In 1845, Alfred Vail compiled and published a "History of the American Electro-Magnetic Telegraph." In this work hardly any mention was made of the important discoveries of Professor Henry, and this caused that gentleman to take great offense, as he believed that Morse was the real author of the work, or had, at least, given Vail all the materials. As a matter of fact he had given Vail only his notes on European telegraphs and had not seen the proofs of the work, which was published while he was absent in Europe. As soon as Morse was made aware of Henry's feelings, he wrote to him regretting the omission and explaining his innocence in the matter, and he also draughted a letter, at Vail's request, which the latter copied and sent to Henry, stating that he, Vail, had been unable to obtain the particulars of Henry's discoveries, and that, if he had offended, he had done so innocently. Henry was an extremely sensitive man and he paid no attention to Vail's letter, and sent only a curt acknowledgment of the receipt of Morse's. However, at a meeting somewhat later, the misunderstanding seemed to be smoothed over, on the assurance that, in a second edition of Vail's work, due credit should be given to Henry, and that whenever Morse had the opportunity he would gladly accord to that eminent man the discoveries which were his. There never was a true second edition of Vail's book, but in 1847 a few more copies were struck off from the old plates and the date was, unfortunately, changed from 1845 to 1847. Henry, naturally, looked upon this as a second edition and his resentment grew. Morse's opportunity to do public honor to Henry came in 1848, when Professor Sears C. Walker, of the Coast Survey, published a report containing some remarks on the "Theory of Morse's Electro-Magnetic Telegraph." When Professor Walker submitted this report to Morse the latter said: "I have now the long-wished-for opportunity to do justice publicly to Henry's discovery bearing upon the telegraph. I should like to see him, however, previously, and learn definitely what he claims to have discovered. I will then prepare a paper to be appended and published as a note, if you see fit, to your Report." This paper was written by Morse and sent to Professor Walker with the request that it be submitted to Professor Henry for his revision, which was done, but it was not included in Professor Walker's report, and this naturally nettled Morse, who also had sensitive nerves, and so the breach was widened. In this paper, after giving a brief history of electric discoveries bearing on the telegraph, and of his own inventions, Morse sums up:--