INTRODUCTION. 33 



as marine deposits. Tci/iamgJwas written in 1715 and 1716, 

 but did not appear until 1748. On account of its heterodoxy, 

 De Maillet would not allow its publication until after his death. 

 The book is written in the form of dialogues between an 

 Indian philosopher, Telliamed, and a French missionary. All 

 the heterodox ideas of the author are placed in the mouth of 

 the oriental, and it is left to the listener to adopt them or to 

 reject them. 



The subject-matter is divided into six dialogues. The first 

 dialogue starts upon the hypothesis that in the beginning the 

 whole earth was covered by water. As the water diminished 

 in volume, mountains, islands, and continents made their 

 appearance. The highest or primitive mountain-systems 

 emerged from the world-ocean at a time when the seas were 

 very sparsely inhabited by organisms, hence these rocks are 

 either unfossiliferous or poorly fossiliferotis. By the erosion 

 and fragmentation of these primitive rocks the material for 

 the further formation of rock was obtained. Sediments were 

 continually in process of deposition in the seas, and the 

 younger the rocks, the more richly they became filled with 

 the remains of animals and plants. Telliamed also notes that 

 many species of fossil mollusca are apparently now extinct. 



The second dialogue brings forward a number of evidences 

 in support of Telliamed's hypothesis that the level of the ocean 

 was formerly higher. Telliamed reckons the lowering of the 

 sea-level at a foot in three hundred years, or three and a quarter 

 feet in a thousand years. The third dialogue suggests various 

 methods by which a more accurate determination of the lower- 

 ing of the sea-level might be obtained. The fourth is devoted 

 to fossils, the origin of which from living organisms Telliamed 

 firmly believed in. The fifth and sixth dialogues treat of the 

 cosmology of the earth, but are distinctly weaker than the fore- 

 going. If we except these concluding chapters, the Telliamed 

 far outshines other geological writings of the eighteenth century 

 in its wealth of observed facts, its daring originality, and its 

 charm of style. 



A few other notable works of the eighteenth century may 

 be briefly mentioned. The Englishman Needham, writing 

 in 1769, assumed, like Leibnitz, a central fire in the earth, 

 and traced to it the origin of mountains and volcanoes. 

 He thought the concentric arrarigement of the strata upon 

 mountains indicated that these strata, and the fossils contained 



3 



