Geography of Europe is not surrounded by sea and its southeastern border has always been variously defined for centuries. In terms of shape, Europe is a collection of connected peninsulas and nearby islands. The two largest peninsulas are mainland Europe and Scandinavia to the north, divided from each other by the Baltic Sea. Three smaller peninsulas—Iberia, Italy and the Balkans—emerge from the southern margin of the mainland. The Balkan peninsula is separated from Asia by the Black and Aegean Seas. Italy is separated from the Balkans by the Adriatic Sea, and from Iberia by the Mediterranean Sea, which also separates Europe from Africa.
Iron metallurgy in Africa 20th century in many parts of sub-Saharan Africa, whereas in Europe and most parts of Asia they were replaced by the blast furnace before most varieties of bloomeries could be recorded. W.W. Cline's compilation of eye-witness records of bloomery iron smelting over the past 250 years in Africa is invaluable, and has been supplemented by more recent ethnoarchaeological and archaeological studies. Furnaces used in the 19th and 20th centuries ranges from small bowl furnaces, dug down from the ground surface and powered by bellows, through bellows-powered shaft furnaces up to 1.5 m tall, to 6.5m natural-draft furnaces (i.e. furnaces designed