Information
ILLUSTRATED DISSERTATION ON STRUCTURE OF THE EARTH
WITH A JESUIT ADVISOR
STENGEL, Stefan Leopold von. De Structura Exteriore Globi Terraquei, et quomodo corpora marina, aliaque petrificata in montes, terraeque strata pervenerint? Dissertatio. ... praeside P. Joanne Jung, S.J. ... MDCCLXVII.
Heidelberg, Joannis Jacobi Haener, [1767]. Small 8vo (16 x 9.5 cm). A doctoral dissertation on the structure of the earth's crust, with 1 folding engraved plate showing a cross-section of the earth and eight smaller figures with fossils, shells, etc. Contemporary stiff blue paper wrappers, covered with early nineteenth-century lilac paste-paper. Lacking the half-title.
| Orders and Information | € 975 |
Rare first and only edition of a little-known Heidelberg doctoral dissertation on the structure of the earth's crust and its changes over the ages (discussing the formation of mountains, the distribution of fossils and shells, etc.). We have located no other copy outside Germany (Hulthem had a copy, but none is listed in the on-line catalogue of the Belgian Royal Library). Though advised by a Jesuit professor of church history, the dissertation presents surprisingly modern views and cites Leibnitz's 1749 Protogaea, Moro's 1751 Veränderungen des Erdbodens and other pioneering works of scientific geology, as well as the more traditional literature influenced by theology, including the eccentric Kircher (it also cites more general natural histories and classical sources). Stengel presents and analyses propositions from many of these sources. The folding plate, drawn by the author and engraved by Egidius Verhelst the younger (1733-1818), has in its centre a large crosssection of the earth clearly based on that in John Woodward's 1695 Essay Toward a Natural History of the Earth (probably via the French translation published at Amsterdam in 1735). At a scale of about 1:90,000,000, it shows a four-layer crust surrounding a water core. The scale of the crust is greatly exaggerated, so that the mountains rise to nearly 1000 kilometres (and buildings to about 300 kilometres) and a 2000 kilometre-deep mine shaft (one of Stengel's additions to Woodward's image) runs through the first three of the four layers. The thickness of the crust nearly coincides, no doubt accidentally, with modern measurements of the thickness of the mantle, so that the liquid core is very nearly correct, though without a solid centre and containing water rather than molten iron or rock. Water sinks or sources run down through all four layers to the water core. Surrounding the cross-section are eight smaller figures (also new to Stengel's plate) showing what at the time would have been called fossils.
The dissertation is often catalogued under the name of the advisor, the Jesuit professor of church history at Heidelberg University, Johann Jung (1746-1773), more prominently displayed on the title-page than Stengel's. Stengel (b. ca. 1745) was the son of Jung's most important patron, Johann Georg von Stengel (1721-1798), secretary to the Palatine Elector Karl Theodor (dedicatee of the present book) and director and co-founder (in 1763) of the Palatine Academy of Sciences. Stengel's thesis must have inspired another Heidelberg thesis in the following year: Joannes Stephanus de Scheben, De Structura Interiori Globi Terraquei.
One can see traces of the original blue paper wrappers, but they have been covered with paste-paper made from a discarded early nineteenth-century map. Lacking the half-title, but otherwise in good condition, with a library stamp removed from the title-page (affecting a few letters of the title) and a few minor stains. A fascinating view of the state of knowledge about the structure and evolution of the earth, during the transition from the theological to the scientific approach.
