The right speed accumulates only the heavy materials and allows all of the lighter stuff to flow through. This optimum speed is dependent on the size of the gravel you need to move through the system.

There are three basic power sources for rock drills—electricity, gasoline and compressed air. Before we go into big pneumatic drills, we’ll start with a quick rundown of each.

With successively lower temperatures as the water mixture cools, new sets of minerals are formed and many of those stable at a higher degree of heat became subject to alteration as the temperature progressively moved lower.

In last month’s issue we covered the initial discovery of gold, the subsequent gold rush that occurred around Nome, some of the geology of the area and past production. We’ll conclude the article in this issue with a further examination of the geology and deposit types, discuss the resources...