“Matter?—matter enough! The bottom has dropped out of the well!”
“Bottom dropped out of the well!” exclaimed the husband, beginning to become interested.
“Yes: the bottom has dropped out of the well, and I am not at all surprised—I am not one bit astonished! I knew when I saw the men putting the bottom in that well that it would never be of any account!”
The cause of the accident was simple enough. The well had been dug in the line of a tunnel advancing from a distant point below. The miners, all unconscious[unconscious] of the presence of the well, had drifted under it, and at no great distance below its bottom. Being without adequate support the bottom must soon have fallen out, of its own accord, but the sudden jar of the bucket on the surface of the water undoubtedly precipitated the event. A peculiar kind of clay is found in many places on the Comstock lode which is not a little curious on account of its creeping propensities. A stratum of this clay will be seen to crawl out into tunnels and other openings in a manner much resembling the action of the toy known as Pharaoh’s serpents.[serpents.] You are unable to see where it is coming from or what moves it, yet it is constantly crawling out into all the openings that reach it.
In places where drifts have been run into this clay it is necessary to keep one or two men constantly at work at cutting it away in order to keep the drifts open and passable. This is not owing to the slaking and swelling of the exposed surface, as in that case after a few removals of the surplus material a hole would be left, and there would be no more trouble. The whole body of the clay appears to be creeping. It has the almost imperceptible motion of the glacier, irresistibly advancing, crushing everything in the shape of timbers that may be placed before it. All that can then be done is to set men to work at cutting it off as fast as it comes out. The cause of this creeping is probably to be found in the pressure, of the superincumbent or surrounding strata of rock. Its motion is not unlike that seen in the straightening out of a piece of pith that has been compressed. There is a limit to this creeping power of the clay, but it is not reached till many feet have crept out into the drift, tunnel, shaft, or chamber, and have been cut off and removed. Its actions is so mysterious that some of the miners are ready to explain it by saying that the clay comes out and fills up the drifts because “Nature abhors a vacuum.”
If left to its course the clay would very soon close up the drift, as completely as if none had ever been made. Thousands of feet of drifts and tunnels in the mines are closed in this way.
In the Caledonia mine, American Flat, much trouble was experienced with this creeping clay. On one occasion a streak of it two or three feet in width continued to rise from the floor of a tunnel until over thirty feet had thus come up and been cut off. It is bad anywhere, but is most mischievous in the main shaft. For this reason mining men always seek a spot in which to put down such shafts, where they are likely to pass through solid “country-rock” to a great depth below surface. The sad experience of early days taught them this lesson. The clay is generally found within the wall of the vein. It abounds in the mines south of Gold Hill, about American Flat. The ordinary clay found next to the foot, and hanging walls in all mines is liable to swell—on account of the lime it contains—when exposed to atmospheric action, but after the pressure on the timbers has been eased by cutting[cutting] away behind them a few times, there is no more trouble.
The power of this swelling, slacking clay is immense. It crushes in, and splinters all the timbers that can be placed before it: it somewhat resembles the power exerted in the expansion and contraction of large masses of iron, as seen in iron bridges and similar structures. The following curious Comstock “find” may be of interest to some readers.
In working out the first or upper bonanza of the Ophir mine, there was brought to light a human skull of a very ancient and curious type. The skull was dug out where a drift was being run in the ore-body at a depth of about three hundred feet below the surface. It was brought out, and dumped with a car-load of ore, not being observed by the miners. United States District Judge A. W. Baldwin, since killed by a railroad accident in California, happened to be present when the car-load of ore was dumped. Seeing an object of peculiar shape roll toward his feet among the ore dumped from the car, the Judge picked it up, and found it to be a human skull of a peculiar form and thickly crusted over with sulphuret of silver. He carried it into town and presented it to Wm. Shepard, of the firm of Tinker & Shepard, who placed it in a cabinet of curiosities, where it still remains.
The skull attracted no attention outside of Virginia City until 1874, when, mention being made of it in the newspapers, the Academy of Sciences, of San Francisco, sent for it for the purpose of making a critical examination of it. While it was in San Francisco a plaster cast was made of it, and at a meeting of the Academy of Sciences, Dr. Blake exhibited the cast and spoke of it as follows: “There is in this skull a peculiarity that is seen in some of the ancient Peruvian skulls, namely, on interparietal bone. The general contour of the skull is of a very low type; the anterior portion is very slightly developed and receding; the hinder portion is largely developed. It bears a similarity to the skull of the carnivorous apes, the cavity for the lower jaw-bone being very deep and not allowing of any grinding motion of the jaws. The skull when found was covered with a metallic layer. It is of a different type from any that have been found, and belonged to a carnivorous man, who could walk easier on all fours than on two feet.” Several ancient Peruvian skulls were then produced in[in] order to show the interparietal bone.