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Classic book on the internal heat of the globe, the chief work from Bischof's volcanistic period. "In this work he presented a critical compilation of all that was known at the time, together with many of his own observations on the thermal properties of the earth's surface, including observations made in mines. From these he derived his theories of thermal gradients, which were essentially correct, and his ideas on the origin of volcanism and the heat required for his kind of `metamorphic' transformation... The evidence presented in this book was used immediately to support the plutonist theories dominant at the time" - D.S.B., II, p.158. With the bookplate of John Sinkankas. Formerly in the Seattle Public Library, with gilt-stamping to the covers, bookplate, a few rubber and perforated stamps within, page edges rubberstamped.