The court are of opinion that the rulings at the trial were erroneous in several important particulars
*581. The contract between the parties was made in writing, and is contained in the letter of the defendants to Hawes, and his reply. As soon as the defendants assented to the modifications stated in the reply, the contract was complete. In construing the contract, the judge ruled that the words, “ like the one furnished you in February,” did not apply to quality, but only to shape, exterior form, &c. But the court are of opinion that this is too restricted a construction of these words. They do not apply to weight, because the weight is expressly designated; but they apply to the material; and this should not only be iron, but the same ldnd of iron that was used in the sample referred to; and they also apply to the quality of the workmanship, which should be like that referred to. The language implies that the iron shall be merchantable of its kind. Gardiner v. Gray, 4 Camp. 144. Shepherd v. Pybus, 3 Man. & Gr. 868. Chit. Con. (8th Amer. ed.) 450. But it does not imply that the retorts shall be fit for the particular use alleged in the declaration. It is only when a party undertakes to supply an article for a particular use, that he is held to warrant that it shall be fit and proper for that purpose. Chit. Con. 450, and cases there cited. Brown v. Edgington, 2 Man. & Gr. 279. Dutton v. Gerrish, 9 Cush. 89. When the contract is in writing, an additional warranty, not expressed or implied by its terms, that the article is fit for a particular use, cannot be added either by implication of law or by paroi proof. Chanter v. Hopkins, 4 M. & W. 399. The general doctrine that paroi evidence is inadmissible to vary or add to a written contract would exclude the paroi proof; and the ordinary doctrine of construing contracts by adopting the fair import of the language which the parties have used would exclude such warranty by implication of law. Some of the cases cited are also authorities on this point. The question whether there was such warranty should not have been submitted to the jury ; but they should have been instructed that the contract of the parties did not contain such warranty.
2. The instructions given to the jury as to the directions given by Messrs. Hawes & Gessner were incorrect. The reply of Hawes to the defendants’ proposal directed the making of the *59retorts “ as per memorandum and terms in yours of March 29, and directions given by myself and Henry Gessner.” Such reasonable directions as he and Gessner might choose to give would come within this clause, and be binding on the plaintiffs. The plaintiffs allege, as one of their grounds of complaint, that the retorts were cast horizontally, and in green sand. They offered evidence tending to show that the retorts were thus cast that this method of casting is unusual and improper; that a horizontal casting is much more liable to cold-shuts, blow-holes, shrink-holes and other defects; and that, in a green sand casting, the liability to blow-holes and shrink-holes is much greater than in a dry sand casting. In reply to this, the defendants offered evidence tending to show that, when applied to by Hawes and Gessner, they told them, and that it was understood mutually, that, if they made them, they should have to cast them horizontally, as they could not get the necessary fixtures to cast them vertically in season; that they began to cast them, and had cast a number horizontally in dry sand, when Hawes & Gessner desired them faster, and were told by the defendants that they could not get them out faster, unless they cast them in green sand, and if so cast they would be more likely to contain blow-holes, shrink-holes, &c., and thereupon they ordered the defendants to cast them in green sand, as they must have them; that seven were accordingly cast in green sand, and horizontally, it being impossible to cast them vertically in green sand; that all those cast were cast horizontally, and some of them in presence of Hawes & Gessner, one or both of them, without objection; that they furnished a plan specifying the dimensions and shape and thickness of the retorts, which was followed by the defendants, as they claimed, and that the said Gessner examined the retorts.
If casting the retorts horizontally was an unusual and improper method, such casting would not be a compliance with the contract; and no conversation which was had prior to the making of the contract would be admissible to vary the writing. The casting in green sand was also in violation of the written contract, which provides that the casting shall be in dry sand. *60But Hawes & Gessner might waive a compliance with their obligation to cast the retorts according to the requirement of the contract; and if, because they were in haste to get the work completed, or for any other reason satisfactory to them, they did waive their rights in this respect, and consent that the retorts should be cast horizontally, and in green sand, the plaintiffs are bound by such waiver and consent. The amount of their knowledge as to the quality of iron, and as to how much better vertical casting is than horizontal casting, or dry sand casting than green sand casting, is immaterial; and the instructions on this subject were erroneous. The only question which was material is, whether they or either of them did in fact direct or give consent to the use of the green sand, and the method of casting horizontally, as adopted by the defendants.
3. The evidence offered to show that there was in Boston and its vicinity a custom that founders should not be held, in the absence of an express agreement, to warrant their castings against any latent defects; also that there was a custom that they should, in case of apparent defects, and in the absence of any express agreement, be entitled to have the castings returned in a reasonable time, and a right to replace them with new ones, was properly rejected. It would be difficult to state a principle which would reconcile all the numerous decisions that have been made on the subject of local customs or usages. Story, J., in The Schooner Reeside, 2 Sumn. 569, says: “ I rejoice to find that, of late years, the courts of law, both in England and in America, have been disposed to narrow the limits of the operation of such usages and customs, and to discontinue any further extension of them.” In the present case, the usage cannot be considered as forming a part of the contract.
If the claim of the plaintiffs is founded merely in an implied warranty that the retorts should be fit for the particular use alleged, the court are of opinion that the action cannot be maintained. If it is to be further prosecuted on the ground that the contract, as interpreted by the court, has been broken, then the rule of damages, if the action is maintained, will be the difference in value between the retorts actually furnished, and such *61retorts as should have been furnished. This is the rule when goods are not furnished for any particular use. Bartlett v. Blanchard, 13 Gray, 429.
Exceptions sustained.