When Warren Buffett and William H. Gates III, the two richest men in America, walk into the New York Public Library this morning, they will pass by the oil paintings and marble panels that carry the names of those who created the library, whose full corporate name is The New York Public Library, Astor, Lenox and Tilden Foundations. John Jacob Astor, James Lenox, and Samuel Tilden would no doubt be smiling to know that the first thing the Sages of Omaha and Seattle did after announcing what looks to be the largest philanthropic transfer of wealth in history was to meet in New York at an institution that is one of the great successes of private philanthropy.