The Evolution of Gold Mining
The methods of gathering gold changed rapidly as the 'easy pickings' disappeared. Tools were invented at a rapid rate as miners from all over sought new and more effective means of mining the ore. Here is a look at three basic stages in the evolution of gold mining.
The Early Days
Gold could be found loose in riverbeds. Miners would divert streams, sending smaller streams off to each side, leaving stream beds exposed. The dry days of summer and early fall were best as low water levels exposed stone areas where gold may have been hiding.
1 Placer mining
Land ownership became an issue as gold grew scarcer and the population grew. A miner could claim an area from 10 to 50 square feet as their own.
A piece of personal property signified claim.
This claim was filed with the camp's claim officer.
If not worked within a certain amount of time, it could be claimed by another miner.
Using shallow metal pans, miners mixed water with soil from the riverbed. By gently swirling in circular motion, the lighter soils washed away, leaving the gold.
Chileans, Sonorans from Mexico and Indians gently bounced dry soil on wool sarapes. Wind took the dried sand, leaving the heavier gold.
3 Crushing quartz
This and similar devices of Mexican origin were powered by mule, horse or man. Quartz was crushed between a heavy stone above and tightly fitted stones beneath. The pulverized soil was then processed through traditional mining techniques. Although effective, most Americans considered the process too slow.
4 The rocker or cradle
With one man to load water and soil and a second to rock it, this gold washing machine could process 200 bucketfuls per day.
It is set on sloping ground to allow water to run through it.
Wooden or metal spikes were fastened on the bottom level to catch heavier gold.
5 The long tom
With a two men, it is capable of handling 400-500 bucketfuls per man per day.
1. Miner shovels dirt into the long tom.
2. Another removes large rocks and keeps dirt moving through the trough and across an iron plate with holes in its bottom.
3. Sand and gold drops through holes.
4. Particles of gold lodge in the riffles of a lower box while sand washes away.
5. The final separation is done by panning.
Wooden flume widens at one end.
6 The waterwheel
A downward slope allowed water to run through it continuously.
Introduced by the Chinese, it could be placed in a bypass flume. The water- driven wheel powered various mining operations.
It powered the bailers needed to keep the working area dry.
Water and paydirt are lifted into the sluicing flume.
Although widely used, this method was not very profitable as gold deposits were more frequently found along river banks and bars than in the main river channel.
Into the Earth
Once the earth's surface had been picked clean, miners organized into larger camps and began digging deeper into the earth.
10 Quartz or hardrock mining
Shafts were sunk and large machinery was needed to remove the veins of gold from the quartz rock. Drilling could be done by hand or by compressed air-drill. Dynamite was placed into the holes created and detonated.
8 Hydraulic drills
A hole would be started using a drill bit. As the hole deepened, bits would be exchanged for progressively longer and narrower ones. Water was added to the hole to create a grinding compound and to help remove dirt and debris.
9 The stamp
Larger rocks removed from the mines were crushed by these machines.
Rock was fed from bins into dies at the base of the machine.
Heavy iron crushers called stamps rose and fell onto the rock.
Pulverized soil was then processed using traditional mining methods.
By 1858, only those with big machinery could effectively mine the hills. Individual miners and their small claims were replaced by large companies that worked large tracts of land, employing scores of men. Many of the miners moved on to newer diggings in such places as Pike's Peak in Colorado and Nevada's Comstock Lode.
10 Hydraulic mining
This method was developed to explore the soil of older, dried riverbeds and later, any available soil.
1. Riveted pipes guided water down from higher elevations. As the water travelled down, its pressure increased.
2. The water was channeled into iron nozzles called monitors.
3. By this time, the pressure was sufficient to blast away hillsides.
4. The monitors were systematically waved back and forth, boring into the land.
5. The soil would run down into a valley and a series of sluices where the silt and water would be separated through traditional mining techniques. The environmental effects of hydraulic mining
Water that was diverted to dry land created a boggy mud that destroyed habitats and flooded the land of farmers living downstream.
Sources: "The Great American Gold Rush" by Rhoda Blumberg, "The Gold Rush" by Liza Ketchum, "The California Gold Rush," published by American Heritage, "The California Gold Rush" by Elizabeth Van Steenwyk, "Hunting for Gold" by William Downie.
Researched and illustrated by Bee staff artist Sean McDade