process. This title will distinguish it from processes used on other fields. It is accomplished thus—the quartz, as it comes from the mine, is shovelled from time to time into a stamper box, in which usually work five stampers, of about eight cwts. each, at about seventy (70) strokes a minute. Water is conducted into the box to the amount of about eight (8) gallons per stamp per minute. The quantity of water varies according to the material operated upon, whether it be mullocky or not. A small quantity of quicksilver is poured into the box, to amalgamate the gold with which it may come in contact. In front of the box there is a perforated iron grating, through which the pulverised quartz, when fine enough, is forced by the impact of water caused by the continuous fall of the stamps. The constant outflow of crushed quartz and water from the stamp boxes is received on a table, having on it grooves or ripples, containing quicksilver and a large extent of amalgamated copper plates smoothly nailed on. This may be called the silver table; it catches a large proportion of the free or amalgamated gold which escapes from the battery. The flow then passes over blanket tables, which arrest mechanically all the heavier particles. The blankets are frequently washed in tanks, to remove the rich deposit on them. The blanket tailings thus produced are treated in large berdans with quicksilver, one berdan being allowed for five stamps. By this means a fair proportion of extra gold is extracted from them. Settling pits are provided beyond the blanket tables, so that, if deemed advisable, the tailings are saved for after treatment, or for sale to those who make it their special business to manipulate tailings. The entire battery is cleaned up at the end of each crushing, or once a week, if the crushing be continuous. All the amalgam from the stamp boxes, from the silver tables, and berdans are carefully cleaned and retorted in cast iron retorts, to separate the gold from the quicksilver. The spongy gold is then taken out, and sent to the bank for melting. Such is the usual process resorted to for private or public crushings; and the object of this paper is to criticise the modus operandi; to point out what I consider its errors, and to suggest a method of working which is likely to prove more profitable.

The engine-power required will vary according to circumstancea, such as weight of stamps, size and number of berdans, and the amount of water required to be pumped. If each stamp be not heavier than eight cwts., and there is a berdan of five feet in diameter to five stamps, and water is required to be raised, say 20 feet, for battery purposes, one and a half horse-power to each stamp will be about the required power. I have known engines working beyond that, but it was not considered profitable, as the speed became variable, and a larger proportion of coal was consumed in comparison to the steam-power obtained.

Stamp boxes are generally constructed to hold five stamps; they are of cast iron in one piece, are three inches thick at the bottom and an inch and a half to one inch at the sides. The bottoms and sides are protected from the corroding action of the stamps and quartz by cast iron dies and linings. The boxes have two hoppers behind for feeding, and two openings in front for the gratings, to screen the crushed quartz. It has been attempted to have grating openings behind the box as well, but found not to answer, there being greater trouble to regulate the flow of water over the two tables. This remark applies to side openings also. The stamp boxes used at present are excellent, the only improvement I can suggest in them is that the openings for the gratings, which are now made vertical, should have a forward inclination on the top. This, I think, would allow the crushed material to escape more freely.

The shoes of the stamps and dies in the boxes, as well as the linings, are at present made of comparatively soft iron. They should be made of the hardest white iron, and chilled. If battery proprietors took the trouble of sending to England for their shoes, dies, and linings, they would find it to their advantage, not so much in cost as the great saving in material and time lost in changing the different parts when worn out.

The cams for raising the stamps are very seldom of a proper shape; they are either too curved or too straight. They should be so constructed that the motion of the stamp be uniform, and, as soon as the stamp is raised to its greatest height, it should drop, and not for one moment before it is elevated for the next stroke. There is no trouble in constructing a cam with the necessary curve to do exactly as required, and, if so constructed, a battery may be driven up to 80 strokes a minute, without the risk of the discs striking the cams.

The screens or grates for sifting the crushed quartz usually used are perforated iron plates; the number of perforations are from 100 to 132 holes to a square inch, the greater the number the finer the holes. It is surprising how this kind has not been superseded by the iron wire grating, which is superior in many respects, especially in allowing more material to pass through in a given time, thus causing a great saving in cost of crushing; and I am further convinced more gold would also be saved, as, by the present use of quicksilver in the boxes, the amalgam formed is unnecessarily battered and converted into black and spongy amalgam, from being pulverised with base minerals. This sickened amalgam will pass over silver tables, blankets, and even the settling pits, and no device can save it. The silver tables are sometimes made in one plane, but generally in two or thee steps; the inclination is usually one in ten. The quicksilver ripples are three inches broad, three-eighths of an inch deep at the top, and half an