Opinion by
Mr. Commissioner Slater.
1. The averment of the complaint is that plaintiff’s intestate was, on April 20,1906, in the employ of defendant. The particular services he was to perform for defendant are not stated, but it is alleged generally that he was instructed to assist in completing the sewer between East Seventh street and Thompson street. The answer admits that the relationship of master and servant existed between defendant and plaintiff’s intestate on April 20, 1906, but denies the alleged instruction to assist in the completion of the sewer between those streets, and affirmatively alleges that on that day “plaintiff’s intestate with other employees was engaged by defendant to remove said remaining bank of dirt to the depth of 27 feet, and said deceased and other employees engaged at the same work were directed in digging said remaining body of earth to carry the face of the embankment where said tunnel was to be located down perpendicular, and not to disturb the face of the standing bank.” Hence there is an issue as to the scope of the employment, which must be *547determined before other matters can be considered. The bill of exceptions recites that “it is stipulated and agreed between the parties hereto that the testimony offered by the plaintiff in support of the issues on his part tending to show * * that on the 19th day of April, 1906, the deceased, J. H. Larsen, was employed by the defendant to work, shoveling dirt in the ditch for the sewer at a point just east of Seventh street at Thompson street; * * that plaintiff introduced witnesses who testified that the deceased and his fellow workmen had orders from Mr. O’Neil, superintendent for the defendant, who had charge of the work and the direction of the men employed, to commence digging the tunnel into the face of the embankment on the east side of Seventh street, he (O’Neil) having first indicated on the face of the embankment where the tunnel was to be dug.” This evidence is undoubtedly sufficient to support the issue on plaintiff’s part as to the scope of the employment, and that the injury was received by Larsen while he was in the performance of the duties of his employment in a place directed by the defendant for him to work. And upon the issue of contributory negligence this evidence is sufficient to take the case to the jury.
2. Defendant’s main contention, however, is that plaintiff’s intestate assumed all the risks incident to the employment, and all extraordinary dangers and hazards of which he had knowledge and appreciated; while plaintiff rests his case wholly upon the rule of law which requires an employer to use reasonable care and diligence to .provide his employees with a reasonably safe place in which to work. There is no controversy over the rule that it is the personal and absolute duty of the master to exercise reasonable care and caution to provide his servants with a reasonably safe place to work; but it is urged by defendant that the master is not an insurer of the safety of the servant, and therefore is not bound to furnish an appliance or machinery or a place that is absolutely safe, *548and that his duty in this regard is discharged when he exercises reasonable care and caution to that end, and the presumption is that he has discharged his duty. This may be conceded to be the law: Duntley v. Inman, 42 Or. 334 (79 Pac. 529: 59 L. R. A. 785).
3. And where a servant is employed to work in a mine, quarry, tunnel, pit, trench or other excavation, the master owes the duty to use ordinary and reasonable care and diligence to make his place of work as reasonably safe as the nature of the work admits. Where, however, it is the duty of the workmen to shore up or otherwise make safe the place as the work progresses, the master’s duty is fulfilled when he furnishes them with suitable materials for the purpose: 26 Cyc. 1119. The evidence discloses that Larsen, plaintiff’s intestate, was employed by defendant on the 19th of April as a common laborer to shovel dirt and assist in that capacity to dig a trench for the construction of a sewer. At that time the trench on Thompson street lacked about 8 feet of being completed. On the 20th he assisted in digging out a portion of this eight feet of earth. At different places, and wherever needed, defendant had previously shored up and protected with timber the banks or walls of this trench to prevent it from falling or caving upon its employees while they were engaged at work therein. This had been done by one of its servants employed for that particular duty, and was not required to be done by those engaged to dig and shovel dirt. But no supports or timbers had been placed across the perpendicular wall or bank at the end of this open trench where the tunnel was to begin, excepting one brace which had been placed about 3 feet from the top of the bank, but slightly removed from it; the