The cradle begat Long Tom and Broad Tom, the 'tom' proper being the upper box with a grating to keep out the pebbles. 'Long Tom's' body is a wooden trough, from twelve to fourteen feet long by a foot or a foot and a half broad, with ripples, riffles, or cross-bars. There is usually another grating at the lower end to intercept the smaller stones. The machine is fixed in a gently sloping position, at an angle determined by circumstances; the wash-dirt is lifted into the upper end by manual labour; when stiff it must be stirred or shovelled, and a stream of water does the rest. The greater gravity of the gold causes it to be arrested by the riffles. Instead of the bars grooves may be cut and filled with quicksilver. When the sludge is very rich, rough cloths rubbed with mercury, or even sheepskins, the lineal descendants of the Golden Fleece, may be used, 'Broad Tom,' _alias_ the 'Victoria Jenny Lind,' is made about half the length of its long brother: the upper end is only a foot wide, broadening out to three below. 'Tom' begat the sluice, which is of two kinds, natural and artificial. The former is a ditch cut in the floor, with a _talus_ of one to forty or fifty. The bottom, which would soon wear away, is revetted with rough planks and paved with hard stones, weighing ten to twenty pounds, the grain being placed vertically. With a full head of water 400 cubic yards a day can easily be washed. The gold, as usual, gravitates through the chinks to the bottom, and finally is cradled or panned out. It is most efficiently treated when the sluice is long; it demands six times more water than the artificial article, but it wants less manual labour. This last property should recommend it to the Gold Coast. Here, I repeat, machinery must be used as much and manual labour as little as possible. The artificial or portable box-sluice is a series of troughs each about twelve feet long, like the upper compartment of 'Long Tom.' They are made of half-inch boards, rough from the saw, the lower end being smaller to fit into its prolongation. Each compartment is provided with a loose metal bottom pierced with holes to admit the dust; the true bottom below it has cross-riffles, and above it are bars or gratings to catch the coarser stones. These sluices are mounted on trestles, and the latter are disposed upon a slope determined by the quantity of water: the average fall or grade may be 1 to 50. In Australia four men filling a 'Long Tom,' or raised box-sluice, will remove and wash twenty-four cubic yards of ground per day. When the ore is fine, mercury may be dropped into the upper end of the sluice; and it picks up the particles, 'tailing,' as it goes, before the two metals have run far down. Both stop at the first riffle or resting-place.