been my sole vocation. I have instituted thousands of experiments, and have travelled over most of the civilized world " in search of light" upon this, the most important of all arts. The information herein imparted has cost me years of toil and 4 PREFACE. a heavy expenditure of money. Still, I cannot regret my devotion, either past or present, to the cause. In its study I have found new truths, serving to increase my admiration of that mysterious Providence who knoweth all things. I have not written this book for gain. It has been to me a work of love. For several years I have been urged by friends to prepare a work on practical telegraphing, and I have in the present volume complied with that wish. I have not confined the work to the telegraph of any particular locality, but, on the contrary, I have grouped together the various systems of both hemispheres. Nearly every combination herein described I have witnessed in operation and most carefully studied. I may have failed to comprehend the full merits of each, and my descriptions of them, respectively, may be imperfect, though I have tried to make them clear and concise. I have not attempted to arrange the various systems with regard to priority of invention, nor as to their relative efficiency. I have given dates wherever it was possible, and have refrained from exhibiting any preferences. I indulge the hope that the many inventors who have distinguished the age by the production of their respective contrivances, will not accuse me of an undue partiality. I have tried to be fair in the consideration of the merits of each discovery and each invention. If I have failed in accomplishing this desideratum, the fault lies, not with the heart, but with the judgment. Notwithstanding that this volume has been greatly extended, I have been compelled to omit several important chapters; such, for example, as the organizations for generating magnetoelectricity, the aurora-borealis, the fire-alarm and railway telegraphs, repeating apparatuses, &c. These will be duly considered in some subsequent edition, together with such emendations and additions to the present work as shall be found necessary. To M. Blavier and his publishers in Paris, to the publishers of Noad's " Electricity," the " Illustrated London News," and others who have given me full permission to copy from their respective works, I am especially indebted. On the other PREFACE. 5 hand, some authors and publishers have refused me that permission; and although I could have copied whatever I might have wanted from any foreign work without legal liability, yet I have not done so, knowingly, in a single case where the privilege was refused me. I cannot conclude this review of my labors, without expressing my most profound thanks to my very able and accomplished friend George Jaques, of Worcester, Massachusetts, for his aid in translating from the various languages of the Old World, and in searching for new light and authorities. For the services thus rendered, I cannot but feel the highest appreciation, and a sincere desire that his future life may be blessed with that which will enable him to fill the measure of his creation, and that his fireside may be surrounded with those jewels which are more brilliant than the pearls and gems that sparkle from and adorn the imperial crown. In. preparing this work I have made copious extracts from various publications, among which may be particularly mentioned, Noad's Manual of Electricity' Highton's History of the Electric Telegraph, Dr. O'Shaughnessy's Electric Telegraph, Bakewell's Manual of Electricity, Moigno's Traite de Telegraphie Electrique, Blavier's Cours Theorique et Pratique de Telegraphie Electrique, Davis's Manual of Magnetisrt, Walker's Electric Telegraph Manipulatioli, Shaffner's Telegraph Com-i panion, Dr. Schellen's Electro-l-magnetische Telegraph,; Vail's Electric Telegraph, Dr. Trumbull's Electric Telegraplt, Shaffner's Telegraph Tariff Scale; Smithsonian Reports, American and European Patent Reports, &c., &c. I have not, in all cases, particularly marked. the extracts taken, because, in many of them, I have blended new matter, and, to a greater or less extent, expressed their ideas in different language. In justice, however, to the respective authorities I make this general acknowledgment. To the respective governments of Europe I feel deeply grateful, especially to the French, Belgian, Prussian, Danish, Swedish, Norwegian, and Russian. For the facilities given, and the vast amount of material placed at my command on 6 PREFACE. my visits to them respectively, and for the documents from time to time transmitted, I have been placed under lasting obligations. To M. Chauvin, director-general of the Royal Prussian Telegraphs, I have to express my sincere thanks for recent valuable documents; though their reception was too late for the present edition, they will serve a good end in the future. It is my purpose to continue this work by subsequent editions, and embrace the improvements continually making in the art of telegraphing. Should the reader find any errors in this volume of either omission or commission, he will serve a good end by informing me of the fact. It is very desirable to promulgate truths well sustained by practical demonstrations; and if there be anything in this volume otherwise, it is for the weal of the enterprise that the false doctrines should be at the earliest moment suppressed. In conclusion, 1 would add, that I have been compelled to write this volume piecemeal, on the steamboat, on the railway, at various hotels, and at places thousands of miles apart. All this I have had to do within the past six months. And while, in obedience to other duties, it has not been possible for me to give that personal attention to its passage through the press I should have wished, the novel and technical character of its contents rendered more difficult the labors of the correctors of the press, to whose care it was necessarily left. With these explanations, I submit the " Telegraph Manual" to the generous and impartial consideration of the telegraphers throughout the world. TAL. P. SHAFFNER. NEW-YORK, July, 1859. CONTENTS. CHAPTER I. THE TELEGRAPH. The meaning of the term Telegraph-Divine Telegraph-Telegraphs mentioned in the Classics and Ancient History-The Telegraph invented by Polybius-Agamemnon's Telegraph, B. C. 1084-North American Aboriginal Telegraph-The American Revolutionary Army Signals....................................... PAGE 17 CHAPTER II. THE SEMAPHORE TELEGRAPH. Origin of the Semaphore Telegraph-Its Adoption by the French Government-Its Extension over Europe-A German Telegraph Station-Russian Telegraph.... 27 C HAPTER III. THE CHAPPE TELEGRAPH, ETC. Description of the Chapp6 Telegraph-Organization of the Signal Alphabet-Process of Manipulation-Its Celerity in Sending Dispatches......................... 32 CHAPTER IV. OTHER SEMAPHORE TELEGRAPHS. The Prussian Semaphore Telegraph-The English Semaphore-The Gonon, Chappe, Guyot, and Treutler's ImDrovements on the Chappe Telegraph................ 46 CHAPTER V, STATIC ELECTRICITY. Static Electricity Explained-Conductors and Non-Conductors-Vitreous and Resinous Electricity-Discovery of the Leyden Jar —Franklin's Electrical Theories-Coulomb's Theories of Electro-Statics -Franklin's Reasons for believing that Lightning and Electricity were Identical-Identity of Lightning and Electricity DemonstratedThe Franklin Kite Experiment-Distribution of Electricity-Phenomena of Resistance to Induction-Phenomena of Attraction and Repulsion-Igniting Gas with the Finger-The Leyden JarExperiments..................................... 61 8 CONTENTS. CHAPTE VI. VOLTAIC ELECTRICITY. Electrical Phenomena Discovered by Galvani-Origin of the Voltaic Pile -Science of the Voltaic.Battery-Onm's Mathematical Formulae-Chemical and Electrical Action of the Battery-The Daniell, the Smee, the Bunson, the Grove, and the Chester Voltaic Batteries-Comparative Intensity and Quantity of the Grove, Daniell, and Smee Batteries.......................................................... 7 CHAPTER VII. MAGNETISM. Native Magnetism of the Load-Stone-Attractive and Repulsive Forces of Permanent Magnets-Componentparts of the Magnet-Induced Magnetism............... 105 CHAPTER VIII. ELECTRO-MAGNETISM. Discovery of Electio-Magnetism by (Ersted-Discoveries of Schweigger, Arago, and Ampere-Discoveries of Sturgeon and Henry-Recapitulation of the Discoveries on Electro-Magnetism-English Telegraph Electrometers-Magnetometers-The De La Rive Ring and other Experiments................................ 114 CHAPTER IX. EARLY ELECTRIC TELEGRAPHS. Suggestions of Science-The Telegraph of Lomond-Reizen's and Dr. Salva's Electric Spark Telegraph-Baron Schilling's, Gauss and Weber's, and Alexander's Telegraphs..................................................... 132 CHAPTER X. SOEMMERING S ELECTRO-CHEMICAL TELEGRAPH. Soemmering's Electric Telegraph of 1809-The Apparatus and Manipulation Described -Signal Keys for opening and closing the Circuits........................... 142 CHAPTER XI. RONALD S ELECTRIC TELEGRAPH. Invention of Ronald's Electric Telegraph-Experiments and Description of the Apparatus-Description of an Electrograph..................................... 147 CHAPTER XII. STEINHEIL'S ELECTRIC TELEGRAPH. Experiments and Discovery of the Earth Circuit-The Electric Telegraph as Invented -The Electric Conducting Wires-Conductibility of the Earth Circuit-Apparatus for Generating the Electric Current-The Indicating Apparatus-Construction of the Apparatus-Application of the Apparatus to Telegraphing-The Alphabet and Numerals-The Discovery and Invention of Steinheil......................... 157 CONTENTS. 9 CHAPTER XIII. HISTORY OF THE ENGLISH ELECTRIC TELEGRAPH. William Fothergill Cooke and the Telegraph-Moncke's Electrometer ExperimentsThe English Electric Telegraph invented-Invention of the Alarum-The Mechanical Telegraph-The Escapement Apparatus-Mr. Cooke's Efforts to put his Telegraph in Operation-The Second Mechanical Telegraph-Wheatstone's Permutating KeyBoard-Messrs. Cooke and Wheatstone become associated-The Secondary Circuit invented-Mr. Cooke improves his Original Telegraph-All the Improvements combined-Description of the Apparatuses-Improvements patented in 1838-Wheatstone's Mechanical Telegraph-Further Improvements by Mr. Cooke........... 179 CHAPTER XIV. THE ENGLISH ELECTRIC TELEGRAPH. English Telegraph, and Description of its Electrometer-The Single-Needle Apparatus -Formation of the Alphabet-Single-Needle Instrlment and Voltaic Circuit-The Double-Needle Instrument, Alphabet, and Manipulation-The Alarum ApparatusCombining and Arranging of Circuits........................................ 216 CHAPTER XV. INTERIOR OF THE ENGLISH TELEGRAPH STATIONS. Interior Arrangements of a Station-Rate of Signalling-The Strand Telegraph Station -The Public Receiving Department-Blank Fornis of the English Telegraphs. 233 CHAPTER XVI. DAVY S ELECTRO-CHEMICAL TELEGRAPH. Nature of the Invention described-The Transmitting Apparatus-The Receiver-The Instruments combined-The Manipulation-The Signal Alphabet.............. 255 CHAPTER XVII. BAIN S PRINTING TELEGRAPH. Description of the Printing Telegraph Apparatus.............................. 269 CHAPTER XVIII. THE BRETT PRINTING TELEGRAPH. Brett's Printing Telegraph-Description of the Composing Apparatus-The Printing Apparatus and Manipulation-The Compositor or Commutator described-Mr. Brett's Last Im provem ent..................................................... 273 CHAPTER XIX. THE MAGNETO-ELECTRIC TELEGRAPH. Application of Magneto-Electricity to Telegraphing-Its Advantages-Description of Henley's Apparatus-The Bright's Apparatus-Its Comparative Celerity........ 286 .10 CONTENTS. CHAPTER XX. HIGHTON S ELECTRIC TELEGRAPHS. High Tension Electric Telegraph-Gold Leaf Instruments-Single and Double Pointer Needle Apparatus-Revolving Pointer-Improvements in Batteries andInsulation 295 CHAPTER XXI. BAKEWELL'S ELECTRIC COPYING TELEGRAPH. Manipulation of the Electric Copying Telegraph of F. C. Bakewell of England-The Apparatus Described-Secrecy of Correspondence, its Advantages and Disadvantages........................................... 304 CHAPTER XXII. NOTT'S ELECTRIC TELEGRAPH. Description of the Apparatus........................................... 310 CHAPTER XXIII. SEIMENS AND HALSKIE S GERMANIC TELEGRAPH. Description of the Telegraph Apparatus-The Alarum Bell-Electric Circuits and Manipulation-The Transmitter and its Application....................... 313 CHAPTER XXIV. FRENCH ELECTRIC TELEGRAPH. The Nature and Origin of the System-The Receiving Apparatus-The Manipulating Apparatus-The Process of Sending Signals-The Formation of the Alphabet.. 325 CHAPTER XXV. THE FRENCH RAILWAY ELECTRIC TELEGRAPH. Principles of the French Railway Telegraph-Description of the Receiving Instrument -The Manipulating Apparatus-Process of Manipulation between Stations-Portable Apparatus for Railway Service-Breguet's Improvement...................... 334 CHAPTER XXVI. ELECTRIC TELEGRAPH BELL APPARATUS. The French Telegraph Bell Instruments-Vibratory Bell Apparatuses-Use of Bells in Telegraph Offices........................................................ 346 CHAPTER XXVII. THE ELECTRO-CHEMICAL TELEGRAPH. Bain's Electro-Chemical Telegraph-Apparatus and Manipulation-Smith and Bain's Patented Invention-Bain's Description and Claims-Morse's Electro-Chemical Telegraph-Westbrook and Rogers' Electro-Chemical Telegraph................ 354 CONTENTS. 11 CHAPTER XXVIII. FROMENT S ALPHABETICAL AND WRITING TELEGRAPHS. Alphabetical Apparatus and Manipulation-The Writing Apparatus............. 373 CHAPTER XXIX. VAIL'S PRINTING TELEGRAPH. Description of the Telegraph Apparatus-Manipulation and Celerity of Communicating -Arrangement of the Alphabet.......................................... 382 CHAPTER XXX. THE HOUSE PRINTING TELEGRAPH. Early History of the House Telegraph-The Composing and Printing Apparatuses-The Axial Magnet-The Air Valve and Piston-The Manipulation-The Patented Claim................................................................. 391 CHAPTER XXXI. HISTORY OF THE AMERICAN ELECTRO-MAGNETIC TELEGRAPH. Invention of the Telegraph-The First Model of the Apparatus-Specimen of the Telegraph Writing-The Combined Circuits Invented-Favorable Report of the Committee on Commerce in. Congress-Construction of the Experimental Line-Invention of the Local Circuit-Improvements of the Apparatus-Administration of the Patents, by Hon. F. J. Smith, and Hon. Amos Kendalt-Extension of Lines in America.,. 402 CHAPTER XXXII. THE MORSE TELEGRAPH APPARATUSES. The Early Telegraph Instruments-Modern Lever Key-The Early Circuit ChangerModern Circuit Closers-Nottebohn's Circuit Changer-Binding Connections-The Electro-Magnet of 1844-The Modern Relay Magnet-The Receiving Register-The Sounder.............................................................. 422 CHAPTER XXXIII. INTERIOR OF AN AMERICAN TELEGRAPH STATION. Receiving Department of a Telegraph Station-The Operating or Manipulating Department-Receiving Dispatches by Sound-Incidents of the Station-Execution of an Indian Respited by Telegraph.....................,.............. 458 CHAPTER XXXIV. THE MORSE TELEGRAPH ALPHABET. Composition of the American Morse Alphabet-The Alphabet, Numerals, and Punctuation-The Austro-Germanic Alphabet of 1854-European Morse Alphabet of 1859...................................................... 469 12 CONTENTS. CHAPTER XXXV. TELEGRAPH ELECTRIC CIRCUITS. Electric Circuits on European Lines-Circuit of the Main Line described-Adjustment of the Line Batteries-Early Experimental Circuits —The Stager Compound Circuits -Combining of Electric Circuits....................................... 480 CHAPTER XXXVI. ELECTRIC CURRENTS. Electric Currents Explained-Electric Circuits-Quantity and Intensity CurrentsPhenomena of the Return Current-Retardation of the Current Illustrated-Estimated Velocity of the Current-Working of the Mediterranean Telegraphs-Scale of the Velocity of the Current on Subaqueous Conductors....................... 496 CHAPTER XXX II. ELECTRIC TELEGRAPH CONDUCTORS. Composition of Telegraph Circuits-Conductibility of Metals and Fluids-Conducting Power of different sizes of Copper Wire-Conducting Power of Telegraph WiresAdvantage of Zinc-Coated Wires-Conductors composing a Voltaic Circuit-Strength of Telegraph Wires-Scale and Weight of Telegraph Wires.............. 513 CHAPTER XXXVIII. GUTTA-PERCHA INSULATION. Application of Gutta-Percha as an Insulation-Discovery of Gutta-Percha, its Nature, Qualities, and Chemical Properties.........2......................... 524 CHAPTER XXXIX. TELEGRAPH INSULATION. English Telegraph Insulators-The American, the French, the Sardinian, the Bavarian the Holland, the Baden, the Austrian, the Seimens and Halskie's, and the Hindostan Insulators-Tightening the Wires in Asia, England, and on the Continent...... 529 CHAPTER XL. PARATONNERRE, OR LIGHTNING ARRESTER. Lightning on the Telegraph-Highton's Paratonnerre-Reid's American ParatonnerreVarious Apparatuses on American Lines-Attachment of Paratonnerres at River Crossings-Incidents of Lightning'striking the Line-Steinheil's, Fardley's, Meisner's, Nottebohn's, Breguet's, the French, and Walker's Paratonnerres.............. 564 CHAPTER XLI. SUBTERRANEAN TELEGRAPHS. Subterranean Lines in America, Prussia, Russia, Denmark, and France-Lines in Great Britain-Underground Lines in Hindostan-Mode of Testing-Subterranean Telegraphs Repairing the Insulated Wires............................... 587 CONTENTS. 13 CHAPTER XLII. AMERICAN SUBMARINE TELEGRAPHS. Disasters to Mast Crossings over Rivers-Adoption of Submarine Cables-Submarine Cables Perfected-Submerging of the Cable-Bishop's Submarine Cables-Chester's Cable MIanufactory-Leaden-Covered Telegraph Wires....................... 599 CHAPTER XLIII. EUROPEAN SUBMARINE TELEGRAPHS. The English and French Cables-Mode of Shipping and Submerging Cables-Holyhead and Howth Telegraph-The Irish Channel Cable of 1852-The English and Belgian Submarine Telegraph-Donaghadee and Port Patrick Submarine Line-English and Holland Submarine Cable-Prince Edward's Island Cable-Danish Baltic Sea Telegraph-The Gulf of St. Lawrence Telegraph-The Balize, Hudson, and Zuyder Zee Cabes —The Black Sea Telegraphs-The Mediterranean Submarine Telegraph Lines........................................................... 607 C HAPTER XLIV. ATLANTIC OCEAN TELEGRAPHY. The Atlantic Telegraph Company Organized-Principles of Philosophy Presumed by the Company-The Expedition for Laying the Cable in 1857-The First Expedition of 1858-The Second Expedition of 1858-Working of the Telegraph Cable-Cause of the Failure of the Cable to operate...................................... 622 CHAPTER XLV. OCEAN TELEGRAPHY. The Depths ot the Ocean-Description of the Brooks Lead-The Elements of the Ocean-Maury's View of a Deep Sea Cable-Atlantic Telegraphs Projected.... 649 CHAPTER XLVI. TELEGRAPH CROSSINGS OVER RIVERS. Telegraph Crossings in Europe-The Great Crossing over the River Elbe-Wide Spans of Wire on the Continent-River Crossings in America-Description of the Great Mast on the Ohio River-Suspension of the Wire over the Masts-A Western Frontier Telegraph Crossing.......................................... 657 CHAPTER XLVII. CONSTRUCTION OF TIIE AMERICAN LINES. Organization for Digging the Holes-Erection of the Poles-Suspension of the WireInsulating the Poles...................................................... 668 14 CONTENTS. CHAPTER XLVIII. THE TIMBER AND PREPARATION OF TELEGRAPH POLES. The Size, Preparation, and Durability of Telegraph Poles, including the Red-Cedar, White-Cedar, Walnut, Poplar, White-Oak, Black-Oak, Post-Oak, Chestnut, HoneyLocust, Cotton-Wood, Sycamore, and other Timbers......................... 681 CHAPTER XLIX. POLES ON THE FRENCH TELEGRAPH LINES. Preparation of Poles on the French Lines-Injection with Sulphate of Copper-Size Cost, and Durability of different Kinds of Wood........................... 688 CHAPTER L. POLES ON THE ENGLISH AND OTHER EUROPEAN LINES. Baltic Squared Timber-Saplings of Larch, Pine, Spruce, &c.-Poles on the Hindostan Line-Bamboo, Iron-Wood, Teak, Saul, and other Timbers-Their Preparation and Durability.............................................................. 