January 17, 1851

Jan 17^th: Friday 17^th

Arose as usual and went to school. In the afternoon I had a journal, but a foolish one, however I read it and much to my sorrow received a subject for the week following, “Geological Researchers.” I shall try to write on it as well as I can.

Serena may choose to write about the geologists of ancient history, such as Theophrastus, a pupil of Aristotle, who described all then-known rocks and minerals in “Concerning Stones.” Pliny the Elder wrote a thirty-seven volume manuscript including all Roman knowledge about rocks, minerals, and fossils. It is more likely that her focus will be on the modern day researchers who are making news in the early nineteenth century. These include Abraham Gottlob Werner from Germany, who believed that the earth had once been completely covered with water and that all rocks and minerals were deposited as sediment. He and his followers believed that there would not be any more changes in the surface of the earth. In contrast, James Hutton, from Scotland, believed that heat was involved in the formation of some rocks. He proposed the principle of uniformitarianism, the concept that the earth would continue to change. John Playfair expanded on Hutton’s ideas in Illustrations of the Huttonian Theory of the Earth. Nicolas Demarest, Leopold von Buch and Alexander Von Humboldt studied various volcanic areas and reinforced Hutton’s theories. These theories were further supported by Sir Charles Lyell’s textbook Principles of Geology, published in 1830. Louis Agassiz studied European glaciers in the 1830s and 1840s and suggested that a sheet of ice had once covered Europe and changed its surface. Robert Mallet started studying earthquakes in 1846 by exploding gunpowder underground (World Book G: 97-99). This is an exciting time of expanding knowledge and understanding.