Opinion by
Mr. Justice Green,We experience difficulty in disposing of this case, on account of the character of the most important testimony in support of the plaintiff’s claim of damages. The charge of the learned court below was substantially correct, and in accordance with our decisions in this class of cases. Yet the testimony as to the most serious cause of damage, alleged by the plaintiffs, was of such a speculative, remote, and imaginary character, that we do not feel at liberty to give it sanction. So far as the testimony goes, in relation to the injury to the surface of the ground, there is no ground of complaint. The amount of land disturbed by laying the pipe line, the permanent occupancy of a part of it as a path, to walk over for purposes of inspection or repair, and the injury to the crops, were legitimate subjects of testimony, and the effect of it would be entirely for the jury. But there was a much larger cause of damage set up by the plaintiffs, and testimony was given in support of it, with which we are not satisfied. It was of this nature : The plaintiffs’ land was largely underlaid with bituminous coal. The defendant *212laid a gas-pipe, of sixteen inches diameter, over the surface of plaintiffs’ land, at a depth of three feet below the level of the ground. The underlying coal was at a varying distance below the surface, ranging between 87£ and 217 feet, the average depth being about 148 feet. It was claimed by the plaintiffs that they were damaged by the necessity of leaving a wide strip of coal permanently underneath' the pipe, so as to be at all times a sufficient support for the pipe, and, therefore, the same could not be sold. It was also claimed that there was danger in the mining of the coal, in that, if the surface should sink, it might cause a break in the pipe, and a consequent liberation of the gas, which would, or might, find its way down through the ground into the chambers where the coal mining was going on, and cause serious damage there. Testimony was admitted, under objection and exception by the defendant, in support of these theories, and, upon the supposition' that the theories were correct, witnesses testified to an opinion that the market value of the entire farm was diminished by sums varying from a few dollars an acre to fifty dollars an acre.
The difficulty we have with this kind of testimony is that it is not founded upon any actual facts within the knowledge or experience of any witness, but entirely upon theory and imagination. Thus, no witness testified that he had ever known an instance in which, as a matter of fact, the surface beneath a pipe line had actually sunk in consequence of taking out the coal at a distance of 140 feet or at any other distance below the surface. It was all a matter of conjecture. Such a thing might happen, or probably would happen, but no one knew that it would happen. Nor did any one testify, from actual experience, that, if the pipe did break, the gas, instead of escaping through three feet of overlying surface, would penetrate downward, through the solid earth or rock, a distance of one or two hundred feet, and enter the chamber of any mine in that vicinity. There was no such proof, or anything of that character. But there was plenty of theory that all this might happen, and, if it did happen, much damage might be done, an explosion, like that of fire-damp, might take place; and, on the strength of these theories, the witnesses testified to an opinion as to the amount of damage. One witness said he would not be willing to buy the land at any price if the pipe line was laid over it. *213An illustration of the character of the evidence occurs in the testimony of one of the plaintiffs’ witnesses, who was asked to state why it would be unsafe to take the coal out from under the pipe, and said: “ The matter is a very simple one. The mines, as we operate them, are ventilated by a powerful ventilating apparatus, usually drawing air from whatever open place there may be through the mine. If a break, by reason of taking coal out from under the pipe line, should occur, break in the surface, as is often the case, it would form an inlet for the air ; a break in the pipe would be caused by the .same fault, would be very likely, and the gas, escaping, would be naturally carried into the mine, and a very small body of the gas in the mine, coming in contact with the air, would explode. You would have the same result as the explosion of fire-damp in a mine.
