Medium includes graphite. Inscribed by the artist, lower right, 'Gatun Locks'. Previously titled 'Panama thro' Glass', possibly because written on the back (?). The Gatun Locks are the Atlantic entrance to the Canal, lying towards the south-eastern end between Lake Gatun and sea-level in Limon Bay, north of the city of Colon. Wyllie's view is looking north-west to landward, from Limon Bay, showing the laddder of locks rising to Lake Gatun level. The foreshortening and the 'glass' note suggest it may be a view through a telescope. [PvdM 5/13]