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The New Zealand Railways Magazine, Volume 12, Issue 8 (November 1, 1937)

Gold-Mining in Central Otago

page 37

Gold-Mining in Central Otago

(S. A. Rockliff, photo.) Crossing the Manuherikia River, Otago Central Railway, South Island, New Zealand.

(S. A. Rockliff, photo.)
Crossing the Manuherikia River, Otago Central Railway, South Island, New Zealand.

How many city residents, reading with interest the fact that a rich strike of gold has been made at X, or that gold has attained its peak price, know just how that gleaming metal is won from the earth? Even many folk who tour through the gold districts know little of the process of gold-mining.

This article deals exclusively with mining in Otago Central. There are several rich fields in Central Otago, Naseby, Kyeburn Diggings, and Cromwell being centres of great activity. Where a company has the working, the claim is attacked by means of a dredge. The individual miner, however, has not the advantage of this large scale apparatus. He has the choice of three methods, his choice depending largely upon the nature of his claim, the amount of water he has at his disposal, and the general topography of the locality. He may sluice, cradle, or work with the shovel.

Let us examine each method in turn, taking first the shovel-method. This is the “hard-labour” method, and is used in flat areas. The necessary apparatus and requirements are: a “box,” shovel (and pick, sometimes), prospecting dish, and, last, water, without which the miner could not work. Before proceeding to describe the process, let me sketch the “box” and the prospecting dish. This latter is the miners' inseparable companion. The dish is an ordinary tin dish, very strongly made. The edge is rolled, and, an inch below the edge, for half the circumference, on the innerside, is a groove in the dish. The object of this will be revealed when we take a prospect (below).

The Box.

This consists of a bottom usually two and a-half feet by four feet. The two sides are about eight inches in height. The front is left open, while a board at the back, about six inches in height, forms the third side. Thus there is a bottom, two sides, a third side being only half (approximately) the height of the other two, the fourth side being open. There is no top. On the floor of the box is placed sacking, and on this, cocoanut matting. Perforated iron plates are next laid on, their edges resting on ledges on the sides. Thus there is a clearance between the plates and the mats.

(S. A. Rookhill, photo.) A goods train crossing Flat Stream Viaduct, Otago Central Railways, South Island, New Zealand.

(S. A. Rookhill, photo.)
A goods train crossing Flat Stream Viaduct, Otago Central Railways, South Island, New Zealand.

The box is now ready for work. This is used either for shovelling or sluicing.

Let us now find a spot, and set in our box.

Shovelling is done where the ground is fairly level. To find a suitable spot, we must take some prospects and decide whether they are sufficiently promising. We proceed to a likely spot (all miners are able to pick out likely spots). Most likely we shall be in the river-bed, or in a fairly wide gully. Knowledge of the behaviour of gold will cause us to take a prospect just where the bed widens, having come through a narrower part, or at the edge of the swifter part.

To Prospect

Gold deposited usually sinks to a “wash,” that is some conglomerate that will hold it. Silt will not hold it, so we dig a hole until we come to the “wash,” sometimes grey, sometimes yellow, sometimes blue. Twelve to eighteen inches in depth will suffice. We fill our dish with wash, and take it to the nearest stream. Here we carefully wash off all the stones and page 38 page 39 silt. The gold being the heaviest will sink to the bottom. Gold will not stay on wet surfaces, so it goes into the dish as we wash out the sand and stones. Careful washing leaves our prospect in the dish. According to the number and nature of the colours we decide whether it is a payable place.

So the prospector seeks until he finds a suitable place. No place is suitable unless it can be supplied with water, either by a race, or by river or stream or burn.

The first process is the setting-in of the box. The box is placed so that the water can flow over the iron plate. There must be sufficient fall in the situation for the water to wash out the silt and smaller rubble. Having set his box to his satisfaction, the miner sets to work in earnest. This is where the real shovelling comes in. He shovels the dirt and stones from his “paddock,” on to the iron plate. The water running over the plate washes the gold from the dirt; the gold sinks through the holes in the plate, on to the matting and sacking. The stones are removed from the plate when they are sufficiently washed. Thus he toils, removing yards of stone and silt, ever hoping for reward, ever thinking and talking in terms of “wash” and gold.


This method requires not such hard labour as does shovelling. Sluicing is adopted usually in areas where there is a face commanded by a water supply that will give an adequate pressure. There must be a slope or “fall” at the base, to allow the tailings and water to run off. The usual system adopted is to bring the water, by race, to a point above the claim. This water is brought to the required point by a hose with a nozzle attached. The water, forced through the nozzle and directed towards the face breaks down the wash, which is forced by the water (extra water flowing in from the race if required) down to and over the box. It is obvious that much more wash will be worked with the nozzle, and that it will be put through at a faster rate than by the manual method. The actual work required, after the preparatory work of race-making and setting-in, is in keeping the “tail-race” clear, and in keeping the nozzle directed. It is somewhat monotonous work in the winter (when one has the water) as actually the miner usually has to stand by the nozzle.

One ingenious miner suggested to me the building of a cage, large enough to sit in; a heater would be installed and hey presto! sluicing was a gentleman's job.


The method adopted by some miners, usually when water is short, is that of cradling. The principle is similar to that of the box. A cradle consists of a box (a kerosene case is about the size) in which is fitted, on angles set obliquely to the sides, layers covered with matting. An iron perforated plate is set in the top. A projecting handle allows the cradle to be “rocked.” The rubble is wheeled to the cradle in a barrow (if the “paddock” is not at the water) and put on to the iron plate. Water is poured over the rubble, from a cannister, the cradle being rocked during this process. The gold and silt are washed through the plate, on to the matting, and the tailings are removed. Thus it
(Thelma B. Kent., photo.) The Hurunui River Gorge, on the way to Lake Summer. South Island, New Zealand.

(Thelma B. Kent., photo.)
The Hurunui River Gorge, on the way to Lake Summer. South Island, New Zealand.

is apparent that this is the slowest method.


This is the most interesting part to the miner, because now he will see the result of his period of labour. A bath is filled with water, and the mats are carefully removed from the box. These mats, together with the silt on the floor of the box, are transferred to the bath. Here, the mats are beaten on the water, and the gold forced from the weaves. The resulting debris in the bottom of the bath is poured off into the prospecting dish, where it is panned, just as a prospect. More care, of course, is taken. The final course is one of choice, sometimes dependent on the nature of the

(Continued on page 42).

page 40