The whole force of this testimony depends upon an uncertain and problematical event, which may never occur. “ If,” says the witness, “ a break, by reason of taking the coal out from under the pipe line should occur .... it would form an inlet for the air. A break in the pipe would be caused by the same fault, would be very likely, and the gas, escaping, would be naturally carried into the mine,” etc. That is, if a break through the earth and rock, from the surface down to the mine, should occur, a break in the pipe would be very likely to occur, and, if it did occur, the escaping gas might, or would, naturally be carried down into the mine, and might cause an explosion. The witness did not, at any stage of his examination, say that he had ever known such a thing to happen, nor did any other witness testify to that effect; yet the witness, proceeding upon the idea that his theory would necessarily be verified in actual experience, testified, later on, and under exception, that “ to be on the safe side,” though it was a hard question to answer, “ he would leave a strip of coal 100 feet wide, at the depth at which this coal laid, to support the pipe line at the surface.” On cross-examination he modified this by saying it might be done with a less width of cJll than 100 feet, but that he thought that he would not leave less than a strip 60 feet wide. In estimating the decrease in the value of the farm he assumed the length of the strip at 160 or 170 rods, and said: “I would say that the value of it was decreased about $12 to $16, according to my calculation, depre*214ciated on tbe whole.” He only valued the farm, coal and all, at $200 an acre, but he estimated the value of the strip 100 feet wide and 160 or 170 rods long, and apparently deducted the resulting price of the coal left in place from the whole value of the farm, and reached the conclusion that the entire 202 acres were reduced $12 to $15 per acre on account of the supposed necessity for leaving this strip of coal in place. His estimate was the most moderate of all the witnesses for the plaintiff, but the other witnesses, adopting his method, but valuing the land at $400 or $450 per acre, reached very much larger results, one of them $50 an acre, and another $100 per acre, as the amount of decrease of value in the entire farm. The amount of damage by diminution of value on account of the strip, as estimated by the witness last referred to, was $20,000 or $40,000, accordingly as his testimony was considered by the jury. He was the witness, "J. Rath, and was asked in regard to the decrease in value: “ Q. Have you a judgment about it, or an opinion? A. It would be worth, I suppose, a hundred dollars or two less at the present time than fit was before the pipe line went across. Q. Do you mean the farm would be worth $100 less an acre? A. Yes, sir, $100 less an acre.” This ridiculous testimony was the natural result of the vicious method allowed to be pursued by the witnesses in ascertaining the amount of the diminution in value on account of the presence of the pipe line. The whole quantity of coal which might be left in place to support the surface, on the theory that the strip should be 100 feet wide and 170 rods long, was testified to be about 12 acres, and even at $400 an acre, which was an exaggerated estimate, would amount only to $4,800„ yet he was able to testify, and did, that the amount of the cjiminution was $100 an acre on the whole farm of 202 acres, 67 of which had no coal at all underneath, and of the remaining 137 acres of coal only 12 acres were required to be left in place by the theory upon which all of this testimony was based. The witness, Taylor, estimated the value of the whole farm at $200 an acre including the coal, and that a strip 60 feet wide would take about 8 acres. According to this the actual reduction in value for loss of coal would be $1,600.
The speculative and imaginary character of this kind of evi*215dence is more strongly illustrated by the testimony of another of the plaintiff’s witnesses, who manifestly had very little confidence in the theory that a strip of coal 100 feet wide must be left in order to support the surface. It' was the witness McRoberts, called by the plaintiffs. He was a civil engineer, and an expert in coal-mining: He said: “ If I had charge of the mining of the coal, I would go on and take it out regardless of the pipe line and run the risk — try and protect myself as best I could.” He said, further, it would be very hard to say how much the market value of the land would be damaged, but thought the whole thing taken together ought to be worth seven to ten per cent less per acre than it would be without the pipe line. He was asked: “ Q. Then this strip that would have to be left would take about twelve acres? A. No, sir; I didn’t say it would have to be left. I say if I was mining the coal I wouldn’t leave it. . . . Q. Now, what would be the necessity for leaving a pillar of coal there? A. I don’t know that there would be any; that was your presumption, and I am deciding upon that. Q. If there is any, what is it? A. To support the pipe line. Q. If their pipe line was not supported what would be the result? A. Possibly nothing; if I were mining that coal, as I have testified, I would not leave that pillar; I would take the risk and guard against accidents all I could, and take the result when it would come, and then try and settle with the gas company, just as we did in one case I was interested in, if you remember. That is the true way to settle a question of this kind with regard to coal.” In reply to another question, he said: “ This gas when liberated would obey the universal law of nature and flow towards the weakest point of resistance. If that is in the mine it is hard to tell what the result would be, and for that reason we can’t tell what the result would be. I would let the coal alone until I practically mined the coal and found out. Q. Do you regard a risk of that sort as remote or imminent? A. Well, in this case it is possibly a little remote.” After testifying further to the remoteness of the risk, and its probable value at seven per cent in the additional care required in the mining, and the probability that the surface could be let down without breaking the pipe, he was asked: “ Q. As to what amount of breakage of the soil would be nec*216essary to cause a rupture of this pipe line, you have only an opinion, and not founded upon any actual experience ? A. No, sir. That is simply my opinion as a mining engineer. If you could let the surface sink at once, as you intimated by your question, you could possibly drop it; there is a bare possibility you might drop that entire surface and not injure the pipe line. Q. When you let it down, is there much likelihood of the surface from 87 to 200 feet breaking in places ? A. Yes, sir. After the coal is mined out of Mr. Wallace’s if you travel over that premises you will see the surface undulating. To a party going over the land without knowing what is the matter, it will excite his curiosity. Q. Will that be to the extent of breaking a wrought-iron pipe ? A. Well, possibly not; I don’t think it will break the pipe. I think it would strain it enough to possibly liberate the gas. Q. Isn’t there more of a likelihood that that gas will go up to the surface, two or three feet distant, than go down into the mine? A. Yes, sir. Q. Isn’t the risk of gas getting down into the mine a remote one? A. Well, yes, sir, I think it is. That is what I have testified in this case. I think it is remote, yet it is possible. Q. Do you know of any pipe lines in this neighborhood being constructed over coal land which has been worked since the pipe line was put there ? A. I don’t know that I do. I can’t recall. There is no doubt numerous instances of that kind. Q. You don’t know of this result having happened ? A. No, sir.”
