How did William Smiths map change the world?
I think the two crucial words here are “predict” and “extrapolate.” Once you knew what was on the surface of the earth and you could identify different rocks in different places as being the same rocks—because you knew what fossils were in them—then you could follow the precepts Smith laid down and begin to extrapolate the way those rocks disappeared under and curved and wiggled about below the surface of the earth. And once you could do that you could then predict, with great accuracy (obviously the accuracy increasing as the sophistication of your mapping increased), what mineral resources you would find under the surface of the earth; the coal, the gas, the oil, the uranium, the gold, and whatever else. So in a heartbeat, really, nations were suddenly able to realize and then to exploit what lay beneath them. Up to that point, up to 1815, you really only managed to scratch the surface, almost literally, of the earth. You saw coal outcropping; you saw gold glinting in the hills. You
