(after stating the facts). The first assignment of error discussed in defendant’s brief relates to the testimony of Alvin E. Schmidt and to the admission of Exhibits B, C, and E with reference to which he gave evidence. It appears that the icehouse as originally constructed was 100 feet broad by 200 feet long. After plaintiff acquired the property, it caused to be erected, upon each side of the original structure, an addition 100x200, so that when it was destroyed the icehouse was a building 300x200. Witness Schmidt was in charge of the work when the additions were built. The exhibits in question were prepared by him and contained a statement of the kind and amount of material used in the structure together with his estimate of the value thereof. His testimony as to value was based upon the figures he had previously placed in the exhibits. These, in turn, were in part predicated upon his own knowledge and in part resulted from his inquiries from others as to certain materials, with the value of which he was not familiar. We are of opinion that the evidence was properly admitted. Close v. Railroad Co., 169 Mich. 392 (135 N. W. 346). It is obvious that the exhibits themselves are not substantive evidence of the facts and figures they purport to contain, and we do not understand they were admitted as such. They are but papers of convenient reference, which enable the witness to testify to voluminous and complicated computations previously made by himself, the details of which it would be utterly impossible for any witness to carry in his head. Aside from this, no evidence was offered on behalf of defendant questioning the correctness of the estimates of materials and values made by Schmidt, and it is not now claimed that the verdict is excessive.
*351Joseph Wendell, an engineer of 22 years’ experience upon the Grand Trunk Railroad, was permitted to give evidence that in his opinion a locomotive in proper condition would not emit sparks capable of setting a fire at a distance of 40 or 50 feet from the track. The objection to this testimony was that Wendell had driven only locomotives equipped with a woven wire spark arrester, whereas defendant’s engine was equipped with a perforated plate spark arrester. The question to which objection is made refers to neither type of spark arrester, but refers to an engine “in proper condition for arresting sparks.” We think the witness was, through his experience, qualified to give expert evidence, and that his answer was properly admitted.
The next question arises with reference to the subrogation agreements and the contract, Exhibit H, between plaintiff and the insurance companies. After a very extended colloquy between court and counsel and the taking of the testimony of Mr. Hicks, in the absence of the jury, the exhibits were excluded by the court, and the evidence of Mr. Hicks was not placed before the jury. Counsel for defendant took exception to this action and now insists that the whole matter should have been submitted to the jury; the authority of Mr. Hicks to execute the Exhibit H having been questioned. We can readily appreciate the fact that it might be of advantage to defendant to be able to show that certain insurance companies would participate in any judgment which might be rendered against it, but we are of opinion that it had no legal right to do so. Its tort (if one was committed) was against this plaintiff, and the right of action which grew out of the tort was one and indivisible. Continental Ins. Co. v. Lumber Co., 93 Mich. 139 (53 N. W. 394, 32 Am. St. Rep. 494). The plaintiff undoubtedly was possessed of the substantive right and was the proper party to bring the suit. Had it done *352so, without executing the various subrogation contracts, it would still necessarily have acted in the capacity of a trustee, as regards the judgment, for the benefit of the insurance companies, in accordance with the terms of the policy contract. The relation would be implied by law. Federal Ins. Co. v. Insurance Co., 202 Fed. 648, 121 C. C. A. 58; Southern Bell, etc., Co. v. Watts, 66 Fed. 460, 13 C. C. A. 579; Phoenix Insurance Co. v. Transportation Co., 117 U. S. 312 (6 Sup. Ct. 1176). The defendant is interested only in knowing that a judgment, in the suit brought, will relieve it from all liability for the consequences of its tort. As we have seen, the cause of action is indivisible. No one of the insurance companies could bring an action in its own behalf even in the name of the insured. We conclude that the court properly ruled that the entire question of insurance was immaterial to the issue, and that the defendant is not legally interested in knowing how the judgment against it shall be divided, or whether the contract providing for its division is or is not legally executed.
It is strenuously contended on behalf of defendant that a verdict should have been directed in its favor because (it is claimed) there is no evidence that the engine in question was not in “good order.” Defendant caused an inspection of the engine to be made a few hours after the fire occurred and offered evidence to show that the spark arrester, as well as all other parts of the engine, was in perfect condition. Plaintiff was unable to meet this evidence with any direct proof that the spark arrester was not in good order, but there was abundant testimony (introduced for the most part by defendant) to the effect that an engine in “good order” would not emit sparks capable of kindling a fire at a distance of 40 to 50 feet from the track. The eyewitnesses first upon the ground agree that the fire started at a point quite that distance from *353the track over which the engine in question ran. Under these circumstances, we think the question was for the jury, and that a directed verdict was properly refused. Peter v. Railway Co., 121 Mich. 324 (80 N. W. 295, 46 L. R. A. 224, 80 Am. St. Rep. 500); Clark v. Railway Co., 149 Mich. 400 (112 N. W. 1121, 12 Am. & Eng. Ann. Cas. 559); Potter v. Railway Co., 157 Mich. 216 (121 N. W. 808, 22 L. R. A. [N. S.] 1039).
Defendant submitted a request to charge upon the question of plaintiff’s contributory negligence based upon the fact that plaintiff had permitted sawdust, hay, and chaff to remain upon the ground in close proximity to the icehouse, thus materially increasing the risk from fire. The request was properly refused under the authority of Peter v. Railway Co., supra. The decisions upon the point are not without conflict, but the weight of authority is with the rule announced. Error is assigned upon the charge of the court. The charge taken in its entirety is a correct exposition of the applicable law.
The judgment is affirmed.
McAlvay, C. J., and Kuhn, Stone, Ostrander, Bird, Moore, and Steere, JJ., concurred.