At the beginning of the third session I ventured a remonstrance, saying that it was a historical, and not a legal, question; that it could not possibly be settled by legal argument; that the first thing to know was why the clause was inserted in the treaty, and that the next thing was to find, from the whole history leading up to it, who those "other persons" thus vaguely referred to and left by the Spaniards to the tender mercies of the Dutch might be; and I insisted that this, being a historical question, must be solved by historical experts. The commission acknowledged the justice of this; and on my nomination we called to our aid Mr. George Lincoln Burr, professor of history in Cornell University. It is not at all the very close friendship which has existed for so many years between us which prompts the assertion that, of all historical scholars I have ever known, he is among the very foremost, by his powers of research, his tenacity of memory, his almost preternatural accuracy, his ability to keep the whole field of investigation in his mind, and his fidelity to truth and justice. He was set at the problem, and given access to the libraries of Congress and of the State Department, as also to the large collections of books and maps which had been placed at the disposal of the commission. Of these the most important were those of Harvard University and the University of Wisconsin. Curious as it may seem, this latter institution, far in the interior of our country, possesses a large and most valuable collection of maps relating to the colonization history of South America. Within two weeks Professor Burr reported, and never did a report give more satisfaction. He had unraveled, historically, the whole mystery, and found that, the government of Brazil having played false to both Spaniards and Dutch, Spain had allowed the Netherlands to take vengeance for the vexations of both. We also had the exceedingly valuable services, as to maps and early colonization history, of Mr. Justin Winsor, librarian of Harvard University, eminent both as historian and geographer, and of Professor Jameson of Brown University, who had also distinguished himself in these fields. Besides these, Mr. Marcus Baker of the United States Coast Survey aided us, from day to day, in mapping out any territories that we wished especially to study.