The plates that had been in the custody of Laban. These enabled them to study history and genealogy.
The Ball, or Compass. Critics of the Book of Mormon, at one time, used to quote this as an evidence against the authenticity of the Book, the compass, they said, not being known before the 12th century A.D. But they had the mariners' compass in mind. This compass in the Book of Mormon was a special instrument prepared by the Lord to guide Lehi on the road, and it was operated by faith. (Acts 28:13 for another meaning of that word)