According to Jonathan Hadley, Joseph said that he used a huge pair of spectacles to translate the BOM.
Jonathan A. Hadley, "Golden Bible," Palmyra Freeman (August 11, 1829) in Rochester Advertiser and Daily Telegraph [New York], August 31, 1829
. . . the Bible was found, together with a huge pair of spectacles! . . . By placing the spectacles in a hat, and looking into it, Smith could (he said so, at least,) interpret these characters. . . .