The boring of this well by the Messrs. Mulot occupied seven years, one month, twenty-six days, to the depth of 1794-1/2 English feet, or 194-1/2 feet below the depth at which M. Elie de Beaumont foretold that water would be found. The sound, or borer, weighed 20,000 lb., and was treble the height of that of the dome of the Hospital des Invalides, at Paris. In May, 1837, when the bore had reached 1246 feet 8 inches, the great chisel and 262 feet of rods fell to the bottom; and, although these weighed five tons, M. Mulot tapped a screw on the head of the rods, and thus, connecting another length to them, after fifteen months' labour, drew up the chisel! On another occasion, this chisel having been raised with great force, sunk at one stroke 85 feet 3 inches into the chalk!^[7]