696 CHAPTER LI. REPAIRING OF TELEGRAPH LINES. Qualification and Duties of Repairers-Continuous and Uniform Metallic ConductorsThe Joining of Telegraph Wire-Repairing a Break of the Line Wire-The Interruption of the Line by the Falling of Trees-The Great Sleet of 1849, and the Telegraph Lines-Destruction of the Telegraph Lines by Lightning-A Silk Cord Splice found in the Line-Novel Cases of Repairing the Line-Removal from the Line of all Foreign Conductors-To preserve the Insulation of Wire-To Secure the Permanency of the Structure of the Line........................................... 701 CHAPTER LII. IMPROVEMENTS IN TELEGRAPH APPARATUS. Kirchhof's, Farmer's, Hughes', Partridge's, Baker's, Coleman's, Channing's, Smith's, Clay's Woodman's, Humaston's, and Wesson's, Patented Improvements in Telegraphing.................................................................. 718 CHAPTER LIII. ELECTRIC TIMIE-BALL. Utility of Electric Time-Balls for Correction of Chronometers-Nelson's Monument and Time-Ball......................................................... 741 CHAPTER LIV. ORGANIZATION AND ADMAINISTRATION OF AMERICAN TELEGRAPHS. Organization of Telegraph Lines-Organization of Companies-Charter-By-LawsOffice Regulations-Rules for Sending and Receiving Messages-Lines in British Provinces-Patent and Parliamentary Monopolies......................... 745 CONTENTS. 15 CHAPTER LV. ADMINISTRATION O' AMERICAN TELEGRAPHS. Tariff on Dispatches in America-Words Chargeable and Free-Arrangement of Local Tariffs-Qualifications of Employds-Protection of the Telegraph-Secrecy of Dispatches-Penalty for Refusing to Transmit Despatches-Patent Franchise Inviolable - The Right of W ay for Telegraphs....................................... 758 CHAPTER LVI. ORGANIZATION AND ADMINISTRATION OF EUROPEAN TELEGRAPHS. The Telegraph in France-Decrees permitting the Public to Telegraph-Regulations on receiving and transmitting Dispatches-Conditions of Admission of Supernumeraries -Programme of Preparatory Education required of Candidates............... 768 CHAPTER L VII. ADMINISTRATION OF RUSSIAN TELEGRAPHIS. Russian Government Telegraph-Categorical Arrangement of Dispatches-Regulation for Receiving and Sending Dispatches-Classification and Tariff of Charges-Regu lation of the Clocks.................................... 777 CHAPTER LVIII. EUROPEAN INTERNATIONAL TARIFFSo European International Tariff-English International Tariff-Rules and RegulationsThe French Range.......................................... 784 CHAPTER LIX ORGANIZATION AND ADMINISTRATION OF ASIATIC TELEGRAPHS. History of the Telegraph in Hindostan-Rules and Regulations on the Bengal Lines -Classification and Qualification of Employes............................ 799 APPENDIX. BIOGRAPHICAL SKETCHES OF EMINENT TELEGRAPHERS, WITH PORTRAITS ON STEEL. SAMUEL F. B. MORSE, OF NEW-YORK................................ 8O., 03 AMOS KENDALL, oF THE DISTRICT OF COLUMBIA.................................. s808 FRANCIS O. J. SMITH, OF MAINE.......................... 811 WILLIAM MI. SWAIN, OF PENNSYLVANIA................................... 822 WILLIAM TANNER, OF ALABAMA............................................. 825 JOHN J. SPEED, JR., OF MICHIGAN........................................... 829 JEPTHA H. WADE, OIoF 01......................................,..... 831 LEVI L. SADLER, OF MASSACHUSETTS............................................ 833 ANSON STAGER, or OHIO....................................................... 837 TALIAFERRO P. SHAFFNER, OF KENTUCKY................................... 840 TELEGRAPH CHESS-BOARD 57 15 7 59 552 i 53 2 l Wll::I/ 51 9119lillI 41 1\li008dll 4S13 W1 ll, 45 7lil ll _ 25 21 ij a M i51 9o,~l~tll ~ I tI i 3 I jiell 5 7Bf^^ THE TELEGRAPH. CHAPTER I. The meaning of the term Telegraph-Divine Telegraph-Telegraphs mentioned in the Classics and Ancient History-The Telegraph invented by PolybiusAgamemnon's Telegraph, B. C. 1084-North American Aboriginal Telegraph-The American Revolutionary Army Signals. THE MEANING OF THE TERM TELEGRAPH. TELEGRAPH-Greek, T-I~e. at a distance, and ypdcm, to write. The original meaning of the word, as taken from the Greek, is to perform the act of writing at a distance. In its modern application it means the art of "communicating at a distance." For example, the semaphore telegraph, composed of angles, communicated intelligence by certain mechanical contrivances, which had to be seen and understood by the operator miles distant. Also the needle systems of the electric telegraphs of Europe: they do not write, yet they communicate to points far distant. The term has been applied to any and all systems of transmitting information by signs or sounds to another beyond the reach of speech. The art of conveying intelligence by the aid of signals has been practised for centuries, and for aught we know since Adam and Eve commenced their pioneer career in the Garden of Eden. I have searched the Bible in vain for some tangible mode of signaling among the early nations. The most definite reference to communicating by signals mentioned in the Old Testament is to be found in chapter vi., verse 1, of the prophet Jeremiah, viz.: "0, ye children of Benjamin, gather yourselves to flee out of the midst of Jerusalem, and blow the trumpet in Tekoa, and set up a sign of fire in Beth-haccerem; for evil appeareth out of the north, and great destruction!" The writings of Jeremiah date 588 years before Christ, and the above reference to communicating intelligence to others by the "sign of fire," or by any means of signaling is the carliest on reliable record. 2 18 THE TELEGRAPH. DIVINE TELEGRAPH. In the New Testament there is nothing more potent and more sublime than the signat placed in the heavens to indicate that the Son of God was born. The humble shepherds in the open fields of Judea, while guarding their flocks, beheld in the vaulted firmament a STAR, the brilliancy of which had no twin. It was a signal-a Divine signal-communicating to man the glad tidings of the birth of the Prince of Peace. iA~ ~ ~ ~ ~ ~~~~~;~~;-~~i-=-= —==~== ANCIENT TELEGRAPHS. 19 The Gospel of St. Matthew teaches that the signal light suspended in the heavens by the hand of the Creator was seen by the wise men of the east: "Now when Jesus was born in Bethlehem of Judea, in the days of Herod the king, behold, there came wise men from the east to Jerusalem, " Saying, Where is he that is born King of the Jews? for we have seen his star in the east, and are come to worship him." TELEGRAPHS MENTIONED IN THE CLASSICS AND ANCIENT HISTORY. In profane history and the classics, various methods of communicating by signals are mentioned. Homer is the first who mentions the telegraphic art. He compares the lambent flame which shone round the head of Achilles, and spread its lustre all round, to the signals made in besieged cities by clouds of smoke in the daytime, and by bright fires at night, as certain signals calling on the neighboring states for assistance, or to enable them to repel the powerful efforts of the enemy. Julius Africanus minutely details a mode of spelling words by a telegraph. It appears that fires of various substances were the means made use of. He says the Roman generals had recourse to such media of distant communication. In Livy, in Vegetius, and in the life of Sertorius, by Plutarch, it is mentioned that these generals frequently communicated by telegraphs. In book iv., page 238, of Brumoi's account of the Theatres of the Greeks, it is stated that fire signals were used to communicate the events of wars, and likewise to direct the commencement of battles. This description of signals was anterior to the use of trumpets. A priest, crowned with laurels, preceded the army, and held a lighted torch in his hand. He was respected and spared by the enemy, even in the heat of battle. Hence the old proverbial expression for a complete defeat, that even the very torch-bearer had not been spared. Hence, also, it is highly probable that the usage arose of rep- senting discord with inflamed torches. The Chinese, like the ancient Scythians, communicated intelligence by lighting fires or raising a cloud of smoke at different stations. Polybius gives the general appellation of Pyrsia to the telegraphic modes then practised; indicating that fires were the principal means made use of. An ingenious though limited species of telegraph was invented by 2Eneas, who lived in the time of Aristotle, and who wrote on the duties of a general. Two oblong boards had various sentences written on 20 THE TELEGRAPH. their surfaces, as, " The enemy have entered the country," " The invasion has been repelled," " The enemy are in motion," &c., &c. These boards were fixed perpendicularly in pieces of cork which fitted very nearly the mouth of two similar circular vessels filled with water, and having a cock adapted to each vessel. One of the vessels was stationed where the intelligence originated, and the second at the place to which it was to be conveyed. A person, as at present, was always on the lookout; and when he perceived one or more torches raised up at the primary station, he understood that intelligence was about to be communicated. On observing a second torch raised, he instantly answered the signal and opened or turned the cock of the vessel he was in charge of; the cock of the vessel at the primary station having been turned immediately on raising up the second torch at that station and on observing this signal answered. As the cocks were opened simultaneously at both stations, the circular corks with the board standing perpendicular to their respective centres, would descend in the vessels equally, as the water subsided. At the instant when the sentence to be communicated descended or sunk to the level of the edge of the vessel at the primary station, the person in charge there raised a torch. The person at the second station, on observing this, instantly answered this signal, and turned the cock of his vessel, and thus stopped the flowing of the water, reading at the same time the sentence then level with the edge of the vessel, such sentence, on account of the equal flow of the water, corresponding to the one, similarly situated at the original station. TELEGRAPH INVENTED BY POLYBIUS-PUNIC WAR, B. C. 264. Polybius writes, in his history of the Punic wars, that he improved a mode of communicating ideas by the letters of the alphabet applied to a telegraph invented by Cleoxenus, or according to some authors, byDemoclitus. The letters of the Greek alphabet were divided into five parts, and those in each division were inscribed on a board fixed perpendicularly to an upright post for each of those divisions of the alphabet. These posts stood in an opening between two walls about ten feet by six, and situated on each side of the posts. Two long tubes (a dioptical instrument) were fixed in one position or direction. The telegraph workers could readily perceive through these tubes, which excluded all lateral rays, the right or left of the station viewed, and what number of torches might be raised above the top of the wall, either on the right or left of the station looked to. Things being thus prepared at the primary AGAMEMNON S TELEGRAPH. 21 and second station, the person in charge at the primary station would raise. up two torches as a commencing signal that intelligence was about to be conveyed. The looker-out at the other station would, on perceiving this, hold up a couple of torches, thus indicating that he was prepared. The ideas to be communicated were reduced previously to as few words as possible. The posts on which the letters were, being numbered 1, 2, 3, 4, and 5, one or more torches raised up above the left-hand wall, would indicate to the person at the second station, on what post was situated the first letter of the sentence to be communicated. The person at the second station, on observing through one of his tubes the torch or torches held up, would immediately raise torch or torches corresponding to the display exhibited. The person at the primary station, seeing his signal taken up, would lower his torch or torches, which would at once disappear on sinking under the level of the top of the wall. The column on which the letter was, being thus ascertained, the person at the primary station would hold up from behind the right-hand wall, a torch or torches, indicating the position of the letter on the post already pointed out. For instance, if it was the first letter at the top of the column, he would hold up one torch, and if the second, two torches, and so on to the fifth letter on the column. The person at the second station would exhibit a corresponding number, to make it appear that he understood the signal. Every letter in each word would be communicated in this manner; and we are to suppose that an agreed-on signal would be made to indicate the termination of a word and of a sentence. It is further evident that information could be conveyed along any number of stations, on the principle of the modern telegraph of keeping up every signal until taken up at the succeeding station. But in this case two parallel walls would be requisite on each side of the posts, in order that the torches, when depressed, might disappear to the two contiguous stations at the same instant. This was a night telegraph; but it could obviously and readily have been converted into a day telegraph by substituting flags in lieu of torches. AGAMEMNON'S TELEGRAPH, B. C. 1084. iEschylus, who was born five hundred and twenty-five years before Christ, wrote a tragedy in which he gave an account of the fall of Troy, which occurred 1084 years before the Christian era. For ten years the city had been besieged by Agamemnon. The news of the memorable event was signaled to his queen, Clytsemnestra. The following is from fEschylus: 22 THE TELEGRAPH. "WATCHMAN. I pray the gods a deliverance from these toils, a remedy for my year-long watch, in which, couching on my elbows on the roofs of the Atreidse, like a dog, I have contem-lated the host of the nightly stars, and the bright potentates at bear winter and summer to mortals, conspicuous in the Firmament. And now 1 am watching for the signal of the beacon, the blaze of fire that brings a voice from Troy, and tidings of its capture; for thus strong in hope is the woman's heart, of manly counsel. Meanwhile I have a night-bewildered and dew-drenched couch, not visited by dreams, for fear, in place of sleep, stands at my side, so that I cannot. firmly close my eyelids in slumber. And when I think to sing or whistle, preparing this the counter-charm of song against sleep, then do I mourn, sighing over the sad condition of this house, that is not, as of yore, most excellently administered. But now, may there be a happy release from my toils as the fire of joyous tidings appears through the gloom. Oh hail! thou lamp of night, thou that displayest a light as like the day, and the marshalling of many dances in Argos on account of this event. Ho! ho! I will give a signal distinctly to the wife of Agamemnon, that she, having arisen with all speed from her couch, may raise aloud a joyous shout in welcome to this beacon, if indeed the city of Ilion is taken, as the beacon light stands forth announcing; and I myself will dance a prelude. For I will count the throws of my lord that have fallen well; mine own, since this kindling of the beacon light, has cast me thrice six. May it then befall me to grasp with this hand of mine the friendly hand of the sovereign of this palace on his arrival. CHORus. But thou, daughter of Tyndarus, Queen Clytoemnestra, what means this? What new event? What is it that thou hast heard? and on the faith of what tidings art thou burning incense sent around? And the altars of all our cityguarding gods, of those above and those below, gods of heaven and gods of the forum, are blazing with offerings; and in different directions different flames are springing upward, high as heaven, drugged with the mild, unadulterated cordials of pure ungent, with the royal cake, brought from the inmost cells. Concerning these things, tell one both what is possible and lawful for thee to say, and become thou the healer of this distracting anxiety, which now, one while, is full of evil thought, but at another time, because of the sacrifices, hope blandly fawning upon me repels the insatiate care, the rankling sorrow that is preying upon my heart. X * * I have come revering thy majesty, Clytemnestra; for right AGAMEMNON S TELEGRAPH. 23 it is to honor the consort of a chieftain hero, when the monarch's throne has been left empty. And gladly shall I hear whether thou, having learned aught that is good or not, art doing sacrifice with hopes that herald gladness-yet not if thou continuest silent will there be offence. CLYThEMNESTRA. Let morning become, as the adage runs, aherald of gladness from its mother night; and learn thou a joy greater than thy hope to hear, for the Argives have taken the city of Prian. CH. How sayest thou? thy word escaped me from its incredulity. CLYT. I say that Troy is in the power of the Argivesspeak I clearly? CH. Joy is stealing over me, that calls forth a tear. CLYT. Ay, for thy countenance proves thy loyalty. CH. Why, what sure proof hast thou of these things? CLYT. I have a proof-why not?-unless the deity hath deluded me. CH. Art thou then reverencing the vision of dreams that win easy credence? CLYT. I would not take the opinion of my soul when sunk in slumber. CH. But did some wingless rumor gladden thy mind? CLYT. Thou sharply mockest my sense as that of a young girl. CH. And at what time hath the city been sacked CLYT. I say in the night that hath now brought forth this day. CH. And what messenger could come with such speed? CLYT. Vulcan, sending forth a brilliant gleam from Ida; and beacon dispatched beacon of courier-fire hitherward. Ida, first, to the Hermsean promontory of Lemnos, and third in order Athos, mount of Jove, received the great torch from the isle, and passing o'er so as to ridge the sea, the might of the lamp as it joyously travelled, the pine-torch transmitting its goldgleaming splendor, like a sun, to the watch towers of Macistus. And the watchman omitted not his share of the messenger's duty, either by any delay, or by being carelessly overcome by sleep; but the light of the beacon coming from afar to the streams of the Euripus gives signal to the watchmen of Mlessapius, and they lighted a flame in turn and sent the tidings onward, having kindled with fire a pile of withered heath. And the lamp in its strength not yet at all bedimmed, bounding over the plain of the Asopus, like the bright moon to the crag of Cithheron, aroused another relay of the courier fire. And 24 THE TELEGRAPH. the watch refused not the light that was sent from afar, lighting a larger pile than those above mentioned; but it darted across the lake Gorgopis, and having reached mount ZEgiplanctus, stirred it up that the rule of fire. might not be stint, and lighting it up in unscanting strength, they send on a mighty beard of flame, so that it passed glaring beyond the headland that looks down upon the Saronic frith, then it darted down until it reached the Arachnaean height, the neighboring post of observation, and thereupon to this roof of the Atreide here darts this light, no new descendant of the fire of Ida. Such, in truth, were my regulations for the bearers of the torch fulfilled by succession from one to another; and the first and the last in the course surpass the rest. Such proof and signal do I tell thee of my husband having sent me tidings from Troy. CH. To the gods, my queen! I will make prayer hereafter, but I could wish to hear and to admire once more, at length, those tidings as thou tellest them. CLYT. On this very day the Greeks are in possession of Troy. I think that a discordant clamor is loud in the city. If you pour into the same vessel both vinegar and oil, you will pronounce that they are foemen, and not friends. So you may hear the voices of the captured and the conquerors distinct because of a double result; for the one party having fallen about, the corpses of men, both those of brothers, and children those of their aged parents, are bewailing, from a throat that is no longer free, the death of those that were dearest to them. But the other party, on the contrary, is hungry, fatigued from roaming all the night after the battle, arranging at meals of such things as the city furnishes, by no fixed law in the distribution, but as each hath drawn the lot of fortune. Already are they dwelling in the captured houses of the Trojans, freed from the frost beneath the sky, and from the dews, thus will they, poor wretches, sleep the whole night through without sentries." NORTH AMERICAN ABORIGINAL TELEGRAPH. The most remarkable signaling records are to be found on various parts of the North American continent. The aborigines, or a race of people centuries since extinct, had their signal stations or mounds. Upon the loftiest summits beacon fires were built, and the rising smoke by day and the red flame by night communicated intelligence to others far distant. These mounds, these beacon remains, are still to be seen in different parts of America. An eminent author upon this subject says, that the most commanding positions on the hills bordering the NORTH AMERICAN ABORIGINAL TELEGRAPH. 