[1] Although the declaration avers two grounds of negligence—accumulation of inflammable dust and spontaneous” combustion of some ground grain (shives) which had been allowed to remain undisturbed in a bin—the main thing relied on by the plaintiff was the dust. This is manifest from his counsel’s opening address (which has been printed in the record) and from the testimony. If the jury were satisfied that the cause of- the explosion was the presence of this dust, and that reasonable care had not been taken to remove so much of it as to render the premises safe, they were warranted in finding defendant negligent, even though they were not satisfied that the flame was produced by spontaneous combustion. If premises are allowed to become unsafe because they are filled with dust which would explode on the application of spark or flame, and the exercise of reasonable care would have prevented the premises from -becoming thus unsafe, the person whose neglect brought about such a dangerous condition would not be excused because the actual spark which fired the train was produced by some intruder undertaking to light his pipe.

There was abundance of proof that there had never been any real effort to get rid of dust accumulations. All there is on this point is the statement of the witness Marsha, that they “used to sweep the floor when they were not at work on other work.” All the other places where dust could lodge and be set free by jarring were wholly neglected.

[2] There was testimony from which the jury could reasonably conclude that there was more than one system of dust removal which, if installed and properly operated, would have reduced the volume of suspended dust sufficiently to avoid the risk of its exploding in the presence of a flame. There is no testimony controverting that given by the witness Day; not a suggestion that his systém does not accomplish all that he claims for it, nor that there was anything in the structure of this particular plant which would make it impracticable, or even difficult, to introduce such a system. In reference to the evidence relating to devices for the alíaying and removal of dust, the judge charged the jury:

“If you find that there was a known device in common use and adaptable to the work that was being done in that building, which a man of ordinary prudence would adopt, to keep dust out of the air, then it was the duty of the defendant to have installed such a device, and the failure to install such a device would be negligence on the part of the defendant.”

Defendant excepted to this portion of the charge, but it is so manifestly an accurate statement of the law that it would be a waste of time to discuss it. With this instruction as their guide, and upon the testimony which this record discloses, it is difficult to conceive how *445any intelligent jury could do otherwise than find that defendant was negligent in that respect.

[ 3 ] Such a finding would sustain a general verdict against defendant. It is unnecessary, therefore, to discuss the-other branch of the case. viz.:

•‘Whether the fire that ignited the dust was caused by defendant’s negligence in allowing spontaneous combustion to be generated in its stored shives.”

This question was separately submitted for a special verdict, and was answered in the affirmative. But the jury was told that the defendant would be liable whether there was negligent spontaneous com-' bnstion or whether there was a negligent accumulation of dust which lias ignited by a flame or spark which had not been produced by any negligence of defendant. It must not be assumed from our failure further to discuss the evidence that we assent to the defendant's contention that there was not sufficient testimony to support the jury's verdict on the special question. With a general verdict against the defendant it is unnecessary to do so. Upon whose suggestion this special finding was asked for does not appear, nor what purpose it was expected to subserve. K it were intended to ascertain whether the jury found defendant negligent under both charges or only under one, the question should have been supplemented with another concerning the removal of dust.

[ 4] The first six assignments of error are waived. The others may next be considered. The seventh assigns error because the witness Marsha who worked at one of the bins was allowed to testify that the grain (or shives) in the bin got very hot when he was there 15 days before the explosion. It is objected that this was too remote, but the evidence was relevant in view of the fact that the plant was shut down for want of water for two weeks, and that the explosion occurred the very day work was resumed. 'Moreover, other testimony tended to show that materal such as these shives, if left undisturbed, would tend to grow hotter and hotter.

