Find number abcIf 5659a - a8ab6 = c8b67 find number abc. Multiple solutions may exist.
Correct answers: 34
The first user who solved this task is Djordje Timotijevic.
Dry dock patentIn 1816, the first U.S. patent for a dry dock was issued to John Adamson of Boston, Mass. A floating dry dock was built a few years later in Weehawhen Cave, Hoboken, N.J. for the dry docking and repair of canal boats. The patent was extended 14 years by act of Congress, 2 Mar 1831 (6 Stat. L. 458).