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 A agrees to mine coal on B's land, paying a specified royalty to B on the amount mined, such royalty not to be less than a specified minimum sum annually, A impliedly agrees to do nothing to incapacitate himself from mining all the coal on B's land that can profitably be mined. Accordingly, if A mines a lower vein first, so that it is impossible for A to mine the upper veins thereafter, this is a breach. A is liable in actual damages, and it has been held that he can not escape liability by paying the minimum royalty.1 If A agrees with B to operate a certain mill for five years, A's sale of such mill to X, without requiring X to perform such agreement, is a breach.2 If an insurance company terminates its business and transfers its policies and assets to another company, the insured may treat this as a breach and recover whatever he may be entitled to out of the assets.3 If A has entered into a contract to box with B for ten rounds, and A disables B by a foul blow at an early period of such contest, A can not recover his compensation;4 and it has been said that this principle applies whether the foul blow was delivered intentionally or accidentally.5 If A and B, who are partners, have entered into a contract by which they agree to sell goods to C, and D agrees to become surety for C, the act of A and B in dissolving such partnership before performance discharges D.6 If A and B, acting as partners, have employed X, the dissolution of the firm is a breach of the contract of employment.7 If A has employed X to carry on a certain business, A's act in selling such business to B is a breach of A's contract with X.8 If A has entered into an agreement by which he is to secure a certain position for B, A's act in making a similar contract with C operates as a discharge which gives to B a right of action.9 If A has entered into a contract to marry B, and A then marries C, such conduct on A's part is a renunciation of his contract with B.10
1 Genet v. Delaware & Hudson Canal Co., 136 N. Y. 593. 19 L. R. A. 127, 32 N. E. 1078.
2 Hudson v. Archer, 9 S. D. 240, 68 N. W. 541.
3 Lovell v. St. Louis Mutual Life Ins. Co., Ill U. S. 264, 28 L. ed. 423.
4 Moha v. Hudson Boxing club, 164 Wis. 425, L. R. A. 1917B, 1238, 160 N. W. 266.
5 Moha v. Hudson Boxing. Club, 164 Wis. 425, L. R. A. 1917B, 1238, 160 N. W 266.
6 Black v. Albery, 89 O. S. 240, 106 N. E 38
See Sec. 2681.
7 Brace v. Calder , 2 Q. B. 253.
8 White v. Lumiere North American Co., 79 Vt. 206, 6 L. R. A. (N 8 ) 807, 64 Atl. 1121
9 Lloyd v. Dickson, 116 La. 90, 40 So. 542.
10 Dyer v. Lalor, - Vt. - 109 Atl. 30.