25 valleys of the west, are often crowned with mounds, generally intermediate but sometimes of large size; suggesting at once the purposes to which some of the cairns or hill-mounds of the Celts were applied, namely, that of signal or alarm posts. Ranges of these mounds may be observed extending along the valleys for many miles. Between Chillicothe and Columbus, on the eastern border of the Scioto valley, not far apart, some twenty may be selected, so placed in respect to each other, that it is believed, if the country was cleared of the forest, signals of fire might be transmitted in a few minutes along the whole line. On a hill opposite Chillicothe, nearly six hundred feet in height, the loftiest in the entire region, one of these mounds is placed. A fire built upon it would be distinctly visible for fifteen or twenty miles up, and an equal distance down the valley. In the Miami valley similar works are found. Upon a hill three hundred feet in height, overlooking the Colerain work, and commanding an extensive view of the valley, are placed two mounds, which exhibit marks of fire on and around them. Similar mounds occur at intervals along the Wabash and Illinois, as also on the Upper Mississippi, the Ohio, the Miamis, and Scioto. On the high hills, overlooking Portsmouth and Marietta, mounds of stone are situated; those of the former place exhibit evident marks of fire. These mounds, or beacon hills, are to be found in different parts of the continent. The remains of these beacon fires are silent records left by a people, long since gone. Above the cinders have grown stately oaks, and upon the surface of the earth nothing but the new soil is to be seen. On removing the 26 THE TELEGRAPH. earth some few feet, the charcoal and ash beds are found. How many centuries they have been there no human being can divine. It remains a sealed history to the world. The savage Indians, that rove in the wild regions of America, have their means of communicating by beacons and other modes of signaling. When Lieut. Fremont penetrated into the fastnesses of Upper California, his appearance created an alarm among the Indians. He there observed the primitive telegraph communicating his presence to tribes far distant. In his report, he says: " Columns of smoke rose over the country at scattered intervals-signals, by which the Indians, here, as elsewhere, communicate to each other, that enemies are in the country. It is a signal of ancient and very universal application among barbarians." AMERICAN REVOLUTIONARY ARMY SIGNALS. During the American Revolutionary war, the people had their modes of signaling to each other the movements of the enemy, and especially when they were approaching. Among the different plans of communicating between the divisions of the army, was the next representation, of a barrel at the head of a mast, a flag below it, and the basket hanging to a cross-beam. This mast was moveable. The parts were moveable, and any arranged system of signaling could be carried out by this simple contrivance. For example, suppose the enemy was approaching, the pole might be left bare, so that there would be no reason for the enemy to suspect the objects of its use. The basket or either of the others, alone or combined, or any transposition, could be made to communicate a variety of information. di /,ff~ THE SEMAPHORE TELEGRAPH. CHAPTER II. Origin of the Semaphore Telegraph-Its Adoption by the French Government -Its Extension over Europe-A German Telegraph Station-Russian Telegraph. ORIGIN OF THE SEMAPHORE OR AERIAL TELEGRAPH. THE visual telegraph system, of late in universal use over Europe and a part of Asia, has been superseded by the electric system. Notwithstanding it has passed away, yet a description of its beautiful mechanism must ever be of interest to the telegrapher. The most perfect aerial telegraph was that invented by the Messrs. Chappe, and first adopted in France. There were three brothers Chappe, nephews of the celebrated traveler, Chappe d'Auteroche, who were students —one at the Seminary d'Angers, and the other two were at a private school about a half league from the town. Claude Chappe, the pupil of the seminary, wishing to alleviate the separation with his brothers, contrived the following means by which they might correspond one with the other. He placed at the two ends of a bar of wood two wing pieces of wood, to be moved at pleasure, by means of which he was enabled to produce 192 signals, which were distinctly visible by means of a spy-glass. He conceived the idea of making words of these signals, and he communicated the same to his two brothers. This took place a few years before the French revolution in 1793. His invention was first tried in 1791, but, like all inventors, Chappe met with great opposition and discouragement. The people were opposed to the use of the telegraph at all, and his first telegraphs and the stations were destroyed by the populace. His second telegraph shared the same fate, and was burnt to the ground, and poor Chappe narrowly escaped with his life; the people threatened to burn him with his telegraph. Not daunted by these misfortunes he renewed his efforts for government aid, with increased zeal, until sucess crowned his efforts. 27 28 SEMAPHORE TELEGRAPH-ITS EXTENSION. ADOPTION OF THE SEMAPHORE TELEGRAPH IN FRANCE. Continuing his efforts with the zeal common to great inventors, he finally succeeded in getting the government to favor his project, and a commissioner was appointed to examine into it. The commissioner reported favorably, and his system was adopted, and Chappe was honored with the appointment of telegraphic engineer to the French government, Fortunately, before the presentation of the invention to the government, the Chappe brothers perfected the system entire, and in the preparation of the signals they had the aid of Leon D elaunay, who had formerly been consul, and who was well acquainted with the cipher language of diplomacy. In this perfect state it was presented to the convention, adopted and subsequently executed. Circumstances favored these inventors remarkably; for their telegraph, after it had been once adopted by the government, it was fortunately inaugurated by the announcement of a victory. The following was the first dispatch, having been transmitted by the telegraph from the frontier of France to Paris, viz.: " CONDE IS TAKEN FROM THE AUSTRI ^NS.;' To which the convention, then in session, responded as follows, viz.:' THE ARMY OF THE NORTH DESERVES THE GRATITUDE OF THE COUNTRY." These two dispatches ran like an electric shock through the convention, and soon thereafter throughout Paris. The Chappe telegraph was then the pride of the nation! The telegraph and the victory were rejoiced over as twin-sisters in French glory. From this time the telegraph spread with wonderful rapidity to all parts of France, and thence to the other governments of Europe. The line from Paris to Lille was constructed in 1794, and two minutes only were occupied in the transmission of a dispatch In the perfection of the beautiful mechanism for the production of the signals, Chappe had the invaluable assistance of that most ingenious mechanic, M. Breguet, whose fame as a watchmaker had spread throughout Europe EXTENSION OF THE SEMAPHORE TELEGRAPH OVER EUROPE. After the perfection of the semaphore telegraph in France, its usefulness was observed by the other governments of Europe. In 1802, a modified system was adopted in Denmark. About the same time it was adopted in Belgium. About 1795, it was SEMAPHORE TELEGRAPH-ITS GENERAL ADOPTION. 29 adopted in Sweden, with some improvements over the Chapp6 system of that time. Soon after the establishment of the lines in France, the telegraph was erected in some parts of Germany. But the mechanism of the stations of that day was not so perfect as it has since been made by the brothers Chappe, and as will be described hereafter. In 1823, the visual telegraph was established between Calcutta and the fortress of Chunore, in Asia. A year later it was erected between Alexandria and Cairo, in Egypt, by Mohammed All. In some form or other it has spread mostly over the inhabited globe. Fig. 1. C C _B T H K X: _ d t __~-_ --- B D 71 F l 9iG A tatA io 178 German Telegraph Station, 1798. 30 GERMAN AND RUSSIAN SEMAPHORE TELEGRAPHS. THE GERMAN TELEGRAPH STATION. While at Frankfort on the Main, Germany, in 1854, I found a drawing of the ancient semaphore telegraph, used in that country more than a half century ago. The house or station was a plain hut, and the mechanism for manipulation very simple, as will be seen in figure 1. The ropes were drawn by the hand, moving the regulator B B, and the indicators B c, as desired. The position of the regulator and the indicators, in the figure above, forms the letter A. Suppose the indicators A c were let down so as to hang below B B, the position then would form the letter E. The different angles assumed by the regulator and the indicators form letters, as illustrated by the alphabet given in figure 1. A A is an upright post made permanent in the earth or to the house. The descending cords move B B and B c separately. The organization of the mechanism, and the mode of manipulation, will be more particularly described in the next chapter, in reference to the Chappe telegraph. THE SEMAPHORE TELEGRAPH IN RUSSIA. It was not until the reign of the great Emperor Nicholas I., that Russia organized a complete telegraphic system, which was executed in the most gigantic style in the principal directions required by the government. From Warsaw to St. Petersburg, to Moscow, and on other routes, the towers and houses were constructed for permanency and beauty. They were neatly painted, and the grounds were beautifully ornamented with trees and flowers. I have seen these stations, situated on eminences along the routes mentioned, every five or six miles, and the towers were in height according to the face of the country, and sufficiently high to overlook the tall pine so common in Russia. The system employed was, like those of all the other governments of Europe, the Chappe telegraph. The erection of these towers cost several millions of dollars, and the expense of maintaining them was very great. The line from the Austrian or Prussian frontier, through Warsaw to St. Petersburg, required about 220 stations, and at each of these stations were some six employes, making an aggregate of 1,320 men. Besides these, there were managing men at different localities having charge of the general administration. That great Emperor Nicholas I.-ever watchful and progressive-at an early day inaugurated the semaphore telegraph in a manner commensurate with the vastness of his government and its wants; and, notwithstanding the immense cost that it had been to the government, as soon as he saw a superior tele RUSSIAN SEMAPHORE TELEGRAPH. 31 graph he adopted it, and bade farewell to the visual signals which had served him so faithfully for a quarter of a century. It was a noble example to the fixedness of the bureau departments of other governments. These stations are now silent. No movements of the indicators are to be seen. They are still upon their high positions, fast yielding to the wasting hand of time. The electric wire, though less grand in its appearance, traverses the empire, and with burning flames inscribes in the distance the will of the emperor to sixty-six millions of human beings scattered over his wide-spread dominions. Fig. 2. Russian Telegraph Station, 1858. CHAPTER III. Description of the Chappe Telegraph-Organization of the Signal AlphabetProcess of Manipulation-Its Celerity in Sending Dispatches. DESCRIPTION OF THE CHAPPE SEMIAPHORE TELEGRAPH. I WILL nOW proceed to describe the Chappe sempahore telegraph according to the modern mode of operating it. The description is from the best authorities, and I presume it will be sufficiently clear, to enable any one to understand the system in its most complete sense. The Chappe telegraph is composed of three pieces: one is large and called a regulator, and two small ones, which are called indicators. The regulator A B, fig. 1, is a long rectangular piece, 18 inches wide and 14 feet long, and from 11 to 2 inches thick. At its centre, and in the direction of its centre, it is traversed by an axis, which traverses also a mast or vertical post D D at its upper extremity. The regulator, thus situated and elevated little over 14 feet above the roof T T, can turn freely on its axis, and describe a circle of which the plane is vertical. It can therefore give as many signals as it can represent distinguishable diameters of a circle; but to avoid all confusion Chappe wisely reduced its telegraphic positions to four, and it can never take any other but the four, namely, the vertical, horizontal, right oblique, and left oblique; the oblique Fig. 4. forming an angle of 45 degrees. It would be impossible to find four positions better defined and more distinct. They are represented in figs. 2, 3, 4 and 5. The two indicators A c and B c, fig. 1, are also two rectangular pieces, six feet long, one foot wide, and of a thickness a little less than that of the regulator. They are attached to the two ends of the regulator as the figure represents.. Each indicaFig. 5 tor has at its extremity A and B an axis which traverses the regulator at the same point. The extremity c c is free and moveable, each indicator can therefore describe a circle, of which the plane is parallel to the plane of the circle, which the regulator may describe; thus, in this manner, all the signals are made in the same way, vertical and perpendicular to theline of vision. 32 THE CHAPPE SEMAPHORE TELEGRAPH..3 yi;.i 3 v^..3 iT T 34 CHAPPE SIGNAL ALPHABET. The regulator having its axis of rotation at its centre of form and gravity, remains indifferently in whatever position it is put; but the indicator, revolving on an axis placed at one of the ends, are free, and are disposed to fall toward the earth. To counteract this tendency, the visible branches of the indicators B c and A c are counterbalanced by a weight placed on a branch invisible at distance A K and B K. This branch at first formed of two rods of iron ~ of an inch in diameter, fixed at the extremities B and A of the indicators, was soon changed into a single rod, by forming with the two an acute angle. Toward its extremity the branch has a counterpoise K of lead, which keeps the indicator in equilibrium in all its various positions around its axis. It is understood thatthe two indicators should be of the same weight, and that their axis should be at equal distances from the axis of the regulator. The distance from the centre of rotation of the regulator to the centre of rotation of the indicators is 6~ feet, that from the centre of rotation of the indicators to their movable extremities is 5- feet; when, therefore, the two indicators are turned inwardly, their moveable ends are two feet apart. The regulators and the indicators are made like a window shutter with alternate slot or bar, and aperture, one half of the bars setting to the right and the other half to the left, to divide the force of the wind, and to produce light and shade. The assemblage of these three pieces forms a complete whole, elevated in space, and sustained by a single point of support, namely, the rotating axis of the regulator, which axis turns with a hug sufficiently tight to stand at any given point, at the upper extremity of the post through which the said axis traverses horizontally. The mast, or post sustaining the telegraph, ought to be very solid and strong. It may be double, but whether single or double, the surface which is presented to the eye ought always to be much less than the width of the regulator and indicator, to avoid confusion. The line presented by this elongated surface is nevertheless useful as the datum line, since it always indicates the direction of the vertical line. This post is furnished with iron pins on each side to serve as a ladder by which to ascend. ORGANIZATION OF THE CHAPPE SIGNAL ALPHABET. The regulator should only occupy four positions: the vertical, fig. 2; the horizontal, fig. 3; the right oblique, fig. 4; and the left oblique, fig. 5; each separated from the other by an angle of 45 degrees. CHAPPE SIGNAL ALPHABET. 35 Let us now suppose the regulator Fig.. placed in a horizontal position, and hav- n ing a single indicator B E, describe a L circle around its axis B, and by stopping it at every 45 degrees we thus give to it Al -------- 8 different positions in regard to the regulator B A. Of these 8 positions, 6 are r angular B L, B M, B N, B F, B E, and B D. Two are parallel B c and B o. This last position has been abandoned, because as it is merely a prolongation of the regulator, it is not seen distinctly. The 7 relative positions of the indicator and of the regulator thus give 7 distinct indexes, all combining to form the desired signals. For whatever be the position of the regulator, the indicator is always placed in a horizontal, or vertical, or right oblique, or left oblique position, respectively. Of these seven signals, one, c B, confounds itself with the regulator, and is called zero. Two, B L and B D, form with the regulator an angle of 90 degrees, and two, B N and B r, an angle of 135 degrees. It is necessary, therefore, to find simple means of distinguishing them. In the method adopted for the formation of signals, the indicator in the positions B L, B hr, and B N, has always its free extremity turned toward the sky, and its other extremity toward the earth, in the positions B F, B E, and B D. In designating angles, the words sky and earth will be used to avoid prolixity. On the other hand, it would be tedious to say 45 degrees sky, 90 degrees sky, 135 degrees sky or earth. These different terms have been adopted to economize in the language. The terms used are zero, 5 sky, 10 sky, 15 sky, 15 earth, 10 eaearth arth, and they are written as indicated in fig. 7. The regulator being fixed in any Fig.7 - 7 - -j - -, -7 of the four positions which it can take, a single indicator produ- " s_ _ _ ces with it 7 distinct and separate signals. It is evident that the indicator placed at the left 9 - -, — of it, will produce the same number, and these are called the same, except they are described as at the left of the indicator as seen in fig. 8. Now, if we consider the signals which may result from the combination of the seven signals of one indicator with the seven signals of the other indicator, we shall see that if one of the indicators is placed at zero, and the other is passed through its seven positions, we shall obtain, in the first place, the double 36 CHAPPE SIGNAL TELEGRAPII. horizontal, or rather the horizontal closed line, then, zero 5 sky, zero 10 sky, zero 15 sky, zero 15 earth, zero 10 earth, and zero 5 earth, as seen in fig. 8. Elevating and keeping at " 5 sky" one of the indicators, we shall have 5 sky zero, two 5 sky, 5 and 10 sky, 5 and 15 sky, 5 sky and 15 earth, 5 sky and 10 earth, 5 sky and 15 earth, which makes 7 other signals, as seen in fig. 9. Elevating and keeping at " 10 sky" one of the indicators, we will obtain seven more signals, and so on, until the seven signals of one indicator have been combined with each of the seven signals of the other, giving in all 49 signals, without changing the position of the regulator; but the regulator takes four different positions, giving four different values to the 49 signals, and raising the whole number of possible signals to 196, furnished by the Chappe semaphore telegraph. These signals are clear, simple, and easy to name and to write. It is impossible to commit an error, on a clear day, in seeing, designaing, or writing them. One grave difficulty, however, presented itself in communicating, that is, how to designate to the neighboring station that the signals formed were correct, and how to indicate the time to repeat them. The brothers Chappe decided that no signals should be formed, with the regulator in a horizontal or perpendicular position; that all signals should be formed on the right oblique or left oblique. They also decided that no signal should have value until the regulator should be returned to a vertical or horizontal position. In this way the operator who sees a signal formed on the right or left oblique, notices, and prepares himself to repeat it back to the station; but he does not record it. As soon as he sees it carried to the horizontal or vertical position, he knows it to be correct, and he immediately writes it down, and then repeats it to the same station. This manceuvre is called "' verifying the signal." From that time each signal formed on each oblique takes a double value. Since it may be carried to the horizontal or vertical line, 49 signals, there can be received 98 significations in passing from the right oblique to the horizontal or vertical line; and the same for the left oblique, in all 196 signals. Nevertheless, the signals of the two obliques would not be intelligible if the signals of the right oblique were not different from those of the left oblique; for both being brought to the horizontal or vertical line, they being in all respects similar, would really represent only 98 signals, unless we noticed the direction in which they are moved to a horizontal or vertical position. THE CHAPPE SIGNAL ALPHABET. 