James Hart wrote that Joseph used a seer stone in a hat for the translation of the BOM.
James H. Hart, "About the Book of Mormon," Deseret Evening News 17, no. 104 (March 25, 1884): 2
“In regard to the translation,” said Mr. Whitmer, “it was a laborious work for the weather was very warm, and the days were long and they worked from morning till night. But they were both young and strong and were soon able to complete the work.
“The way it was done was thus: Joseph would place the seer-stone in a deep hat, and placing his face close to it, would see, not the stone, but what appeared like an oblong piece of parchment, on which the hieroglyphics would appear, and also the translation in the English language, all appearing in bright luminous letters. Joseph would then read it to Oliver, who would write it down as spoken. Sometimes Joseph could not pronounce the words correctly, having had but little education; and if by any means a mistake was made in the copy, the luminous writing would remain until it was corrected. It sometimes took Oliver several trials to get the right letters to spell correctly some of the more difficult words, but when he had written them correctly, the characters and the interpretation would disappear, and be replaced by other characters and their interpretation.
“When the seer-stone was not placed in the hat, no characters or writing could be seen therein, but when so placed then the hieroglyphics would appear as before described. Some represented but one word, or name, some represented several, and some from one to two lines.
“Emma, Joseph’s wife, came to my father’s house a short time after Joseph and Oliver came, and she wrote a little of the translation, my brother Christian wrote some, but Oliver wrote the greater portion of it."