intention being to put lagging or planks behind it to hold the earth in place, but this was not done. On the next day, when Larsen returned to work, he and another employee were directed to begin digging into the face of this bank. They had been working about three hours when a quantity of *549earth broke off the face of the bank just above and at the entrance of the tunnel, fell on Larsen, and so injured him that he soon thereafter died. The testimony is conflicting as to how far into the bank the tunnel had been excavated when the accident occurred, but it is stated by some witnesses for plaintiff that its extreme depth was six feet. All agree that it was six feet high and six feet wide, presumably the intended dimensions of the tunnel when completed. At the time of receiving the injury Larsen could not have been entirely within the tunnel, but was just at the entrance thereof, for the body of falling earth came from the northeast corner of the “face” or entrance thereof, and, according to the testimony of J. S. Reagan, defendant’s witness, the bulk of it came from the bank above the entrance and extended from the surface of the ground down to the roof of the tunnel. The place where Larsen was put to work had been created by defendant before it employed him, and that it was a. dangerous place the casualty establishes. There is evidence that the defendant knew, or was 'bound to know, of the imminence of that danger. It is contended by defendant, however, that the danger was so apparent, open, and manifest that a person of ordinary intelligence could observe and appreciate it, and that Larsen, when he first entered the trench, then about 25 or 26 feet deep, must have seen that the end thereof was not shored, and that to dig into the base of a perpendicular bank of that height and undermine it would cause the unsupported part above to fall upon and injure him; that this danger was so apparent and obvious to him that the law will not permit him to deny knowledge of the ordinary and universal law of nature—the law of gravity.
4. The doctrine of assumption of risk is wholly dependent upon the servant’s knowledge, actual or constructive, of the dangers incident to his employment. Where he knows, or in the exercise of reasonable and ordinary care should know, the risks to which he is ex*550posed, he will as a rule be held to have assumed them; but where he either does not know, or knowing, does not appreciate such risks, and his ignorance or nonappreciation is not due to negligence or want of due care on his part, there is no assumption of risk: 26 Cyc. 1196; Roth v. N. P. L. Co. 18 Or. 205 (22 Pac. 842); Carlson v. Oregon Short Line Ry. Co. 21 Or. 450 (28 Pac. 497); Wagner v. Portland, 40 Or. 389 (60 Pac. 985, 67 Pac. 300); Geldard v. Marshall, 43 Or. 438 (73 Pac. 330).
5. Plaintiff’s intestate entered the employment of the defendant as an ordinary laborer to dig and shovel dirt in the bottom of a trench. He did not thereby impliedly represent to the defendant that he had any knowledge or skill in digging a tunnel or constructing a sewer. The evidence shows that he was a cement worker, and had little skill in handling a pick and shovel, or, as stated by one witness, “he handled a shovel like a greenhorn.” When told by the master to begin digging into the bank for a tunnel, he must have seen that it was 25 feet high, and that no protection against its falling or caving had been made by his employer. But there is a difference between knowledge of the surrounding circumstances and appreciation of a risk: Roth v. Northern Pacific Lbr. Co. 18 Or. 205 (22 Pac. 842). In that case it is said that “one may know the facts, and yet not understand'the risk; or, as Mr. Justice Byles observed: ‘A servant knowing the facts may be utterly ignorant of the risks’: Clark v. Holmes, 7 Hurl. & N. 937. For, after all, Mr. Justice Hallet said: Tt is not so much a question whether the party injured has knowledge of all the facts in his situation, but whether he is aware of the danger that threatens him. What avails it to him that all the facts are known, if he cannot make the deduction that peril arises from the relation of the facts ? The peril may be a fact in itself of which he should be informed.’ ” The evidence shows that at the place where the tunnel was to be dug the earth was composed of clay and loam which, when *551not undermined, would ordinarily stand at a perpendicular height of 28 feet. But the defendant knew that it had been necessary in some places to shore up the sides of the sewer trench to prevent it from caving upon its employees, and it had expended a large sum of money in doing so. It also knew that a day or two before this accident occurred a dangerous crack had appeared on Seventh street close to the bank of the trench at the opposite end of this strip of ground 17 feet long, which was to be tunneled. And after Larsen went to work defendant’s superintendent, O’Neil, came into the trench and marked upon the wall or end thereof where the tunnel was to be dug, and told one Barnes, a co-employee, to put the men to work at that place. Barnes testifies that after Larsen had gone to work he had a talk with O’Neil about the kind of ground they were to tunnel. The conversation given is as follows: “I said I thought the dirt was rotten and would not stand. He said he thought it would. I didn’t know anything about the crack on the Seventh street end. The dirt on the Seventh street end and on Thompson street was apparently the same.” From plaintiff’s testimony it appears that in the evening of the day before, or two days before, the accident happened, O’Neil had observed a serious crack in the street at or near the opposite end of this section which was to be tunneled, and for that reason refused to allow the night shift to work that night, but sent them home. But there is no evidence that Larsen knew anything of this. One J. S. Reagan testifies in defendant’s behalf that he worked for defendant upon the Seventh street end of the sewer. He says: “We ran up against a straight cut on the Seventh street side, perpendicular, and went down. We then completed the sewer and put in this tunnel about 2 feet on the Seventh street side. We put it underground there, the tunnel, two feet. No accident nor sign of dirt falling at this time.” O’Neil, according to his own testimony, had had wide experience in mining, bridging, and sewer *552building; that this sewer ran along various' streets and that a tunnel had to be constructed where the sewer started from the Willamette Eiver; this .tunnel ran through sand and had to be supported with timbers; that at Seventh and Thompson streets the earth was sandy loam, which would stand when cut perpendicular, but was liable to nave if undermined; that the only caves that had occurred during the work were caused by the proximity of water mains or rain or water wetting the bank. He described th,e means employed to timber or shore the sides of the trench; that Larsen was employed at his own request, on the day before he was injured, and was placed at work with other men to remove dirt out of‘the ditch on the Thompson street side of Seventh street; that on the morning of April 20, Larsen, with two other employees, was placed at work near the face of the embankment where the tunnel was to be constructed, and a mark was placed across the face of the embankment showing where the top of the tunnel was to be; that Larsen and his fellow-workmen were instructed to clear the dirt away at the sides, near the embankment, for the purpose of placing timbers there, perpendicularly, to cut the tunnel; that he gave no orders for the men to begin digging into the embankment. He also testifies that he has no recollection of the crack spoken of by a witness for plaintiff, and gives as his reason, for not carrying on the work at night, it looked like rain and he sent the men home.
6. Can it be said, as a matter of law, that the circumstances related in this record show conclusively that the extraordinary risk and danger of this bank caving was so obvious to an ordinarily intelligent person that it would be perceived and appreciated at once? Mr. Chief Justice Moore, in Johnston v. O. S. L. & U. N. Ry. Co. 23 Or. 95-105 (31 Pac. 283, 286), has defined such a risk as follows: “An open, visible risk is such a one as would in an instant appeal to the senses of-an intelligent person: Wood, Mas. & Ser. 763. It is so patent that it would be instantly *553recognized by a person familiar with the business. It is a risk about which there can be no difference of opinion in the minds of intelligent persons accustomed to the service. It is not expected that the servant will make close scrutiny into all the details of the instrumentalities with which he deals. His employment forbids that he should thus spend his time.” The disastrous result shows that the work which Larsen was directed to perform and was performing was highly dangerous, and indicates that before attempting it, precautions should have been taken to prevent the earth caving. The record shows quite clearly that defendant’s superintendent knew it was dangerous, but we are not able to say .that the facts show conclusively that Larsen knew the facts or appreciated the danger. The question whether it would be safe to dig a tunnel into the particular bank in question depends upon something else besides the height of the bank, and it not being timbered or shored, but rather upon the cohesiveness of the soil and other collateral facts. It was not a danger so patent that it would be involuntarily recognized by one inexperienced and unfamiliar, with the business, as is plainly shown by the testimony of Barnes, who says .that O’Neil thought the tunnel could safely be dug without timbering, while he did not.
