The validity of the agreements whereby appellant City of Buffalo undertook to bear the expense of repairing the structures here involved can not be questioned. (Matter of Ward v. Erie R. R. Co., 215 N. Y. 629.) In the light of the settled principle that a statute will not — in the absence of an unequivocal expression of such legislative intent — be given retrospective effect so as to interfere with antecedent rights (Hastings v. Byllesby & Co. [Granbery], 293 N. Y. 413, 419; see, also, Shielcrawt v. Moffett, 294 N. Y. 180, 189; Jacobus v. Colgate, 217 N. Y. 235, 240), the 1937 amendment .(L. 1937, ch. 889) can not be construed as affecting plaintiffs’ rights — and defendant’s correlative duty — which had accrued many years before. In short, we decide that the Legislature did not disclose an intent that the statute should apply to contracts' previously made. We consider no other question.

The judgment should be affirmed, with costs.

Loughban, Ch. J., Lewis, Conway, Desmond, Thacheb, Dye and Fuld, JJ., concur.

Judgment affirmed.