The existence of the promise or authority will be a matter to be proven by evidence and inference from circumstances,1 and may be proven by any competent evidence, such as an admission of the party2 or by correspondence.3 If the promise or authority is in writing it constitutes the sole evidence, and the person acting upon it will not be affected by any arrangement or equities or understanding between the drawee and the drawer,4 unless such arrangements were known to the payee either from actual knowledge 5 or through knowledge imputed to him from customary methods of business.6 In both the latter instances he will be bound by his knowledge. The construction of the writing determines the promise or authority. A written authority to draw7 or letter of credit8 is sufficient. A telegram in answer to one describing a certain check, which says: "T. is good, send on your paper," is sufficient.9 A telegram promising to pay a certain draft is an acceptance, both at common law10 and under the statute requiring a writing.11 But a written statement that " we expect to take care of them and pay drafts as heretofore " is said to be not sufficient,12 and though the writer says he will accept, the phrase may be controlled by other language in the letter.13 A letter agreeing to carry the maker of a promissory note is no authority to draw a draft for the amount of the note.14 A written promise to pay a bill when corrected is good as to the bill when corrected.15 If the authority to draw is countermanded, it cannot afterwards protect any one.16

264; Townsley v. Sumrall, 2 Pet. 170; Boyce v. Edwards, 4 Pet. Ill; Kennedy v. Geddes, 8 Port. 263; Storer v. Logan, 9 Mass. 55; Greele v. Parker, 5 Wend. 414 The letter may be pleaded as an acceptance (Ontario Bank v. Worthington, 12 Wend. 593); so of an authority to draw against shipments (Burke v. Utah Nat. Bank, 47 Neb. 247); but the authority is conditional upon the shipment. Germania Nat. Bank v. Tooke, 101 N. Y. 442.

16Mayhew v. Prince, 11 Mass. 55; Vance v. Ward, 2 Dana, 95; Beach v. State Bank, 2 Ind. 488.

17 Ulster Co. Bank v. McFarlan, 5 Hill, 432; O'Donnel v. Smith, 2 E. D. Smith, 124

18 Ontario Bank v. Worthington, 12 Wend. 593. But see note 11, ante.

19 Wildes v. Savage, 1 Story, 22; Brown v. Ambler, 66 Md. 391.

20 See cases to notes 8 and 9, Sec. 217, post, which do not seem to recognize the distinction.

21 Woodard v. Commission Co., 43 Minn. 260. Practically the detriment to the holder, who acts upon the authority, is always a consideration. See Carnegie v. Morrison, % Met. 381, where no consideration seems to have existed.

1 See the cases cited in next two notes.

2 Crumb v. Phettiplace, 53 I11. App. 337.

3 Union Bank v. Shea, 57 Minn. 180; Berckhead v. Brown, 5 HilL 634

4Naglee v. Lyman, 14 CaL 450; Carrollton Bank v. Tayleur, 16 La. 490.

5 See last case and Storer v. Logan, 9 Mass. 55.

6 Compare for the principle, First Nat. Bank v. Fiske, 133 Pa. 241.

7 Smith v. Ledyard, 49 Ala. 279; Pollock v. Helm, 54 Miss. 1; Adoue v. Fox, 30 Mo. App. 98 (under statute requiring writing): Rinz v. Renauld, 100 N. Y. 256; Gates v. Parker, 43 Ma 544; Michigan Bank v. Ely, 17 Wend. 50a

8 Monroe v. Pilkinton, 14 How. Pr. 250; Merch. Ex. Nat. Bank v. Cardago, 35 N. Y. Super. Ct 162; Bussell v. Wiggin, 2 Story, 213. And see cases cited in note 11, supra.

9North Atchison Bank v. Garretson, 51 Fed. R 168, 4 U. S. App. 557.

10 In re Armstrong, 41 Fed. R 381.

11 Molson's Bank v. Howard, 40 N. Y. Super. Ct. 15. And see, as to checks, Sec. 150, ante.

12State Nat Bank v. Young, 14 Fed. R 889. This case is wrong. Any ordinary business man would have acted upon the letter. The court's remarks are simply foolish.

13Musgrove v. Hudson, 2 Stew. (Ala.) 464.

14 Atlanta Nat Bank v. Fertilizing Co., 83 Ga. 356. This decision is an egregious error. The letter was clearly sufficient

15 Harrison v. Sternan, 4 Phila. 315. 16 First Nat Bank v. Clark, 61 Md. 400.