7. Now it is contended by defendant that, although Larsen may have been directed to commence digging the tunnel, he must have known that to dig into and undermine this bank would cause the unsupported earth to fall and injure him; that his danger was so apparent and obvious to him that the law will not permit him to say that he did not appreciate the danger, because that would permit him to deny knowledge of the ordinary and universal law of nature—the law of gravity. It has been held in some cases that, if one removes the foundation from a bank of earth composed of sand, gravel, and clay, it is liable to fall, and he will not be heard to say that he did not appreciate the danger. The cases cited m support *554of this contention are such as involve injury received in a stope of a gravel pit, where the very object of the employment was to loosen the material of the bank so that the law of gravitation may operate and precipitate it to the bottom of the pit. This is usually accomplished by undermining for a considerable distance at and along the base of the bank, and after a time, either with assistance or by itself, according to the cohesiveness of the material, the bank falls. In such case the laborer expects it to fall. That is the object sought by the expenditure of his labor. In most, if not all, these cases the injured party had either previous experience in that kind of work, or had worked at the place of injury sufficiently long to acquaint himself with the risks and dangers incident to that class of work. Of such are Christienson v. Rio Grande Western Ry. Co. 27 Utah, 132 (74 Pac. 876: 101 Am. St. Rep. 945); Olson v. McMullen, 34 Minn. 94 (24 N. W. 318); Swanson v. Great N. Ry. Co. 68 Minn. 184 (70 N. W. 978); Simmons v. Chicago & T. R. R. Co. 310 Ill. 340; Griffin v. Ohio & Miss. Ry. Co. 124 Ind. 326 (24 N. E. 888). But the risks and danger of driving a tunnel through material of the same character would depend upon a different state of facts, and would not necessarily be the same. The respective sides of a tunnel as the result of an arched roof mutually afford some support to each other. Whether the roof of a tunnel, which is 6 feet wide and 6 feet high, will remain firm and be safe, or will fall when the tunnel is driven into a bank of clay and loam, which will stand at a perpendicular height of 28 feet, depends upon the cohesive power of the soil, the saturation of the soil by water, and the length of time it may have been exposed to the action of the air: Fulger v. Bothe, 43 Mo. App. 44. Under such circumstances it was a question for the jury and not a matter of law for the court to say whether or not Larsen had such knowledge of the facts and appreciation of the danger as would constitute an assumption of the risk by him: Christian-*555son v. Pacific Bridge Co. 27 Wash. 582 (68 Pac. 191); Coan v. City of Marlborough, 164 Mass. 206 (41 N. E. 238); City of Ft. Wayne v. Christie, 156 Ind. 172 (59 N. E. 385); Chiappini v. Fitzgerald, 191 Mass. 598 (77 N. E. 1030); Van Steenburgh v. Thornton, 58 N. J. Law, 160 (33 Atl. 380); Kielty v. Buehler-Cooney Const. Co. 121 Mo. App. 58 (97 S. W. 998); Illinois Steel Co. v. Schymanowski, 162 Ill. 447-459 (44 N. E. 876, 879). In the last case cited it is said:
“Even if the servant has some knowledge of the attendant danger, his right of recovery will not be defeated, if, in obeying the order, he acts with the degree of prudence which an ordinarily prudent man would exercise under the circumstances. When the master orders the servant to perform his work, the latter has a right to assume that the former, with his superior knowledge of the facts, would not expose him to unnecessary perils. The servant has a right to rest upon the assurance that there is no danger which is implied by such an order. The master and servant are not altogether upon a footing of equality. The primary duty of the latter is obedience, and he cannot be charged with negligence in obeying an order of the master unless he acts recklessly in so obeying. Whether he acted thus recklessly in obeying his master’s order, or whether he acted as a reasonably prudent person should act, are questions of fact to be determined by the jury.”
8. This last proposition is met by defendant with the argument that O’Neil who, it is testified on plaintiff’s behalf, gave the order to Larsen to begin the digging of the tunnel, was a fellow-servant, and therefore defendant would not be liable for the result of obeying the order. But whether he was or not cannot now be considered, because there is no basis for it in the answer. The defense that the injury was the result of the negligence of a fellow-servant is an affirmative defense, and must be pleaded in order to be of avail: Duff v. Willamette Steel Works, 45 Or. 479 (78 Pac. 363, 668).
No error was committed by the court in denying the motion for a nonsuit, or in refusing the requested instruction. Affirmed.