purpose than any I have better for this seen, it having a two-fold principle, viz. first, that of making a perpendicular draft, and discharging the load at the same time (without any intermediate space); and, secondly, raising the same a sufficient height, so as to place the article in a cart, or other carriage, for conveyance. I leave the merit of the plan to the judgment of the Society, and shall be pleased with such encouragement as they may award. Description of Mr. Thomas Gent's Crane. Plate VII. Fig. 1 and 2. A. The crane, three feet in length from the centre B. B. The centre, upon which it turns under the cross-beam. C. The quadrant, two feet eight inches in length from the centre B. D, A chain, which works upon the quadrant, and communicates with the roller E, on which is a toothed wheel put in motion by a small pinion on the axis of the winch-handle F. G. A rope, which passes over the. pulley H at the end of the crane. The weight to be raised is fastened to the block I, and is lifted up by the other end of the rope winding round the roller K. K. K. Is a roller, on which a toothed wheel is placed, and worked by a pinion fixed on the axis L, moved by the handle M. NN. Are catches, which are slided occasionally into the teeth of the wheels on the rollers, to keep them stationary. O. The cross-beam of the machine, from which the crane is suspended underneath. PP. Two upright posts, which support the cross-beam. When a weight is to be lifted from within the shaft of a mine, over which the machine is to be placed, the pulley H should be drawn down, and the point of the quadrant C raised upright in a perpendicular line; then, by working the handle M, the weight is raised from within the shaft, until it clears the surface of the ground, at which period, by turning the handle F, the point of the quadrant quadrant C is brought gradually into an horizontal line, which projects the crane and weight so far from the shaft, as to allow a cart to be placed underneath to convey the article which has been thus raised. Fig. 2. shews the method by which the chain is connected with the roller. D. The same chain as in the former figure, but in a different point of view. E. The roller mentioned in the former figure. SS. A double cord, the two extremities of which are fastened at TV to the roller E, and joined to the lower end of the chain at W: this double cord serves to keep the chain regularly in the centre of the quadrant. The |