Tlwirsiminw of the gear is of Tapanui black pine.- Bxß. : A descrip tion of. the gear, which contains one or two improvements suggested by experi ence, may not prove uninteresting. On the top of the shaft there is a small pinion working into a spur wheel fixed in an upright intermediate shaft, at the bottom of which it is fitted into a spur wheel. The spur is fixed to a horizontal intermediate at the end of which is another spur working into another similar wheel below, which im parts motion to the cam shafts. The water supplying the wheel is conveyed from a dam at the top of the hill by wrought iron pipes, 17 inches in diameter at the top, decreasing till at the bottom they are only' 7£ inches. The water passes into a cast iroi cistern, which forms the seat for the wheel, at the top of which there is a stop valve, which enables the machine to be stopped instan taneously without its being necessary to cut off the water at the dam. After passing from the turbine, the water is carried on to and used for the ripple tables. About a head of water suffices for the whole work of the machine. As previously mentioned, the stone is sup plied to the machinery by a self-feeding apparatus, and it is carried from the mine on a self-acting tramway. When the stone is broken out, it is filled into trucks which are run out on a level tram way 7 chains in length Their contents are then emptied into a hopper situated at. the top of the self-jicting tramway, which is on an inclined plain with a gradient of lin 4J. This hopper fills a truck which is worked with a wire rope passing round a cast iron drum, fitted with a self noting brake. It runs down the tramway until it comes to the hopper at the machine ; just pre vious to reaching, which it goes on a level platform. The weight of the loaded truck tips up this platform, and when it arrives at a certain position the door of the truck opens, and its contents fall into the hopper. The loaded trucks iv their progress down pull up the empty ones. 