SEC. 4. The corporation or association aforesaid shall, within six months after the approval of this ordinance by the mayor, file its written acceptance thereof with the city register, and make its selection of the park to be used as aforesaid; and said corporation or association shall also, within the same time, file its bond in the sum of one hundred thousand dollars, with good and sufficient sureties, to be approved by the mayor and council, conditioned for a full compliance with and performance of all the terms, requirements, and conditions of this ordinance. Said board of public improvements shall have the right, however, at any time before the opening of said fair or exposition, if it deems it necessary in the interest of the city, to require an additional bond in such amount as it may believe to be proper, whereupon said corporation or company shall give such bond with sureties to be approved in like manner, and said corporation or association shall have no authority to open or hold any fair or exposition upon the site so selected, and no machinery or improvements of any kind shall be removed from the premises of said world's fair site until said bond in the sum so demanded shall have been so filed and approved. Approved May 16, 1901. Considerable correspondence ensued between the Commission and the Exposition Company in reference to the proposed site, the Commission particularly insisting upon an adequate water supply and proper drainage and grading of the property. On June 28, 1901, the site was formally approved by the Commission and, according to section 9 of the act authorizing the exposition, the President of the United States was duly notified. Prior to August 15, 1901, the National Commission having ascertained that due provision had been made for grounds and buildings for the uses contemplated by the act of Congress, so certified to the President of the United States, who did thereafter, to wit, on the 20th day of August, 1901, in behalf of the Government and the people, invite foreign nations to take part in said exposition, and to appoint representatives thereto, the President's proclamation reading as follows: Whereas notice has been given me by the Louisiana Purchase Exposition Commission, in accordance with the provisions of section 9 of the act of Congress, approved March 3, 1901, entitled "An act to provide for celebrating the one hundredth anniversary of the purchase of the Louisiana Territory by the United States by holding an international exhibition of arts, industries, manufactures, and the products of the soil, mine, forest, and sea in the city of St. Louis, in the State of Missouri," that provision has been made for grounds and buildings for the uses provided for in the said act of Congress: