The rale that prior or contemporaneous negotiations can not be used to contradict, add to, or otherwise vary, a written contract applies not merely to the letter of the written contract, but also to its legal effect.1 Thus where no time is fixed for performance, and the implication therefrom would be that a reasonable time was allowed, evidence that a specific time had been agreed upon is inadmissible.2 While evidence of the intention of the parties can not be considered for the purpose of fixing a definite time for the performance of the contract which did not specify the time in which it was to be performed, the surrounding circumstances may be considered for the purpose of determining what a reasonable time is.3

1 California. Fisk v. Casey, 119 Gal. 643, 51 Pac. 1077.

Georgia. Bond v. Perrin, 145 Ga. 200,

88 S. E. 954.

Idaho. Jensen v. McConnell, 31 Ida. 87, 169 Pac. 292.

Iowa. State Security Bank v. Hos-kins, 130 Ia. 339. 8 L. R. A. (N.S.) 376,

106 N. W. 764.

Kentucky. Johnson v. Tackitt, 173 Ky. 406, 191 S. W. 117. Maine. Bassett v. Breen, - Me. - ,

107 Atl. 832.

Massachusetts. Taylor v. Kennedy, 228 Mass. 390, 117 N. E. 901; Graves v. Apt, - Mass. - , 124 N. E. 432.

Michigan. In re Johnson's Estate, 177 Mich. 500. L. R. A. 1916E, 217, 143 N. W. 627; Kincade v. Peck, 193 Mich. 207, 169 N. W. 480.

Oklahoma. Cameron Coal & M. Co. v. Universal Metal Co., 26 Okla. 615, 110 Pac. 720 [sub nomine, Cameron Coal & M. Co. v. Block, 31 L. R. A. (N.S.) 618].

Rhode Island. Boston Floor Machine Co. v. Looff, - R. I. - , 103 Atl. 626.

Washington. Smith Sand & Gravel Co. v. Corbin, 89 Wash. 43, 154 Pac. 150; United Iron Works v. Wagner,

89 Wash. 293, 154 Pac. 460.

West Virginia. Light v. Grant, 73 W. Va. 56, 51 L. R. A. (N.S.) 792, 79 S. E. 1011.

Wyoming. Stickney v. Hughes, 12 Wyom. 397, 75 Pac. 945.

2 Georgia. Central R. R. v. Hassel-kus, 91 Ga. 382, 44 Am. St. Rep. 37, 17 S. E. 838.

Illinois. Loeb v. Stern, 198 111. 371, 64 N. E. 1043.

Indiana. Barney v. Ry., 157 Ind. 228, 61 N. E. 194.

Massachusetts. Tripp v. Smith, 180 Mass. 122, 61 N. E. 804.

Michigan. Stange v. Wilson, 17 Mich. 342; Harrow Spring Co. v. Harrow Co.. 90 Mich. 147, 30 Am. St. Rep. 421, 51 N. W. 197; Sloman v. Express. Co., 134 Mich. 16, 95 N. W. 999.

Minnesota. Liljengren, etc., Co. v. Mead, 42 Minn. 420, 44 N. W. 306.

Oklahoma. Cameron Coal & M. Co. v. Universal Metal Co., 26 Okla. 815, 110 Pac. 720 [sub nomine. Cameron Coal & M. Co. v. Block, 31 L. R. A. (N.S.) 618].

Rhode Island. Boston Floor Machine Co. v. Looff, - R. I. - , 103 Atl. 626.

Washington. Smith Sand & Gravel Co. v. Corbin, 89 Wash. 43, 154 Pac. 150; United Iron Works v. Wagner, 89 Wash. 293, 154 Pac. 460.

Wisconsin. Irish v. Dean, 39 Wis. 562.

3 Berry v. Marion County Lumber Co., 108 S. Car. 108, 93 S. E. 328.

Among other circumstances evidence of conversations between the parties to the contract may be considered to show what they considered to be a reasonable time.4 Evidence of a statement by the party who agreed to perform as to the time within which such performance would take place, may be considered for the purpose of determining the understanding of the parties as to what amounted to a reasonable time.5 The rule that wherever a reasonable time is inferred from the written contract, extrinsic evidence is inadmissible to show that a definite time was actually fixed, is to be distinguished from the rule that if the written contract shows on its face that there had been a definite agreement as to time and that such agreement had been omitted, or if it shows on its face that it is but an incomplete memorandum, extrinsic evidence is admissible to show the real terms of the contract, including that as to time, as long as such terms are not inconsistent with the written memorandum.6 The two rules have apparently been confused, however, and without discussion as to the legal effect of whether a failure to fix the time of performance amounted to fixing it at a reasonable time, it has been assumed that such contract must be incomplete; and it has been held that if a written contract does not specify how long it is to continue in force, extrinsic evidence is admissible to show the actual agreement of the parties as to such time.7 If the contract in legal effect calls for prompt performance, an oral contract delaying performance until some specified time in the future is unenforceable.8 Thus where a bill of exchange has been drawn, an oral contract that it should not be presented for payment until another draft had been paid, was unenforceable.9 It has been held, however, that an oral contract, made when a check was delivered, that it should not be presented until a certain date in the future, was valid.10 So under a contract of sale, with delivery in installments at a gross price, the legal effect of which was to make the price payable when the entire quantity was delivered, an oral contract that at the delivery of each installment the price therefor should be paid, was unenforceable.11 So a guaranty for a specified amount to be advanced by the maker, payable on demand after thirty days, can not be modified by showing that the guaranty was to last for thirty days only.12 If the written contract is so drawn that time is not of its essence, the parties can not show a contemporaneous oral agreement that time should be of the essence.13 It has been held, however, that prior negotiations may be considered for the purpose of showing that a higher bid was accepted because of the fact that performance was to be made in a shorter time for the purpose of determining that time was of the essence and that an amount to be paid for delay was liquidated damages.14 If a contract for the sale of realty contains a provision for a survey in a specified time and for payment for an area in excess of that stipulated in the contract, the purchaser has been permitted to show that the time within which such survey was to be had was of the essence of the contract, at least if the contract is ambiguous upon such point.15 Under a contract appointing an agent "in the immediate vicinity of" a certain town, extrinsic evidence is inadmissible to show that he was to have the exclusive agency.16 Where a check was given, payable on the date thereof, the drawer could not show an oral agreement that the check was not to bear interest.17 So where two persons have signed a contract in such a way that they are jointly liable thereon, an oral agreement that each shall be severally liable for one-half of the liability can not be used to modify the contract.18 So where A, a member of a firm, made and signed a written entry of part payment on a partnership note barred by the Statute of Limitations, the legal effect of which was to make A liable for the entire amount of the note, A can not show that he signed under an oral contract that he should be liable for only one-half the amount of the note.19