Note 33 — Chapter VII · Camps, Fortifications, Vitrified Forts; Santorin; The Towns upon the Hill of Hissarlik.

Sir J. Lubbock compares the ruins of Aztalan, in America, with the vitrified forts of Scotland; but we think this is a mistake, for the walls of Aztalan consisted of irregularly shaped masses of hard, reddish clay, full of hollows, retaining the impression of the straw or dried grass with which the clay was mixed before it was subjected to the action of heat, whether the application of that heat was intentional or accidental. There is nothing about this at all resembling the melted granite of the vitrified forts.