~ A Portuguese bronze signalling cannon of significant size being 40.5 inches length and with a 3 inch bore. It is on a later sea service type truck ~
It is similar to a Lyle line-throwing cannon but with a large bore (3" vs 2.5") and a much longer barrel (40.5" vs 24"), but I suppose it could be dual purpose.
The cannon is signed REI Portugal 1889.
The Rei De Portugal was built in 1889 by Scott & Co. at Greenock with a tonnage of 3198grt, a length of 363ft 6in, a beam of 42ft 2in and a service speed of 10 knots. She was launched for the Mala Real Portugueza's mail service to Portugal's African colonies. When she entered service in February 1890 the route was not a success as she was competing against Cia Nacional. In 1902 she was acquired by Prince Line for the Livorno-Genoa-Naples- Palermo-New York service and renamed Napolitan Prince. After nine years service she was sold to Cie. de Navigation Mixte of Marseilles in November 1911 and renamed Manouba. She was subsequently modernised and continued with Mixte until 14th February 1929 when she was sold for demolition in Italy.