A memorial: or, A short account of the Bahama-Islands [electronic resource] : Of their situation, product, conveniency of trading with the Spaniards: the benefit that ariseth by the great quantities of salt that is made by the sun; and the safety all ships that are in distress near those ports do find, by having so good a harbour as Providence to bear away to for succour. Deliver'd to the Lords, proprietors of the said islands, and the Honourable Commissioners of Her Majesty's Customs. By John Graves, collector of Her Majesty's Customs in those islands. And now humbly presented to both Houses of Parliament.