with plaque reading Invented By T.H. Williams, Utica, N.Y. and pencil inscribed initials to interior lid of case.
model employs compressed air to raise and lower bridge, with original spigot and tubing for air pump included.
housed in original case and affixed to carved wood base.
Height of model 10 x width 16 x depth 6 inches.
Height on base 14 1/2 x width 24 x  depth 10 inches.
Height of case 15 x width 25 x depth 11 inches.