As mining operations became more complex, the long tom and the sluice came into widespread use. The long tom was a shallow trough 15 feet long and 15 inches high and often increasing in width near the low end and through which a constant stream of water ran. A miner would toss in ore and it would wash down through a sieve tacked across the top, called a riddle, where the rocks and stones could be easily picked out but the fine particles would pass through and fall into a shallow box with cleats, much like the rocker, where the gold dust was collected.
The sluice was a larger variation on the long tom, often as wide as 20 feet. At some point along the sluice was a grate of iron bars called a grizzly that worked to collect the large stones just as the riddle in the long tom did. Several sluices, one running into another, were often used to further refine the ore and even old tailings from the days of the rocker were known to produce a good wage when reprocessed. The Chinese, often barred from the more productive claims, were famous for making older diggings pay off this way.
The use of a long tom or sluice to refine gold from the ore bearing soil required a constant stream of water. Men would dig ditches to divert a stream. They built dams and flumes, sometimes transporting water great distances to where it was needed. One common method of moving water was a wheel, much like the paddlewheel of a riverboat that was connected to a series of buckets on a belt or to a pump. In river mining operations where the stream was diverted so the bed could be mined waterwheels were common and often placed as close to one another as possible.
I see. So this is how they gather and collect gold before. I wonder what methods they use now that there are better equipments and advanced technology. Perhaps they have maintained some of the methods but only somehow refined it for faster and more systematic collection.
They still mine placer gold much the same way, Justin, only they use modern sluice boxes that work a little better. In some parts if the world they still use mercury, otherwise known as quicksilver to separate the gold. It works well but it’s a terrible hazard to the environment.
wow.