The programme of the Congress, as outlined in the previous pages, was in this case somewhat more than a mere programme. It not only invited to do a piece of work, but it sought to contribute to the work itself. Yet the chief work had to be done by others, and their part needed careful preparation. Yet very little of the preparation showed itself to the eyes of the larger public, and few were fully aware what a complex organization was growing up and how many persons of mark were coöperating. It was essential to find for every address the best man. Specialists only could suggest to the committees where to find him. It has been told before how our invitations were brought to the foreigners first till the desired number of foreign participants was secured, and how the Americans followed. As could not be otherwise expected, interferences of all kinds disturbed the ideal configuration of the first list of acceptances; substitutes had sometimes to be relied on; and yet, when on the nineteenth of September President Francis welcomed the Congress of Arts and Science in the gigantic Festival Hall of the St. Louis Exposition, the Committee knew that almost four hundred speakers had completed their manuscripts, and that it was a galaxy which far surpassed in importance that of any previous international congress. And the list of those who stood for the success of the work was not confined to the official speakers. Each Department and each Section had its own honorary President, who was also chosen by the consent of leading specialists and whose introductory remarks were to give additional importance to the gathering. At their side stood the hundred and thirty Secretaries, carefully chosen from among the productive scholars of the younger generation. And a large number of informal, yet officially invited contributors, had announced valuable discussions and addresses for almost every Section. Invitations to membership finally had been sent to the universities and scholarly societies of all countries.