
96 U.S. 168 (1877)
BRAWLEY
v.
UNITED STATES.
Supreme Court of United States.

*170 Mr. John B. Sanborn for the appellant.
The Solicitor-General, contra.
*171 MR. JUSTICE BRADLEY, after stating the case, delivered the opinion of the court.
From an examination of the authorities, it seems to us that the general rules which must govern this case may be expressed as follows: 
Where a contract is made to sell or furnish certain goods identified by reference to independent circumstances, such as an entire lot deposited in a certain warehouse, or all that may be manufactured by the vendor in a certain establishment, or that may be shipped by his agent or correspondent in certain vessels, and the quantity is named with the qualification of "about," or "more or less," or words of like import, the con tract applies to the specific lot; and the naming of the quantity is not regarded as in the nature of a warranty, but only as an estimate of the probable amount, in reference to which good faith is all that is required of the party making it. In such cases, the governing rule is somewhat analogous to that which is applied in the description of lands, where natural boundaries and monuments control courses and distances and estimates of quantity.
But when no such independent circumstances are referred to, *172 and the engagement is to furnish goods of a certain quality or character to a certain amount, the quantity specified is material, and governs the contract. The addition of the qualifying words, "about," "more or less," and the like, in such cases, is only for the purpose of providing against accidental variations arising from slight and unimportant excesses or deficiencies in number, measure, or weight.
If, however, the qualifying words are supplemented by other stipulations or conditions which give them a broader scope or a more extensive significancy, then the contract is to be governed by such added stipulations or conditions. As, if it be agreed to furnish so many bushels of wheat, more or less, according to what the party receiving it shall require for the use of his mill, then the contract is not governed by the quantity named, nor by that quantity with slight and unimportant variations, but by what the receiving party shall require for the use of his mill; and the variation from the quantity named will depend upon his discretion and requirements, so long as he acts in good faith. So where a manufacturer contracts to deliver at a certain price all the articles he shall make in his factory for the space of two years, "say a thousand to twelve hundred gallons of naphtha per month," the designation of quantity is qualified not only by the indeterminate word "say," but by the fair discretion or ability of the manufacturer, always provided he acts in good faith. This was the precise decision in Gwillim v. Daniell, 2 Cromp., M. & R. 61, where Lord Abinger says: "The agreement is simply this, that the plaintiff under takes to accept all the naphtha that the defendant may happen to manufacture within the period of two years. The words, `say from one thousand to twelve hundred gallons [per month],' are not shown to mean that the defendant undertook, at all events, that the quantity manufactured should amount to so much. If by fraud the defendant manufactured less than he ought to have done, the breach should have been shaped accordingly. Here it does not appear that, in the ordinary course of his manufacture, the defendant ought to have produced a larger quantity than he has done; and we cannot, therefore, say that he has broken his contract."
We think that there is manifest reason in this decision, and *173 that the present case is within it. The contract was not for the delivery of any particular lot, or any particular quantity, but to deliver at the post of Fort Pembina eight hundred and eighty cords of wood, "more or less, as shall be determined to be necessary by the post-commander for the regular supply, in accordance with army regulations, of the troops and employés of the garrison of said post, for the fiscal year beginning July 1, 1871." These are the determinative words of the contract, and the quantity designated, eight hundred and eighty cords, is to be regarded merely as an estimate of what the officer making the contract at the time supposed might be required. The substantial engagement was to furnish what should be determined to be necessary by the post-commander for the regular supply for the year, in accordance with army regulations. The post-commander, as soon as he learned of the contract, and within four days after it was signed, informed the claimant that but forty cords of wood would be required thereon, and forbid his hauling any more to the government yard. About a fortnight later, on the 1st of July, 1871, written notice to the same effect was served on the claimant, signed by the post-commander. And the Court of Claims finds, as a fact, that the post of Fort Pembina did not need for the fiscal year in question more than the forty cords of wood which were accepted by the defendants; thus precluding any plea that, in fixing and determining the amount required, the post-commander was actuated by any want of good faith.
Reference is made to the previous negotiations which led to the making of the contract, the bid of the claimant, the fact that the contract was awarded to him on his bid as early as May, and that, on the faith and expectation that the quantity named would be wanted, he had cut the eight hundred and eighty cords of wood before the contract was signed.
All this is irrelevant matter. The written contract merged all previous negotiations, and is presumed, in law, to express the final understanding of the parties. If the contract did not express the true agreement, it was the claimant's folly to have signed it. The court cannot be governed by any such outside considerations. Previous and contemporary transactions and facts may be very properly taken into consideration to ascertain the *174 subject-matter of a contract, and the sense in which the parties may have used particular terms, but not to alter or modify the plain language which they have used.
Judgment affirmed.
