Opinion by

The difficulty in the way of the plaintiff’s contention, sustained by the court below, is twofold. In the first place there is no ambiguity in the contract declared upon, to be explained by parol evidence, and, in the second place, the effect, if any, *53and certainly the manifest object of the testimony offered and admitted under objection, was not to éxplain anything that was written, but to reform or write into the contract a stipulation that was not to be found there. The language of the contract, “ to divide equally the expense of making the American Steam Heater and the profits on the same,” was alike appropriate to the business actually carried on, and to that which- the plaintiff says was contemplated. Whether the defendant employed mechanics to work by the day upon boilers in a shop fitted up by him for the purpose, or employed Boyer, the patentee, to do the same thing for him, the cost of the boilers would be the “ expense of making ” them, within the spirit of the contract. Nothing contained in the contract itself, or in the evidence offered in supposed explanation of it, indicates that any advantage was to accrue, or was likely to accrue, to the plaintiff in case, the boilers were actually manufactured by or under the personal direction of the defendant, which would not accrue to him if they were ordered from the patentee. There was, therefore, no reason for an attempt to vary what was, by the very offer of the testimony, conceded to be the plain meaning of the Avords used by the parties.

The real object, however, of the testimony, was not to explain, but to reform, or add to the contract. The plaintiff admitted that he was to bear half of the expense of making such boilers as the defendant should personally manufacture, and therefore as to such the provision must stand as written. None had been so manufactured, but all had been ordered from Boyer and paid for by the defendant, who had not been reimbursed by collections from patrons. To escape from liability for one half of the expense of the boilers that had not been paid for by patrons, and at the same time come in under the terms of the contract as to division of profits, the plaintiff must read into the contract a further stipulation. Neither fraud, accident nor mistake Avas alleged, but something like an attempt Avas made to prove, by the unsupported oath of the plaintiff, a cotemporaneous parol agreement inducing him to execute, or accept the written contract. It would be a waste of time to consider whether his testimony Avas sufficiently clear and precise upon this subject to entitle it to be submitted to the jury. Unsupported as it was, and contradicted by the oath of the defendant, *54it could not go to the jury. This subject has been so fully discussed in Thomas v. Loose, 114 Pa. 35, and Jackson v. Payne, Id. 67, and other recent cases, as to require no further notice.

Declarations of persons for whom work was done by the defendant, as to their dissatisfaction, were not evidence, nor should the fact that they resisted payment be permitted to prejudice the defendant, unless their resistance was effectual, and that upon the ground of negligence in the performance of the work, not of the unsuitableness of the boilers.

The judgment is reversed, and a venire facias de novo is awarded.