PART I
INTRODUCTORY
The Electric Telegraph—First Land Telegraphs—First Submarine Cables: Dover to Calais, 1850-’51—Other Early Cables: England to Ireland, 1853, etc.
The Electric Telegraph.—The advances made in electric science are so bold and rapid that our still comparative ignorance of the precise nature of electricity must always seem strange. We are not, however, here directly concerned with electricity as a physical science, but rather with its practical applications to the still present system of telegraphy, by way of introduction to the gradual development of Trans-Atlantic telegraphy. The electric telegraph, together with the railway-train and the steamship, constitute the three most conspicuous features of latter-day civilization. Indeed, it may be truly said that the harnessing of this force of nature (electricity) to the service of man for human intercourse has effected a change in political, commercial, and social relations, even more complete than that wrought by steam locomotion. Like its fellow emblems, the telegraph was the outcome of many years of persevering effort on the part of numerous scientific investigators and inventors; like them also, it was perfected for practical use on both sides of the Atlantic by men of our own race{14} and speech, such as Cooke, Wheatstone, and Morse.
The First Land Telegraphs.—The first practical telegraph-line in the world—namely, that on the Great Western Railway from Paddington to West Drayton, shortly afterward extended to Slough—was within the year of Queen Victoria’s accession to the throne, and in the same year as the first trunk line of railway and the first ocean steamer.[1] Improvements and novelties in telegraphic instruments were rapidly made by inventors from all the civilized nations—e. g., Morse, Vail, and Henry in America; Breguet in France; Steinheil and Siemens & Halske in Germany; and Schilling in Russia; besides Alexander Bain, Bright, and Hughes in England. Commercial interests were soon formed to work the new invention, and in England the Electric and International Telegraph Company, the British and Irish Magnetic Telegraph Company, and other large concerns were the means of establishing telegraphic communication throughout the kingdom—only to be absorbed by Government later on. Our theme does not include—even in the course of introduction—a study of the development of land telegraphy. The apparatus and methods employed are, to a great extent, entirely different; indeed, the only point in common between the cardinal principles and submarine telegraphy is that electricity, as generated by a voltaic battery, is the common agent, and consequently{15} the metal conducting-wire is employed in both.[2] But in subaqueous (as well as in subterranean) telegraphy the poles and porcelain insulators require to be substituted by an insulating covering round the entire conductor; and the point of contact in practise between land and marine telegraphy is really, therefore, in the matter of insulation for subterranean or subaqueous wires.
First Submarine Cables.—A Spaniard named Salva appears to have suggested the feasibility of submarine telegraphy as far back as 1795, and in 1811 Sommering and Schilling conducted a series of experiments, more or less practical, when a soluble material—said to have been india-rubber—was first used for insulating the wire.
But the earliest records of practical telegraphy under water of which there are any particulars relate to the experiments conducted by Dr. O’Shaughnessy (afterward Sir William O’Shaughnessy Brooke, F.R.S.) across the River Hugli on behalf of the East Indian Company in 1838.[3] Referring to his practical researches a little later, O’Shaughnessy remarked: “Insulation, according to my experiments, is best accomplished by enclosing the wire (previously pitched) in a split rattan, and then paying the rattan round with tarred yarn; or the wire may—as in some experiments by Colonel Pasley,{16} R.E., at Chatham—be surrounded by strands of tarred rope, and this by pitched yarn. An insulated rope of this kind may be spread across a wet field—nay, even led through a river—and will still conduct the electrical signals, without any appreciable loss.” In 1840 Professor Wheatstone (afterward Sir Charles Wheatstone, F.R.S.) explained to a committee of the House of Commons the methods by which he thought it possible to establish telegraphic communication between Dover and Calais. He appears to have been unaware of the prior experiments just alluded to, for his system of insulation, though more fully developed, was practically the same.
Prof. S. F. B. Morse, the well-known inventor of the telegraph apparatus bearing his name, also made a study of this problem in 1842, when he laid down an insulated copper wire across New York harbor, through which he transmitted electric currents. Hemp soaked in tar and pitch, surrounded with a layer of india-rubber, constituted the insulation. Morse was a great letter-writer, and records of his early work are solely based on his own statements at a time when he noted in his diary: “I am crushed for want of means. My stockings all want to see my mother, and my hat is hoary with age.” In 1845 Ezra Cornell, who was afterward the founder of Cornell University, laid a cable, twelve miles long, to connect Fort Lee with New York, in the Hudson River. The cable consisted of two cotton-covered copper wires, insulated with india-rubber, and enclosed in a leaden pipe. It worked well for several months, but was broken by ice in 1846. In that year Mr. Charles{17} West paid out by hand an india-rubber insulated wire in Portsmouth harbor, through which he signaled from a boat to the shore. The experiment was intended as the forerunner of the establishment of telegraphic communication between England and France, but for want of the necessary funds was not followed up.