It is not the breach of every covenant of a contract that may operate as a discharge of the adversary party. To have this effect the covenant broken must be a vital term of the contract, breach of which makes performance impracticable, and the accomplishment of the purpose of the contract impossible. Breach of a minor and subsidiary covenant may give rise to an action for damages but it cannot operate as a discharge.1 Thus a contract to erect and maintain a mill is not discharged by the adversary party's failure to maintain it for the entire time, but an action for damages is the only remedy.2 Similar results have been reached where a contract to construct waterworks is departed from in minor points and no opportunity has been given to the water company to correct them,3 where a contract to feed cattle is broken only by a failure to construct racks to save the hay, the owner having suffered no loss thereby,4 and where a contract to ship goods under the vendee's form of charter party is broken only by using another form of charter party which omits a clause that if the vessel is freed from wharfage during discharge of cargo, freight is to be reduced four and a half pence per ton.5 In all these cases the party not in default must perform and sue for damages if he has suffered any.

14 Ledon v. Havemeyer, 121 N. Y. 179; 8 L. R. A. 245; 24 N. E. 297.

15 Penobscot Lumbering Association v. Bussell, 92 Me. 256; 42 Atl. 408.

16 Penobscot Lumbering Association v. Bussell, 92 Me. 256; 42 Atl. 408.

1 Plummer v. Kelly, 7 N. D. 88;

73 N. W. 70; Hathaway v., 63 Vt. 527; 22 Atl. 633.

2 Vandegrift v. Engineering Co.. 161 N. Y. 435; 48 L. R. A. 685; 55 N. E. 941.

3 Jewett Publishing Co. v. Butler. 159 Mass. 517; 22 L. R. A. 253; 34 N. E. 1087; Southern Lumber Co. v. Supply Co., 89 Mo. App. 141.