David Whitmer describes the translation as Joseph putting a hat into a stone and clearing his mind of earthly things.
David Whitmer, An Address to All Believers in Christ by a Witness to the Divine Authenticity of The Book of Mormon, (Richmond, MO: David Whitmer, 1887), 30
At times when Brother Joseph would attempt to translate, he would look into the hat in which the stone was placed, he found he was spiritually blind and could not translate. He told us that his mind dwelt too much on earthly things, and various causes would make him incapable of proceeding with the translation. When in this condition he would go out and pray, and when he became sufficiently humble before God, he could then proceed with the translation. Now we see how very strict the Lord is; and how he requires the heart of man to be just right in His sight, before he can receive revelation from him