The testimony of this intelligent and candid witness for the plaintiffs has been quoted in order to show the remote, speculative, uncertain and doubtful character of the testimony, and the theory upon which the plaintiffs’ claim in this respect is founded. Not a single witness testified to the fact that a pipe line at an average distance of 140 feet above the coal actually required support from the coal underneath, or that any breakage of a pipe had ever occurred where the coal was all taken out at such a distance. Not a witness knew of the escape of gas down into the ground a distance of 140 feet, or any distance, instead of escaping above into the open air, a distance of three feet. Not a witness knew that a strip of coal 100 feet wide the whole length of the pipe line would be required to support the pipe above. No instance in which a pipe line had *217ever subsided, or a pipe broken for want of support, was proved, although the witness McRoberts said there were numerous instances of pipe lines being laid over coal lands. No witness testified that there would be any subsidence at any depth over 100 feet below the surface. All of this testimony was merely speculative, imaginary, theoretical, and the most of it extremely doubtful, and founded upon possibilities which were remote and uncertain, yet the great bulk of the plaintiff’s testimony on the subject of damages was made up of just this kind of proof. We think it comes within the operation of several of our decisions declaring that testimony of such character should be excluded.
The case of Searle v. R. R., 33 Pa. 57, is, perhaps, more nearly analogous to this than any other in our books. On the trial of that case the plaintiff offered to prove that the tract in question was coal land, and that the defendant’s railroad crossed it in such place and manner as materially to increase the expense of mining his coal. The offer was rejected on the ground that the damages claimed were speculative, which might never accrue. This court sustained the court below, holding that it would be purely speculative to allow the plaintiff to recover the value of the coal which was required to be left for the support of the railroad, or damages for the increased expense of mining the coal, and that the only true measure of the damage would be the difference in the value of the land as ordinary coal land before and after the road was built.
Other cases in which speculative and remote or uncertain damages have been condemned are Pittsburgh, etc., Ry. Co. v. McCloskey, 110 Pa. 436; Reading & Pottsville R. R. v. Balthaser, 119 Id. 472; Chambers v. South Chester, 140 Id. 510.
The case of Penn Coal Co. v. Versailles Gas Co., 131 Pa. 522, is not at all in conflict with any of these cases. It recognized the right to support on the part of the gas company. And the right of the owner of the coal for compensation for the coal which he would be obliged to lose for the support of the surface, but “ this is to be ascertained not by a calculation of the quantity of the coal, but by the effect of the appropriation on the tract as a whole.”
In the present case the learned court below recognized this rule and endeavored to enforce it. But we think the testi*218mony took too wide a range, and especially was of too remote and speculative a character in many of its details, as we have endeavored to point out.
We sustain the 2d assignment of error because the witness had not shown any knowledge, or experience, or any other means of information as to the width of the strip of coal which would be required to be left to support the pipe line.
We do not sustain the 3d assignment because the witness was not asked at that time to testify as to how much the value of the land was affected, but onty whether it would be affected at all by the presence of a pipe line.
We sustain the 4th assignment, because the witness had not qualified himself to answer the particular question asked, by stating any knowledge, experience or other information that would enable him to answer the question. The only reasons he did give for his belief were purely conjectural and conditional, and were also speculative and remote.
We sustain the 5th assignment on the authority of Searle v. R. R., supra, because the additional cost of mining the coal on account of the manner in which the pipe line crosses the coal is not an element of damage.
We sustain the 6th assignment because the witness testified it was altogether uncertain whether the pipe line would be injured or not, and that he considered the probability of injury to the mine by the escape of gas as remote, and had not qualified himself by any previous testimony to give a definite answer to the question.
We sustain the 7th assignment under the authority of Searle v. R. R., because the increased cost of mining is not an element of damage. For the same reason we sustain the 8th assignment.
We sustain the 9th assignment, because we think the 10th point of the defendant should have been affirmed without qualification.
The first assignment is without merit, and is dismissed.
We said in the case of the Penn Coal Co. v. The Versailles Gas Co. that if the latter company would file a stipulation, agreeing to be bound by the release of the owner of the surface, of the right of support, and accept the risk of subsidence, the injunction would be refused. And so we say here, that if *219the defendant Gas Co. will file a release of the right of support, in this case, or deliver it to the plaintiffs, the element of possible damage from the subsidence of the surface will be eliminated from the case. The possibility of injury from gas escaping; downward to the coal instead of upward to the air, is, under the evidence, too doubtful, remote, and speculative to be considered as an element of damage.
Judgment reversed, and new venire awarded.