The sinking of mine shafts in certain Belgian and French basins, where the coal deposit is covered with thick strata of watery earth, has from all times been considered as the most troublesome and delicate, and often the most difficult operation, of the miner's art. Of the few modern processes that have been employed for this purpose, that of Messrs. Kind and Chaudron has been found most satisfactory, although it leaves much to be desired where it is a question of traversing moving sand. An interesting modification of this well-known process has recently been described by Mr. E. Chavatte, in the Bulletin de la Societe Industrielle du Nord de la France. Two years ago the author had to sink a working shaft at Quievrechain, 111 feet of which was to traverse a mass of moving and flowing sand, inconsistent earth, gravel, and marls, and proceeded as follows: He first put down two beams, A B (Pl. 1, Figs. 2, 3, and 9), each 82 feet in length and of 20x20 inch section in the center, and upon these placed two others, E F, of 16x16 inch section. Beneath the two first were inserted six joists, _c c c c c c_, about 82 feet in length and of 14 or 16 inch section in the center. Finally these were strengthened at their extremities with two others, _d d_, about 82 feet in length. All these timbers, having been connected by tie bands and bolts, constituted a rigid structure that covered a surface of nearly seven hundred square yards. From the beams, A B and E F, there was suspended a red fir frame by means of thirty-four iron rods. Upon this frame, which was entirely immersed in the moving sand, there was established brick masonry (Figs. 1, 2, and 3). As the ends of the timbers entered the latter, and were connected by 11/2 inch bolts, they concurred in making the entire affair perfectly solid. The frame, K K, was provided with an oaken ring, which was affixed to it with bolts. After this, a cast iron tubbing, having a cutting edge, and being composed of rings 3.28 feet wide and made of six segments, was lowered. This tubbing was perfectly tight, all the surfaces of the joints having been made even and provided with strips of lead one-tenth of an inch thick. It weighed 4,000 pounds to the running foot. [Illustration: FIG. 1.--Section through A B. FIG. 2.--Plan. FIG. 3.--Section through C D. FIG. 5.--Section through E F of Fig. 4. FIGS. 6 AND 7.--Work Prepared and finished. FIG. 10.--Section through A B and C D of Fig. 12. FIGS. 11 6 AND 12.--Arrangement of jack-screw. FIG. 13.--Section through A B and C D of Fig. 11. PLATE I.--SINKING A MINE SHAFT.]