Let us now see how the contract has been followed out. The grain market was built in 1767, upon the site of the hotel of Soissons. Of this, nothing was preserved but the astronomical tower of Catherine de Medicis, which still remains. The central part of the market left free was soon covered with a wooden framework, which was destroyed by fire in 1802. This was then replaced by the architect Brunet with an iron cupola covered with sheet copper. This market was designed for the reception of the grain and flour necessary to supply the city, but was soon supplanted by public granaries, and then by general stores. It afterward became a depot in which grain and flour brokers received merchandise from shippers in order to effect a sale of it. The abolition of the _factorat_ gave it its last blow. Let us examine the transformations made by Mr. Blondel in the old structure. He began by excavating under the entire extent of the market a basement 13 ft. in depth. The old foundations of the circular walls, which are more than 6 ft. thick, and which are extremely solid, extend to a depth of about 2½ ft. beneath the surface. The ceiling of the basement, in the annular part between the walls, is formed of large T iron girders, resting upon the circular walls. These support transverse girders, which, in turn, support the floor irons. The flooring of the hall is formed of ordinary floor irons, assembled upon large girders, which are supported here and there by cast iron columns. Under this flooring there is a second one, leaving a free space of about ten inches, in which will be placed the tubes serving for ventilation. To these pipes will be joined vertical ones debouching in the flooring of the hall. The old dome did not have apertures enough, and the skylight even was not transparent, and so the lighting of the hall was very defective. The mode of covering the dome was therefore completely modified. The copper was removed, and upon the old framework was laid a wooden framework, to which will be nailed laths designed to receive a slate roof. The slate will not extend to the summit of the dome, but will leave above it a spherical cap, which will be glazed, and through which the light will enter the hall in abundance. [Illustration: FIG. 2.--INTERNAL VIEW OF THE EXCHANGE.] In the basement will be installed the ventilating and heating apparatus. Another part of the basement will be occupied by the dynamo machines that are to furnish the electric light. Another part will receive the bake ovens that belong to the laboratory of the committee on grain and flour. The rest of the basement will be rented. The central part will probably be converted into a cold room for the preservation of early fruit and vegetables.