37 As the necessity of the telegraph requires a great portion of the signals for the purposes of regulation and police of the line, the rest of the signals being devoted exclusively to the transmission of dispatches, these two classes of signals, being perfectly distinct, cannot be placed in the same journal of business. The signals formed on one. oblique are, therefore, devoted to the administration of the line, and those on the other oblique are devoted to the correspondence. There are thus 98 regulation signals, and 98 dispatch signals, which are all written on horizontal and vertical lines, but written separately in the journal book, marked out for the registration of the respective services. The signals take their names Fig'. 10. when they are formed on the obliques, ig as seen in fig. 10, and it is important \ \ to remark that the designation of a x x > signal must commence always from < the upper extremity of the regu- lator. The signals are never written \ X. > as in the table, fig. 10, but always \ > N, on the horizontal lines, as in fig. 11, \ or in the vertical line, as in table, fig. \ N 12. The station master writes them " N \ as he sees them, but never until he is sure they are correctly understood. It now remains to be explained Fig. 11. how the mechanism which produces these signals is operated. To one not fa- miliar with signaling, Ithe / 7 process may seem surrounded with complications, and ~-~ 1 -' "-' v-7 tardiness of action. Such, v -, however, is not the case; and _ a knowledge of the more Fig. 12. modern electric needle system of telegraphing would 1] [ r I a J [ I prove the error. But as to N T r the rapidity in transmission, I i [ J _ j 1 the facts hereafter stated l CI rf 1 will more fully demonstrate that the Chappe telegraph S J'L $1] ) ( is not a slow process of communicating intelligence, but that it has subserved well the purposes contemplated by its patriotic and enthusiastic founder. 38 MANIPULATION OF THE CHAPPE TELEGRAPH. THE PROCESS OF MANIPULATING THE CHAPPE TELE GRAPH. The axis a a' a", fig 13, which comR mands the regulator, is turned by a pulley, p, fixed at its extremity, a, opposite to that,,,:, of a"/, which carries the regulator; this pulley, from 16 to 18 inches in diameter, contains two deep grooves, and under this pulley in the interior of the post about three feet from the ground is another simFI^ F.o 15 ilar one, q, which also has two grooves. The second pulley, q, is also fixed at the x extremity b, of an axis b b' b", which tra0 0 _ f l | verses horizontally the interior prolongas1 j1 1i I == _ l |tion of the post D D', figures 1 and 13. H. |l In order to receive upon a square b", a double lever I 1, which serves to place it zi nli i in rotation, as well as the pulley fixed at its other extremity. This lever, or double c"right-hand crank, is about three-and-ahalf feet long, and is terminated by two wooden handles situated at right angles from each other, tn tn. Let us suppose now that the lever which represents a diameter, and describes a circle, the plane of which parallel is to that of the circle described by the regulator; let us suppose, I say, that this lever is fixed, in the first' Iel' place, parallel with the regulator, and at the moment we transmit to the pulley p the rotatory movement, which it will give to the pulley q by means of two tightlystrained bright wire cords, of which one passes to the right of the two pulleys in one of their two grooves, and the other to the left in the other groove. Suppose now z ni l, that the free extremities of these two cords are fastened at tlhe bottom of their respect/||p!t i ive grooves, after having surrounded the J/I[fl ||7u upper and lower pulleys by at least half l?t ^ l tile circumferences, it is evident that the A |1 r f movement described by the lever 1 1 will a t Ii Wrs be transmitted by the axis b b' b" to the pulley q, which will transmit it exactly ID D, by means of the two cords c c' c" to the pulley p; and that this latter will trans MANIPULATION OF THE CHAPPE TELEGRAPH. 39 mit by the axis a a' a" to the regulator R R, and to all the parts which it carries, and that the regulator will also follow the movement of the lever I 1, and remain perfectly parallel with it. It is also evident that the lever and the regulator may describe at least a circle, because the cords are wound upon each pulley for each half of a circumference at each extremity. As a substitute for the cords, and to give them easily the proper tension which the movement causes them to lose, the middle portion of them, which is never required to pass over the pulley, are iron rods with screws, by which they may be lengthened or shortened at pleasure. These rods are terminated above and below by hooks which hold the cords by a single ring in the end of the cord. The extremity of the cords which answer to the pulleys, traverses the bottom of the groove, through a hole made for that purpose, and is attached to a spoke of the pulley which is shortened or lengthened by means of a screw. By this very simple system a station-master may change very rapidly the cords or the rods, and lengthen or shorten them at pleasure. The rods or cords pass through the roof of the house, through holes, in such a way as to avoid friction as much as possible. To communicate movement to the indicators, the mechanism is the same as above described, only a little more complicated or extended, because there must be two return cords, one from the extremities, the lever 1 1 at its axis b" and the other from the axis of the regulator a" to its extremities R i. In the second place the rotary movement must be transmitted to two different and independent circles. Let us consider in the first place, the transmission of the movement to a single indicator. The indicator is governed by an axis i' i", which also governs the pulley with two grooves zm; this pulley is fastened to the pulley o' by two metallic cords, which renders all their movements dependent and identical; the pulley o' forms a single piece with the pulley o; these two pulleys are united by a hollow axis traversed by the axis of the regulator a a' a", around which it turns freely. The pulley o, and consequently the pulley o' receives all its movements from the pulley u', which receives them from the pulley u, to which it is connected by a hollow axis, which turns upon the axis b b' b" of the lever; the pulley u receives its movement from the pulley r; this last pulley is controlled by an axis which traverses the lever I 1, in which it turns; the extremity 1" of this axis is fixed to one lever forming the ray 1" u"; this lever, or handle or hand, in describing a circle, causes the pulley r to describe a circle in the same 40 MANIPULATION OF THE CHAPPE TELEGRAPH. direction, which causes the same result to the pulley u, which in its rotation draws the pulley u', and this rotation is transmitted to the pulley o, which communicates it to the pulley o', and this latter causes the pulley m to turn, which causes the regulator I I to describe a complete circle in the same direction as the hand l/ n"' has done. By causing this hand to describe a circle, in an oppesite direction, it is easily seen that the indicator will do the same thing. Let us now follow the transmission of the movement to the second indicator. By causing the hand l' n'to turn, the pulley r' is made to turn, which causes the pulley u/'/ to turn. This pulley forms a single piece with its neighboring pulley u", and both turn by means of one common hollow axis; around the common hollow axis of the two pulleys u u', the pulley iu", transmits the movement to the pulley o', united by a hollow axis to its neighbor o"'/. This hollow axis turns, also, around the hollow axis common to the pulleys o' and o. The pulley o"' puts in rotation the pulley m', which makes the indicator i' i' describes identically the same movement which the hand 1' n had made. If we observe, now, that the large lever 1 1 makes the regulator describe movements similar to its own, and that it draws by these movements the rays 1' n' 1" n'/, without changing the relations established between them and itself, and that the indicators cannot change their relative positions with the regulators, but by change of relation with the said rays of the grand lever, without changing the relation of the said rays to the grand lever, we shall easily understand. 1st. That the rays 1 in'' l n", making any angle with the diameter 1 1, the indicators I I I/ I' will make precisely the same angles with the regulator R R. 2d. Whatever be the horizontal, vertical, right oblique, or left oblique, in which we put the lever I 1, the regulator will take the same position; and, as this same movement affects no change in the value of the angles formed by 1' rn' 1" n" with 1 1, the indicators will also remain invariably in their angles with the regulator. Thus the interior mechanism gives a constant and exact image of the exterior mechanism, and the signals are always reproduced with precision before the eyes of the operator. In order that the angles of the indicators and of the regulators should be invariably fixed, the hands 1/ n' n" n" are furnished with a spring and a tooth. This spring is designed to make the tooth t enter into the notches of the steel dividing circle d. These divisions are seven in number, of 45 degrees MANIPULATION OF THE CHAPPE TELEGRAPH. 41 each. The axis of the large lever also carries a divisor of 8 notches; but while the divisors of the two hands are fixed in relation to the axis which traverses them, said divisor of the large lever is fixed upon the axis and turns with it. When we wish to hold the regulator on account of high wind, or for other cause, we place a kind of bolt fixed in the post to enter one of these notches, and this bolt stops all movements of the regulator. As the indicator ought always to remain motionless, when the regulator is moved after a signal is made, the spring above mentioned always holds the tooth of the hand fixed in the notch of the divisor when said hand has been placed in such a way that the operator is obliged, when he wishes to change the position of an indicator, to draw the hand toward himself in order to disengage the tooth, and to let go of the hand when the tooth has arrived opposite the new notch in which the tooth is to be fixed. From these facts it will be seen that the mechanism of the Chappe telegraph is a model of simplicity and precision. It fulfills the conditions of rapidity, clearness, and variety in execution. Let us suppose that the telegraph is at rest in the position represented in fig. 13, which position is called the vertical closed, and that the operator enters his office in the morning; he commences by applying his eye alternately to first one, and then the other of his neighboring telegraph stations, to see if either of them are giving a signal, and, in the meantime, he arranges on his desk, pen, ink, and record-book. As soon as he sees one of the two stations move, he draws the bolt which holds the large axis at rest, and puts one hand upon the upper handle of the great crank, and then looks at the signal which has been formed. If the regulator is to be carried to the right oblique, or left oblique, which is indispensable, he pushes the upper extremity of the handle to the right or left, aiding the movement at the same time by pushing the lower extremity with his leg, at the same time he puts his other hand upon the small lower crank 1' n in order to commence moving the indicator; the regulator being once set in motion, he lets go the upper handle in order to take hold of the handle l' n.", and move the second indicator, thus the signal being formed, he stops it on the oblique which belongs to it. He thus looks through his telescope to the station whence the signal came, to see if said signal has been carried to the horizontal or to the vertical. If it has been carried, he knows it to be correct, and accordingly records it as he sees it horizontal or vertical in the square 42 CELERITY OF DISPATCH BY CHAPPE TELEGRAPH. of signals of correspondence; if it has been formed on the other oblique, he records the hour and minute at which the labor commences; and lastly, he makes his own signal, and watches to see if the station to which he communicates the dispatch repeats and carries it correctly. If he is sure that the signal has been well understood and properly reproduced, he turns to the first telescope, repeats the signal which he sees on the oblique, waits till it is carried to the horizontal or vertical, in order to record it, repeats it in his turn, watches if it is correctly taken by the other station, and the operation thus continues indefinitely. CELERITY OF DISPATCHING BY THE CHAPPE TELEGRAPH. The greatest speed which can be attained in the passage of signals without producing confusion, is three signals a minute, whence it follows that 20 seconds is necessary to execute all the steps of a signal, to record it, and to verify it. All the signals, however, do not require this period of time, as there are half signals. These half signals are four in number-the double zero or vertical closed, the closed or double horizontal zero, the right oblique closed and left oblique closed. These are all made in their place, and it is only necessary to fold in the two indicators. These demi-signals are very useful, because they serve to distinguish groups of signals; and, because, being frequently necessary, they waste less time than a signal execution, of which requires several steps and movements. The movements of the regulator are so easy, when the machine is in good order, and there is no wind, that generally the operator can, by using the two hands to develop the indicators, at the same time bring the regulator to the position which it is to occupy. The complete operation of a signal is as follows 1st. Observe the signal which is formed on the oblique. 2d. Form it. 3d. Observe if it is carried to the horizontal or to the vertical. 4th. Carry it in a corresponding manner. 5th. Record it. 6th. See if the next station reproduces it exactly. These six steps ought to be equal in duration of time; if it were otherwise a signal would be badly observed by the two stations corresponding. We also remedy inequalities of strength and of agility, in the operators, by directing that there must never be a change of a signal carried, before the station to which it is communicated has also carried it. Suppose a passage of 3 signals a minute, the different steps ought to be thus divided:for observing, 4 seconds; forming on the oblique, 4 seconds; observing the carrying, and carrying, CELERITY OF DISPATCH BY CHAPPE TELEGRAPH. 43 4 seconds; recording, 4 seconds; and verifying with the next station, 4 seconds: total, 20 seconds. This rapidity of three signals a minute is far from being constant. It can only be depended upon when the weather is fine, when the operators are well disposed, experienced, and faithful. Chappe said, that when the weather was fine, and the fogs and haziness of the atmosphere are not a hindrance to vision, the first signal of a communication ought not to occupy more than 10 or 12 minutes in passing from Toulon to Paris, cities situated 215 leagues or 475 miles apart, and connected by a telegraph line of 120 stations; but Chappe added, that if we suppose a continuous correspondence between Paris and Toulon, there would ordinarily arrive at Toulon but one signal a minute. To recapitulate, the Chappe telegraph gives 98 primitive signals for the correspondence, and 98 primitive regulating and indicating signals. These two classes of signals, although alike, must not be confounded, because they are formed one on the left oblique, and the other on the right oblique; and because they are recorded one in the regulation column, and the other in the column of correspondence. This record I have arranged in the following form, viz.: REGULATIONS AND OFFICE SIGNALS. SIGNALS OF CORRESPONDENCE. o Right Oblique. Left Oblique. Right Oblique. Left Oblique. Hw Carried. How Carried. How Carried. How Carried. _ ______ These signals may succeed each other with the rapidity of 3 per minute. They form figures easy to observe, easy to record, and without an effort of the mind; the machine is solid, light, and elegant. A man of moderate intelligence is entirely competent to manage the correspondence. To show the immense superiority of the Chappe telegraph over all other aerial telegraphs which have been devised or temporarily established, either before or since his time, it would be sufficient to describe them and notice their resources; and 44 CELERITY OF DISPATCH BY CHAPPE TELEGRAPHI. we shall see that none of them, if we except the Swedish telegraph invented by Edelcrantz, can be said to have subserved the purposes of science or telegraphic art. In France, where the most perfect model has been before their eyes, all efforts made previous to the time of Chappe were but rude approaches to the Chappe system, and but one of those efforts still in existence. The system of Chappe produced, as a first and inevitable result, a diminution of just one third in rapidity of the signals. By analyzing its movements it is easy to anticipate such a result; but it is more easy to be convinced of it by taking such a position as to have a view of the towers of St. Sulpice. Upon one of these towers is the Chappe telegraph, and upon the other, the telegraph devised by Mr. Flocon, the third administrator of the telegraph. By watching these two telegraphs for an hour, and counting exactly the number of the signals, it will be seen that the Chappe telegraph gives exactly three signals, while the other gives two. A second objection to Mr. Flocon's telegraph is, that it requires a greater degree of intelligence to operate it; consequently it is more liable to fault in transmitting correspondence and in recording them. The regulator is placed upon a vertical mast or post, and the indicators are attached to the extremities of a fixed horizontal bar; all the signals are therefore given horizontally. We must observe the regulator separately, in order to know if we understand whether the signals belong to the right oblique or to the left oblique, and we must record them vertically or horizontally. If they are to be recorded vertically, we must then make an abstract of what we have seen, and after arranging the figure in the head, then make a draft of it. The telegraph, modified by Mr. Flocon, nevertheless offers one advantage, that of being less difficult to operate when the wind is light; but, it is said that it is not by means of new machines, or retrenchments, or additions to them, as perfected by Chapp6, that the aerial telegraphing can be improved. The true and only way of progress in semaphore telegraphing is to find the means of multiplying the number of primitive signals; to combine these signals in such a way as to express, with the least motion and in the shortest time possible, the greatest quantity of numbers; to represent by these numbers as many ideas as possible, and to double the period of correspondence by continuing it through the night. The greatest effort and the most active inventive talent have been thwarted in every effort to make an aerial telegraph effective at night, and even Chappe admitted its impracticability after the most arduous labors to consummate the object. Like CELERITY OF DISPATCI BY CHAPPE TELEGRAPH. 45 result has followed the labors of others down to the present time. " We may at present," says Mr. Jules Guyot, from whom much of this description has been copied, " without changing anything in the exactitude of the signals, and without changing anything in the mechanism that produces them, double their number. We may raise them to 82,944 words; parts of, or the whole of phrases, by two signals expressed by 4, 5 and 6 movements; and we may devise plans to establish the Chappe telegraph by night as it is by day. Thus the resources of the telegraphic art are far from being exhausted, and to accomplish these ends the inventive mind can be directed." CHAPTER IV. The Prussian Semaphore Telegraph-The English Semaphore —The Gonon, Chappe, Guyot, and Treutler's Improvements on the Chappe Telegraph. THE PRUSSIAN SEMAPHORE TELEGRAPH. Fig. 1. THE Prussian telegraph, represented by fig. 1, was introduced into Prussia in X0/ Ethe year 1832, when the government appropriated 170,000 thalers for the establishment of a line of stations between m { \TI I Berlin and Treves, passing through Potsdam, Magdeburg, Cologne, and Coblcntz. a.___ The mechanism of the apparatus differs 0r essentally from that of the Chappe. A vertical post traverses the platform of the ji| —r-r~'n'r''|'. _station, and rises to the height of 20 feet. The post bears three pairs or couples of wings moveable around their extremities. The wings are 4 feet long, and. 1~ feet wide. Each wing is fixed to a pulley, over which passes a cord. This cord, in the room of the station-master, passes around a second pulley, to which a handle is attached. The rotation of the handle causes each wing to describe a semi-circle; but only four of these positions are used, those which the wing forms with the vertical angles 0~, 45~, 90~, and 1350. While one of the upper wings remains in the same position, the second wing may take four different positions, so that each pair of wings furnishes 16 signals. One of these signals being given, the second or middle pair of wings may, in their turn, take 16 relatively different positions, and consequently the first two wings give together 16 x 16=256 signals. This product multiplied by the sixteen signals of the third pair, gives a total of 4.096. Such is the number of signals at command by the Prussian telegraph. The Prussian telegraph was perfected and extended over the kingdom with a degree of enterprise highly commendable to the nation. Experts were called into the service, and nowhere could be found a system more admirably conducted. Wherever improvements could be made, they were promptly adopted, and, at an early day after the establishment of the semaphore in Prussia, it was materially simplified. 46 SEMIAPHORE TELEGRAPH IN ElNGLAND. 47 THE ENGLISH SEMAPHORE TELEGRAPH. Fig. 2. The English telegraph is Fig. 8. sists of a quadrangular f |j _ f * =, ll _1Ii l~fri~~~Enamelish Telegrap h Station. The English telegraph is Fig. 3. representecd in fig. 2. It colHi _ sists of a quadrangular frarne, in which six octag- ____ onal plates or panels turn'' around a horizontal axis,. |These six panels are divi- I l ~' ded into two groups, eachi formed of three plates, placed | vertically above each other. A simple mechanism of pulleys and cranks enables the // \' operator to exhibit each pan. 48 IMPROVEMENTS OF SEMAPHORE TELEGRAPH. nel either its face or edge, and as each panel takes two different positions the whole will give 64 very distinct signals. This telegraph was introduced into England in 1795, and has performed much valuable service for the government and commerce. In searching for facts upon this subject in the British Museum in London, some years since, I found the above drawings. They represent their erection close to the earth, as was the case some half a century ago. High hills were then chosen, and upon them a rude structure was placed, as seen in fig. 2. THE GONON IMPROVEMENT OF THE SEMAPHORE TELEGRAPH. This improvement is composed of two columns, one of which is 33 feet, and the other 28 feet high. To each of these two columns are fitted two moveable arrows. Between these four arrows the distance is nine feet, which space is filled with six windows or openings, arranged so as to be opened and closed at pleasure. There are four dial plates with a crank corresponding to the four arrows, and six keys corresponding to the six sashes or openings. With this simple mechanism the operator can from his room move the arrows, shut and open the sashes, and form 40,960 signals, which Mr. Gonon found was all that would be wanted for a general correspondence. By adding two fixed lights to each of the sashes, and two moveable lights to each of the arrows, Mr. Gonon said he could, after some little preparation, operate his machine as a night telegraph, the signals being exactly the same. ABRAHAM CHAPPE'S IMPROVEMENT ON THE ORIGINAL SEMAPHORE. More recently Mr. Abraham Chappe proposed an improvement on the system first erected, which he described in substance, as follows: Fig. 4. Fig. 5. "In my new system of numeration and com-—'f ~ — ~ --- - - 7 bination of signals, all the official signals are given on the horizontal line as represented in fig. 4. During the entire dispatch the indicator alone Fig. G. moves. Each indicator, in describing its -^ ~ \ v-^- icircle, stops as here)r.1 V _J, _-, x - i tofore described at the -_ —, -,- -- v —, - six positions, marked e- ~- -7 -7 - r- -T 7 in fig. 4, that is, 5, 10, and 1.5 sky; 5, GUYOT'S IMPROVEMENT OF SEMAPHORE TELEGRAPH. 49 10, and 15 earth. Each angle of fig. 5, of an indicator, signifies a single number, and each corresponding angle of the opposite indicator represents the same number. The closed alone represent nothing. "Inclosing the left indicator and opening successively the right indicator under its six angles, I shall have in the same order the number 1, 2, 3, 4, 5, and 6, by the signals represented in fig. 5. In developing both indicators at once, I shall obtain 36 combinations of two figures each, as seen in fig. 6. The numbers given by these 36 combinations are 216 series, and combining signals sufficient to represent 58,190 more than was used by the older system." GUYOT'S IMPROVEMENT OF THE SEMAPHORE TELEGRAPH. Mr. Jules Guyot proposed an im- Fig. 7. provement which is thus described. At distances of two to three miles a post was fixed about 30 feet high, strongly fastened at the foot. The upper extremities were stayed by guys of four iron cords. A stationhouse, some eight feet square at the foot, was erected for manipulating. The posts were fitted with ladder pins, by which they could be ascended at o pleasure. Each pole, or mast, bore near its upper end a fixed axis parallel to the line, upon which a needle or indicator turned in a vertical plane. Fifteen feet lower was a second and a similar axis and indicator, and between these two axes was a moveable piece or regulator which could raise as high as the upper axis, or descend to the lower one. They were about nine feet long, and about three feet wide at the smaller end, and about four feet at the widest end. They were constructed with slats as the window blind, painted a heavy black through the centre, and white on the lateral bands. This ingenious contrivance of Mr. Guyot's was never practically established, but it unquestionably possessed very great merit. The night telegraph, proposed by Mr. Guyot, was constructed with two liquid hydrogen lanterns, suspended at the 4 50 TREUTLER IMPROVEMENT OF SEMAPHORE TELEGRAPH. Fig. 8. lower indicator of the (lay telegraph, so as to give a light in both directions. He also pro/ 8N \ posed to use lanterns on the Chappe telegraph, by placing A /o / A two white lights at each extremity of the regulator, and two bright green lights at the extremity of the indicators. By means of an arrangement of these lights the Chappe telegraph was made to serve for the night. Fig. 8 represents the signals on the right oblique indicating signals 10 earth, and 10 sky, and in. which all the lanterns are outside of the mechanism, illustrating the day telegraph transformed into the night. Fig 9. THE TREUTLER IMPROVEMENT IN SEMAPHORE TELEGRAPHING. \ /, Mr. Treutler, of Ber- Fig. 10. —. lin, constructed a sema- phore telegraph to be e f used principally in the <.:.I railway service. Fig. _~ 1 ~"9 represents the whole ----- _ mechanism invented by -. —-'/ him. It was a mast........... with a single pair of'........ wings. These movea-......... -—...ble wings were furnished with two series of mirrors as represented in fig. 10, designed to reflect the parallel to the line, and in two opposite directions. STATIC ELECTRICITY. CHAPTER V. Static Electricity Explained-Conductors and Non-Conductors-Vitreous and Resinous Electricity-Discovery of the Leyden Jar-Franklin's Electrical Theories-Coulomb's Theories of Electro-Statics-Franklin's Reasons for believing that Lightning and Electricity were Identical-Identity of Lightning and Electricity Demonstrated-The Franklin Kite Experiment-Distribution of Electricity-Phenomena of Resistance to Induction-Phenomena of Attraction and Repulsion-Igniting Gas with the Finger-The Leyden Jar Experiments. STATIC ELECTRICITY EXPLAINED. THE name, electricity, is derived from the Greek word ~sxeK-rov, which signifies amber, the first substance upon which, electrical properties were seen. Since the discovery of this mysterious phenomenon in nature, the whole world has been startled from time to time, by its extraordinary developments. It was unknown to the ancients, and as a science, it dates with the eighteenth century. I do not propose to discuss the intricacies of this science, except in general terms, and to a very limited extent. The facts herein mentioned, are from many standard works. Static electricity is more commonly called frictional electricity. The term " static" is applied, to distinguish the action of the force excited by friction, from that excited by chemical action. Frictional, or static electricity, exhibits itself in a state of equilibrium, and remains comparatively at rest, except during the instant of discharge; while voltaic, or chemical electricity, appears to be constantly in motion, from one pole of the voltaic battery to the other, and has hence been called current electricity. Static electricity is sometimes called " electricity at rest," and voltaic, or current, is called " electricity in motion." The subject-matter, considered in this chapter, will be " static 52 STATIC ELECTRICITY electricity,'" and in another chapter will be explained the different elements organized, to generate voltaic or " electricity in motion," as applied for telegraphic purposes. It is supposed. that electricity, in some form or other, exists in all nature, nevertheless, some substances manifest a greater degree of its presence than others. CONDUCTORS AND NON-CONDUCTORS. The metals were found to rank highest in this property. It has been subsequently discovered that all bodies are conductors of electricity more or less. No substance is at present known which is an absolutely perfect non-conductor. With all bodies, the passage through them of a definite amount of electricity is but a question of time. The great object to be maintained in the construction of an electric telegraph is, to.give the greatest possible facility for the passage of the power to a particular distant station, and to throw every possible obstacle in the way of the escape of any portion of the power in any other direction than the one desired. For such purpose, the most perfect conductors are used for the conveyance of the power, and the most perfect insulators made to surround such conductors. The following table exhibits the conducting power of several bodies with respect to electricity. It begins with the most perfect conductors, and ends with those which are the least perfect conductors. The properties, therefore, of these latter bodies, approximate most closely to that of non-conductors or insulators. The exact order, however, is by no means fully substantiated as yet, and the table must therefore only be taken as a general guide. All the metals, viz.: Silver, Metallic ores, Moist earths and stones, Copper, Animal fluids. Powdered glass, Gold, Sea-water, Flour of sulphur, Brass, Spring-water, Dry metallic oxydes, Zinc, Rain-water, Oils-heaviest the best, Tin, Ice above 13~ Fahr. Ashes, vegetable bodies, Platinum, Snow, Ashes of animal bodies, Palladium, Living vegetables, Many transparent crysIron and Living animals, tals, dry, Lead, Flame, Ice below 13~ Fahr., Well-burnt Charcoal, Smoke, Phosphorus, Plumbago, Steam, Lime, Concentrated acids, Salts soluble in water, Dry chalk, Powdered charcoal, Rarefied air, Native carbonate of baDilute acids, Vapor of alcohol, rytes, Saline solutions, Vapor of ether, Lycopodium, DISCOVERY OF THE LEYDEN JAR..53 Gum elastic, Parchment, Mica, Camphor, Dry paper, All vitrifications, Some silicious and argil- Feathers, Glass, laceous stones, Hair, Jet, Dry marble, Wool, Wax, Porcelain, Dyed silk, Sulphur, Dry vegetable bodies, Bleached silk, Resins, Baked wood, Raw silk, Amber, Dry gases and air, Transparent gems, Shellac. Leather, Diamond, Gutta-percha, has recently been discovered, and it is found in practical service to be a better non-conductor than glass. and possibly than shellac. It has proved of wonderful utility in the art of telegraphing. VITREOUS AND RESINOUS ELECTRICITY. The celebrated philosopher, Dufaye, discovered that there were two distinct kinds of electricity, one of which he called vitreous, or that of glass, rock-crystal, precious stones, hair of animals, wool, and many other bodies: and the other resinouzs, that of amber, copal, gum-lac, silk-thread, paper, and a vast number of other substances. He showed that bodies having the same kind of electricity repel each other, but attract bodies charged with electricity of the other kind; and he proposed that test of the state of the electricity of any given substance which has ever since his time been adhered to, viz.: to charge a suspended light substance with a known species of electricity, and then to bring near it the body to be examined. If the suspended substance was repelled, the electricity of both bodies was the same; if attracted, it was different. DISCOVERY OF THE LEYDEN JAR. It was in the year 1746, that those celebrated experiments, which drew for many succeeding years the almost exclusive attention of men of science to the new subject, and which led the way to the introduction of the Leyden vial-were made by Muschenbroek, Cuneus, and Kleist. Professor Musehenbroek and his associates, having observed, that electrified bodies, exposed to the atmosphere, speedily lost their electric virtue, conceived the idea of surrounding them with an insulating substance, by which they thought that their electric power might be preserved for a longer time. Water contained in a glass bottle was accordingly electrified, but no remarkable results were obtained, till one of the party, who was holding the bottle, attempted to disengage the wire communicating with the prime conductor of a powerful machine; the conse 54 STATIC ELECTRICITY. quence was, that he received a shock, which, though slight, compared with such as are now frequently taken for amusement from the Leyden vial, his fright magnified and exaggerated in an amusing manner. In describing the effect produced on himself, by taking the shook from a thin glass bowl, Muschenbroek stated in a letter to Reaumer, that "he felt himself struck in his arms, shoulders, and breast, so that he lost his breath, and was two days before he recovered from the effects of the blow and the terror," adding, "he would not take a second shock for the kingdom of France." M. Allamand, on taking a shock, declared, " that he lost the use of his breath for some minutes, and then felt so intense a pain along his right arm, that he feared permanent injury from it." Winkler stated, that the first time he underwent the experiment, " he suffered great convulsions through his body; that it put his blood into agitation; that he feared an ardent fever, and was obliged to have recourse to cooling medicines!" The lady of this professor took the shock twice, and was rendered so weak by it, that she could hardly walk. The third time it gave her bleeding at the nose. Such was the alarm with which these early electricians were struck, by a sensation which thousands have since experienced in a much more powerful manner, without the slightest inconvenience. It serves to show how cautious we should be in receiving the first accounts of extraordinary discoveries, where the imagination is likely to be affected. After the first feelings of astonishment were somewhat abated, the circumstances which influenced the force of the shock were examined. Muschenbroek observed that the success of the experiment was impaired if the glass was wet on the outer surface. Dr. Watson showed, that the shock might be transmitted through the bodies of several men touching each other, and that the force of the charge depended on the extent of the external surface of the glass in contact with the hand of the operator. Dr. Bevis proved that tin-foil might be substituted successfully for the hand outside, and for the water inside the jar; he coated panes of glass in this way, and found that they would receive and retain a charge; and lastly, Dr. Watson coated large jars inside and outside with tin-foil, and thus constructed what is now known as the Leyden vial. FRANKLIN'S ELECTRICAL THEORIES. It was in the year 1747, that, in consequence of a communication from Mr. Peter Collinson, a Fellow of the Royal Society of London, to the Literary Society of Philadelphia, Franklin first directed his attention to electricity; and from that period, FRANKLIN S ELECTRICAL THEORIES. 55 till 1754, his experiments and observations were embodied in a series of letters, which were afterward collected and published. " Nothing," says Priestley, " was ever written upon the subject of electricity, which was more generally read and admired in all parts of Europe, than these letters. It is not easy to say, whether we are most pleased with the simplicity and perspicuity with which they are written, the modesty with which the author proposes every hypothesis of his own, or the noble frankness with which he relates his mistakes when they were corrected by subsequent experiments." The opinion adopted by Franklin with respect to the nature of electricity differed from that previously submitted by Dufaye. His hypothesis was as follows: " All bodies in their natural state are charged with a certain quantity of electricity, in each body this quantity being of definite amount. This quantity of electricity is maintained in equilibrium upon the body by an attraction which the particles of the body have for it, and does not therefore exert any attraction for other bodies. But a body may be invested with more or less electricity than satisfies its attraction. If it possesses more, it is ready to give up the surplus to any body which has less, or to share it with any body in its natural state; if it have less, it is ready to take from any body in its natural state a part of its electricity, so that each will have less than its natural amount. A body having more than its natural quantity is electrified positively or plus, and one which has less is electrified negatively or minus. One electric fluid is thus supposed to exist, and all electrical phenomena are referable either to its accumulation in bodies in quantities more than their natural share, or to its being withdrawn from them, so as to leave them minas their proper portion. Electrical excess then represents the vitreous, and electrical deficiency the resinous electricities of Dufaye: and hence the terms positive and negative, for vitreous and resinous." The application of this theory to the explanation of the Leyden vial will appear in its proper place. Besides this theory, we are indebted to Franklin for the discovery of the identity of lightning and electricity, for the invention of paratonnerres, and for the discovery of induction, which latter principle was immediately taken up, and pursued through its consequences by Wilke and CEpinus, and soon led to the invention of an instrument, which in the hands of Volta, became the condenser, now so useful in electroscopical investigations. Franklin's hypothesis was investigated mathematically by CEpinus and Mr. Cavendish, between the years 1759 and 1771. 