Upon the most favorable construction for the plaintiff, the defendant made no more than a conditional promise to pay when he should be able; and upon such promise no action can be maintained without proof of his ability to pay. Tanner v Smart, 6 B. & C. 603; S. C. 9 D. & R. 549. Gould v. Shirley, 2 Moore & Payne, 581. Hart v. Prendergast, 14 M. & W. 741. Meyerhoff v. Froehlich, 3 C. P. D. 333. Tompkins v. Brown, 1 Denio, 247. United Society in Canterbury v. Winkley, 7 Gray, 460. St. 1856, c. 18. Gen. Sts. c. 105, § 3. tío competent evidence of this fact was offered. The tax-book was incompetent to prove the value of the property for any other purpurpose than the assessment and collection of the tax. Commonwealth v. Heffron, 102 Mass. 148, 154.

In Lerow v. Wilmarth, 7 Allen, 463, and Cook v. Shearman, 103 Mass. 21, cited for the plaintiff, the defendant’s promise to pay was more positive, and not qualified by the condition of his ability to perform his promise.

Judgment for the defendant.