The structure is supported by cylindrical hollow iron uprights that are firmly connected with the ground as follows: At the places where they are to be fixed, small catches are inserted in the ground so that their upper surface comes flush therewith. These catches consist of two cast iron sides bolted together, and of a bottom and ends formed of flat iron--the end pieces being bent so as to form cramp irons. Each of the sides is provided internally with a projecting piece, and an inclined plane as a wedge. In case the catch becomes filled with dirt, it can be easily cleaned out with a scraper. The iron upright terminates in a malleable cast iron shoe, which is screwed on to it, and which is provided beneath with a projection in the form of a reversed T, the upper part of the horizontal branches of which is beveled off in a direction opposite that of the inclined planes of the catch. This projection enters through the slit and fits into the two wedges, and a simple blow of a hammer suffices to make the adherence perfect. The front and hind uprights differ only in length, and the roof timbers are joined at their upper extremities. The figures so well show how the parts are fitted together as to render an explanation unnecessary. The dimensions of these structures vary from 6.5 to 5.75 feet in length by 6.5 in width and 6 in height. The rafters are prolonged so as to project 4.25 feet in front, in order to form a protection for the purchaser. This part of the rafters, as well as the longitudinals, is supported by three curved iron braces, which are put in place as follows: The timbers are provided with a ring fixed by a screw, and one extremity of the brace is inserted into this, while the other is held against the upright by a sliding iron socket. The longitudinal timbers are supported between each two uprights by an iron rod that rests upon a block of stone fixed in the ground. The front ends of the rafters are connected by a longitudinal, 18 feet in length. The structure is covered with waterproof canvas held in place by wooden rods, to which it is attached. The wood employed is pitch pine. An entire market of 300 stalls can be put up in three hours by one workman and four assistants.--_Le Genie Civil._ [Illustration: THE MOVABLE MADELEINE FLOWER MARKET AT PARIS.] FIG. 1.--GENERAL VIEW OF A MOVABLE MARKET. FIG. 2.--SHOES. FIG. 3.--MODE OF JOINING THE ROOF TIMBERS. FIG. 4.--IRON SUPPORT. FIG. 5.--SECTION OF A SHOE INSERTED IN THE CATCH. FIG. 6.--CATCHES. FIG. 7.--WATERPROOF CANVAS.] * * * * * DINOCRATES' PROJECT.