Where To Dig

Sometimes it's easy. Sometimes there's a copper deposit, or a silver or even a gold deposit, right there on the surface of the soil, staring you in the face. If you can see something like that, well, go ahead and dig. Dig even if your deposit is in an inconvenient place - say, on the side of a cliff, on a very tall mountain, or in the middle of a big plateau with no water or people anywhere close.

But most of the time it isn't so easy, and when you go prospecting, there isn't a sure chance of finding anything. In that case, you can fall back on some very human advice: Start digging somewhere that you wouldn't mind staying for a while. You're going to need water, wood (for shelter and also, if you do find something, for your underground structures), and settlements near. Water can be piped in, of course, but if there are no settlements nearby, you'll have trouble keeping your workmen happy and they'll go somewhere else.

So, the recommendation is a forest, or a medium-sized mountain, not too far away from town.

Agricola didn't know about that most ubiquitous of metals in our modern age, aluminum. He gives instructions for extracting compounds that contain aluminum (alum and cimolite, a valued clayey substance), but he never knew there was metal locked up in these compounds. In this case, the reader knows more than the writer did.

Investment Advice

You probably haven't gone into mining just for the fun of it, or even just for the common good. Probably, you intended to get rich. Agricola provides some sage advice for how to do that without risking too much of your own capital.

First, he notes that there are some ways of mining that can be done without any capital outlay at all - he's talking about panning gold or tin ore from river beds, or something called trench prospecting. But if you want to explore deeper into the earth, there gets to be more and more risk that you will spend a lot of money and time getting rights to land and digging a big hole, only to find that there's nothing there.

Xenophon advocated having each of ten tribes go digging with the understanding that they would share whatever was found. You'd probably hit some sort of metal deposit in four tries out of the ten. By Agricola's time society had become too complex for that. Mining was more likely either a State enterprise, or undertaken by a private individual with money to invest. But share purchase arrangements also existed, and Agricola provides suggestions for getting the most out of these.

He recommends that one purchase a mixture of high-priced and low-priced shares. These would represent mines that are already productive (the high priced ones), and mines that are not yet productive (unknowns, thus lower priced shares). Some people buy low, then sell at the first sign of an increase, but Agricola recommends that you hold your shares. Many mines are productive for a long time, and they can be valuable even when apparently used-up.

The mining art is complex, and no one understands all of it. So, a successful mine owner needs to delegate, and also needs to know what's going on by living there or at least in the neighborhood, and visiting often.