If performance of the covenants of the contract, on the one side, has not been waived by the adversary party, no recovery upon a contract can be had by one who has not performed a precedent covenant, at least substantially; or who is not ready and willing to perform concurrent covenants at least substantially, and who has not notified the adversary party thereof and has demanded performance from him.1 Failure to perform either of these classes of covenants, at least substantially, amounts to breach which gives rise to a cause of action for damages, and which may operate as a discharge of the contract as far as the covenants of the adversary party are concerned.2 Prom the nature of the independent covenant, failure to perform such a covenant substantially does not operate as a discharge of the contract, although it will give rise to a cause of action for damages.3 Apart from questions of whether performance is less than substantial performance, which are considered in the following sections,4 the consequences of failure to perform at least substantially, are treated in connection with the subject of breach.5

14 Turner v. Osgood Art Colortype Co., 223 111. 629, 79 N. E. 306.

15 Turner v. Osgood Art Colortype Co., 223 111. 629, 79 N. E. 306.

16 The contract is said to be "not only substantially but literally complied with." Turner v. Osgood Art Colortype Co., 223 111. 629, 79 N. E. 306.

17 Simmons Hardware Co. v. Bucket Pump Co., 18 0. C. C. 878, 10 0. C. D. 285 (a deficiency of one-fourth of one per cent., which the seller offered to make up).

18 Hansen v. Baltimore Packing Co., 86 Fed. 832.

1 United States. Bush v. Jones, 144 Fed. 942, 6L.R.A. (N.S.) 774; Bosch Magneto Co. v. Rushmore, 255 Fed. 465.

Alabama. . Green v. Linton, 7 Port. (Ala.) 133, 31 Am. Dec. 707; Higgins Mfg. Co. v. Pearson. 146 Ala. 528, 40

So. 579; Hartsell v. Turner, 196 Ala. 299, 71 So. 658.

Georgia. Bull v. St. Johns, 39 Ga. 78.

Idaho. Olympia Mining Co. v. Kerns, 13 Ida. 514, 91 Pac. 92; Nave v. Mc-Grane, 19 Ida. 111, 113 Pac. 82.

Illinois. Swanzey v. Moore, 22 111. 63, 74 Am. Dec. 134; Angle v. Hanna, 22 111. 429, 74 Am. Dec. 161.

Iowa. Jordan v. Hill, 172 Ia. 414, 154 N. W. 579.

Kentucky. Vincennes Bridge Co. v. Walker, 181 Ky. 651, 205 S. W. 778.

Louisiana. Barr v. Henderson, 105 La. 691, 30 So. 158.

Maryland. Gill v. Vogler, 52 Md. 663.

Massachusetts. Olmstead v. Beale, 36 Mass. (19 Pick.) 528.

Minnesota. Nelichka v. Esterly, 29 Minn. 146, 12 N. W. 457; Taylor v. Marcum, 60 Minn. 292, 62 N. W. 830;

In many cases performance less than substantial is tendered by one party and is accepted by the other. Whether the consequences of such acceptance are to prevent such defective performance from amounting to breach, or whether they also prevent the adversary party from maintaining an action for such defective performance, is a question which is considered subsequently under the so-called heading of waiver.6

Another question which is sometimes confused with substantial performance is the right of the party who is in default to recover from the adversary for the benefits conferred upon the latter by reason of such defective performance. This question is considered subsequently under the topic of the quasi-contractual right of recovery which arises on discharge.7

Literal performance may exist though substantial performance is lacking. The law does not regard this as performance.8 A contract for an electric light plant, to be paid for when "found to be in good working order," is not performed by so constructing the plant that it works properly at the very moment of completion, but soon proves deficient.9 A contract to construct a furnace to heat a dwelling to a given temperature by means of hot air is not substantially performed if in fulfilling the requirement as to temperature the furnace generates coal gas and fills the house with it so as to render the rooms unsuitable for use.10

Uldrickson v. Samdahl, 92 Minn. 297, 100 N. W. 5; Hoglund v. Sortedahl, 101 Minn. 359, 112 N. W. 408.

Mississippi. Butt v. Williams (Mis*.). 15 So. 130.

Missouri. Miller v. Goddard, 34 Mo. 102, 56 Am. Dec. 638; Henson v. Hampton, 32 Mo. 408; Earp v. Tyler, 73 Mo. 617.

Nebraska. Omaha Consolidated Vinegar Co. v. Burns, 44 Neb. 21, 62 S. W. 301.

New York. Jennings v. Camp, 13 Johns. (N. Y.) 94,7 Am. Dec. 367; Acme Realty Co. v. Schinasi, 215 N. Y. 495, L. R. A. 1916A, 1176, 109 N. E. 577; Steel Storage & Elevator Const. Co. v. Stock, 225 N. Y. 173, 121 N. E. 786.

Ohio. Mehurin v. Stone, 37 O. S. 49; Petersburg Fire Brick & Tile Co. v. American Clay Machinery Co., 89 O.

S. 365, L. R. A. 1915B, 536, 106 N. E 33.

Oklahoma. Robinson v. Beaty, - Okla. - , 181 Pac 941.

Pennsylvania. Martin v. Schoenberg, 8 Watts & S. (Pa.) 367.

Vermont. Kelley v. Bradford, 33 Vt. 35.

Washington. Roudebush v. Gannon, 92 Wash. 508, 159 Pac. 680.

2 See eh. LXXXIV.

3 See ch. LXXXIV.

4 See Sec. 8 2790 et seq. 5 See ch. LXXXIV.

6 See ch. LXXXIV.

7 See ch. LXXXVIII.

8 Edison, etc.. Electric Co. v. Navigation Co., 8 Wash. 370, 40 Am. St. Rep. 910, 24 L. R. A. 315, 36 Pac. 260; Fuller-Warren Co. v. Shurts, 95 Wis. 606, 70 N. W. 683.