On board the ship Sully, in which Morse sailed from Havre to New York, in the autumn of 1832, the recent discovery in France of the means of obtaining an electric spark from a magnet was a favorite topic of conversation among the passengers, and it was during the voyage that Morse conceived the idea of an electro-magnetic and chemical recording telegraph. Before he reached New York he had made drawings and specifications of his conception, which he exhibited to his fellow passengers. Few great inventions that have made their authors immortal were so completely grasped at inception as this. Morse was accustomed to keep small note-books in which to make records of his work, and scores of these books are still in existence. As he sat upon the deck of the Sully, one night after dinner, he drew from his pocket one of these books and began to make marks, to represent letters and figures to be produced by electricity at a distance. The mechanism by which the results were to be reached was wrought out by slow and laborious thought, but the vision as a whole was clear. The current of electricity passed instantaneously to any distance along a wire, but the current being interrupted, a spark appeared. This spark represented one sign; its absence another; the time of its absence still another. Here are three signs to be combined into the representation of figures or letters. They can be made to form an alphabet. Words may thus be indicated. A telegraph, an instrument to record at a distance, will result. Continents shall be crossed. This great and wide sea shall be no barrier. "If it will go ten miles without stopping," he said, "I can make it go around the globe." He worked incessantly all that next day and could not sleep at night in his berth. In a few days he submitted some rough drafts of his invention to William C. Rives, of Virginia, who was returning from Paris, where he had been minister of the United States. Mr. Rives suggested various difficulties, over which Morse spent several sleepless nights, announcing in the morning at breakfast-table the new devices by which he proposed to accomplish the task before him. He exhibited a drawing of the instrument which he said would do the work, and so completely had he mastered all the details that five years afterward, when a model of this instrument was constructed, it was instantly recognized as the one he had devised and drawn in his sketch-book and exhibited to his fellow passengers on the ship. In view of subsequent claims made by a fellow passenger to the honor of having suggested the telegraph, these details are interesting and important. [Illustration: The First Telegraphic Instrument, as Exhibited in 1837 by Morse.]