This is a very nice map of Africa.  Plenty of detail is offered mostly along the coast; however, majority of the interior is unexplored by Westerners.  A large Lake Chad (Tchad) is shown.  Western Africa coatline is identified, from west to east, as Grain Coast, Ivory Coast, Gold Coast and Slave Coast.  From A New General Atlas of the World.  Teesdale maps are increasingly scarce.