Makers of Electricity

by Brother Potamian; James J. Walsh

Like all interested in the enterprise, Thomson was greatly shocked when the news reached him that signals could no longer be transmitted through the cable, which, after costing so much money, so much thought and labor, now lay a useless thing in two and a half miles of water. Attempts were made to raise it, but without success.

During its short life of less than a month, 366 messages were flashed through the cable, aggregating 4359 words of 21,421 letters.

The failure of the pioneer cable has been attributed to a variety of causes, chief of which were defective construction and imperfect paying-out machinery, which produced unequal strains in the cable. Defective as the cable was at the moment of immersion, the various troubles became intensified with time, until at last, when provoked by the feebleness of the signals, the injudicious electrician at Valentia had recourse to the great penetrative power of the induction coil, and gave the dying cable the coup de grâce.

An experiment made by Mr. Latimer Clark is not only germane to the subject, but is also of very great interest. Writing from Valentia on Sept. 12th, 1866, Mr. Latimer Clark says: "With a single galvanic cell, composed of a few drops of acid in a silver thimble[36] and a fragment of zinc, weighing a grain or two, conversation may easily, though slowly, be carried on through one of the cables (1865, 1866) or through the two joined together at Newfoundland; and although in the latter case, the spark, twice traversing the breadth of the Atlantic, has to pass through 3700 miles of cable, its effects at the receiving end are visible in the galvanometer in a little more than a second after contact is made with the battery. The deflections are not of a dubious character, but full and long, the spot of light traversing freely a space of 12 in. or 13 in. on the scale; and it is manifest that a battery many times smaller would suffice to produce similar effects."

Not to be outdone by the English electrician, Mr. William Dickerson devised the gun-cap cell, which he used in 1866 with success in transmitting signals from Heart's Content, Newfoundland, to Valentia on the Irish coast.

A piece of No. 16 bare copper wire was procured, one end of which was firmly twisted around the head of an empty percussion-cap. To one end of another similar length of wire was bound, with fine copper wire, a short strip of zinc bent at a right angle to form the anode element of the diminutive cell. After charging the cell with a drop of acidulated water of the size of an ordinary well-formed tear, and properly connecting the terminals with earth and cable, signals were transmitted over the cable by the infinitesimal current generated by this novel cell. The receiving operator reported that the signals were "awfully small"; but they were intelligible, and messages were successfully transmitted under the ocean by this tiny element.

Contrast with this Lilliputian cell the enormous power that was used on the cable of 1858 toward the end of its short existence, when batteries of 380 and 420 Daniell cells were employed to force signals across.

When, in 1865, it was decided to make another attempt at laying a cable under the Atlantic, Prof. Thomson, whose reputation was enhanced during the seven intervening years by a number of communications on the theory and practice of submarine telegraphy, was again retained as scientific expert in a consultative sense, with Mr. Cromwell F. Varley as chief electrician. In accordance with the costly experience that had been gained, a new cable was made and coiled on board the Great Eastern,[37] a leviathan which was well fitted for the work by the great manœuvring power afforded by its screw and paddles combined. Leaving Valentia, the big ship steamed with her prow to the west at a slow rate of speed, in order to give the cable time to sink beneath the waves and adapt itself to the configuration of the ocean floor. Eleven hundred miles had been successfully paid out when, to the consternation of all, the cable suddenly snapped and disappeared in more than two miles of water. Attempts were made during the next nine days to recover it from those abysmal depths; and, though grappled many times during those trying hours, it gave way each time under the strain to which it was subjected. Like its predecessors of 1857 and 1858, the cable of 1865 was finally abandoned to its fate, and the Great Eastern returned home with three greatly disappointed men on board, viz., Prof. Thomson, Mr. C. F. Varley and Captain (later Sir James) Anderson.

In the following year, a sum of three-quarters of a million sterling, nearly $4,000,000, was offered to the Directors of the "Telegraph Construction Company" if they would complete the cable of 1865 and lay a new one. After consultation and careful consideration, the offer was accepted and the cable constructed according to the best engineering knowledge available.

In 1866, Prof. Thomson was again on board the Great Eastern with Captain Anderson; and this time the big ship had snugly coiled up in her deep, cavernous tanks the cable that was destined to put Europe and America in permanent telegraphic communication. With a well-manufactured cable, improved paying-out machinery and an experienced staff of mechanical engineers, not to mention the foremost electricians of the day, the immersion of the cable was successfully effected, after which the American end of the cable of 1865 was raised, a new length spliced on, and the shore-end safely landed in Trinity Bay. Europe and America were thus united together by two electric bonds.