Porto Praya Island of St Jago. The Cape Verde Islands, off the west coast of Africa, were a Portuguese colony and were used as a staging post for slaving vessels. Image taken from Observations upon the Windward Coast of Africa, the religion, character, customs, andc. of the natives With an appendix, containing a letter on the means of abolishing the slave trade. With plates.. Originally published in G. and W. Nicol; James Asperne: London, 1807. Author Joseph Corry, Illustrated by Joseph C Stadler.