Atkinson, Justice.
The plaintiff, as the next friend of his minor, son, brought an action against the defendant, for personal injuries alleged to have resulted to his son in consequence of the negligence of the defendant in failing to inform the child of the dangerous character of certain machinery about which he was put to work in the defendant’s factory, in consequence of which failure to inform the boy of the dangerous character of the machinery, he was injured. The evidence was somewhat conflicting as to the age of the boy, though the greater *616weight of it seems to fix his age at about eight years. His father knew that he was to be employed, or was employed by the defendant in its factory; knew of the character of the business in and about which he was employed; and the testimony shows, though the minor himself stated to the contrary, that the child had been repeatedly advised by various employees of the defendant, including the assistant superintendent who was immediately in chai’ge of the department in which the boy was employed, as to the danger attendant upon a negligent attention to his business connected with the-machinery. It was shown that, notwithstanding these-repeated warnings, the boy was accustomed, in his spirit of idle playfulness, to manipulate various cog-wheels connected with the machine. He was at work upon the machine, cleaning out trash that had accumulated' in the cogs of the machine by which he was injured. The testimony of the minoi’’s father who bi’ings this-suit, was to the effect that, while not specially bright, he was a child of ordinary intelligence and capacity. It appears that he was furnished with a stick and a piece of waste and instructed how to use them in getting the machinery cleaned. There was no evidence that he did not know of the dangerous character of the machine, or that he was not of sufficient capacity to-have performed his work without injury, if he had been, attentive to his duties. The question in the case turned upon whether the master had exercised ordinary care in instructing the minor as to the uses of the machinery and'the dangers incident to his employment in connection therewith. There was abundant evidence of the fact that he had been repeatedly advised that the machine -was dangerous, and that he himself knew it; and under this state of facts, the court charged the jury, in effect, that the mere notifying him that the machine was dangerous by an employee would not be sufficient-*617to relieve the defendant, unless that employee pointed out to him where the dauger consisted — not simply to-notice that what he was doing was dangerous. The-vice of this instruction consists in the expression by the court to the jury of an opinion upon the weight of the-evidence. The question of negligence is one for the jury exclusively, and the law does not undertake to-point out how, nor in what manner, a master shall in-. struct a minor servant in the handling of dangerous, machinery. If, as in this case, the danger be manifest, and obvious, the jury might have found, had they been free so to do under the charge of the court, that no instruction at all was necessary, and if necessary, that the precautionary words of a eoemployee were sufficient to-apprise the boy of the danger to which he was then exposing himself, and in consequence of which he ultimately suffered injury. Whether such instruction would suffice, would depend to a very great degree upon the-character of the machinery. If it were exceedingly intricate, invested with many latent dangers, a jury would probably find that a more detailed instruction were necessary than was given by the master to the servant in this case. But if it were a simple contrivance, easily understood, more general instructions might suffice to-satisfy them. At all events, whenever the jury find that the master, with reference to this particular matter,, has exercised ordinary and reasonable care, he is entitled to an acquittal. Upon all questions of fact involved they are the arbiter’s chosen of the law. The court has-no more powrer to invade the province of the jury, than the jury has to entrench upon the prerogatives of the court. In view of the strong evidence submitted in behalf of the defendant in vindication of its diligence in the premises, we cannot say that this expression of opinion by the presiding judge was harmless; and even if we felt at liberty so to do, we are confronted by the *618positive enactment contained in section 3248 of the code, •enjoining upon this court the duty of directing a new trial. We do not deem it necessary to consider in greater detail each of the many exceptions to rulings in this case.
Let the j udgment of the court below be Reversed.