 The ships set sail for Rio de Janeiro , arriving there on 10 September when the slaves were transferred to the hulk Crescent under the supervision of Sir Thomas Paisley . Paisley said that he had " never witnessed anything so shocking " , particularly as most of the slaves were suffering from emaciation and sores and others were infected by smallpox and had to be quarantined aboard the Vincedora . The slaves included parentless children , babies and a harem of women for the brigantine 's crew . Although the slaves continued to die over the next month , most recovered to be set free . The event was recorded in the memoirs of Sir Astley Cooper Key . 
