Sheldon, J.
The agreement between these parties substantially provided in the first place that when cars of the defendant were operated upon the plaintiff’s tracks in charge of the plaintiff’s servants, the plaintiff should be ultimately liable for all damage *88caused by its negligence or that of its servants, provided that it was not due to faulty construction or lack of repair of the defendant’s cars or the mechanism, machinery or appliances thereof; and the plaintiff agreed, upon certain conditions, to indemnify the defendant for all damages suffered by the latter or for which the defendant should be held responsible for which the plaintiff thus had made itself liable. The defendant on its part agreed, upon conditions not now material, to indemnify the plaintiff for all damages for which the plaintiff should be held responsible, “ where such injury or damage has been occasioned in a manner to render . . . [the defendant] hable as provided herein.”
The accident in question was due to two causes acting together: the excessive speed of the car due to the negligence of the plaintiff’s servants; and the defective condition of the axle of the defendant’s car, which condition was due to the negligence of the defendant. That is, the accident was due to the combined effect of the negligence of both parties, and cannot be attributed to the negligence of either one of them alone.
Under these circumstances, we think it plain that upon that part of the agreement which we have stated the action cannot be maintained. The case is not covered by that clause of the agreement, giving to it its broadest construction against the defendant; for at most it dealt only with accidents which were due to the fault of one party rather than of the other. Nor can there be a recovery in tort; for where, as here, both of the parties are at fault, the loss must rest where it has fallen. Churchill v. Holt, 131 Mass. 67, 69. The plaintiff has contended indeed that the, excessive speed of the car was not the proximate cause of the accident, but merely a condition which contributed to it, and but for whose existence it perhaps would not have happened. Snow v. New York, New Haven, & Hartford, Railroad, 185 Mass 321. Gibson v. International Trust Co. 186 Mass. 454. Bellino v. Columbus Construction Co. 188 Mass. 430, 433. Stone v. Boston & Albany Railroad, 171 Mass. 536. But the judge found, with manifest reason, that the excessive speed was one of the proximate causes of the accident; that the accident was directly due to the negligence of both parties as its proximate causes. That finding we cannot revise.
But the agreement contained further provisions. There was a stipulation that at the trial of an action brought against either of *89the parties, in which the defendant therein claimed that the other might be hable, some attorney to be selected by their counsel should attend and follow the testimony, and in case of a verdict for the plaintiff therein hear such additional evidence as might be offered by either company and decide which one of these parties should be finally liable. The agreement then contained these further clauses: “If such attorney should be of opinion, in any case submitted to him hereunder, that the accident in respect of which the suit is brought and tried was the joint result of negligence on the part of the Old Colony Company [the plaintiff], its agents or employees, and of the defective condition of the Plymouth Company’s [the defendant’s] car, he shall have power to apportion the liability between the two companies in such manner as he shall deem just and equitable, and they hereby agree to pay such proportions of any judgment recovered by the plaintiff in such case as he shall award against them respectively. If the parties, by their respective counsel, shall be unable to agree as to which company is liable, under the provisions of this contract, for any injury or damages occurring, suit or claim for which shall be settled and paid without trial or out of court, both companies hereby agree to let the question be determined by a third person, some attorney at law agreed upon by their respective counsel for the purpose; and they will abide by his determination as conclusive.”
The suits and claims against the plaintiff growing out of this accident were settled, not by trials, but by adjustments made between this plaintiff and the respective parties who made those claims. The first action was indeed tried in court, and Mr. Colt was selected1 by the parties and attended the trial. A verdict therein was rendered against this plaintiff, but the judge set it aside and ordered a new trial. Thereupon this plaintiff made a settlement of all the suits and claims pending against it by reason of this accident, but upon terms approved by this defendant. This defendant then refused to proceed before Mr. Colt as an arbitrator under the stipulations above quoted, and the plaintiff brought this action.
The agreement between these parties as to the adjustment between themselves of actions brought against either party by reason of accidents which were the joint result of the negligence of both of them is that the arbitrator appointed to attend the trial of such *90suits and determine which one of the parties was ultimately responsible may, if he finds that both were at fault, apportion the damages between them in such manner as lie shall deem just and equitable. If we assume in favor of the plaintiff that this stipulation applies to cases like the present, in which no trial or a merely fruitless trial was had, yet the fact remains that there is here no agreement that in cases where both parties are at fault the damages shall be apportioned justly and equitably between them. The agreement is merely that the arbitrator shall have power to apportion them according to his view of what is just and equitable; and the court has no means of determining whether he would exercise that power or what his individual view might be. Munson v. Straits of Dover Steamship Co. 102 Fed. Rep. 926. The judgment of a judge or jury cannot be substituted for that of the arbitrator. This is an action at law. The rule at law is well settled that in such a case as this there could be no contribution, no apportionment, between these parties. A court of law cannot say that this rule, established and constantly adhered to, can be departed from or altered or varied, except so far as the parties have agreed that it shall be. These parties well may have been willing to leave the question to the determination of a lawyer selected by themselves, presumably not only for his knowledge of the law, but for his practical familiarity with street railways whereon cars are propelled by electricity and with all the machinery and appliances used for that purpose. But this does not imply a consent that the same question, with all the sound judgment and all the technical knowledge that it may demand, should be left to the determination of an ordinary jury or of a judge, who, however great his knowledge of the law might be, would be scarcely likely to combine with that knowledge the trained skill of experienced electricians and railway men. There is no agreement like those which were considered in such cases as Humaston v. Telegraph Co. 20 Wall. 20, or Dinham v. Bradford, L. R. 5 Ch. 519. The defendant has not received property from the plaintiff, which according to the ordinary rules of law should be paid for by the defendant, and we have not a merely subsidiary agreement for fixing a price by arbitration, so that justice can be done by ascertaining the value of what the defendant has obtained at the expense of the plaintiff. Here the parties have agreed that upon certain conditions the ordinary rule of law shall not govern the adjustment *91of their affairs; and we cannot say that their agreement shall be extended beyond the scope of those conditions. The reasoning of the court in Deerfield v. Arms, 20 Pick. 480, though upon different facts, is applicable here. No more than in that case can we give to the agreement of the parties an effect for which they did not choose to stipulate. It is true, as the plaintiff has contended, that all agreements, if possible, are to be construed so as to give them effect, and so as to be in harmony with law and justice. Noonan v. Bradley, 9 Wall. 394. Merriam v. United States, 107 U. S. 437. In re Dunkerson & Co. 4 Biss. 227. Watts v. J. B. Camors & Co. 10 Fed. Rep. 145. McElroy v. Swope, 47 Fed. Rep. 380. Collis v. Emett, 1 H. Bl. 313. Russell v. Phillips, L. R. 14 Q. B. 891, 901. But that principle does not authorize us to make a new contract, or to bind parties to terms beyond the fair meaning of the language which they have used. Jessel, M. R., in Smith v. Lucas, 18 Ch. D. 531, 542.
The result is that the plaintiff cannot maintain its actions. We do not need to discuss the specific rulings made by the judge at the trial. We find no error in any of them. Judgment must be entered for the defendant on the finding in its favor.
So ordered.