Per Curiam.
Oral evidence, tending to establish an independent collateral agreement as a condition precedent to a contract becoming operative, is not evidence tending to vary or impeach a written instrument; and its exclusion constitutes reversible error. Benton v. Martin, 52 N.Y. 575; Burke v. Delaney, 153 U.S. 228.
Present: GILDERSLEEVE, FITZGERALD and DAVIS, JJ.
Judgment reversed and new trial ordered, with costs to appellants to abide event.