which can be reached by shaft only; and, as the water cannot be discharged by gravity alone, it must necessarily, as part of the process of mining, be lifted to the surface by artificial means, and thence be discharged through the ordinary natural channels for the drainage of the country."

"We do not say that a case may not arise in which a stream, from such pollution, may not become a nuisance, and that the public interests as involved in the general health and well-being of the community may not require the abatement of that nuisance. This is not such a case; it is shown that the community in and around the city of Scranton, including the complainant, is supplied with abundant pure water from other sources; there is no complaint as to any injurious effects from the water to the general health; the community does not complain on any grounds. The plaintiff's grievance is for a mere personal inconvenience, and we are of opinion that mere private personal inconvenience, arising in this way and under such circumstances, must yield to the necessities of a great public industry, which, although in the hands of a private corporation, subserves a great public interest. To encourage the development of the great natural resources of a country, trifling inconveniences to particular persons must sometimes give way to the necessities of a great community."

Gallagher v. Kemmerer, 144, 509 (1891). In trespass for injury to plaintiff's lands, it was shown that refuse and waste from defendants' coal breaker, on their own lands, were carried down the stream, filled the bed thereof, overflowed, and accumulated upon plaintiff's bottomland, rendering the same unproductive and worthless. It was made to appear that a portion of the accumulated refuse, fouling the stream and injuring the plaintiff's land, had come from the coal breaker of another company operating independently, on their own lands, on the same stream, and above the coal works of the defendants.

The liability of the defendants sued began with their own act on their own land, and, being independent of the acts of the other operators, it was several when committed, and did not become joint because the general consequences were united. Wherefore the defendants were liable separately for the results of their own act, though difficult of exact ascertainment; and they were not discharged by a prior quitclaim and release executed by the plaintiff to the upper operators, for all injury done by them in their operations.

Williams v. Fulmer, 151, 405 (1892). Where the owner of a quarry, by depositing the waste thereof in a navigable river, obstructed the water power of a riparian owner below, and diverted the stream from its natural channel in front of his land, he could recover damages for the latter, but not for the former. The stream being navigable, he was without title to the water, but it was an actionable injury to deprive him of the advantages of his location.

Williams v. Union Imp. Co. & J. T. Co., 1 Dist. Rep. 288 (1892). Defendants, owning coal mines, instead of draining into the stream running through the valley in which they were situated, proposed to conduct their waste water by means of a tunnel five miles long, through the mountain, and discharge it into another basin, which formed the drainage of a valley containing no mines, but devoted to agricultural

purposes. This will be enjoined at the suit of owners along the stream in this valley. The case differs from Pennsylvania Coal Co. v. Sanderson, and is not rendered analogous by the fact that the water was deposited on ground belonging to defendants.

Elder v. Lykens Valley Coal Co., 157, 490 (1893). Williams, J.: "If the drainage from the mines falls into and pollutes a stream of ́water and injuriously affects lower riparian owners, this fact alone will not impose liability on the owner of the coal. Sanderson v. Coal Co., 113 Pa. 126. He may deposit the culm and refuse from his mines on his own land, where they will be safe from encroachment by ordinary floods. If an extraordinary flood should reach and carry away any portions of the culm so deposited, and leave it on the lands of lower riparian owners, he is not liable for the injury so sustained. But he must deposit the culm and refuse on his own lands. He has no right

to throw it into the streams, or leave it where ordinary floods will carry it down upon the lands of others; Lentz v. Carnegie Bros., 145 Pa. 612. If he does throw it into the stream, or leave it where ordinary floods will carry it away, then the injury that his neighbor may suffer therefrom is not the natural and necessary consequence of the rightful mining of coal, but of the want of proper care in disposing of the refuse product of the mines. For an injury resulting from the want of care an action will lie."

"If, on the other hand, the evidence satisfied the jury that the defendant had thrown the culm into the stream where every flood, as well as the ordinary current, would act upon it, and carry it gradually down the stream, the fact that an extraordinary flood quickened its descent and gave the final impulse that lodged it on the plaintiff's land is not enough to bring the case within the rule."

Pfeiffer v. Brown, 165, 267 (1895). Defendant, boring an oil well, pumped therefrom salt water, which was turned into a storage tank, and thence drawn off and allowed to flow by a natural depression over plaintiff's land. Plaintiff afterwards diverted it into a neighboring brook by means of a ditch ploughed along the line of depression. Prima facie, defendant, having increased the aggregate quantity of water discharged, concentrated it at an artificial point of flow and changed its character from fresh to salt, whereby it became more injurious to plaintiff's land, was liable for the injury caused thereby. He claimed to be excepted from the general rule, because the water was discharged in a lawful and proper use of their own land, under the authority of Pennsylvania Coal Company v. Sanderson.

It was held, however, that this exception did not go beyond proper use and unavoidable damage, and the defendant was liable for the injury, if he could have avoided inflicting it by reasonable care and expenditure.

"If the expense of preventing the damage.

is such as practically to counterbalance the expected profit or benefit, then it is clearly unreasonable, and beyond what he could justly be called upon to assume. If, on the other hand, however large in actual amount, it is small in proportion to the gain to himself, it is reasonable in regard to his neighbor's rights, and he should pay it to prevent damage, or should make compensation for the injury done. Between these two extremes

lies a debatable region where the cases must stand upon their own facts, under the only general rule that can be laid down in advance, that the expense required would so detract from the purpose and benefit of the contemplated act as to be a substantial deprivation of the right to the use of one's own property. If damages could have been prevented short of this, it is injuria which will sustain an action."

A proper standard of estimating damage is not given where the court charges that if the injury could have been avoided "at slight expense or at small expense," it was the duty of defendant to make such expenditure.

