The following opinion was filed November 29, 1901:
Dodge, J.
This case was .argued with great vigor, ability, and refinement by counsel upon both sides, invoking most of the well-known rules for construction of contracts, which, however, in the ultimate analysis, all come to the proposition that the duty of every court in the construction of a contract is to ascertain the intention of the parties; limited, however, in so doing, to the language of the contract, read in the light of the surrounding circumstances, and purposes presumably in the minds of the parties at the time of reducing their agreement to writing. Heryford v. Davis, 102 U. S. 235, 243; Brittingham & H. L. Co. v. Manson, 108 Wis. 221, 225.
The situation at the time of making the contract under consideration was that of the respondent exercising its right by statute to cross the existing railway of the plaintiff at a point remote from settlement or habitation. It had a right to do this by putting in and maintaining the physical crossing, and by paying such sum as might be fixed by commissioners in a proceeding under subd. 6, sec. 1828, Stats. 1898, which was the same in 1884 as it is now. By the agreement between the parties, the duty to put in and maintain the physical crossing was, as under the statute, to be borne by the respondent. That duty was subject to increase as the appellant, in its discretion, might desire to put in additional tracks. This was the extent of the obligation assumed by the respondent, except in one contingency, *167namely, that specified in tbe fourth section of tbe contract, — “in case flagmen or switchmen are required at or by reason of said crossing.” Then, and then only, were certain expenses to be paid, namely, tbe hire of “such flagmen or watchmen,” etc. It is probable that tbe word “switchmen,” in tbe first clause, was intended to be “watchmen,” since it is rendered entirely apparent by tbe evidence that a man whose duty it was to attend upon a crossing would be called a “watchman” or “flagman.” But, waiving that consideration, if the word “switchmen” was intentionally used, as perhaps we must presume, their function would doubtless be in connection with the possibility contemplated by the crossing statute above referred to, that there might be put in certain turn-outs, sidings, switches, and other conveniences in furtherance of the object of the connection. A mass of evidence was introduced bearing upon the functions of various men employed at railroad crossings, and the appliances used by them, as also with reference to the names used to describe both the employees and their implements. That evidence renders certain, beyond dispute, that, within railroad terminology, neither the designation “flagmen,” “switch-men,” nor “watchmen,” would ever be used or understood to describe or include operators of interlocking plants. Although such operator does perform the duties of a watchman, in that he looks out for trains; duties of a flagman or signalman, in that he signals approaching trains; and of a switch-man, in that he opens and closes the derailing devices, often called -“switches,” — yet the plant which he operates is so distinguished by its purpose, its method of construction, and its importance that he is always distinguished in designation by reference to the plant so operated, and never confused with flagmen, watchmen, or switchmen. Nor can we discover in the surrounding circumstances anything to warrant belief that the parties intended by these words more than their ordinary import in railroad parlance. It therefore *168would seem clear that tbe contingency lias never arisen wbicb by tbe contract was to impose on tbe defendant tbe expenses specified in tbe fourth paragraph; that no flagman, switchman, or watchman, within any reasonable meaning of those words, has ever been required at or by reason of this crossing j hence that no duty has arisen to do* the acts sought to be compelled in this action by a decree of specific performance.
This conclusion, based upon the very words of the contract, makes unnecessary consideration or decision of the very extensively discussed question whether an interlocking plant falls within the calls of the contract for “all watch houses, signal stations, signals, and other similar appliances that may now or at any time hereafter be required,” or whether it is so differentiated therefrom as to be dissimilar, instead of similar. That question would involve so extended investigation and so many conflicting considerations that we cannot justify ourselves in entering upon it, although fully debated, and apparently deemed the crucial one by the circuit court. The judgment of that court was right, however this latter question be resolved.
By the Court. — Judgment affirmed.
Marshall, J., dissents.
The appellant moved for a rehearing, and the following opinion was filed February 18, 1902:
Dodge, J,
By the former opinion this case was disposed of, and the judgment affirmed on the ground that until plaintiff required of defendant a flagman, switchman, or watchman, no duty rested upon the latter to employ such men, or to erect and maintain the structures and appliances specified in the contract, and that no such requirement had yet been made. That served to affirm the judgment, and the *169further question whether, when that condition precedent occurred, an interlocking plant would be included within such structures and appliances, while fully considered by the court, was not treated, as not affecting the result. Upon a review of the case upon motion for rehearing, it is apparent that the latter question is ah important one, upon which the parties are at issue, and which very likely will have to come up again for decision'after proper demand shall have been made. It is therefore deemed advisable, since the subject has been fully argued and considered, to express our decision upon it.