56 STATIC ELECTRICITY. About the same time the electrophorus was constructed by Volta; Watson and Canton fused metals by electricity, and Beccaria decomposed water, although at the time he had no idea he had done so, supposing it to be a simple elementary substance. COULOMB S THEORIES OF ELECTRO-STATICS. In the year 1785, the foundation of electro-statics was laid by Coulomb, a most profound philosopher, who reduced electricity, the most subtile of all physical agents, to the rigorous sway of mathematics, and caused it to become a branch of mathematical physics. By means of his torsion electrical balance, he made three valuable additions to the science; establishing-ist, That electrical forces, viz., attraction and repulsion, vary inversely as the square of their distances, following, it will be observed, the same law as gravitation;-2d, That excited bodies, when insulated, gradually lose their electricity free from two causes; from the surrounding atmosphere being never free from conducting particles, and from the incapacity of the best insulators to retain the whole quantity of electricity with which any body may be charged, there being no substance known altogether impervious to electricity-Coulomb determined the effect of both these causes;-3d, That when electricity is accumulated in any body, the whole of it is deposited on the surface, and none penetrates to the interior. A thin hollow sphere may contain precisely as much electricity as a solid of the same size. Hence, accumulation is not a consequence of attraction for mass of matter, but on the contrary, is solely due to its repulsive action. These observations of Coulomb on the distribution of the electric fluid on the surfaces of conductors, illustrated satisfactorily the doctrine of points which formed so prominent a part of Franklin's researches. FRANKLIN S REASONS FOR BELIEVING THAT LIGHTNING AND ELECTRICITY WERE IDENTICAL. It was in the year 1749, that the celebrated American philosopher, Franklin, in a letter to Mr. Collinson, stated fully his reasons for considering the cause of electricity and lightning to be the same physical agent, differing in nothing, save the intensity of its action. When," says he, "a gun-barrel, in electrical experiments, has but little electrical fire in it, you must approach it very near with your knuckle before you can draw a spark; give it more fire and it will give a spark at a greater distance. Two gun-barrels united, and as highly electrified, will give a spark at a still greater distance. But if two gun-barrels electrified will strike at two inches distance, and IDENTITY OF LIGHTNING AND ELECTRICITY. 57 make a loud snap, to what a great distance may ten thousand acres of electrified cloud strike, and give its fire, and how loud must be that crack?" He next states the analogies which afford presumptive evidence of the identity of lightning and electricity. The electrical spark is zig-zag, and not straight; so is lightning. Pointed bodies attract electricity; lightning strikes mountains, trees, spires, masts, and chimneys. When different paths are offered to the escape of electricity, it chooses the best conductor; so does lightning. Electricity fires combustibles: so does lightning. Electricity fuses metals: so does lightning. Lightning rends bad conductors when it strikes them; so does electricity when rendered sufficiently strong. Lightning reverses the poles of a magnet; Electricity has the same effect. A stroke of lightning when it does not kill, often produces blindness. Lightning destroys animal life, and so do electrical shocks. In his memorandum-book of November 7th, 1749, Franklin wrote the following reasons, which induced him to believe, that the lightning and electricity were identical: "Electric fluid agrees with lightning in these particulars: 1, giving light; 2, color of the light; 3, crooked direction; 4, swift motion; 5, being conducted by metals; 10, melting metals; 11, firing inflammable substances; 12, sulphurous smell. The electric fluid is attracted by points. We do not know whether this property is in lightning, but since they agree in all the particulars in which we can already compare them, is it not probable they agree likewise in this? Let the experiment be made." From the effect of points on electrified bodies, Franklin inferred that lightning might also be drawn silently and safely from the clouds, by a metallic point fixed at a great elevation, and he waited with considerable anxiety the completion of a spire at Philadelphia, to enable him to try the experiment. In the meantime, he published his discoveries, and suggested to others to make the necessary experiment. He published to the world the following plan: " To determine this question, whether the clouds that contain lightning be electrified or not, I would propose an experiment to be tried, where it may be done conveniently. On the top of some high tower or steeple, place a kind of sentry-box, big enough to contain a man and an electrical stand. From the middle of the stand let an iron rod rise, and pass, bending out of the door, and then upright twenty or thirty feet, pointed very sharp at the end. If the electrical stand be kept clear and dry, a man standing on it, when such clouds are passing low, might be electrified, and afford sparks, the rod drawing 58 STATIC ELECTRICITY. fire to him from a cloud. If any danger to the man be apprehended, let him stand on the floor of his box, and now and then bring near to the rod the loop of a wire that has one end fastened to the leads, he holding it by a wax handle; so the sparks, if the rod is electrified, will strike from the rod to the wire, and not affect him." IDENTITY OF LIGHTNING AND ELEOTRICITY DEMONSTRATED. In accordance with the above suggestions, two Frenchmen, M. Dalibard and M. Delor, each erected an apparatus for the purpose of drawing from the clouds the lightning. M. Delibard coastructed his at Marly-la-ville, about six leagues from Paris, and M. Delor had his on a high part of Paris. M. Dalibard's apparatus consisted of an iron pointed rod, forty feet long, the lower end of which was inserted in a sentrybox, protected from rain, and on the outside it was fastened to three wooden posts by silk cords, also defended from the rain. It was this rod that first attracted electricity from the clouds. M. Dalibard was absent from Marly at the time, and had left the apparatus in charge of an old soldier, named Coiffier, who was at the time engaged as a carpenter. On the 10th of May, 1752, between two and three o'clock in the afternoon, a sudden clap of thunder made Coiffier hurry to his post, and, according to the instructions given him, he presented a vial furnished with a brass wire to the rod, and immediately saw a bright spark, accompanied by a loud snapping noise. After having taken another spark stronger than the first, he called in the neighbors, and sent for the cure. The latter ran to the spot with all speed, and his parishioners seeing him running, followed at his heels, expecting that Coiffier had been killed by lightninog; nor were they prevented from hastening to the spot, notwithstanding a violent hail-storm. The cure was equally successful in drawing sparks from the iron rod, and instantly dispatched an account of the important event to M. Dalibard. The cure stated that the sparks were of a blue color, an inch and a half long, and smelt strongly of sulphur. He drew sparks at least six times in about four minutes, and in the course of these experiments he received a shock in the arm, extending above the elbow, which he said left a mark, such as might have been made by a blow with the wire on the naked skin. Eight days after this experiment, the rod erected by M. Delor, which was ninety-nine feet high, yielded electric sparks; and the same phenomenon was afterward exhibited to the French king, and to members of the nobility. IDENTITY OF LIGHTNING AND ELECTRICITY, 59 Fig, 1, - - - JIo., / / __ ~ -ri, G- _I ~,~~t ~ ~i(~i ~ ONODALLASMKHWJ i~~~~~~\ii ~ ~ ~ ~ ~ v ii,f~~~~~~~~~~~~~~~~~~~~~~~~~~~Zk ~-~-~-~-~-= —~-~-X, -- l! -IM~ ~~I~ I~~ —-~~ME~;~~~,= —~.-~~= —-~ 60 STATIC ELECTRICITY. THE FRANKLIN KITE EXPERIMENT. The experiment made by Franklin was in June, 1752; the description of which will be found in the following: Fig. 2. "He prepared his kite by making a small cross of two light strips of cedar, the arms of sufficient length to extend to the four corners of a large silk handkerchief stretched upon them; to the extremities of the arms of the cross he tied the corners of the handkerchief. This being properly supplied with a tail, loop, and string, could be raised in the air like a common paper kite; and being made of silk, was more capable of bearing rain and wind. To the upright arm of the cross was attached an iron point, the lower end of which was in contact with the string by which the kite was raised, which was a hempen cord. At the lower extremity of this cord, near the observer, a key was fastened: and in order to intercept the electricity in its descent, and prevent it from reaching the person who held the kite, a silk ribbon was tied to the ring of the key, and continued to the hand by which the kite was held. Furnished with this apparatus, on the approach of a storm, he went out upon the commons near Philadelphia, accompanied by his son, to whom alone he communicated his intentions, well knowing the ridicule which would have attended the report of such an attempt should it prove to be unsuccessful. Having raised the kite, he placed himself under a shed, that the ribbon by which it was held might be kept dry, as it would THE FRANKLIN KITE EXPERIMENT. 61 become a conductor of electricity when wetted by rain, and so fail to afford that protection for which it was provided. A cloud, apparently charged with thunder, soon passed directly over the kite. He observed the hempen cord; but no bristling of its fibres was apparent, such, as was wont to take place when it was electrified. He presented his knuckle to the key, but not the smallest spark was perceptible.. The agony of his expectation and suspense can be adequately felt by those only who have entered into the spirit of such experimental researches. After the lapse of some time, he saw that the fibres of the cord near the key bristled, and stood on end. He presented his knuckle to the key and received a strong bright spark. It was lightning. The discovery was complete, and Franklin felt that he was immortal. A shower now fell, and wetting the cord of the kite improved its conducting power. Sparks in rapid succession were drawn from the key; a Leyden jar was charged by it, and a shock given: and, in fine, all the experiments which were wont to be made by electricity were reproduced, identical in all their concomitant circumstances." Franklin afterward raised an insulated metallic rod from one end of his house, and attached to it a chime of bells, which, by ringing, gave notice of the electrical state of the apparatus. These interesting experiments were eagerly repeated in almost every civilized country, with variable success. In France, a grand result was obtained by M. de Romas: he constructed a kite seven feet high, which he raised to the height of 550 feet by a string, having a fine wire interwoven through its whole length. On the 26th of August, 1756, flashes of fire, ten feet long, and an inch in diameter, were given off from the conductor. In the year 1753, a fatal catastrophe from incautious experiments upon atmospheric electricity, occurred to Professor Richmann, of St. Petersburg; he had erected an apparatus in the air, making a metallic communication between it and his study, where he provided means for repeating Franklin's experiments: while engaged in describing to his engraver, Sokoloff, the nature of the apparatus, a thunder-clap was heard, louder and more violent than any which had been remembered at St. Petersburg. Richmann stooped toward the electrometer to observe the force of the electricity, and " as he stood in that posture, a great white and bluish fire appeared between the rod of the electrometer and his head. At the same time a sort of steam or vapor arose, which entirely benumbed the engraver, 62 STATIC ELECTRICITY. and made him sink on the ground." Several parts of the apparatus were broken in pieces and scattered about: the doors of the room were torn from their hinges, and the house shaken in every part. The wife of the professor, alarmed by the shock, ran to the room, and found her husband sitting on a chest, which happened to be behind him when he was struck, and leaning against the wall. He appeared to have been instantly struck dead; a red spot was found on his forehead, his shoe was burst open, and a part of his waistcoat singedl; Sokoloff was at the same time struck senseless. This dreadful accident was occasioned by the neglect on the part of Richmann to provide an arrangement by which the apparatus, when too strongly electrified, might discharge itself into the earth. DI.SCRIPTION OF ELECTRICAL MACHINES. I have, now, sufficiently explained to the reader the wonderful experiments of Franklin, and those in France, made in the month of May, 1752, in accordance with the plans published by him. I will proceed to notice the means of manifesting Fig. 3. / 0, ~ ~ ~ ~ I I II lllllllllllllllllllzline lllllll llIIII line'IIIIII III ii1i Iiii..".,",i,', " iPW P T'I;~~~~~~~~~~~~~~~~IL DESCRIPTION OF ELECTRICAL MACHINES. 63 frictional electricity, commonly known as static, in contradistinction to that generated by chemical action. Static electricity, as I have already stated, is sometimes called " electricity at rest," and a voltaic current, is called " electricity in motion." The former remains comparatively at rest, excepting during the instant of discharge. The following are descriptions of electrical machines, viz.: There are two kinds of electrical machines in general usethe cylindrical, and the plate machine. The former is shown in fig. 3. It consists of a hollow cylinder of glass, supported on brass bearings, which revolve in upright pieces of wood attached to a rectangular base; a cushion of leather stuffed with horse-hair, and fixed to a pillar of glass, furnished with a screw to regulate the degree of pressure on the cylinder; a cylinder of metal or wood covered with tin-foil, mounted on a glass stand, and terminated on one side by a series of points to draw the electricity from the glass, and on the other side by a brass ball. A flap of oiled silk is attached to the rubber to prevent the dissipation of the electricity from the surface of the cylinder before it reaches the points. On turning the cylinder, the friction of the cushion occasions the evolution of electricity, but the production is not sufficiently rapid or abundant without the aid of a more effective exciter, which experience has shown to be a metallic substance. The surface of the leather cushion is therefore smeared by certain amalgams of metals, which thus become the real rubber. The amalgam employed by Canton, consisted of two parts of mercury, and one of tin, with the addition of a little chalk. Singer proposed a compound of two parts by weight of zinc, and one of tin, with which in a fluid state six parts by weight of mercury are mixed, and the whole shaken in an iron, or thick wooden box, until it cools. It is then reduced to a fine powder in a mortar, and mixed with lard in sufficient quantity to reduce it to the consistency of paste. This preparation should be spread cleanly over the surface of the cushion, up to the line formed by the junction of the silk flap with the cushion; but care should be taken that the amalgam should not be extended to the silk flap. It is necessary occasionally to wipe the cushion, flap, and cylinder, to cleanse them from the dust which the electricity evolved upon the cylinder always attracts in a greater or less quantity. It is found that from this cause, a very rapid accumulation of dirt takes place on the cylinder, which appears in black spots and lines upon its surface. As this obstructs the action of the machine, it should be constantly removed, 64 STATIC ELECTRICITY. which may be done by applying to the cylinder, as it revolves, a rag wetted with spirits of wine. The production of electricity is greatly promoted by applying, with the hand to the cylinder, a piece of soft leather, five or six inches square, covered with amalgam. This is, in fact, equivalent to giving a temporary enlargement to the cushion. The use of the oiled silk flap is to prevent the dissipation of the electricity evolved on the glass by contact with the air; it is thus retained on the cylinder till it encounters the points of the prime conductor, by which it is rapidly drawn off. It is usual to cover with a varnish of gum lac, those parts of the glass beyond the ends of the rubber, with a view of preventing the escape of the electricity through the metallic caps at the extremities of the cylinder, and the inside of the flap is also sometimes coated with a resinous cement, consisting of four parts of Venice turpentine, one part of resin, and one of bees' wax, boiled together for about two hours in an earthen pipkin over a slow fire. Fig. 4. When the cylindrical machine is arranged for the development of either positive or negative electricity, the conductor is placed with its length parallel to the cylinder, and the points DISTRIBUTION OF ELECTRICITY. 