The squadron sailed from Plymouth on the 10th of June.  The weather was favorable for the first two or three clays of the voyage, but on the 13th a severe gale set in, which lasted for over a week, and came near causing the “Agamemnon” to founder beneath her immense load, a portion of which broke loose in her hold.  All the vessels succeeded in weathering the storm, however, and on the 25th reached the rendezvous in mid-ocean.  The next day the splice was made, and the ships set out for their respective destinations.  Before they had gone three miles the machinery of the “Niagara” caught the cable and broke it.  A second splice was made, but when each ship had paid out about forty miles, the electric current suddenly ceased.  The cable was cut promptly, and the two vessels at once returned to the rendezvous, where they rejoined each other on the 28th.  A comparison of the logs of the two ships “showed the painful and mysterious fact that at the same second of time each vessel discovered that a total fracture had taken place, at a distance of certainly not less than ten miles from each ship, in fact, as well as can be judged, at the bottom of the ocean.”  A third splice was made without delay, and the two ships again set out for the opposite shores of the Atlantic.  This time about two hundred miles of the cable were successfully laid, when it parted about twenty feet from the stern of the “Agamemnon.”  The “Niagara,” being unable to communicate with the English frigate, bore away for Queenstown, where she was joined a few days later by the “Agamemnon.”

This second failure greatly disheartened the directors, and it required all Mr. Field’s persuasiveness to induce them to sanction another attempt.  Yet he prevailed, and, hastening from London to Queenstown, sailed with the telegraph fleet on the third attempt to lay the cable, leaving Queenstown on the 17th of July.  The rendezvous was reached on the 28th, and on the 29th the splice was made; and the “Niagara” and “Agamemnon” parted company.  This time the undertaking was successful.  The cable was laid across the Atlantic, the “Niagara” reaching Trinity Bay, Newfoundland, on the 5th of August, and the “Agamemnon” arriving at Valentia, Ireland, a few hours later on the same day.  Signals were sent across the entire length of the line, from shore to shore, with ease and rapidity, and nothing occurred to mar the success of the mighty undertaking.

The successful laying of the cable was hailed with the liveliest joy on both sides of the Atlantic, and those who had participated in it were regarded as heroes.  But great as was the achievement, it was not destined to be a lasting success.  After working for four weeks, the electric current suddenly ceased on the 1st of September.  It never worked perfectly at any period of its existence, but it did transmit a number of messages with intelligibleness, and thus put an end to all doubt in the minds of the scientific men of the expedition of the feasibility of laying a successful line across the ocean.