William Smith says Joseph used the Urim and Thummim to translate the BOM.
William Smith, On Mormonism: A True Account of the Origin of the Book of Mormon (Lamoni: Herald Steam Book and Job Office, 1883), 11
In consequence of his vision, and his having the golden plates and refusing to show them, a great persecution arose against the whole family, and he was compelled to remove into Pennsylvania with the plates, where he translated them by means of the Urim and Thummim, (which he obtained with the plates), and the power of God. The manner in which this was done was by looking into the Urim and Thummim, which was placed in a hat to exclude the light, (the plates lying near by covered up), and reading off the translation, which appeared in the stone by the power of God.