Opinion by
Mr. Justice Dean,On January 21, 1893, plaintiffs were carrying on the business of gold, silver and nickel plating in a three story brick building in Lancaster city; at that date, they took from defendant a policy of insurance against fire in the sum of $1,500 for the term of one year on all their tools, machinery, gas fixtures and water pipes in the building. One of the printed conditions of the policy read thus:
“ This entire policy, unless otherwise provided by agreement endorsed hereon, or added hereto, shall be void, if, (any usage or custom of trade or manufacture to the contrary notwith*161standing) there be kept, used or allowed, on the above described premises, benzine, benzole, dynamite, ether, gasoline, greek fire, gunpowder exceeding twenty five pounds in quantity, naphtha, nitro-gljmerine, or other explosives.”
The property insured was destroyed by fire on the night of September 7, 1893; the loss largely exceeded the amount insured. The plaintiffs used gasoline in their plating process, and also for the cleaning of tools and molds; it was not, however, kept or stored in the building where the property was insured, but in another building about fifteen feet distant; the quantity kept there seldom exceeded one barrel; when needed in the factory it was drawn from the barrel through a spigot, and carried to the third story of the factory and emptied into an open kettle, which had a capacity of three to four gallons; from the kettle it was taken as needed for use in cleansing tools and molds. On the night of the fire there was no gasoline in the kettle, all put in that day having been used. After the fire the barrel of gasoline in the other building was found undisturbed; so the fire did not originate from the gasoline in -either the kettle in the factory, or barrel in the outbuilding.
The insurance company refused to pay the loss, alleging the poliej' was void because of the violation of the condition by the insured in using and allowing to be used gasoline in the building where the machinery was insured. Thereupon plaintiffs brought suit. At the trial there was practically no dispute as to the facts as we have stated them; the learned judge of the court below, however, submitted the evidence to the jury to find: 1. Was the use of gasoline necessary in carrying on the business of silver plating and cleaning tools ? 2. Was gasoline so used when the policy was issued, and was this use continued up to the date of the fire? 3. Was it properly and carefully used? If they answered these three interrogatories in the affirmative, then they were directed to find a verdict for plaintiff in the amount of the policy. There was a verdict for plaintiff, and judgment having been entered thereon the defendant brings this appeal, preferring thirteen assignments of error, which it is conceded may be considered as raising really but three questions:
1. What interpretation is to be given the words “ This entire policy .... shall be void if (any usage or custom of trade or *162manufacture to the contrary notwithstanding), there be kept, used or allowed on the above described premises .... gasoline ? ”
The premises described is the three story brick building used as a factory; the building in which the barrel of gasoline was stored was not insured, nor was it within any prohibition of the policy.
As the finding of the jury was against defendant on the facts, if there were no error in the admission or rejection of evidence, then, as appellee’s counsel argues, “ the case presents a pure question of the construction of a contract.”
We assume that to constitute a contract there must be the assent of two minds to the same thing in the same sense. When defendant issued and plaintiffs accepted the policy, on what sort of property did plaintiffs want to be indemnified, and what did defendant know it was insuring? Defendant viewed the machinery and tools in the building then being operated in the work of gold, silver and nickel plating, and by the express terms of its policy its indemnity is to the “ Lancaster Silver Plate Company.” Bringing the parties together at the factory, for the purpose of contracting for insurance on the machinery and tools in the building to be used in gold, silver and nickel plating, what must we assume defendant knew ? Certainly, that it knew what was necessary to carrying on the business. We cannot assume that a party honestly accepting another’s money as a consideration for the faithful performance of a very important contract, was wholly ignorant of the subject of the contract. Plaintiffs were engaged in gold, silver and nickel plating; in carrying on this business it is well known, certain materials, chemicals and combinations of chemicals are necessary, and without them it could not be carried on; the jury have found as a fact, from the evidence, that the small quantity of gasoline used was necessary to the operation of these works, and that it was in use at the date of the policy; if necessary, then the cessation of its use meant the stoppage of the business, or so crippling it that it must prove unprofitable. Is it a reasonable interpretation of the contract to suppose either party intended that result? To conclude they did not, is only to assume the insured were not idiots and the insurers were not cheats.
*163The general rule, deducible from the text books and adjudicated cases, as to such prohibitions, is, that it is the intent of the parties to insure the subject of insurance as it necessarily is and must continue to be during the life of the policy. And, as is said in Stacey v. Ins. Co., 2 W. & S. 506, “ Policies are to be construed largely according to the intention of the parties, and for the indemnity of the assured and the advancement of trade. Facts and circumstances dehors the instrument may be proved in order to discover the intention of the parties.” So, where the printed portions of a policy prohibited the use of extra hazardous material, necessarily used in operating the machinery, or business insured, and the written or inserted description of the subject of insurance did not prohibit them, it was held, the use of the hazardous material did not avoid the policy: Ins. Co. v. Brock, 57 Pa. 74; Hayward v. Ins. Co., 19 Abb. Pr. 116; Mears v. Ins. Co., 92 Pa. 15; Ins. Co. v. McLaughlin, 53 Pa. 485.
