A Voyage to Abyssinia: And Travels Into the Interior of that Country, Executed Under the Orders of the British Government, in the Years 1809 and 1810; in which are Included, an Account of the Portuguese Settlements on the East Coast of Africa, Visited in the Course of the Voyage; a Concise Narrative of Late Events in Arabia Felix; and Some Particulars Respecting the Aboriginal African Tribes, Extending from Mosambique to the Borders of Egypt; Together with Vocabularies of Their Respective Languages