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.