This is an antique hand-pump fog horn manufactured by L.D. Lothrop in Gloucester Massachusetts. L.D. Lothrop operated a fishing and boating supply store in Gloucester from the 1880 through the early 1900's. This is a more unusual model #4 with a folding pump handle at the end of the box rather than the center of the side.
It is in working condition and I see no damage to the bellows but the fabric is a little stiff from age making it more difficult to pump. The brass tag at the top identifies it with a patent date of Aug 20th 1901 and a number 19869. The outer box shows some wear from age and use. Size is 16" X 11" X 8 1/2".