Dodge, J.
1. The first ground of attack upon the complaint is predicated upon the contention that on its face it shows that the plaintiff continued his exposure to the known risk from his fellow-servant’s incompetence and negligence. *306for more tban tbe time reasonably necessary to enable tbe master to perform its promise to substitute a competent and careful workman. Tbe law on tbis subject is in no wise in dispute. Tbe employee is relieved from bis ordinary assumption of tbe risks of bis fellow-servant’s negligence upon tbe master’s promise to remove tbat danger only for a time reasonably required to perform tbat promise. Heathcock v. Milwaukee-Platteville L. & Z. M. Co. 128 Wis. 46, 107 N. W. 463; Coolidge v. Hallauer, 126 Wis. 244, 105 N. W. 568; Erdman v. Ill. S. Co. 95 Wis. 6, 69 N. W. 993; Ferriss v. Berlin M. Works, 90 Wis. 541, 63 N. W. 234; Stephenson v. Duncan, 73 Wis. 404, 41 N. W. 337. When sucb reasonable time bas expired tbe master’s promise is broken to tbe knowledge of tbe employee, and be can no longer be considered as relying tbereon. Wbat sucb reasonable time may be will, of course, vary very mucb witb tbe circumstances. An engineer or a bead sawyer in a sawmill, remote from settlement, might be mucb more difficult to- replace witb a competent substitute tban a mere common laborer in a vicinity where laborers were numerous; or tbe defect in a machine might be of sucb character as to necessitate sending for new parts to a remote place of manufacture. Hence, ordinarily, tbe question is one for tbe jury. Nevertheless, tbe situation presented may be so clear tbat reasonable minds could not differ witb reference to tbe inference from all tbe circumstances, and in sucb case it may well be tbe duty of tbe court, witb all tbe facts before it, to bold as matter of law tbat tbe reasonable time bas been exceeded. Tbis we did in tbe recent case of Heathcock v. Milwaukee-Platteville L. & Z. M. Co., supra, where it was held tbat seven days, under tbe circumstances there presented, transgressed tbe reasonable time necessary to guard tbe mouth of a mine by a railing. Upon tbe authority of tbat case there could be little doubt tbat ten days exceeded tbe time required either to procure a common laborer in tbe place of tbe one whose incompetence was complained of or to substitute some *307other common laborer already in. defendant’s employ, in the absence of very clear showing of serious obstacles to so doing. But it is not at all essential to good pleading that the evidence of such excuse, if any there be, should be pleaded, hence the failure of such facts to appear in the complaint does not necessarily negative their existence; and, while we confess that it is difficult to conceive of any circumstances which could protract for so long a period the time requisite, we are not prepared to say that none could exist, and therefore must hold that the mere allegations of the complaint, construed of course with broad liberality in favor of the cause of action, do not necessarily show that the ten days’ period in question was unreasonable.
Our attention is urged to Stephenson v. Duncan, 73 Wis. 404, 41 N. W. 337, where it was held that the complaint itself showed a similar period of ten days to be unreasonable for protecting a dangerous saw.' That case, however, turned upon an express allegation of the complaint that, before the injury and after the promise to repair, the defendant had ample time and opportunity to make the repair but neglected to do so. Indeed, the court expressly said that but for such allegation it could not be said, as matter of law, that ten days was so unreasonable a period as to exclude expectatiQn that the defendant would make good his promise to repair. In ..the complaint before us we find no such allegation, except, perhaps,‘that the defendant negligently continued the block piler in its employ after said promise to remove him. We cannot say that this allegation must be construed as denying plaintiff’s cause of action. It must be remembered that the master owes the duty of immediate removal of an incompetent employee whenever he acquires knowledge of such incompetence ; hence he is guilty of negligence in failing so to remove, in the sense at least of conduct subjecting him to liability to other employees. Kamp v. Coxe Bros. & Co. 122 Wis. 206, 219, 99 N. W. 366.
*3082. Certain other radical grounds of attack upon the complaint are presented, though not with perfect clarity as to either the principle contended for or their application to the situation. One of these positions taken by the trial court, and apparently still sought to be sustained by respondent, is thus-stated by the trial court:
“That the rule where the danger is known and appreciated by the servant, and he remains in the employment upon the promise of the master to remedy, he does not assume the risk, applies only in cases of dangerous machinery where the master is presumed to have a better knowledge of the danger than the servant. In other words, that it has no application to ordinary labor which requires only the use of implements with which the servant is as familiar as the master. This seems to be a tolerably well-settled rule according to the authorities.”
