This section is from the book "The Law Of Contracts", by William Herbert Page. Also available from Amazon: Commercial Contracts: A Practical Guide to Deals, Contracts, Agreements and Promises.
If the party who is not in default has led the other party to believe that he will not insist upon performance in strict compliance with the terms of the contract,1 or if he has requested performance which differs from that provided for by the original contract, and performance has been made in accordance with his request,2 or if he makes strict performance impossible,3 he can not subsequently recover damages for departure from strict performance caused by such representations or conduct. One who accepts an unfinished boat before the time for its completion can not recover a fixed amount per day agreed upon as damages for delay in completion.4 If provision is made for a test, the party who has prevented such test from being made is regarded as having waived defects which would have been discovered thereby.5 In cases of this sort, this result may be justified on the theory that the rejection of goods which did not correspond to the test, was intended by the parties as the sole consequence of the failure of the performance to conform to the test.
If the person for whom work is done inspects it as it progresses, and accepts it after such inspection, as'full performance of the contract, he can not thereafter recover damages for alleged breach which such inspection could have disclosed.6 The same principle applies where the contract provides for inspection by the architect and he inspects and accepts the work.7 The fact that the engineers of the property owner have inspected a tunnel which has been timbered, and have approved of such performance, prevents the property owner from recovering damages because of the subsequent caving in of the tunnel.8 If a contractor acquiesces in rejection of material by the inspector appointed by the adversary party and procures other material, he can not claim damages for such delay.9 Cases of this sort, however, may be explained on the theory that the contract has made the determination of the architect or engineer final and conclusive as between the parties, and that the real meaning of the contract is that the contractor shall perform to the satisfaction of the engineer, as long as the latter is acting in good faith, whether the engineer demands more or accepts less than the remaining provisions of the contract require.
10 See Sec. 2457 et seq. 11 See Sec. 2501 et seq.
1 Delaware, Lackawanna & Weatern Ry. Co. v. Monroe County Water Power & Supply Co., 221 Pa. St. 387, 70 Atl. 797.
2 District of Columbia v. Iron Works, 181 U. S 453, 45 L. ed. 948; Young v. Glass Co., 187 111. 626, 58 N. E. 605.
3 Vandegrift v. Engineering Co., 161 N. Y. 435, 48 L. R. A. 685, 55 N. E. 941; Slinger v Totten, 38 S. D. 249, L. R. A. 1917C, 539, 160 N. W. 1008.
See Sec. 2912 et seq.
4 Vamlegrift v. Engineering Co., 161 N. Y. 435, 48 L. R. A. 685, 55 N. E. 941.
5 Slinger v. Totten, 38 S. D. 249, L. R. A. 1917C, 539, 160 N. W. 1008; Hurley-Mason Co. v. Stebbins, 70 Wash. 366, L. R. A. 1913B, 1131, 140 Pac. 381.
6 England. Parker v. Palmer, 4 Barn. & Ald. 387; Beverly v. Coke Co., 6 Ad. & El. 829.
 
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