IN August 1833, an English artist roamed the quays of Montevideo, Uruguay, looking for a British ship. Three months earlier, Conrad Martens, the son of a German merchant and his British wife, had boarded HMS Hyacinth in Falmouth, eager to capture the energy of Rio de Janeiro in watercolour. Once he set foot in Brazil, however, a chance encounter with Lt Robert Hammond, fresh off HMS Beagle, overhauled his plans. The officer revealed that the survey expedition’s artist, Augustus Earle, had taken ill, a new one was urgently needed and the ship, then moored in Montevideo, might soon set sail again. Painting Rio could wait.
A wind-blasted, stormy journey took Martens to the capital of Uruguay. Stretching at a foot of the Mount—‘an ugly lump of ground unbroken by a…