If by this is meant that the rule justifying an employee in temporary exposure to known risk upon employer’s promise to remove the danger has no application except to risks from dangerous machinery, it is directly antagonized by several of our own decisions, holding that it does apply to risks arising from incompetence of fellow-servants which, but for such promise, the employee would be held to assume. Maitland v. Gilbert P. Co. 97 Wis. 476, 485, 72 N. W. 1124; Curran v. A. H. Stange Co. 98 Wis. 598, 606, 74 N. W. 377; Kamp v. Coxe Bros. & Co. 122 Wis. 206, 99 N. W. 366. True, tlieye is an expression of doubt whether it applies to a defective place-of work, such as a caving ditch, in Showalter v. Fairbanks, M. & Co. 88 Wis. 376, 382, 60 N. W. 257, but no attempt at decision to that effect was there made. That doubt would seem to have been resolved in favor of the application of the rule in Yerkes v. N. P. R. Co. 112 Wis. 184, 88 N. W. 33, where it was applied to a place of work rendered unsafe by a slanting footboard, and in Heathcock v. Milwaukee-Platteville L. & Z. M. Co. 128 Wis. 46, 107 N. W. 463, where the danger arose from an unguarded excavation in proximity to plaintiff’s place of work. The argument against the liability of a *309master pending a promise to repair or remove tbe danger that the peril is open and obvious and as well known to the servant as the master indicates complete oversight of the real principle involved. Such fact indeed leads in some cases to a presumption that the servant assumes the risk in absence of protest, but the very principle at the foundation of the rule now under consideration is that the servant rebuts that presumption by a protest and reliance on the master’s promise to remove the peril; which assumes, to start with, that the danger is open and obvious, at least to the servant, or he would have no reason to protest. To hold that a rule which in its very nature can have no application unless the danger is obvious does not apply where it is obvious, is a contradiction in terms, and the negation of the existence of any such rule. The true principle is that a servant may, and in law is presumed to, assume a risk of which he has knowledge, but that he avoids such assumption if he protests and is induced by the master’s promise to remove the danger to incur that risk for a time reasonably requisite for its removal. It is not at all bottomed upon any assumed superiority of knowledge in the master, as is the general duty to furnish reasonably safe tools and appliances (Stork v. Chas. Stolper C. Co. 127 Wis. 318, 322, 106 N. W. 841), but upon the right of the employee to refuse to assume the risk of a peril which he knows as well, or even better, than his employer. Obviously there is no distinction in reason because the danger results from the incompetence of a fellow-servant using complicated and dangerous machinery instead of simple tools and implements, or none at all. The peril from negligence in swinging a sledge or a pick is as much, and no more, assumed than if he were running a saw or an engine. The co-employee has as much right to refuse to submit to the one peril as to the other, and may as well be induced to continue by promise of speedy removal of the incompetent fellow-servant. Indeed, the simplicity of the operation would seem to enhance the probability that he might *310do so consistently with reasonable care. Thorough search discloses no authority for any distinction between such cases. The respondent’s citations all refer to promised repair of tools, appliances, or place of labor and not to removal of incompetent fellow-servants. Whether a promise to repair is any less effective to relieve a workman from assumption of risk from a simple tool than in case of complicated ones has not been decided in Wisconsin and need not be now, for the-question is not presented. We are convinced that no distinction in that respect exists between different incompetent fellow-servants by reason of the relative simplicity or complexity of the work in which they are engaged.
There is of course an exception to the rule we have been discussing where the peril of injury is so obvious, imminent, momentary, and constant, and so unavoidable by any precaution, that no reasonably prudent person rvould expose himself to it even temporarily. Erdman v. Ill. S. Co. 95 Wis. 6, 13, 69 N. W. 993; Maitland v. Gilbert P. Co. 97 Wis. 476, 72 N. W. 1124; Curran v. A. H. Stange Co. 98 Wis. 598, 74 N. W. 377; Jensen v. Hudson S. Co. 98 Wis. 73, 81, 73 N. W. 434; Yerkes v. N. P. R. Co. 112 Wis. 184, 192, 88 N. W. 33; Coolidge v. Hallauer, 126 Wis. 244, 249, 105 N. W. 568. This is really the point decided in several of the foreign cases cited by counsel which dwell upon the open and obvious character of the peril. It is hardly contended that the facts stated in the complaint bring plaintiff within this, exception as matter of law. We are clear that under this complaint facts may appear fairly supporting an inference that an ordinarily prudent person might reasonably believe that, temporarily, he could, by special watchfulness and caution,, escape injury from the negligence of his fellow-servant in piling blocks in the adjoining rack. Indeed, the fact that the plaintiff did escape for so long a period as ten days is not without weight on that subject. Maitland v. Gilbert P. Co., supra; Yerkes v. N. P. R. Co., supra.
*311Our conclusion is that the direct allegations of the defendant’s negligence and plaintiff’s freedom from contributory negligence are not so conclusively refuted by other facts appearing in the complaint that proof admissible thereunder might not sustain a cause of action.
By the Court. — Order sustaining demurrer is reversed, and; cause remanded for further proceedings.
Cassoday, C. J., took no part.