Oil! by Upton Sinclair

Far down in the ground, underneath the Ross-Bankside No. 1, a great block of steel was turning round and round. The under surface of it had blunt steel teeth, like a nutmeg-grater; on top of it rested a couple of thousand feet of steel tubing, the "drill-stem," a weight of twenty tons pressing it down; so, as it turned, it ate into the solid rock, grinding it to powder. It worked in the midst of a river of thin mud, which was driven down through the center of the hollow tubing, and came up again between the outside of the tubing and the earth. The river of mud served three purposes: it kept the bit and the drill-stem from heating; it carried away the ground-up rock; and as it came up on the outside of the drill-stem, it was pressed against the walls of the hole, and made a plaster to keep the walls rigid, so that they did not press in upon the drill-stem. Up on the top of the ground was a "sump-hole," of mud and water, and a machine to keep up the mixture; there were "mud-hogs," snorting and puffing, which forced it down inside the stem under a pressure of 250 pounds to the square inch. Drilling was always a dirty business; you swam in pale grey mud until the well came in, and after that you slid in oil.

Also it was an expensive business. To turn those twenty tons of steel tubing, getting heavier every day as they got longer -- that took real power, you want to know. When the big steam engine started pulling on the chain, and the steel gears started their racket, Bunny would stand and listen, delighted. Some engine, that! Fifty horsepower, the cathead-man would say; and you would imagine fifty horses harnessed to an old-fashioned turntable with a pole, such as our ancestors employed to draw up water from a well, or to run a primitive threshing-machine.