In the case last cited, the insurance was upon a leather factory ; the printed condition prohibited the use of benzole; plaintiff proved the use of this material was essential to successfully operate his factory; the benzole, as the gasoline in this case, was kept in a shed some distance from the building insured, and was carried from the shed to the main building in a bucket when used; a fire originated from the benzole in the bucket after it had been carried into the main building, and destroyed the property covered by the polic}'. This court, by Woodwakd, C. J., said: “ But did they mean to exclude it from the factory as an element or agent in the conduct of the business ? To assume that they did, in the absence of language to that effect, would be to assume that they expected the business to stop or to be carried on out of the usual mode.” That case is a stronger one against the insurers than the one before us, only because the essential fact is an obvious inference from the contract itself. That policy expressly granted to the insured the privilege of keeping five barrels of benzole in the shed, but expressly stipulated the shed was not insured. The inference necessarily was the company knew the benzole kept in the shed was for use in the factory; then following this up with proof that benzole was ordinarily used in the manufacture of leather, plaintiff claimed the manifest intent of the *164contract was that it should not be avoided by such use of benzole. In the case before us, nothing is said about the storage of gasoline in the outbuilding, but on the evidence, dehors the contract, it was submitted to the jury to find whether the use of gasoline was necessary to the business of silver plating, and whether it was in use at the date of the policy; and they found both facts affirmatively; then follows the only warrantable inference, that the insurers knew when they delivered their policy the acceptance of it was not to be as disastrous to the insured as the destruction of their property by fire ; because, on the fact found, that the use of gasoline was necessary to the successful carrying on of the business, and if the policy prohibited such use, then the insured would have offered him the alternative of stopping business, or taking the risk of fire. No one believes an insurance company would tender such a contractor a sane man accept it; such a choice was not intended by either party to the policy. It would be justas probable a supposition that the company would have tendered to a silver plate manufacturer a policy containing a stipulation avoiding it, if the assured kept or used silver plate upon the premises.
This disposes of the first five assignments of error, which complain of the interpretation of the contract by the court below.
2. The sixth and seventh assignments are to the admission of testimony offered by plaintiff to prove that the use of a small quantity of gasoline was necessary in the business of silver plating; that at the date of the policy, and for several years before, it had.been so used by plaintiffs, and that such use was continued without change down to the time of the fire. The appellant argues that this was error, because the insurance was not of machinery and tools to be used in any particular business; was simply an insurance upon the property in a particular building, and as part of the contract the use of an extra hazardous material was prohibited. As the objection assumed defendant’s interpretation of the contract to be the true one, which it was not, as we have already noticed, the objection was properly overruled. The written contract itself shows the defendant insured to a silver plating company its boilers, machinery and tools in its manufactory. It must be assumed the insurers knew for what purpose the machinery *165was then being used, and for what purpose it would be used; just as would be assumed, if they had taken ■ a policy on the machinery in a flour mill, they knew it was to be used in the manufacture of flour.
The eighth and ninth assignments of error are to the rejection of a part of the testimony of John H. Carrow, a witness examined as an expert by defendant. It was proposed to ask the witness what effect gasoline would have when used in cleansing in the process of silver plating; the witness had already stated that he had never seen gasoline so used; that for the same purposes he had always used and had always seen used concentrated lye; that he knew gasoline was a product of petroleum. Clearly, the witness had not the knowledge that warranted him in testifying as an expert to the effect of gasoline, and there was no error in sustaining the objection. He did testify that the use of gasoline, as proven by plaintiff, was not necessary in silver plating, and that he had never heard of it before; this was the most his knowledge warranted.
8. The defendant’s tenth assignment is based on the refusal of the court to instruct the jury that it was incumbent on the plaintiffs to show that the use of gasoline was of such vital importance to the conduct of their business that it could not be ignored, and if any non-prohibited article could have been used in place of gasoline, it was the duty of plaintiffs to use such article.
We do not think such a heavy burden as this was imposed on plaintiff; in effect, the point asked the court to say the necessity must have been absolute. This is not the rule laid down in any of this class of cases. In Hall v. Ins. Co., 58 N. Y. 292, the policy was on a photographer’s establishment; it was held to cover property destroyed, which was necessarily and ordinarily used in that business, although, by the printed conditions of the policy, the use of some of the articles was prohibited. There are but few manufactured articles which could not be produced by more than one process; that one, however, may be properly deemed necessary which is in ordinary use by the trade for the attainment of the result. To this point tended plaintiff’s evidence, and the instruction to the jury, that they must find the use of gasoline was necessary, was as favorable to defendant as the law required; the court was *166not bound to instruct that the necessity must be an absolute one; that is, if silver plating could be done by any other process, plaintiffs were bound to adopt it, or their policy was void.
As to the remarks of the court to counsel when motion for compulsory nonsuit was refused, even if an expression of opinion on the evidence, it does not follow the jury heard them, and it certainly will not be presumed their verdict was controlled by what was not addressed to the jury. If counsel for defendant feared their cause would be prejudiced by what the judge said to them and not to the jury, they should have asked him to instruct the jury to disregard it.
There is nothing in any of the assignments requiring further notice. We are convinced that the ease was tried without substantial error, and that the judgment is just; it is affirmed.