65 project from its side, as in the machine shown in the figure. The negative conductor supports the rubber, and receives from it the negative electricity, not by induction, as is the case with the positive conductor, but by communication. If it be required to accumulate positive electricity, a chain must be carried from the negative conductor (which of course is insulated) to the ground. If on the other hand, negative electricity be required, then the conductor must be put in communication with the earth, and the rubber insulated. The plate electrical machine is shown in fig. 4. It consists of a circular plate of thick glass, revolving vertically by means of a winch between two uprights: two pairs of rubbers, formed of slips of elastic wood, covered with leather, and furnished with silk flaps, are placed at two equi-distant portions of the plate, on which their pressure may be increased or diminished by means of brass screws. The prime conductor consists of hollow brass, supported horizontally from one of the uprights; its arms, where they approach the plate, being furnished with points. With respect to the merits of these two forms of the electrical machine, it is difficult to decide to which to give the preference. For an equal surface of glass, the plate appears to be the most powerful; it is not, however, so easily arranged for negative electricity, in consequence of the uninsulated state of the rubbers, though several ingenious methods of obviating this inconvenience have been lately devised. DISTRIBUTION OF ELECTRICITY. When a substance be- Fig. 5. comes charged with electricity, it is extremely probable, in the opinion of philosophers, that the fluid is confined to its surface, or, at any rate, that it does not penetrate into the mass to any extent. This is a question difficult to demonstrate, and my observations have induced me to believe, that in the case of voltaic currents the electricity moves upon or at the surface, but that the interior of the metallic conductor is under the influence of the fluid, though in a state of rest. Experiments have been made with static or frictional electricity by Biot, and the following facts were arrived at A ball 5 66 STATIC ELECTRICITY. formed of any kind of material, will be equally electrified whether it be solid or hollow, and if it be hollow, the charge which it receives will be the same whether the shell of matter of which it is formed be thick or thin. A sphere of conducting matter, A, is insulated by a silk thread, and two thin hollow hemispheres, B B, made of metallic foil or gilt paper, and provided with glass handles, corresponding with the shape and magnitude of the conductor. The sphere A, is electrified, and the covers are then applied, being held by the glass handles. After withdrawing them from A, they are found to be charged with the same kind of electricity as was communicated to A, and the ball will be found to have lost the whole of its charge, proving that the electricity resided on the surface only. Fig 6. To further demonstrate that the electricity holds its position on the surface, fig. 6 is to illustrate. At the ends of the cylinder, are attached an electroscope, composed of two elderpith balls, suspended to linen threads. The whole is to be electrified, and the pith-balls, c a, will diverge as seen in the figure. In this state take hold of the silken thread at b, and then unroll the metallic ribbon b. When it is unrolled, the pith-balls will come into or near a contact. Replace the ribbon, and the balls diverge again. When the metallic ribbon is taken off, it carries from the cylinder the whole of the electric charge. The outer layer of the metallic ribbon, when around the cylinder, is charged plus, as compared with the inner layer, but as soon as the ribbon has been taken from its circular position, the electricity immediately distributes itself equally throughout the ribbon's surface. Restore the ribbon around the cylinder, and the plus will be found on the exterior surface. ATTRACTION AND REPULSION. 67 Figure 7 is another illustration of the diffusion Fil. 7. of electricity on the outside of vessels. This is a cylinder made of wire-gauze. Let the insulated B be lowered into a wire-gauze cylinder, A, fig. 7, when electrified and mounted on an insulating stand. It may touch every part of the interior without receiving any portion of the electricity, with which the exterior surface is charged, though the slightest touch on the other side of the open wire mesh communicates electricity to the ball. I am fully sensible of the fact, that this important principle in philosophy has not been clearly demonstrated in the foregoing, but the room allowed in this work renders further explanations impossible, and the reader must refer to the standard works on electricity for fuller information in the premises. PHENOMENA OF RESISTANCE TO INDUCTION. Fig. 8. Figure 8 represents the resistance to induction and discharge offered by any given media, such as atmospheric air, &c. The glass tube, a b, two feet long, is furnished at either end with a brass ball projecting into its interior, and carefully exhausted of its air by means of an air-pump; on connecting the end a, with the prime conductor, and the end b, with the earth, when the machine is turned, a becomes positive, and induces the contrary state on the ball b; induction taking place with facility, in consequence of the atmospheric pressure being removedand is followed by a discharge of the two electricities in the form of a beautiful blue flame filling the whole tube, and closely resembling the aurora borealis. Fig. 9. PHENOMENA OF ATTRACTION AND RE- PULSION. The phenomena of attraction and repulsion are well illustrated by the apparatus known as the electric bells, fig. 9. They are suspended from the prime conductor by means of the hook; the two outer bells are suspended by brass chains, while the central, and the two clappers, hang from silken strings; the 638 STATIC ELECTRICITY. middle bell is connected with the earth by a wire or chain; on turning the cylinder, the two outside bells, become positively electrified, and by induction the central one becomes negative, a luminous discharge taking place between them, if the electricity be in too high a state of tension. But if the cylinder be slowly revolved, the little brass clappers will become alternately attracted and repelled by the outermost and inner bells, producing a constant ringing as long as the machine is worked. Fig. 10. Another experiment is often given /\\ t~\, with the toy-head. When attached to the prime conductor of the machine, the hairs stand erect, presenting an exaggerated representation of fright, as seen by fig. 10. Figure 11 represents an experiment with the dancing toys. A brass plate is suspended from the prime conductor, _'|l 0and under it is placed a sliding stand, on which is laid a little bran or sand, or little figures made of pith: on turning the machine, the bran, or sand, or figure is attracted and repelled by the upper plate with such rapidity, that the motion is almost imperceptible, and appears like a white cloud between the plates, and the little figures appear to be animated, dance, and exhibit very singular motions, dependent on inductive action. Fi., 11. Figure 12, represents an inverted tumbler, wiped thoroughly dry, warmed, and the inside charged by holding it in such a direction that a wire proceeding from the prime conductor of a machine in action, shall touch it nearly in every part; im M.... then invert it over a, number of pith-balls; they will be attracted and repelled backward and forward, and effect the discharge of the electricity which induces from the interior toward the plate. They will then remain at rest; but, if the electricity which has been disengaged on the outside, toward surrounding objects be removed by a touch of the hand, a fresh portion will be set free on the IGNITING GAS NVITI THE FINGER. 69 interior, and the attraction and repulsion of the balls will again take place, and thus for many times suc- Fig. 12. cessively the action will be renewed until the glass returns to its natural state. IGNITING GAS WITH THE FINGER. A very interesting experiment is repre- sented by figure 13, showing the lighting of gas with an electric spark fiom the finger. In my apartments, it has been the mischievous practice of my son, to pass several times around a room, rubbing or sliding his shoes on the carpet, charging his body with electricity, in the same manner as produced by the machine. The body being fully electrified in Fig. 13. Til^ i this manner, he would point his finger within a few inches of the nose of some one present; the spark would pass with a noise from the finger to the nose, giving the recipient a sensible shock, unpleasant to the nose, but amusing to others present. 70 STATIC ELECTRICITY. In this manner he frequently lighted the gas. It is a very simple amusement, and any one can, in like manner, at their own homes perform the experiment. The room must be warm, the carpet must have a nap, and the shoes must be perfectly dry. THE LEYDEN JAR EXPERIMENTS. The principles of the Leyden jar have become more or less interesting to the telegrapher, particularly with reference to submarine and subterranean lines. The following, from Bakewell, contains a concise description of the principles of this important apparatus. It is called a Leyden jar because it was first constructed by Muschenbroek and his friends, at Leyden, Holland, in the year 1746. "The power of accumulating electricity by means of the Leyden jar has placed in the hands of electriFig. 14. cians a force of almost unlimited extent. In our sketch of the history of electric science, we have already adverted to the nature of the apparatus. As at present constructed, it con<^Bl h sists of a thin glass jar A, fig. 14, coated within and without with tin-foil, which reaches to about three inches from the top. A wooden cover, B serves as a support to a straight thick brass a Sl- vl wire, c, that passes through the centre of the cover, and has a metallic connection by a chain or wire with the interior coating. This wire rises a few inches above the cover, and is surmounted by a hollow brass ball, which is screwed on to the top of the wire to prevent the dispersion of the electricity from the end. The sizes of the jars vary from half a pint to ten gallons. One holding about a pint will give a shock as strong as most persons like to receive. To charge a jar with positive electricity, connect its small brass ball with the prilme conductor of the machine, and make a connection between the outside coating and the ground. When fully charged it will give indications of its electrical condition by a muttering sound; and in the dark, rays of light. will be seen issuing from the edges of the tin-foil and from the ball. The notion of VMuschenbroek, which led to the discovery of the Leyden jar, was to collect electricity within a phial to prevent its dispersion, and thereby to store up an increased quantity of the electric fluid; but it is now ascertained that a jar when highly charged does not contain more electricity than it did before it was applied to the conductor. The effect pro THE LEYDEN JAR EXPERIMENTS. 71 duced by charging is not to increase the quantity, but only to disturb the natural electricity previously present in a latent state on the inside and outside of the glass. There is injected into the inside, by connection with the electrical machine, an amount of positive electricity, while an equal amount of negative electricity is driven from the outside "by the force of electrical induction; and unless the electricity on the outer surface of the glass can be thus driven off by affording it a connection with the ground, the inside cannot receive a charge. Let a Leyden jar be insulated from the earth by placing it on a glass stand, and it will receive scarcely any electricity from the conductor; not more than equal to the quantity which can escape from the outside to the surrounding air. If the knob of another insulated jar be connected with the ground, and the outside coatings of the two jars be brought near together, sparks will then pass rapidly from the prime conductor F 15. to the knob of the first, and they will also pass as rapidly between the outside coatings of the two jars. In this manner both the Leyden jars become charged, and it will be found that they are charged equally, but with electricity of opposite kinds. The first (B one, that derived its electricity directly from the prime conductor, will be charged positively; the second, that derived its charge from the electricity escaping from the knob to the ground, will be negative. Place the two jars on the table, and suspend between them a pith ball, B, or other light substance, and it will be attracted alternately from one to the other in rapid vibrations, clearly showing that the electricity in the 1,wo jars is of opposite kinds. The phenomena that occur during the charge of a Leyden jar have been adduced as evidence in support of the Franklinian theory of a single electric fluid, the outside being supposed to be in a minus state after parting with its natural quantity to the other jar. But the phenomena are explicable also on the hypothesis of two fluids, it being assumed that they are separated from their neutral state by the coercing force of the free electricity communicated to the inside of the jar. 72 STATIC ELECTRICITY. Franklin attempted to apply practically the charging of one jar from the escaping electricity of another. He inferred, that, if a series of insulated jars were arranged with the outside coatings and knobs alternately touching, the coating of the last one being connected with the ground, by this arrangement the positive electricity expelled from the outside of the first jar would charge the second; that the electricity from the outside of the second would charge the third positively, and so on to any number; and that an immense electric force might be thus accumulated from the same quantity of electricity that is required to charge a single jar. Let AB C represent a series of three jars, A and B being mounted on insulating Fig. 16. glass stands, fig. 16. ~ B A On making connection from the prime conductor of an electrical {itri machine to the knob of A, that jar will be charged positively, and an equal amount of sd a e e iity electricity will be expelled from the outside oIII effect || fa tinto B, which will also be positively charged. t /1he negative e c tThe third jar, c, will bi,1e d Now if a| t c o ein like manner be charged from the outside of B, and the electricity which was expelled from A, on arriving at the outside of the last jar of the series, will be conducted to the earth. To effect the discharge of a jar, it is requisite that a connection be made between the positive electricity within and the negative electricity without, so that the equilibrium may be restored. Now if a metallic connection be imade from the knob of to the knob of A, there will be a discharge of the first jar only; for though the connection is made with the knob of B, none of the positive electricity within can be discharged, for it is restrained by the coercing force of the opposite electricity on the outside If metallic connection be made between the outside of B and the knob of A, both those jars will be discharged, and the third will remain charged; but by bringing a wire from the outside of c to the knob of A, the three jars will be at once discharged. The phenomena exhibited in charging the Leyden jar has THE LEYDEN JAR EXPERIMENTS. 73 been explained; the cause of its accumulating electricity, and discharging tho force instantaneously, will be next considered. We have stated that the cause depends on inductive action operating through the substance of the non-conducting glass. Exemplifications of this action through glass have been previously given. A pane of glass when excited by friction on one side has negative electricity induced on the other, and a glass tumbler may be charged with electricity by exposing the inside to the influence of an electrified point, while the outside is grasped by the hand. The electricity thus collected on the surfaces of the pane of glass and the tumbler is sluggish in its action, and is dissipated by slow degrees, on account of the non-conducting property of the glass surfaces; but if metal plates be applied on each side of the pane of glass, the electricity is instantly concentrated at any point, and on connecting the two surfaces with a wire, a discharge takes place, exactly as in the Leyden jar. The charged tumbler might also be converted into a Leyden jar by the application of interior and exterior casings of metal foil, to serve as conductors, to concentrate at any point the electricity distributed over the surface of the glass. To prove most conclusively that the charge of a Leyden jar is retained on the surface of the glass, and not in the metallic coatings., Leyden jars are made with tin inside and outside casings, so contrived that they may be easily removed. A jar of this kind, when charged and placed on an insulating stand, may have the metal casings removed and others substituted for them; yet after this change the jar will be found to retain its charge. The metal serves only to conduct the electricity simultaneously from all parts of the glass. A plate of glass affords the most convenient mode of illustrating that the electrical charge is retained by the glass and not by the metal. Let a pane of glass, about one foot square, be covered on one side with tin-foil, and laid horizontally on the table. To the other side apply the insulated metal disk of an electrophorus; connect the disk with the prime conductor. and a few turns of the machine will charge the glass. Remove the disk by the insulating handle, and it will manifest scarcely any trace of electricity. Let the same or another disk be again applied to the surface of the glass, and on making connection between the metals on the opposite sides a strong discharge will take place. A moveable metal disk might be applied to each surface of the glass with similar results; but the arrangement indicated is more convenient. When a more powerful charge of electricity is required than 74 STATIC ELECTRICITY. a single jar will retain, several are combined to form an electrical battery. For convenience, the jars are placed in a box with divisions, the bottom being lined with tin-foil, to make connection with all the exterior coatings. The knobs of the jars are connected together by wires, as represented in fig. 16; and there is a metal hook projecting from the side of the box connected with the tin-foil lining. Thus all the interior Fig. 17. and all the outside coatings of the jars are connected; and when communication is made between the prime conductor and any of the knobs of the jars, the whole are simultaneously charged. They are also discharged simultaneously by making connection between the projecting hook and any one of the knobs. The combination of several small jars is found better than having a smaller number of large ones, because the thickness of the glass necessary in jars of large size obstructs induction through it. By an arrangement of many jars, an amount of electric force may be accumulated that would almost equal the destructive power of lightning. The battery used by Faraday in his experiments consisted of fifteen equal jars, coated eight inches upward from the bottom, and twenty-three inches in circumference; so that each contained one hundred and eightyfour square inches of glass coated on both sides, independently of the bottoms of the jars, which were of thicker glass, and contained each about fifty square inches. The total coated surface of the battery consequently comprised three thousand five hundred square inches of coated surface. The electrical battery at the Polytechnic Institution exposes a coated surface of nearly eighty square feet. To receive the full charge of such a battery would be instant death. A battery of nine THE LEYDEN JAR EXPERIMENTS. 