¶1The opinion of the court was delivered by
¶2H. H. Clark sued George Townsend for the reasonable value of his services in negotiating for him the purchase of a number of tracts of land. A verdict was returned for the defendant, on which judgment was rendered. ■The plaintiff appeals.
¶3
¶4
“You are hereby authorized, acting for us and as our agent, to purchase any or all of the following tracts of land at prices not exceeding the prices indicated after said tracts. . . . 'We will guarantee you in the matter of the money you advance on these tracts which are taken •for us.
“You will, of course, get these contracts at just as much lower than these prices as you possibly can.”
¶5The plaintiff contends that in allowing testimony of a prior or contemporaneous oral agreement that his services were to be rendered without charge the court erred, such ruling being in violation of the principle which forbids the reception of parol evidence to vary the terms of a written contract. Wherever the law attaches a fixed consequence to the language *652used, and thus by interpretation reads into a document a term which otherwise might be regarded as omitted, the matter implied is as much a part of the instrument as that which is written, and can not be varied by oral evidence. (Doolittle v. Ferry, 20 Kan. 230; 17 Cyc. 570.) Therefore where a writing is silent as to some particular element of a contract (for instance the time within which it is to be performed, or the amount to be paid), under circumstances compelling the inference of an intention to be governed by the standard of what is reasonable, a specific agreement on the subject, resting in parol, may not be shown. (17 Cyc. 570, 571, notes 66 and 69; 9 Encyc. of Ev. 349; 2 Parsons on Contracts, p. *552; Standard Box Co. v. Mutual Biscuit Co., 10 Cal. App. 746, 103 Pac. 938; Cameron Coal & Mercantile Co. v. Universal Metal Co., 26 Okla. 615, 110 Pac. 720; Smith Sand & Gravel Co. v. Corbin, 81 Wash. 494, 142 Pac. 1163.) But whether oral evidence may be allowed to supplement a contractual writing, by supplying a term not therein referred to, depends upon whether the instrument was intended to cover that feature of the transaction. (4 Wigmore on Evidence, §2430; 17 Cyc. 741.) Language has often been used indicating that this must be determined from a mere inspection of the document. For instance, the second paragraph of the syllabus in Ehrsam v. Brown, 64 Kan. 466, 67 Pac. 867, might be open to that interpretation. But a more accurate statement of the rule allows outside evidence for the purpose at least of showing the conditions surrounding the transaction and the relations of the parties. (17 Cyc. 746, 747; 4 Wigmore on Evidence, § 2431.) Where one performs services at the request of another without any express agreement as to compensation, a contract to pay a reasonable amount is implied, in the absence of circumstances giving rise to a different inference. Yet this fact does not prevent the making of a memorandum covering the character of services to be rendered, but not the amount of compensation.
¶6The presumption that one who performs services at the request of another is entitled to reasonable compensation is rebuttable. A counter presumption may arise from circumstances justifying an inference of an intention to do the work gratuitously. (40 Cyc. 2845.) Here the letter from the defendant to the plaintiff does not purport to set out all the *653terms of a contract between them. It is in substance a certificate of the plaintiffs authority to represent the defendant in making contracts for the purchase of the tracts referred to— in effect a power of attorney. It is equally consistent with an express agreement to pay according to the time consumed, or upon a commission basis, or with an implied understanding that the plaintiff should be paid whatever was reasonable. Therefore evidence was competent that tended to show an express agreement that no charges should be made, or to show circumstances justifying the inference that such was the intention of the parties. An exactly similar situation was presented in “Joannes” v. Mudge & another, 88 Mass. 245, where the opinion concludes thus: “The power of attorney says nothing about compensation. It has its full effect equally whether he was to be paid or not. The law will imply a promise to pay for services rendered by the plaintiff at the request of the defendants, whether the request is written or oral, if the services are of value, and nothing more appears; but the employment is merely evidence of a promise to pay, and the implication may be rebutted by evidence.” (p. 246.) Cases illustrating the principle are collected in 9 Encyc. of Ev. 452, note 84, and in 17 Cyc. 745, note 43.
¶7
“H. H. Clark agrees to lend his aid in procuring such additional land & privileges for the benefit of the Constn. Co.’s project for one-fourth stock in all companies as may be deemed necessary by Geo. Townsend and C. F. Enright without cash remuneration, not to exceed 30 days. The optional money to be paid from sale of the land and Clark to be Industrial Commissioner.”
¶8The plaintiff contends that this document should not have been admitted because it never was executed; because it constituted a part of the negotiations which led up to and culminated in the contract of January 6; and because upon its face it related to an agreement between Clark and a construction company, and not between Clark and Townsend. Clearly it *654was not admitted as a contract binding upon the plaintiff, or for the purpose of affecting in any way the instrument of January 6. It was obviously received as showing one step in the development of the relations of Clark and Townsend, for whatever light it might throw upon the question whether or not their intention was that Clark was to be paid in money for his services in buying the land. In that view we think it was competent. Various circumstances were brought out from which it might be inferred that Clark had such an interest in furthering the projects which Townsend was promoting that he gave his services to that end with the understanding that he was .not to be otherwise compensated. This question seems to have been fairly tried out, submitted and determined, and we' find no reason for interfering with the decision of the trial court.
¶9The judgment is affirmed.