A whole plate negative. A fair quality starboard very near broadside view, taken from only just ahead of the beam, of the passenger/cargo liner Siam (1873) at anchor or moored in Gravesend Reach, River Thames. She has an auxiliary brig rig with the topgallant yards sent down. She has an awning rigged aft and she is flying the blue peter. The paddle tug Powerful (1857) is alongside and Tilbury is in the background. The original negative has been damaged, the emulsion has peeled off and it has been discarded. A sheet film copy negative has been produced from a 12x10 photographic print made from the original negative in the 1950s.