The question so presented is whether the interlocking system or machine was intended to be included within the expression “other similar appliances,” for clearly it is not included in the specific things described as “watch houses,” “signal stations,” or “signals.” Each of these may perhaps be included in the interlocking plant, but neither of them alone, nor all of them together, include the important and characteristic element of the latter. That element is a peculiarity of construction of the tracks of each railroad some 500 feet away from the crossing, connected with each other through the medium of a machine, so as to create absolute physical obstacles to the passage of a taain to collision at the crossing. This is no signal, for that implies merely a notification to the trainmen, by reason of which they are to govern their conduct. The very purpose of the interlocking arrangement is to render signals wholly unimportant and-immaterial to the purpose of preventing collision. True, signals ar§ used in connection with the interlocker, buf not to safeguard the crossing, — merely .to enable the trainmen to avoid the derailing of their own trains.
Turning then to a consideration of the force and meaning of the expression “other similar appliances,” we enter a field for construction and interpretation, for the words are not definite and certain. They may apply to one thing or an*170other, as it may appear to be similar or dissimilar from evidence dehors the writing. We also enter a field where the court must be aided by parol evidence, for several reasons: First. Because the contract relates to a particular trade or calling, having a terminology of its own. Houghton v. Watertown F. Ins. Co. 131 Mass. 300, 303; Walls v. Bailey, 49 N. Y. 464; Tones, Cont. §§ 60, 62. Second. Because ambiguity is shown by parol evidence to exist, and needs such evidence to clear it up. Vilas v. Bundy, 106 Wis. 168. Third. Because the situation and circumstances surrounding the contracting need to be ascertained. Wussow v. Hase, 108 Wis. 382; Brittingham & H. L. Co. v. Manson, 108 Wis. 221, 225. Fourth. Because the words of the contract must be applied to facts ascertainable only by extrinsic evidence. Vilas v. Bundy, supra; Wussow v. Hase, supra. Upon these several subjects the court became a trior of facts, and his decisions thereon are binding and conclusive upon this appeal, unless so in defiance of the clear preponderance of the evidence as to warrant the inference of mistake, oversight, or prejudice. Vilas v. Bundy, supra; Wussow v. Hase, supra; Wyss v. Grunert, 108 Wis. 38; Hill v. American S. Co. 112 Wis. 627. The court has found as a fact that the words used in the contract do not, and at the time of the contract did not, include an interlocking plant, and were not so intended or understood. In support of this finding there is evidence that the interlocking plant was known to railroad men for many years before 1884; that it differed from all ordinary signal devices in the respect above stated, namely, that its purpose and effect were not so much warning not to approach the crossing when dangerous, as actual physical prevention of the approach; that it was vastly more expensive than any system of signal appliances; that whenever railroad-crossing contracts have been intended to require an interlocking system, to the knowledge of the witnesses, they have described it specifically, and not stopped with such expres*171sions as are used in this contract; that none of the expressions nsed in the contract (“flagmen,” “switchmen,” “watchmen,” “watch houses,” “signal stations,” or “signals”) would *be understood or used by railroad men as referring to or suggesting an interlocking plant; that until very recent years railroads have not deemed the expense of an interlocking system warranted, except at very important crossings; indeed, that only two or three had been put in use west of the Alleghanies. There is, too, much evidence that the general use of such plants is due to conditions developed recently and long since the making of the contract, by reason of the greatly increased weight and speed of trains, whereby has been greatly increased the expense of their stoppage, as also, the loss to the business resulting from interruption of rapidity of transit; also because of prosperous conditions of railroads, whereby such expensive appliances are brought within their means. True, on some of these subjects there is conflict of evidence, but not such as to destroy conclusiveness of the trial court’s decision.
Great space is devoted by appellant’s counsel to refutation of the idea that the great and direct purpose of installing interlockers is to avoid necessity of stopping trains at crossings, to which several witnesses testify. He urges upon us the testimony of other witnesses that the purpose, like that of signals, gates, or flagmen, is to safeguard the crossings. After a careful reading of the record, we are satisfied that, while the ultimate object is safety, these devices are not in fact used at crossings, except where stoppage of trains is a serious burden and expense. Of course, in the operation of railroads there is continual balancing of the expense of safeguards,'on the one hand, against the degree of peril and expense of doing without them, on the other. Doubtless the surest guaranty at crossings is to substitute an overhead viaduct for one of the roads, but that is not adopted till peculiar circumstances of frequency of trains, difficulty of observation, *172etc., make tbe probable expense, inclusive of damage from accidents, outweigh, tbe expense of making and operating tbe nongrade crossing. Doubtless tbe ultimate purpose of sucb a change would be safety, but tbat consideration alone would” not induce it. Clearly, sucb a change of construction would not be an appliance similar to signals, merely because safety is tbe ultimate object. Tbat escape from necessity of stoppage is a very important, if not tbe dominant, immediate' object of an interlocking plant, is indicated by many things outside tbe testimony. Thus tbe complaint, while inferentially conceding tbat tbe purpose of safety bad been sufficiently accomplished for fifteen or sixteen years, asserts tbat within a few years past tbe difficulty and expense of stopping trains have greatly increased, because of greater weight and speed, and tbat it would be a great inconvenience and hardship to require sucb stoppage. Tbe response of defendant’s general manager to tbe demand for sucb appliance indicates bis view of its purpose, expressed before litigation. He says: “We have no use for it, as our trains are few and their time is slow.” Again, statutes of various states make tbe stoppage of trains dependent on existence of interlocking plants, indicating legislative view tbat, for safety alone, stoppage of trains is the equivalent of tbe inter-locker. This view is emphasized by one of tbe most intelligent and experienced of tbe witnesses, who* speaking of tbe semaphore signal, says:
“I regard it as a perfectly safe method of guarding a crossing, if you want to undertake tbe plan of stopping all trains.”
