THIS IS A VERY EARLY EXTREMELY RARE PIECE OF TEST EQUIPMENT MADE BY CHARLES WILLIAMS OF BOSTON..HE MADE TELEPHONES FOR BELL AT THE RATE OF 25 PER DAY WHEN HE STARTED OUT..EDISON WORKED IN WILLIAMS SHOP..THE CASE IS DOVETAILED WOOD WITH A FEW CRACKS HERE AND THERE..THE BRASS HAS NUMEROUS NUMBERS WITH SMALL REMOVABLE POSTS THAT HAVE WHAT LOOKS LIKE THERMOPLASTIC FINGER TURNS AT THE TOPS OF THEM..23 INCHES WIDE AND ABOUT 8 INCHES DEEP AND TALL..20 POUNDS OR SO..THERE ARE BRASS POSTS AT EACH END FOR SOME KIND OF CONDUCTIVITY..ONE OF NONE..MUSEUM PIECE HERE..ILL PACK WELL..THANKS TOM