COXE, Circuit Judge.

The defendant was at the time of the accident engaged in making dyeing machines at Amsterdam, N. Y. The plaintiff was employed by tlie defendant as a blacksmith. Henry Higgs was superintendent, and Jolm C. Evenden was foreman of that part of the works where the plaintiff was employed. The work in hand at the time of the accident was fitting a new piston rod into the piston head of a small second-hand engine. One of tlie ways of doing this is heating the piston head until tlie metal expands sufficiently to admit the new rod and then inserting the rod, after the head lias been removed from the fire. The contraction of the metal caused by cooling holds the head firmly on the rod. This was the method adopted in the present instance. Unless the precaution is taken to make a hole in the piston head, to permit the escape of steam and gases generated by the great heat, this process of shrinking on the head is a dangerous one and whs known to be so by those familiar with the business. No vent was made in the present case and while the plaintiff and one Spore, a fellow machinist, were engaged in beating the head it exploded, killing Spore and injuring tlie plaintiff.

The principal question is — was the court justified in submitting the question of defendant’s negligence to the jury?

*964In considering this question, we think the following propositions must be regarded as established:

First. Evenden, the foreman, had full authority in the blacksmith shop and represented the defendant in the work carried on there. If he were negligent in the discharge of his duty while directing the work his negligence, as matter of law, must be imputed to the defendant. He was not a fellow servant.

Second. The work of repairing the piston head by the shrinking process was an exceedingly dangerous operation unless a vent were made to permit the escape of vapor.

Third. Evenden knew of this danger and did not communicate it to the plaintiff or direct any one else to do so.

Fourth. The explosion occurred because this vent was not made.

Fifth. The plaintiff, who was employed as a blacksmith, did not know of this particular danger, at least he swears that he had “never seen one of these heads before” and did not know that they contained moisture and were liable to explode.

In these circumstances the crucial question was one of fact: Did the foreman direct the plaintiff to use the heating process, as the plaintiff contends, or the cold driving process, as the defendant contends? Evenden says he directed the use of the latter and his evidence is not directly contradicted; indeed, this could not well be done, as Spore, to whom the direction was given, was killed by the explosion. There was testimony, however, from which the jury might have found that the heating process was ordered by the foreman. One witness testifies that he heard Evenden say to Spore:

“Be careful, Jim, when you take that out; don’t let Sime (the plaintiff) burn it.”

It would be absurd to use such language regarding the cold driving process, and, if this direction were given, the jury were warranted in assuming that Evenden had directed the use of the heating process. Again, two witnesses swear that about twenty minutes after the accident, they heard Evenden say, “We made a mistake, we forgot to táp it.” This is criticised, because Evenden may have said, “he forgot to tap it,” instead of “we forgot to tap it.” The difficulty with this contention is that both witnesses agree that he said, “We forgot to tap it.” But, in any view, the expression denotes surprise, not that the heating process had been used, but that it had been used carelessly. If Evenden had directed the use of the cold process, would not his first exclamation of surprise and indignation have been — “He made a mistake, he did not use the.process I told him to use?” If the jury believed that Evenden used the language quoted, they were justified in taking it into consideration in determining the question whether the hot process was ordered. It was certainly incompatible with the theory that the cold process was ordered.

The defendant’s brief contains a persuasive argument to prove that the plaintiff’s witnesses upon this question are mistaken and that some of them are unworthy of belief. ‘If we were sitting as triers of the facts, it is quite possible that we might agree with the contention of defendant’s counsel in this regard, but we cannot say as matter of law *965that tlie plaintiff’s proof was so inadequate as to require the court to set aside a verdict based thereon. There was a sharp dispute tipon the testimony as to which process was ordered; this was for the jury to settle and it would have been error for the court to have taken it from them. The inference to be drawn from the plaintiff’s testimony is clearly to tlie effect that the hot process was ordered. Evenden was there immediately before tlie explosion giving directions regarding tlie piston head. The testimony shows that he was a man tenacious of his authority and accustomed to be obeyed. 'Hiere is a strong presumption that the subordinates of such a man, being themselves ignorant of the best methods to pursue, would not deliberately disobey his orders. In other words, the jury, in addition to the testimony, had a right to take into consideration the presumption that the process actually used by tlie workmen was the one which their foreman directed them to use.

The question now under consideration has been already passed upon by this court on the former writ of error. After discussing the hearsay testimony which was improperly received, the court says:

“Undoubtedly tliore was other testimony in tbe plaintiff’s c-ase which, pieced together, would have warranted the jury in finding that Evenden gave instructions through Spore that the plaintiff should heat tlie piston-head.”

We do not think, the trial court misapplied or misconstrued the rule relating to latent defects. There can be no question whatever that the work, if done by the heating process, was exceedingly dangerous. The moment steam was generated in the piston head it became as unsafe as if it contained dynamite or gunpowder. If, however, a vent were made for the escape of steam, it became absolutely innocuous. The foreman knew all these facts. — the blacksmith knew none of them. The danger was hidden, nothing which the blacksmith could see indicated to him the peril lurking in the piston head.

It was clearly the duty of the foreman to inform the plaintiff of this peril which” would confront him the moment heat was applied, unless the escape of steam was provided for. The making of the vent was not a mere incident or detail in the heating process; it was a momentous fact of which it was absolutely essential the plaintiff should know before he was required to do the work.

Various exceptions are directed to the action of the court in examining the witnesses and commenting on their testimony. We have frequently had occasion to say that in the trial of jury causes the wise and orderly course to pursue is to leave the examination and cross-examination of witnesses to counsel. Eor the court to take a prominent part in tlie trial creates misunderstanding and irritation and is quite likely to give the jury a wrong impression as to the attitude of the court. In tlie present case the statements of the court particularly complained of took place during the examination of the expert witnesses and related, generally, to some question of mechanics upon which the court and the witness were not in perfect accord. In no instance did the court express an opinion upon a really vital question. In view of the clear statements of the charge, which presented the issues impartial!}’, we cannot think that any of the statements of the *966court worked injury to the defendant. Assuming that the language of the court can be construed into the expression of an opinion injurious to the defendant, it must be remembered that in the federal courts it is not error for the trial judge to express an opinion upon the facts provided he makes it plain to the jury that in this domain they are the final arbiters.

There is no evidence, certainly no competent evidence, that the verdict was influenced in any way by the suggestion that the defendant was protected by insurance.

Other exceptions have been argued, but we think none of them is well taken and that it is unnecessary, in view of what has already been said, to discuss them in detail.

The verdict was a reasonable one, even before it was reduced, and. the judgment thereon should be affirmed with costs.