"Then let us try the other," said Morse. "If the current won't go underground, it may be coaxed to go above-ground." The plan suggested was to string the wire upon poles, insulating it from the wood by some non-conductor. A suitable insulator was needed. Cornell devised one; another inventor produced another. Morse approved of the latter, started for New York with it to make arrangements for its manufacture, and on his way met Professor Henry, who knew more about electricity than any other man in the country. Morse showed him the models of the two insulators, and indicated the one he had chosen. Mr. Henry examined them closely. "You are mistaken," he said. "That one won't work. This is the insulator you need." He pointed to Cornell's device. In a few words he gave his reasons. Morse saw that he was right. The Cornell insulator was chosen And now the work went forward with great rapidity. The planting of poles, and stringing of wires over a glass insulator at their tops, was an easy and rapid process. And more encouraging still, the thing worked to a charm. There was no trouble now in obtaining signals from the wire. The first public proof of the system was made on May 11, 1844. On that day the Whig National Convention, then in session at Baltimore, had nominated Henry Clay for the Presidency. The telegraph was being built from the Washington end, and was yet miles distant from Baltimore. The first railroad train from Baltimore carried passengers who were eager to tell the tidings to their Washington friends. But it carried also an agent of Professor Morse, who brought the news to the inventor at the unfinished end of the telegraph. From that point he sent it over the wire to Washington. It was successfully received at the Washington end, and never were human beings more surprised than were the train passengers on alighting at the capital city to find that they brought stale news, and that Clay's nomination was already known throughout Washington. It was the first public proof in America of the powers of the telegraph, and certainly a vital and convincing one. Before the 24th of May the telegraph line to Baltimore was completed, the tests successfully made, and all was ready for the public exhibition of its marvellous powers, which had been fixed for that day. Miss Ellsworth, in compliance with the inventor's promise, made her more than a year before, was given the privilege of choosing the first message to go over the magic wires. She selected the appropriate message from Scriptures: "What hath God wrought?" With these significant words began the reign of that marvellous invention which has wrought so wonderfully in binding the ends of the earth together and making one family of mankind.