Rogers, Henry Darwin

ROGERS, HENRY DARWIN

(b. Philadelphia, Pennsylvania, 1 August 1808; d. Shawlands, near Glasgow, Scotland, 29 May 1866)

and ROGERS, WILLIAM BARTON

(b. Philadelphia, 7 December 1804; d. Boston, Massachusetts, 30 May 1882)

geology.

Henry and William Rogers, along with their brothers James (1802–1852) and Robert (1813–1884), were important in the mid-nineteenth-century American scientific community. Their father had fled Ireland in 1798 because he had publicly expressed strong sympathy for the leaders of the rebellion of that year. He settled in Philadelphia, where he obtained an M.D. from the University of Pennsylvania. Later he became professor of natural philosophy and chemistry at the College of William and Mary. Each of the sons studied medicine or chemistry and became professor at William and Mary, the University of Virginia, or the University of Pennsylvania. William and Henry also secured appointments as state geologists of Virginia and Pennsylvania, respectively; the other brothers, who were more exclusively chemists, together wrote one of the earliest textbooks of chemistry in the United States. The Rogers brothers, especially William and Henry, were deeply involved in the organization of the Association of American Geologists in 1840 and in its transformation into the American Association for the Advancement of Science in 1848. Both served as chairman of the former association, Henry in 1843 and William in 1845 and 1847; William served as president of the latter association in 1876.

During much of this period, William and Henry were developing plans for organizing a more rigorous and practical kind of scientific education involving sustained laboratory work. After moving to Boston (Henry in 1845, William in 1853), they pursued the idea vigorously until the state was induced to charter the Massachusetts Institute of Technology. William became its first president (1862–1870, 1878–1881) and is regarded as one of the principal architects of modern scientific and engineering curricula. In 1855 Henry moved to Scotland, and in 1857 he was appointed regius professor of natural history at the University of Glasgow—probably the first native American to be appointed to a chair anywhere in Europe. William and Robert were charter members of the U.S. National Academy of Sciences in 1863, and William became its president in 1879.

In 1832 Henry, fascinated by the social theories of Robert Owen, went to England for a year with Owen’s son to give scientific lectures to workmen. There he was introduced into scientific and especially geological circles, then in great ferment. When he returned to the United States he quickly infected William with his new enthusiasm for geology. It was an auspicious moment; many of the states were launching large-scale geological surveys, and for the most part collaboration among the state geologists (and Logan in Canada) was both cordial and fruitful. The Rogers brothers and their assistants mapped New Jersey, Pennsylvania, and Virginia (which then comprised West Virginia), including the largest sector of the Appalachian Mountains then being studied. They showed extraordinary insight in unraveling concomitantly the stratigraphy and the structure of the mountain chain. They made little overt use of paleontology in stratigraphy, although they were in close communication with the geologists contemporaneously mapping New York State, where James Hall and Lardner Vanuxem were demonstrating the great usefulness of William Smith’s principle of faunal succession in strata continuous with those of Pennsylvania. Whether because of this communication or not, the Rogers brothers made no serious blunders in the stratigraphy like those made by previous workers unacquainted with the use of paleontology.

Concerning structure, the brothers made evident the beautiful simplicity and elegance of the Appalachian fold system and provided the first adequate understanding of the geologic structure of any large mountain belt.

The period of tight money that followed the panic of 1837 halted the brothers’ survey work and prevented the prompt publication of their final reports; Henry’s was published about two decades later, but William’s remained unpublished. Nevertheless, in a joint paper presented in 1842, they described with great clarity and elegance and illustrated in excellent cross sections, with no vertical exaggeration, the great regular, curvilinear, asymmetrical folds that characterize the Valley and Ridge province of the Appalachians, especially in Pennsylvania and northern Virginia, and some of the major thrust faults of southwest Virginia. By demonstrating that any explanation of such folding and faulting must provide for a remarkable uniformity of forces over a large region, they greatly weakened current theories of vertical uplift and strengthened ideas of tangential forces operating perpendicular to the trend of linear mountain belts. Their paper attracted wide and favorable attention both in America and in Europe, especially in Britain, and was recognized as the first major American contribution to geological theory. Henry also showed that slaty cleavage is spatially and geometrically bound to folding and hence must be produced by the same regional forces.

The Rogers’ dynamic explanation of these geological facts leaned toward catastrophism and met with little acceptance, but their work paved the way for James Dwight Dana’s more uniformitarian theory of tangential contraction, which dominated thinking on orogeny well into the twentieth century. Although this theory was seriously challenged in the first half of the present century by a renewal of theories based on vertical uplift (coupled with lateral gravitational sliding to explain the evident tangential shortening) and by theories based on assumed convection inside the Earth, it was not superseded by a new general theory of orogeny until the 1960’s. At that time geophysical evidence was added to the geological facts to establish the existence of slow but very large-scale motions within the Earth’s mantle, of which the tangential shortening observed in mountain belts is simply a side effect (the “new global tectonics” or plate tectonics).

BIBLIOGRAPHY

I. Original Works. The Rogers brothers’ writings include William and Henry Rogers, “On the Physical Structure of the Appalachian Chain, as Exemplifying the Laws Which Have Regulated the Elevation of Great Mountain Chains Generally,” in Reports of the Meetings of the Association of American Geologists and Naturalists (1843), 474–531, abstracts in American Journal of Science, 43 (1842), 177–178; in Reports of the British Association for the Advancement of Science for 1842, pt. 2, 40–42 (also see the 1884 work by William, cited below); Henry Rogers, “On the Direction of the Slaty Cleavage in Strata of the Southeastern Belts of the Appalachian Chain, and the Parallelism of the Cleavage Dip With the Planes of Maximum Temperature,” in Proceedings of the American Association of Geologists and Naturalists, 6 (1845), 49–50; and The Geology of Pennsylvania, 2 vols. (Edinburgh-Philadelphia, 1858); and William Rogers, A Reprint of Annual Reports and Other Papers on the Geology of the Virginias (New York, 1884).

II. Secondary Literature. See J. W. Gregory, Henry Darwin Rogers (Glasgow, 1916); Mrs. W. B. Rogers, Life and Letters of William Barton Rogers, 2 vols. (Boston, 1896); and W. S. W. Ruschenberger, “A Sketch of the Life of Robert E. Rogers, M.D., LL.D., With Biographical Notices of His Father and Brothers,” in Proceedings of the American Philosophical Society, 23 (1886), 104–146, which is not entirely accurate.

John Rodgers