rockers underneath; the bottom board is made a little narrower; the sides on the upper edge from the middle backwards, are bevelled off two or three inches, and the same is done forwards so that the board, when looked upon from the side, presents an irregular hexagon; at the head part of the machine, on the upper edges of the boards, rests a box of boards, called a sieve or riddle, from three to five inches high, with a tin or sheet-iron perforated bottom; it is fixed, sometimes, in a manner to be taken out when necessary, sometimes on hinges to be thrown backwards when it is necessary to throw away the washed stones. The head part of the machine is well boarded; at the opposite extremity a board is likewise placed, the upper half of which is cut out in the shape of a cresent, leaving about three or four inches at the bottom of it; this opening serves for a passage of dirt, stones and water that are thrown in at the head into the sieve. It has also one or two bars or cleets across the bottom board at the distance of a foot each, and about three inches high. The perforations of the sieve or riddle are sometimes triangular, whose base and sides are about an inch, sometimes they are circular, of the diameter of about three-quarters of an inch. Under the riddle, in the interior of the machine, a board inclined diagonally and backwards is fixed, leaving however a sufficient space at the lower edge of it for the passage of the stones, dirt and water; it is called by the miners an apron or screen; the object of it is to throw back the water that it may cover the whole bottom equally and run an even current. In the bottom board, about the centre of it, there is a hole an inch in diameter, made back and close to the first and second cleet, if there be but two of them, which is well stopped and opened only when it becomes necessary to take out the residue, dirt and gold, to separate the latter from the former by washing it in a tin pan, which should be of the size of milk pans used in the States. The tin pans are to be got at San Francisco at from three to four dollars, or in the mines at the trading posts for the double amount. The machines can be got at these posts by paying from two to four ounces; but it is so easily made that any one himself can make it and save the money. If put together by means of screws rather than nails, it could be taken apart and conveniently carried about when necessary. The machine requires also a piece of strong wood of from two to three feet long, to be firmly fixed to both sides across the box to be used as a handle for rocking. To work these machines, in some places, as on the banks of rivers, two persons only are required; while in dry diggings where water and gold dirt are not so conveniently situated, it requires three or four persons to do the same work; one to work the machine, another to dip and throw water on it, a third to carry dirt, and the fourth to dig it; or two to dig and carry, and two to wash dirt.