Several other witnesses testify to tbe dominance of tbe purpose of escaping tbe stoppage of trains, while still others assert pre-eminence to tbe motive of safeguarding tbe crossing. In view of tbe whole record, we should not doubt tbat there was evidence to support the view tbat the main purpose of installing an interlocking plant at a crossing ds ordinarily *173to avoid stopping trains, consistently with safety. We do not, however, consider that a very important question. Devices are not necessarily similar merely because their ultimate purpose is. A conductor’s registering bell punch would hardly be similar to a station wicket and keeper, although the purpose of both be the same. Nevertheless the fact that in the operation of railroads the expense of interlockers at crossings has seldom been incurred, except to avoid the alternate precaution of stopping trains, is significant upon the probable understanding of the parties, for at the time of contract no such result could have been accomplished by installing the appliance. The statute as it then existed required stoppage in any ©vent. Sec. 1808, R. S. 1878. Some light is thrown by authority upon the reasonableness, and therefore the probability, of appellant’s construction of this contract. In Arkansas & O. R. Co. v. St. L. & S. F. R. Co. 103 Fed. Rep. 747, the United States circuit court for the Western district of Arkansas held that demand for an interlocking plant as condition of crossing was wholly unreasonable. In Detroit, Ft. W. & B. I. R. Co. v. Commissioners of Railroads (Mich.), 86 N. W. Rep. 842, the supreme court of Michigan held that the expense of safety devices to facilitate convenience of operation could not be imposed exclusively upon the junior road. See, also, 3 Elliott, R. R. §§ 1126-1129, as to permissible impositions upon railroads seeking to cross others.
One argument much urged by appellant is to the effect that respondent has not been able to suggest any appliance other than the signals in use at the time of making the contract, and therefore included by the -word “signals,” which is ever used to safeguard crossings, except the interlocking, and that the words “other similar appliances” must either apply to such plant or be meaningless. The premise is hardly correct, for there is evidence that gates swihging across the tracks may be, and frequently are, used. While such appliance serves as a signal, it would not be very aptly *174described by that word, and might be by the subsequent phrase. Apart from this, however, many appliances for giving warning to train crews may be conceived other than the flagman, the ball signal, the semaphore, and the gate, which were the only ■ ones in use when the contract was made. Electrical connection between the tracks of the crossing roads, whereby the passage of a train on one toward the crossing is by light or bell notified to the other, may be suggested. The now much-exploited wireless telegraphy may offer another method. In both such cases the warning may be said to be given by signal, but not by means of anything designated by that name at the date of the contract. Appliances for such new methods would be similar to the old, at least in purpose to warn the trainmen. An entirely reasonable and probable intent attributable to the general clause under discussion is that of providing for the case of subsequent discovery or invention, and we do not think it can be said to be meaningless because nothing to which it can apply has yet been generally adopted by railroads.
In the light of all the evidence and of the words of the contract, we axe unable to say that it so clearly appears that the interlocking plant is an appliance similar to those specifically mentioned in the contract, or that the purpose of the parties at the time of contracting was such as to necessarily include it, that we can repudiate the finding of the trial court thereon. We therefore agree with that court in the conclusion that the contract under consideration does not, under any circumstances, require defendant, at its expense, to install and maintain an interlocking plant.
Appellant further urges that, although we so hold, still under the prayer of the complaint should be decreed what duty does rest on defendant, and that such duty be specifically enforced. The trouble with that contention is that defendant has not agreed to do anything until required, and paintiff has not required any other appliance than that al*175ready discussed. Tbe court cannot properly make a cata-logue of tbe various duties wbieb plaintiff bas tbe option to impose on defendant in advance of tbe exercise of sucb op>tion. When requirement is made for performance of a duty witbin tbe contract, tbe defendant may comply, and no aid from a court be needed. We find no reason to change our former judgment of affirmance, and none to make necessary or desirable a rebearing of tbe appeal.
By the Oourt.-~ — Tbe piotion for rebearing is denied, without costs.
Mabshaee, J., dissents.