75 quart jars is sufficient to exhibit the deflagrating effects of electricity on a small scale; nor would it be safe to receive a shock from a battery of that size. It is a fact deserving consideration that the accumulation ot quantity diminishes the intensity of electricity. For instance, an electrical machine when in good action will emit sparks four inches long. When a Leyden jar is charged with twelve. such sparks, the accumulated electricity will not force its passage through more than a quarter of an inch; and if the same quantity be distributed among the jars of an electrical battery, the discharge will not take place through the eighth of an inch. The quantity of electricity is in each case the same, but the state of intensity diminishes in proportion to the surface over which it is diffused. The difference between quantity and intensity is still more remarkably manifested in the different conditions of frictional and voltaic electricity, as will be subsequently noticed. One of the peculiar phenomena of the electrical battery is the residual charge. When communication is made between the inside and outside coatings of a battery consisting of several jars, the whole of the electricity is not immediately discharged. On again making connection between the inside and outside coatings, after a short interval, a second discharge will occur, which, though comparatively feeble, might occasion a disagreeable shock. The cause of this residual charge is partly attributable to the accumulation of electricity on those parts of the jar just above the metallic coating; which portions, not being in direct contact with the metal, are not conducted with equal rapidity. Part of the charge also enters into the pores of the glass, and is thus removed from immediate contact with the metal. The simplest kind of instrument employed for discharging a Leyden jar or an electrical battery is a thick curved piece of brass wire, fitted with a small ball at each end. One of these balls is applied to the outside coating, and when the other is brought near to the knob of the jar the electricity instantly passes through the wire with a smart snap or report, connection being thus made between the two charged surfaces of the jar. When, however, a discharger of this kind is employed for an electrical battery a slight shock is felt, owing to what is termed the lateral discharge; therefore, to avoid the inconvenience and the danger that might arise from holding the wire in the hand, an insulated wire is generally employed. Its form is represented in fig. 18, as applied in discharging a Leyden jar. Two thick brass wires, a a, of equal lengths, and terminated 76 STATIC ELECTRICITY. with brass balls, are jointed together at c for the convenience of adjustment, and are cemented to a glass handle, b, which serves to insulate the wires from the hand, and prevents the Fig. 18. liability of any perceptible portion of the charge being erlG E received by the operator. There has been much discussion among electrilateral discharges, in reference more particularly to a^^ lS B the safety of lightningconductors; we shall therefore notice in this place the cause of the phenomenon. It is the case with electricity, even to a greater extent than with all fluid bodies, that it will discharge itself into every channel that is open to it. Thus, as in a mountain torrent some portion of the water will deviate from the straight and broad course into circuitous and narrow crevices, so will the highly tensive electric fluid force its passage through every conducting medium. Thus when a Leyden jar is discharged with an insulated wire, a small part of the charge passes through the circuitous and comparatively obstructive course offered by the body of the operator, by the floor, and by the table whereon the jar is placed. In the case of a single jar, the quantity of electricity that passes in that direction is imperceptibly small; but when several jars are combined, the lateral discharge may become unpleasantly strong, especially if the wire of the discharging-rod be not very thick. Even when an insulated discharging-rod is employed, it may be inferred that some portion of electricity will force its way along the glass; but it is so infinitesimally small as to be inappreciable. Applying the experience and inferences deducible from experiments with the electrical battery to the more powerful effects of lightning, we are led to consider that every flash of lightning must be accompanied by lateral discharge, and that the quantity thus diverted from the direct and easiest path between the clouids and the earth will depend on the amount of resistance which that direct course offers. Therefore, though lateral discharge must, to some extent always occur, it may be rendered entirely innocuous by a sufficiently thick and unbroken lightning conductor. VOLTAIC ELECTRICITY. CHAPTER VI. Electrical Phenomena Discovered by Galvani-Origin of the Voltaic Pile-Science of the Voltaic Battery-Ohm's Mathematical Formnle -Chemical and Electrical Action of the Battery-The Daniell, the Smee, the Bunson, the Grove and the Chester Voltaic Batteries-Comparative Intensity and Quantity of the Grove, Daniell, and Smee Batteries. ELECTRICAL PHENOMENA DISCOVERED BY GALVANI. THAT remarkable form of electricity, known by the name of Galvanism or Voltaism, owes it origin to an accidental circumstance connected with some experiments on animal irritability, which were being carried on by Galvani, a professor of anatomy at Bologna, in the year 1790. It happened that the wife of the professor, being consumptive, was advised to take as a nutritive article of food, some soup, made of the flesh of frogs: several of these animals, recently killed and skinned, were lying on a table in the laboratory, close to an electrical machine, with which a pupil of the professor was making experiments. While the machine was in action, he chanced to touch the bare nerve of the leg of one of the frogs with the blade of a knife that he held in his hand, when, suddenly, the whole limb was thrown into violent convulsions. Galvani was not himself present when this occurred; but received the account from his wife, and being struck with the singularity of the phenomenon, he lost no time in repeating the experiment, and investigating the cause: he found that it was only when a spark was drawn from the prime conductor, and when the knife or any other good conductor was in contact with the nerve, that the contractions took place; and pursuing the investigation with unwearied industry, he at length discovered that the effect was independent of the electrical machine, and might be equally 78 VOLTAIC ELECTRICITY. well produced by making a metallic communication between the outside muscle and crural nerve. He did not for one moment suppose that the manifestation of electricity was the result of the chemical action upon the metals. Galvani had previously entertained notions respecting the agency of electricity, in producing muscular action: these new experiments, therefore, as they seemed to favor his views, had with him more than ordinary interest. He immediately ascribed the convulsive movement in the limb to electrical agency, and explained them by comparing the muscle of an animal to a Leyden vial, charged by the accumulation of electricity on its surface, while he imagined that the nerve belonging to it performed the function of a wire, communicating with the interior of the vial, which would, of course, be charged negatively. In this state of things, if a communication by a good conductor were made between the muscle and nerve, a restoration of the electric equilibrium, and a contraction of the fibres, would ensue. It is curious to notice how frequently the progress of discovery in the sciences is influenced by fortuitous circumstances, and in no case is it more striking than in the present. Had G-alvani been as good an electrician as he was anatomist, it is probable that the convulsions of the frog would have occasioned him no surprise; he would immediately have seen that the animal formed part of a system of bodies under induction, and he would have considered the movements of the limbs of the frog, as evidence of nothing more than a high electroscopic sensibility in its nerves. To perform the experinent with the frog's legs successfully, the legs of the frog are to be left attached to the spine by the crural nerves alone, and then a copper and a zinc wire being either twisted or soldered together at one end, the nerves are to be touched with one wire, while the other is to be applied to the muscles of the leg. Figure 1 shows the arrangement. There are several ways of varying this experiment. If a piece of copper, as a penny, be laid on a sheet of zinc, and if a common garden snail be put to crawl on the latter, he will be observed to shrink in his horns and contract his body whenever he comes into contact with the penny: indeed, after one or two contacts he will be observed to avoid the copper in his journey over the zinc. The experiments of Galvani excited much attention among the men of science of that period: they were repeated and varied in almost every country in Europe, and ascribed to various causes. Some imagined them the effect of a new and ORIGIN OF THE VOLTAIC PILE. 79 unknown agent: others adopted the views of the discoverer, and recognized them as peculiar modifications of electricity. The hypothetical agent which passed under the name of the Fig. 1. "nervous fluid," now gave way to electricity, which, for a time, reigned as the vital principle, by which " the decrees of the understanding, and the dictates of the will, were conveyed from the organs of the brain to the obedient member of the body;" and this theory for a time so fascinated physiologists, that it was with difficulty that the explanations of Volta, viz. that the electric excitement is due to the mutual contact of two dissimilar metals-that by the contact the natural electricity was decomposed, the positive fluid passing to one metal, and the negative one to the other-and that the muscle of the frog merely played the part of a conductor-obtained assent. ORIGIN OF THE VOLTAIC PILE. It is to Professor Volta, of Pavia, that we are indebted for the first galvanic or voltaic instrument, viz. the voltaic pile; it was described by him in the Philosophical Transactions of 1800, and to him, therefore, the merit of laying the foundation of this highly interesting branch of science is due. The main difference between common and voltaic electricity (which are modifications of the same force) will be found to be this: the first produces its effects by a comparatively small quantity of electricity, insulated, in a high state of tension, having remarkable attractive and repulsive energies, and power to force its way through obstructing media: the latter is more intimately associated with other bodies, is in enormous quantity, but rarely attains a high state of tension, and exhibits its effects while flowing in a continuous stream along conducting bodies. 80 VOLTAIC ELECTRICITY. Galvani was an anatomist and not an electrician. He was firmly impressed with the idea that the convulsion of the frog's limb was owing to muscular action caused by animal electricity. He advocated this theory with the utmost zeal, and his whole efforts were directed toward maintaining this error. Electricians doubted the correctness of Galvani's philosophy, and on the other hand physiologists gave countenance to his notions, and throughout the continent they contended that the convulsions were produced by animal electricity. The extraordinary zeal that was displayed by Galvani and his friends to maintain their physiological theory, caused electricians to investigate its correctness, and among them was Volta, of Pavia. In this state of the question Galvani died, at the close of the year 1798. Two years after the death of Galvani, Volta produced his " pile" which demonstrated the correctness of his theory, as mainly advocated by him for several years previous. The electricians rejoiced over the practical illustration exhibited by the voltaic pile. It dispelled all faith in the erroneous reasoninogs of Galvani and his friends, that the motion of the frog was by animal electricity. Volta's triumphant success in demonstrating that the convulsions were produced by chemical action of the metals, was received with great joy by the electricians. It was a contest between anatomists and electricians, and the latter were the victors. The most strange part of the history was, that the achievement of Volta, was called Galvanism instead of Voltaism, as more modernly termed. The original instrument of Volta is shown in fig. 2. It conFig. 2. sists of a series of silver and zinc plates, arranged one above the other, 1_' _~I I 1 p with moistened flannel or pasteboard I z...between each pair. A series of thirty or forty alternations of plates, I_____ 1 four inches square, will cause the gold leaf electroscope to diverge; the zinc end with the positive, and the silver with the negative elec- ____ tricity; a shock will also be felt on I___ __touching the extreme plates with the "__ c finger, when moistened. with water. *A - __ M This latter effect is much increased ^__ DIm- r,_ when the flannel, or pasteboard, is moistened with salt and water; in this case a small spark will be decomposed; from.this we learn that the increase of chemical action, by the addition of SCIENCE OF THE VOLTAIC BATTERY. 81 the salt, materially increases the quantity of electricity set in motion; but the pile will not in any sensible manner increase the divergence of the gold leaves,-its intensity, therefore, is not materially augmented. The pile, represented by fig. 2, is connected at each end with a wire; A B C is the frame to hold. the plates; s s are the silver plates, and z z are zinc plates; i are the moistened flannels, and i i the top and bottom end boards; p, the positive pole, is connected with the wire at the top, and at the bottom N, the negative, to the wire. This was the voltaic pile as originally introduced by that distinguished philosopher Volta, of Pavia, in the year 1800. In order to increase the intensity of the voltaic or electric current, it is necessary to increase the number of the plates; and to develop the greater quantity current, it is attained by the increase of the size of the plates. The centre of the battery or column is neutral, but the ends are in opposite electrical states; the zinc extremity negative, and the gold, silver, platinum or other metallic applications, positive. TIIE SCIENCE OF THE VOLTAIC BATTERY. The action of the voltaic pile gradually diminishes from the time it is first put together, until at length the effect appears to cease. This diminution of power is more rapid in proportion to the energy given to the pile in the first instance by the larger quantity of acid mixed with the water. To restore the original energy, it is necessary to decompose the pile, to clean the zinc and copper disks, and to moisten the cloths again. Such an apparatus is therefore attended with much trouble. To obviate it, Volta contrived another arrangement, which he called d couronne de tasses. He connected a piece of zinc to a piece of copper by soldering to them a short length of bent copper wire. Having procured a number of such connected plates, he put them into a row of glasses containing acidulated water, taking care so to dispose them that the zinc and the copper connected together should be in separate glasses, in the manner represented in figure 3. To the copper plate in glass 1, a wire is attached to serve as a conductor for forming connection. In the same glass there is a zinc plate connected with the copper immersed in glass 2. In this manner each glass contains a zinc and copper plate connected by a wire, which are kept apart in the fluid, and the series may be continued to any extent. By bringing the wire attached to the first plate in connection with a similar wire 6 82 VOLTAIC ELECTRICITY. soldered to the zinc plate in the last glass of the series, the action immediately commences, and it is more or less intense according to the number of plates. This arrangement is, in Fig. 3. many respects, very superior to the pile. A much larger quantity of fluid can be brought to act on each plate, consequently the effect does not so rapidly diminish; the plates can be readily removed when the apparatus is not wanted, and the acidulated water may remain ready for the immersion of the plates when experiments are renewed. The arrangement d couronne de tasses, as invented by Volta, continues, with some modifications for convenience in use, to form the voltaic battery that is most generally employed. A series of this kind, consisting of one hundred plates of copper and zinc four inches square, will generate electricity in sufficient quantity to exhibit in a powerful manner most of the phenomena of frictional electricity. The metals that excite electricity by their mutual actions are ranged in the following order; those placed first acting in reference to those beneath as copper does to zinc. Platinum. Mercury. Tin. Gold. Copper. Iron. Silver. Lead. Zinc. Any two of the foregoing series will constitute what is termed a voltaic circuit. Thus zinc will excite voltaic action in combination with iron; iron will take the place of zinc when combined with tin; and tin will take the place of iron when combined with copper. The energies of these combinations increase as the metals are more distant from each other in the scale, the most powerful practical combination being zinc and platinum, the most incorrodible of all metals. Though two plates are necessary in such an arrangement, only one of them is active in Ihe excitement of electricity, the other plate serving merely as a conductor to collect the force generated. A metal plate is generally used for that purpose, SCIENCE OF THE VOLTAIC BATTERY. 83 because metals conduct electricity much better than other substances exposing an equal surface to the fluids in which they are immersed; but other conductors may be used, and when a proportionately larger surface is exposed to compensate for inferior conducting power, they answer as well, and in some instances even better than metal plates. The chemical action that gives rise to the excitement of electricity, takes place during the decomposition of the liquid in which the plates are immersed. It is essential, therefore, to the formation of an active voltaic arrangement, that the liquid employed should be capable of being decomposed. Water is most conveniently applicable for the purpose. Its elements, oxygen and hydrogen, are separated by the superior affinity of the oxygen for the zinc; especially when that affinity is heightened by the connection of the zinc with an incorrodible metal, to which the hydrogen gas of the decomposed molecules of water is attracted. Whether the electricity evolved be the cause or merely the effect of chemical action is at present unknown. In whichever way the phenomenon be regarded, the electricity appears to be excited at the surface of the active plate, thence to be transferred to the conducting plate, and back again through the connecting wire to the zinc, forming what is termed an electric current. The terms " electric fluid and " electric current," which are frequently employed in describing electrical phenomena, are calculated to mislead the student into the supposition that electricity is known to be a fluid, and that it flows in a rapid stream along the wires. Such terms, it should be understood, are founded merely on an assumed analogy of the electric force to fluid bodies. The nature of that force is unknown, and whether its transmission be in the form of a current, or by vibrations, or by any other means, is undetermined. At the meeting of the British Association for the Advancement of Science at Swansea, a discussion arose on the nature of electricity, and Dr. Faraday was called on to give his opinion. He then said,' There was a time when I thought I knew something about the matter: but the longer I live, and the more carefully I study the subject, the more convinced I am of my total ignorance of the nature of electricity.' After such an avowal from the most eminent electrician of the age, it is almost useless to say that any terms which seem to designate the form of electricity are merely to be considered as convenient conventional expressions. Water being a very imperfect conductor, it offers so much resistance to the passage of the electric current that a very small quantity of voltaic electricity can be excited when water 84 VOLTAIC ELECTRICITY, alone is employed; especially when the plates are at a considerable distance apart. By the addition of an acid or a neutral salt to the water, the conducting power is greatly increased, and the excitement is augmented in a corresponding degree. It is a disputed point whether the increased action from the addition of acids arises from the improved conducting power alone, or whether it is to be attributed also to the increased affinity of the oxygen to the zinc. The effect is most probably owing to the joint effort of the two forces. In the opinion of Faraday, the conduction of electricity through liquids is accompanied by, if it be not owing to, the successive decomposition of the intervening particles. When a. copper and zinc plate, for example, are connected together and immersed in diluted acid, the oxygen in the particle of liquid contiguous to the plate enters into combination with the metal, and its equivalent quantity of hydrogen is disengaged. The hydrogen is not immediately liberated, but is transferred from particle to particle of the liquid in a continuous chain till it reaches the conducting plate, where, not meeting with any more liquid particles to which it can be transferred, it is liberated in the gaseous form. The intervening particles are supposed to undergo temporary decomposition during this transfer firom plate to plate, and to assume a polar condition, the oxygen and hydrogen occupying opposing places in each particle of liquid. The annexed diagram, fig. 4, shows, in an exaggerated form, Fig. 4. the chain of particles of water through which the decompop ot ^ ="^ siCng, influence is supposed to be transmitted. Voltaic ac||. fA X tion having been established - _through water in the vessel A