¶1The union of two minds is necessary to make a contract. Chitty on Cont. 9; Hazard v. New-England Mar. Ins. Co., 1 Sum. 218.
¶2If it appeared that the parties understood the contract differently, one that the article to be contracted for was to he made in one way and the other that it was to he made in a different way, perhaps in the want of mutual assent as to what was to be done there might be no contract. Poth. on Obl. 11.
¶3So far as the words of this contract are concerned there was a union of two minds ; that the plaintiff should east for the defendant a set of gearing for a horse power, the wheel to he like the one in operation in the plaintiffs’ foundery. What is the construction of this contract ?
¶4like does not mean exactly similar in every respect. Immaterial variations would not be regarded under such a description. The wheel which was adopted as a standard having in it a hole for the shaft, is there any thing to show that a wheel without such a hole -would be like within the intent of the parties ? That the hole was material is evident, for the wheel could not be used without a shaft.
¶5The plaintiffs do not rely upon the absence of this hole being immaterial, but upon the usage and custom of their trade to give a construction of the contract and limit the general operation of its terms. To show the usage alone however will not suffice. It must be further shown in order to prove that the usage entered into the contemplation of the parties in making the contract, that the defendant was conversant of it or in some way chargeable with *168notice of it. B Cow. Phil. Ev. 1412; Stevens v. Reeves, 9 Pick. 198.
¶6Perhaps upon the point of the defendant’s knowledge of the usage there is evidence for the jury.
¶7New trial granted.