Some months before the time with which this story opens, Brace Barlow left Mr. Dustin’s employ, and, much to Arthur’s dismay, became a “moonlighter.”
Now to understand what a “moonlighter” is, one must know at least as much as Arthur did about oil wells. They are holes about the size of an ordinary stove-pipe, bored, by means of immensely heavy iron drills, hundreds and sometimes thousands of feet into the earth, until they reach the layer of porous sandstone that holds the oil, just as a sponge holds water.
With the oil in this sandstone are vast quantities of gas, that exert an enormous pressure upon it; and the moment an opening is made to where it is, this gas forces the oil to the surface, often driving it forth in great spurts and fountain-like jets. Such a well is called a “gusher,” and from it the oil flows for days, weeks, and sometimes for years. After a while, however, the supply of oil or gas, or both, becomes exhausted, so that the stream no longer rises above the mouth of the well. Then a pump is used, and by means of it the oil is pumped up, just as water is from an ordinary well. But the supply of oil always decreases, until, by and by, the pump no longer brings it up in paying quantities.
For some years after the discovery of oil, these exhausted wells were abandoned, and their owners sunk new ones in other places. At length, however, a wise man who had studied the situation very carefully, concluded that if, by any means, the oil-bearing rock could be shattered for a considerable distance around the bottom of these old wells, the flow of oil might be increased, and it might again be produced from them in paying quantities. So he invented a torpedo that could be exploded at any required depth in a well. It was simply a long tin tube, closed at the lower end, and filled with nitro-glycerine. This is one of the most terrible explosives ever discovered; and though it is only ordinary sweet glycerine, such as is used for chapped faces and hands, mixed with nitric acid, it is ten times more powerful than gunpowder, and explodes upon receiving a very slight shock or blow.
A torpedo of this kind, lowered to the bottom of an oil well, and exploded by means of a sharp-pointed iron weight dropped upon it, shatters a large area of oil-bearing rock, and the oil or gas, comes rushing to the surface as when the well was first opened. This operation is called “shooting a well”; the lowering of a torpedo into position, a thousand feet or more below the surface of the earth, is called “placing a shot,” and the men who undertake this dangerous business are called “torpedo men” or “well-shooters.”