Eri Mullin reported that David Whitmer told her that Joseph used both a seer stone and the Urim and Thummim.

Dr. D. Whitmer told me in the year 1874, that Joseph Smith used the Urim and Thummim when he was translating. But now it is said that he lost it when he gave the first part of the book to Martin Harris; after that he used the Stone. Bro. T.W. Smith, I think was right. I for my part know he said that Joseph had the instrument Urim and Thummim. I asked him how they looked. He said they looked like spectacles, and he (Joseph) would put them on and look in a hat, or put his face in the hat and read. Says I, "Did he have the plates in there." "No: the words would appear, and if he failed to spell the word right, it would stay till it was spelled right, then pass away; another come, and so on" . . . Mr. Whitmer carried the idea that the translation was by both, or either Urim and Thummim and the stone.