Claimant appeals from a decision of the Workmen's Compensation Board which denied an award on the ground that the weight of substantial evidence does not support a finding that claimant sustained accidental injury arising out of and in the course of his employment. Claimant alleges that he sustained injuries to his back in two accidents on September 17 and 18, 1953, while working for his brother, who apparently owns or controls the corporate employer. Claimant denied that he had had any previous accident or difficulty with his back. It appears beyond question, and claimant ultimately admitted, that he worked in Detroit up until September 15, 1953; that he sustained an accidental back injury there in July, 1953. Appellant concedes that his credibility was impeached but argues that the decision is against the weight of evidence because there is no evidence that he did not have an accident on September 17 or 18, and the presumption of the validity of his claim under section 21 Work. Comp. of the Workmen's Compensation Law is enough to sustain the claim. Such argument is without merit. Credibility is solely within the province of the board. Decision affirmed, without costs. Foster, P.J., Coon, Halpern and Gibson, JJ., concur.