I found this interesting item in the application for historic landmark designation for the Southern Building at 15th and K, NW which features dozens of lion heads in the facade. "Grand Master James T. Gibbs of the Grand Lodge of the District of Columbia officiated using the same trowel and gavel that George Washington used in the laying of the cornerstone of the U.S. Capitol." I wonder if use of that gavel and trowel was typical of most building in DC at the time. The "lodge" being referred to is the Masonic Lodge.