The simple device resorted to by the plaintiff avoided the injury, and was evidence upon which the jury should have found that defendants should have foreseen the result of their operations and provided against it.

Hindson v. Markle, 171, 138 (1895). The rules laid down in Elder v. Lykens Valley Coal Co., ante, were repeated and followed.

The defendant here pumped water from his mine, used it to wash the coal, and then carried it by troughs to a point on his own land. Some of the culm was dropped and deposited on the land, and some carried by the water in troughs directly into the stream, or into a gully that led into the stream.

Green, J.: "The case of Penna. Coal Co. v. Sanderson, 113 Pa. 126, is not at all in point. That was the mere flowing of natural water which was discharged by natural and irresistible forces, necessarily developed in the act of mining prosecuted in a perfectly lawful manner. While the mine water thus discharged polluted the water of the stream in which it necessarily flowed, it caused no deposit of any foreign substance on the land of the plaintiff and did not deprive her of its use."

Commonwealth v. Russell, 172, 506 (1896). The owners of land which they operated for oil, after separating the oil from the salt water with which it was mixed, allowed the latter to run out upon the surface, whence it drained into a stream, from which the borough of Butler was supplied with water. The water was thus rendered unfit for use. This case was held not to be ruled by Pennsylvania Coal Co. v. Sanderson. The rights of the public stand on higher ground than the personal inconvenience and injury of an individual. The fact that the water from this stream was supplied to the borough by a water company does not alter the public character of the right. This was a bill in equity to enjoin the pollution of the stream. The court below dismissed the bill. The Supreme Court reversed this action, and sent the case back for additional findings as to the condition of the ground, the extent and value of the oil operations, the possibility of working the oil wells without contaminating the stream, whether this contamination could be prevented by any means, whether the plaintiff could obtain a water supply elsewhere, and the expense of so doing, etc.

V. DRAINAGE.

The owner of a mine on a higher level may allow the water therein to flow in natural channels and percolations into an adjoining mine, but he may not, in the absence of an easement or license to do so, discharge it by means of artificial drains into such adjoining mine. He may permit the water to flow where it naturally will in the course of ordinary mining, and is consequently not bound to impound it to prevent its flowing into an adjoining mine. The lower mine is under a natural servitude to an adjoining higher one to receive water flowing down to it naturally by the force of gravitation. The owner of the latter may not, however, allow water to flow into the mine on the lower level, or to fill up his own mine to the destruction of an easement which the owner of a lower level has therein.

The owner of the latter may take out all of his mineral, and the owner of the former, if he wishes to prevent the flooding of his mine, must leave upon his side of the boundary sufficient barriers to protect it. This duty to dam is, however, only for the mine owner's own protection. To an owner of a mine of still lower level he owes no obligation to leave or build such a barrier against higher mines, nor having built is he bound to maintain it, though by building the dam he increases the volume of water, which he may subsequently discharge upon the lower mine." Where, however, the owner of one mine conducts into the adjoining mine water which otherwise would not go there, or causes water to go there at different times or in larger quantities than it otherwise would, he is liable for the damage resulting. He may not, therefore, construct a drain emptying into the neighboring mine. He may not dam up and change the course of a stream so as to discharge its waters into the adjoining mine. He may not break through the barrier left by the adjoining owner to protect his mine. These are all trespasses for which he will be responsible in damages. This responsibility is unaffected by any question of negligence: but he may be likewise held liable for such overflow as is occa

1 The mine owner's right of drainage is the same as the right of surface drainage at the civil law. The law as stated has been applied in at least one State where the common law as to surface drainage is followed. Whether this course would be taken in others is of course doubtful. For

an exposition of the law of surface drainage, see Walker v. Southern Pac. R. Co 165 U. S. 602.

2 See, however, Pennsylvania Act May 15, 1893, art. ix. sec. 4; Act June, 1891, art. iii. sec. 10, P. L. 183.

sioned by bad mining or insufficient pumping of water flowing in from the surface. It is a duty which the mine owner owes to his adjoiner to pump not only what is sufficient for ordinary drainage, but to provide against heavy rains and snows, which, by their periodical recurrence, might be anticipated. There is, however, no duty to pump out water that has accumulated naturally from the force of gravity. A mine owner is under no obligation to keep his mine pumped out for the benefit of his neighbor. Consequently he cannot be charged with the cost to his neighbor of pumping water that has naturally drained into the latter's mine.1

Whether a mine owner may be held liable for failure to support the surface whereby water from the surface is introduced into his mine and flows into the adjoining one, is the subject of dispute. In Pennsylvania, and formerly in New Jersey, the position was taken that the mine owner's duty to support the surface was absolute, and the mine owner was responsible for injury resulting from the introduction of surface water caused by withdrawing the ribs, pillars, or other supports; and he would be enjoined from such removal. This would be undoubted where the defendant had connected his mine with plaintiff's by his own trespass, but as a general principle it is denied in the most recent case in New Jersey. The right of surface support is not a right of the adjoining but of the superjacent owner. To the adjoining owner, the mine owner only owes the duty of mining carefully and in the ordinary way. If he does this he may remove all the minerals from his mine without regard to the damage to his neighbor by flooding.

Where the owner of the upper mine first reaches the boundary and mines over it, and either himself breaks into the lower mine, or the owner of that mine subsequently breaks into the excavation made by him, he is liable in trespass, but cannot be compelled in equity either to close the opening or to prevent the flow of water

into it.

The cause of action is the trespass in mining over the line, not the flowing of the water, and the Statute of Limitations runs from the date of that trespass.

The measure of damages is the actual loss sustained in delay, loss of time, damage to machinery, and the like. If the mine is

1 As to tapping bituminous coal mines in Pennsylvania, see Act May 15, 1893, art. ix. sec. 3.