They arrived at Valparaiso on 23 July. After several walks in the area, Darwin obtained horses and, on 14 August, set off up the volcanic Andes with a companion. Three days later they spent an enjoyable day on the summit of the "Campana or Bell" mountain, Cerro La Campana. Darwin visited a copper mine and spent five days scrambling in the mountains before going on to Santiago, Chile. On his way back, he fell ill on 20 September and had to spend a month in bed. It is possible that he contracted Chagas' disease here, leading to his health problems after his return to England, but this diagnosis of his symptoms is disputed. He learnt that the Admiralty had reprimanded FitzRoy for buying "Adventure". FitzRoy had taken it badly, selling the ship and announcing they would go back to recheck his survey. He then had resigned his command, doubting his sanity, but was persuaded by his officers to withdraw his resignation and proceed. The artist Conrad Martens left the ship and took passage to Australia.