[5, 6] The eighth assignment of error is to a long hypothetical question to the witness Bell, an expert on explosives. The question was objected to on the ground that ‘‘there was no evidence tending lo show that any such conditions (as the question assumed) existed in this plant at or near the time of the explosion.” The colloquy between court and counsel which followed indicates that the assumed conditions then objected to were that the degree of heat assumed to he present in the shives in the bin was the degree testified to by the witness who had worked there 15 days before the explosion. As we have seen, there was evidence in the case tending to show that, if shives were left undisturbed in a bin, they would probably grow hotter. Counsel in reply to an inquiry of the court further objected to the question because it did not appear that the machinery was shut down continuously after the date to which the witness testified. But there is sufficient evidence to show that the machinery ivas shut down for two weeks because the water supply was cut off. Therefore neither of the objections made on the trial are sound. In *446the brief in thiá court a further assumption in the hypothetical question is objected to, viz., that the bin was “chuck full of shives and so remained for nearly a year.” It would be a sufficient answer to this objection that it was not raised at the trial. Counsel who object to a hypothetical question which, when printed, is a page and a half long (and which undoubtedly contains many assumptions which nobody disputes), on the ground that some of its assumptions are not supported by the testimony, should call the attention of the trial judge to the assumptions they object to, so that the question may be modified or the missing testimony supplied. Moreover, one of the witnesses testified that the bin was 70 feet deep and filled with shives for 70 feet; and in response to a question of the court, “How long to your knowledge had this been in the bin?” replied, “I had been there most a year, and it had been there as long as I had been there.” The' jury might 'or might not have believed this witness, but his testimony abundantly justified the including of the assumption in a hypothetical question.

[7] Assignments 10, 11, 13, and 14 (assignments 9 and 12 are waived) all deal with questions put to the witness Day, who testified as an expert in regard to a method of dust removal which he had himself devised and installed in many plants where, as he said, it had operated successfully and also to another system, the “Cyclone” devised by some one else. The first question objected to asked witness to explain how his system operated so as to avoid the explosion of dust that is liable to originate in mills. The second question asked if it was impracticable to use his system in a building that was an elevator and grinding mill combined. The third question asked if he knew of more than two other systems of dust collectors; and the fourth asked whether or not the principle is the same in all systems—the suction principle. These questions were certainly unobjectionable in form. This witness was examined by deposition out of court, and we find nothing in his answers to these questions which was objectionable. He was undoubtedly qualified to testify, and it was proper for him to testify concerning the operation of his dust collector and of others in use in places where explosive dust of this sort is produced whether they were mills, elevators, mixing rooms, or a combination of two or more of them. So, too, it was proper to state the principle common to all dust collectors, the Cyclone or others. Such information would.be useful to the jury when weighing his specific statement that his system was adapted to a plant like the one in question. No one was called by defendant to controvert this last statement, or indeed any other made by this witness.

[8] The fifteenth assignment of error was to the allowance of a question asking a witness whether or not he had trouble with the plaintiff over a debt he owed the plaintiff. The ground of objection is that, while it is always proper to show that a witness is hostile to the party against whom he is testifying, a general inquiry into that fact is all that should be allowed, neither the cause nor the details of the trouble should be shown. Since the trial judge announced that details should not be gone into, and the witness replied merely, *447“There is a little difference between us I think,” this assignment calls for no further consideration.

[9] At the close of the entire evidence, the defendant excepted to the submission of the case to the jury on the ground that no actionable negligence was shown—

“because * * * condition of air and dust in the elevator on the day of the accident was the natural and inevitable result of unloading ground feed and grain in the usual course of business, and there is no evidence tending to show that it could have been avoided by the exercise of the care of a prudent man conducting such a feed mixing business.”

In view of the testimony concerning the conditions of the mill and the testimony concerning dust collectors, there was evidence to show that the accident could have been avoided by the exercise of care and prudence. A very full statement of this evidence will be found in Barney v. Quaker Oats Co., 82 Atl. 113, Supreme Court of Vermont, May Term, 1911 (not yet officially reported), where this same explosion was the subject of discussion. This assignment of error is unsound.

What has been already said disposes of the seventeenth assignment,, which depends for its support on the proposition contended for that there was no evidence tending to show the existence of known practical devices for eliminating dust.

[10] The eighteenth assignment relates to certain instructions to the jury on the subject of exemplary damages. It need npt be considered, since, if erroneous, it was harmless, because the jury gave no exemplary damages. The amount awarded, $2,480.55, was less than the amount which plaintiff offered to prove was the actual value of the property destroyed. While the value of some of the articles destroyed was disputed, it would be straining a point to assume that the jury, which gave considerably less than the plaintiff claimed as compensatory damages, could have awarded anything as punitive damages. Theoretically such a thing might be possible, but it is too highly improbable to call for the reversal of the judgment. Undoubtedly the jury were satisfied that plaintiff had not proved his demand up to the limit and so reduced some of the items and rendered their verdict accordingly without giving any consideration to the question of punitive damages.

The judgment is affirmed.