Boring was recommenced after about a month's labour in taking out the old tubings, leaving the new ones firmly bedded into the lias formation, 112 feet from the surface, and the hole was subsequently bored to a depth of 710 feet in the new red sandstone formation, proceeding at the rate of about 3 feet in the twelve hours, and leaving the hole so as, if requisite, it might be widened out to 4 inches diameter. Fig. 92 shows the action of the knife and spring-cutter when forced down into the tubing, ready to commence cutting. It also shows the lower end of the new tubing, enclosing the others at the commencement of the work. The joints of the new tubes were made by means of a half-lap screw. Fig. 94 is a back view of the knife or cutter _b_. Fig. 93 shows the action of the spring and cutter when the requisite length is cut through and ready for lifting; the position of the tube being maintained perpendicular, or nearly so, by the ball or thickening on the rods at K, and the lower end of the tube being supported by the projecting steel cutter at _b_, the dotted lines from _d_ showing the position of the new steel-ended tube when screwed down ready for another operation. In boring deeper after the tubes were removed, three wooden blocks were used round the rods in the new tube to keep them plumb. In some cases it is necessary to widen out holes below the sharp edge of tubing, so as to permit its descent. This is effected with a rimer, Figs. 81 and 82, and is an operation requiring great care and attention. To reduce the stoppages for the withdrawal of _débris_ the system of Fauvelle was introduced, but it is now very little practised on the Continent, and not at all in Great Britain. The principles upon which it was founded were: first, that the motion given to the tool in rotation was simply derived from the resistance that a rope would oppose to an effort of torsion; and therefore that the limits of application of the system were only such as would provide that the tool should be safely acted upon; and, secondly, that the injection of a current of water, descending through a central tube, should wash out the _débris_ created by the cutting tool at the bottom. The difficulties attending the removal of the _débris_ were great; and though the system of Fauvelle answered tolerably well when applied to shallow borings, it was found to be attended with such disadvantages when applied on a large scale, that it has been generally abandoned. The quantity of water required to keep the boring tool clear is a great objection to the introduction of this system, especially as in the majority of cases Artesian wells are sunk in such places as are deprived of the advantage of a large supply.