The defendant is a corporation engaged in the business of slaughtering live stock and in curing and preparing the product thereof for market. Plaintiff, on the sixteenth day of May, 1902, was in defendant’s employ in the capacity of what was known as a ‘ ‘ tripe cooker, ’ ’ and in charge of certain vats in which tripe were boiled. These cooking vats are tanks about six feet high, about seven feet long and *483four feet wide. The tripe are boiled by means of steam admitted into the vats through pipes, and the amount of steam required is regulated by a valve in the pipes, the valves being manipulated by the use of a wrench. The evidence shows that the plaintiff on the morning of the day mentioned filled a tank with water and then, by use of the wrench, turned the valve sufficiently to allow steam to escape into the tank, and when the water reached the boiling point he put the tripe into the vat. About 9 o’clock he discovered that the valve had changed from the position in which he had placed it, because there was a greater quantity of steam entering the vat, which caused the water to boil over. He then turned the valve back to its proper position, leaving it about one length open, and continued with the cooking. In about one hour afterwards he informed the foreman, Dreben, that the valve was out of repair and was informed by him that he would have it repaired. After plaintiff had reset the valve so as' to prevent the flow of too much steam, he was ordered by the foreman to other work outside of the tripe room. He remained away until about 12 o’clock, shortly after which time he returned to the tripe room, when he found the valve unchanged in its position. He then turned it, he says, so as to entirely cut off the flow of steam into' the vat and then turned to get a fork to raise the lid in order to take out the tripe; and while he was doing so, the valve became loose, permitting a full flow of steam into the vat, which caused the water to overflow onto him whereby he was scalded.
It was shown that defendant kept in its employ a mechanic whose duty it was to inspect its appliances and to keep them in repair. There is no¡ dispute but what the pressure of the steam • caused the valve to change its position and that it was owing to defective wrapping that such change occurred.
The plaintiff was an experienced workman and well acquainted with his work. It was shown that if *484a weight had been hnng upon the valve it would have prevented it from turning when set. At the time plaintiff turned off the steam entirely he had a hook in his hand, but he laid it down and turned his back, as has been stated. The foreman testified that when plaintiff informed him that the valve was not working properly he told him to hang a weight on it until the cooking was over and he would have it repaired. Plaintiff testified that he knew there was danger when the valve was loose and that he was liable to get hurt, but that he relied upon the promise of the foreman to repair the defect and did not know but what it had been done when he went back to the tripe room. The defendant offered to show a custom prevailing at the establishment not to repair a leaky valve while a batch of tripe was cooking, but the offer was refused. As there was no offer to show that the plaintiff had knowledge of such a custom, there was no error in refusing the admission of such evidence. After plaintiff was injured the valve was repaired. This work was accomplished in about fifteen minutes.
The finding and judgment were for the plaintiff. At the close of the plaintiff’s case the defendant offered a demurrer to the evidence which the court refused, after which it introduced its evidence.
The first objection that defendant makes to plaintiff’s right of recovery is, that the petition alleges that the valve was out of order and was allowed to remain so with the knowledge of defendant, but without any knowledge thereof on the part of plaintiff, whereas he was permitted to recover on proof that plaintiff discovered and reported the defect to defendant and received a promise to repair it, and relied on the promise and continued at the work. It was a fatal variance between the allegata and probata. The allegation of the cause of action was unproved in some material particular but there was not a total failure of proof, consequently the petition is subject to amendment under *485section 798 of the code. Ischer v. Bridge Co., 95 Mo. 261.
It is contended that as plaintiff was aware of the danger he assumed the risk. But the rule is different where the servant continues his work relying upon the promise of the master to repair the defective machinery. The plaintiff says he relied upon the promise of the foreman to repair the valve and did not know but what it had been done. In such cases the servant does not assume the risk if the master has had reasonable time to remedy the defect before the injury. “Where a master has expressly promised to repair a defect, the servant can recover for an injury caused thereby within such a period of time after the promise as it would be reasonable to allow for its performance, and for an injury suffered in any period which would not preclude all reasonable expectations that the promise might be kept. ’ ’ Conroy v. Vulcan Iron Works, 62 Mo. 35; which ruling has been uniformly followed by all the appellate courts of the State. The evidence showed that it only took a few minutes to repair the defect in the valve, and it was a question for the jury to determine under the circumstances whether plaintiff was justified in relying upon the foreman having complied with his promise at the time he resumed his work at the vats.
But it is insisted that the danger was obvious and the risk so great that a person of ordinary prudence would not have gone on with the work as the plaintiff did. But it is a rule that, “mere knowledge by the servant that an appliance is defective, and that risk is incurred in its use, will not, as a matter of law, defeat the servant’s action for injury received in using it when the danger is not such as to threaten immediate injury, or, where it is reasonable to suppose that the appliance may be safely used by the exercise of care and caution, and it is generally a question for the jury whether the surrounding circumstances made it contributory negli*486gence for the servant to continue using the appliance.” Hamilton v. Mining Co.,108 Mo. 375.
Yet defendant, while not controverting this rule, insists that where the servant has equal knowledge with his master of the defects and danger attending the use of an appliance, the master is not liable to the servant for an injury received in the use of such appliance, Steinhauser v. Spraul, 127 Mo. 541. That case, however, is scarcely authority for the position assumed by defendant when the facts therein are considered. The appliance was a ladder which was said to have been too short for the purpose for which it was used. There was no defect in its construction. The court held that the risk was incident to plaintiff’s employment.
The rule that defendant invokes is stated clearly in Devitt v. Railway, 50 Mo. 302, viz: “If the principal 'has been guilty of fault or negligence, either in providing suitable machinery, or in the selection or employment of agents or servants, and injuries- arise in consequence, he must respond in damages. But when the servant himself well knowing the default of his principal as in providing defective or unsuitable machinery, voluntarily enters his employment, he assumes the risk and can not hold his employer for the consequences.”
The distinction between that class of cases and this is clear. In the latter the plaintiff did not enter, the em-. ployment of defendant with a knowledge of unsuitable implements in use by his master. The implement in use was suitable when in proper condition, consequently there was no assumed risk. He did not assume the risk of its getting out of order and he was justified in its continued use, if it was reasonable to suppose that by the exercise of ordinary care he might do so in safety; and, as has been said that is generally a matter to be submitted to a jury. Hamilton v. Mining Co., 108 Mo., supra.
All defendant’s instructions, excepting No. A, were given. The court was justified in refusing the latter. *487Plaintiff fully presented the law of the case upon the theory on which it was tried.
For the error noted the cause is reversed and remanded in order that the plaintiff, if he so desires, may amend his petition.
All concur.