W.W. Blair relates translation details from Morse; Joseph would place the Seer Stone in the crown of a hat to exclude all light.
W. W. Blair, Letter to the editor, Saints’ Herald 26, no. 12 (June 15, 1879): 191
When Joseph was translating the Book of Mormon, he, (Morse), had occasion more than once to go into his immediate presence, and saw him engaged at his work of translation. The mode of procedure consisted in Joseph’s placing the Seer Stone in the crown of a hat, then putting his face into the hat, so as to entirely cover his face, resting his elbows upon his knees, and then dictating, word after word, while the scribes—Emma, John Whitmer, O. Cowdery, or some other, wrote it down.