Scotland during the Roman Empire of the geography of Scotland had extended to the "Hebudes" (The Hebrides), "Dumna" (probably the Outer Hebrides), the Caledonian Forest, and the Caledonians. Ptolemy, possibly drawing on earlier sources of information as well as more contemporary accounts from the Agricolan invasion, identified 18 tribes in Scotland in his "Geography", but many of the names are obscure. His information becomes much less reliable in the north and west, suggesting early Roman knowledge of these area was confined to observations from the sea. Famously, his coördinates place most of Scotland north of Hadrian's Wall bent at a right angle, stretching due eastward
History of the Great Wall of China feature prominently. The French philosopher Voltaire (16941774), for example, frequently wrote about the Great Wall, although his feelings towards it oscillate between unreserved admiration and condemnation of it as a "monument to fear". The Macartney Embassy of 1793 passed through the Great Wall at Gubeikou on the way to see the Qianlong Emperor in Chengde, who was there for the annual imperial hunt. One of the embassy's members, John Barrow, later founder of the Royal Geographical Society, spuriously calculated that the amount of stone in the Wall was equivalent to "all the dwelling houses of England and Scotland" and would