| Wire, prepared, per mile, | $ 150.00 |
| Lead pipe, with solderings, | 250.00 |
| Delivery of the pipe and wire, | 25.00 |
| Passing wire into the pipes, | 5.00 |
| Excavations and filling in about 1,000 yards per mile, | |
| or 3 feet deep, at 15 cents per square yard, | 150.00 |
| Laying down the pipe, | 3.00 |
| 583.00 | |
| One register, with its machinery, comprising a galvanic | |
| battery of four pairs of my double-cup battery, | $ 100.00 |
| One battery of 200 pairs, | 100.00 |
| Expense for thirty nine miles, | $ 22,837.00 |
| Two registers, | 200.00 |
| Two batteries, | 200.00 |
| Services of chief superintendent of construction, per annum, | 2,000.00 |
| Services of three assistants, at $1,500 each, per annum, | 4,500.00 |
| $ 29,637.00 |
As experience alone can determine the best mode of securing the conductors, I should wish the means and opportunity of trying various modes, to such an extent as will demonstrate the best.
Before closing my letter, sir, I ought to give you the proofs I possess that the American telegraph has the priority in the time of its invention.
The two European telegraphs in practical operation are Professor Steinheil’s of Munich, and Professor Wheatstone’s of London. The former is adopted by the Bavarian Government; the latter is established about 200 miles in England, under the direction of a company in London. In a highly interesting paper on the subject of telegraphs, translated and inserted in the London Annals of Electricity, March and April, 1839, Professor Steinheil gives a brief sketch of all the various projects of electric telegraphs, from the time of Franklin’s electrical experiments to the present day. Until the birth of the science of electro magnetism, generated by the important discovery of Oersted, in 1820, of the action of electric currents upon the magnetic needle, the electric telegraph was but a philosophic toy, complicated and practically useless. Let it be here noticed, that, after this discovery of Oersted, the deflection of the needle became the principle upon which the savants of Europe based all their attempts to construct an electric telegraph. The celebrated Ampère, in the same year of Oersted’s discovery, suggested a plan of telegraphs, to consist of a magnetic needle, and a circuit for each letter of the alphabet and the numerals—making it necessary to have some 60 or 70 wires between the two termini of the telegraphic line.
This suggestion of Ampère is doubtless the parent of all the attempts in Europe, both abortive and successful, for constructing an electric telegraph.
Under this head may be arranged the Baron Schilling’s at St. Petersburg, consisting of 36 magnetic needles, and upwards of 60 metallic conductors, and invented, it seems, at the same date with my electro magnetic telegraph, in the autumn of 1832. Under the same head comes that of professors Gauss and Weber, of Göttingen, in 1833, who simplified the plan by using but a single needle and a single circuit. Professor Wheatstone’s of London, invented in 1837, comes under the same category; he employs five needles and six conductors. Professor Steinheil’s, also invented in 1837, employs two needles and two conductors.
But there was another discovery, in the infancy of the science of electro magnetism, by Ampère and Arago, immediately consequent on that of Oersted, namely: the electro magnet, which none of the savants of Europe who have planned electric telegraphs ever thought of applying, until within two years past, for the purpose of signals. My telegraph is essentially based on this latter discovery.
Supposing my telegraph to be based on the same principle with the European electric telegraphs, which it is not, mine, having been invented in 1832, would still have the precedence, by some months at least, of Gauss and Weber’s, to whom Steinheil gives the credit of being the first to simplify and make practicable the electric telegraph. But when it is considered that all the European telegraphs make use of the deflection of the needle to accomplish their results, and that none use the attractive power of the electro magnet to write in legible characters, I think I can claim, without injustice to others, to be the first inventor of the electro magnet telegraph.
In 1839, I visited London, on my return from France, and through the polite solicitations of the Earl of Lincoln, showed and explained its operation at his house, on the 19th of March, 1839, to a large company which he had expressly invited for the purpose, composed of Lords of the Admiralty, members of the Royal Society, and members of both Houses of Parliament.
Professor Wheatstone has announced that he has recently (in 1840) also invented and patented an electro magnetic telegraph, differing altogether from his invention of 1837, which he calls his magnetic needle telegraph. His is, therefore, the first European electro magnetic telegraph, and was invented, as is perceived, eight years subsequent to mine, and one year after my telegraph was exhibited in the public manner described at the Earl of Lincoln’s residence in London.