We therefore conclude that the deposit in question was discovered by the petitioner. The authorities relied on by the respondent, principally, Alamo Coal Co., 31 B.T.A. 869, and Clarence P. Sidwell, 11 T.C. 826, are distinguishable on their facts from this proceeding. In each of the cited cases, it was found as a fact that the taxpayer had purchased or leased a proven tract of land.