Davis, William Morris

(b. Philadelphia, Pennsylvania, 12 February 1850; d. Pasadena, California, 5 February 1934)

geography, geomorphology, geology, meteorology.

William Morris Davis was the son of Edward M. Davis and Martha Mott Davis, both members of the Society of Friends. His father, a Philadelphia businessman, was expelled from the society for enlisting in the Union army during the War Between the States. His mother was the daughter of Lucretia Mott, an early and strenuous worker for women’s rights and a firm antagonist of slavery. She resigned from the Society of Friends shortly after the expulsion of her husband from the group.

Davis received a bachelor of science degree from Harvard University in 1869 and a master of engineering degree in 1870. He went directly thereafter to the national observatory at Córdoba, Argentina, as a meteorologist. After three years he returned to the United States and served on the Northern Pacific survey as an assistant to Raphael Pumpelly. In 1877 he was appointed assistant to Nathaniel S. Shaler, professor of geology at Harvard College. From 1879 to 1885 he was instructor in geology at Harvard and in 1885 was appointed assistant professor of physical geography. In 1890 he became full professor of physical geography and in 1898 was appointed Sturgis Hooper professor of geology, becoming emeritus in 1912. He was a visiting professor at Berlin University in 1908 and at the University of Paris in 1911.

After retirement from Harvard, Davis devoted his time to field studies and to writing, and served as visiting lecturer at the University of California at Berkeley (1927–1930), the University of Arizona (1927–1931), Stanford University (1927–1932), the University of Oregon (1930), and the California Institute of Technology (1931–1932). He held honorary degrees from the universities of the Cape of Good Hope, Melbourne, Greifswald, and Christiana (Oslo). Davis was a founding member of the Geological Society of America, its acting president in 1906, and its president in 1911. He was instrumental in founding the Association of American Geographers and served as its president in 1904, 1905, and 1909. He was a member of the American Academy of Arts and Sciences, the American Philosophical Society, the National Academy of Sciences, the Imperial Society of Natural History (Moscow), and the New Zealand Institute. He was an honorary or a corresponding member of more than thirty scientific societies throughout the world and received more than a dozen medals and citations for his work. Daly lists 501 titles in Davis’ bibliography, the first entry dated 1880 and the last 1938.

In 1879 Davis married Ellen B. Warner of Springfield, Massachusetts. After her death he married Mary M. Wyman of Cambridge, Massachusetts, and after her death he married Lucy L. Tennant of Milton, Massachusetts, who survived him.

Davis’ contributions are in the separate but related fields of meteorology, geology, and geography (now better called geomorphology) and in their teaching at the high school and college levels. He was active in all these fields throughout his life, although the emphasis changed. Geological studies dominated his early publications (1880–1883). During the decade beginning in 1884 he produced some forty meteorological studies. Davis’ first published concern with geography, which was one of his few collaborative works, was done with Shaler and focused on the role of glaciers in fashioning the landscape. In 1889, with the publication of “The Rivers and Valleys of Pennsylvania,” he laid the cornerstone of his greatest contribution to physical geography: the “Davisian system” of landscape analysis. To this subject he devoted much of his scholarly energy for the rest of his life. From the time he joined the Harvard faculty, Davis was concerned with teaching, particularly of meteorology and physical geography. Not only were his formal courses centered on these subjects, but he was active in promoting them as proper pursuits of learning in both secondary schools and colleges. During the years from 1893 to 1903 he actively expressed this concern in seventeen papers on the subject.

When Davis took his first job with the national observatory in Córdoba, Argentina, the systematic collection of weather data by government was just beginning in the United States. In 1870 a federal service was established in the U.S. Army Signal Corps, a service that later became the U.S. Weather Bureau. It was against this background of developing interest in weather that Davis organized his first formal course shortly after joining the Harvard faculty. He continued to teach this course until 1894, and during this time he organized some of his students and interested amateurs into an informal organization of weather observers in the New England area. The data thus collected allowed early description of such phenomena as the sea breeze, thunderstorms, precipitation, and atmospheric convection. Davis’ Elementary Meteorology (1894) was an admirable synthesis of the state of meteorological knowledge at that time and was used for more than thirty years as a college text.

Davis’ early fieldwork was in geology, as his first reports indicate. His most important contribution was his study, supported by the U.S. Geological Survey, of the Triassic basins of New England and New Jersey. The first of fifteen preliminary reports appeared in 1882, but the most inclusive is his final report, “The Triassic Formation of Connecticut” (1898). This set forth for the first time a comprehensive history of the Triassic volcanic sequence, laid out criteria for distinguishing between intrusive and extrusive rocks, and demonstrated techniques by which subsurface geologic structures could be deduced from the surface topography. Of considerable interest also was his demonstration that the Tertiary “lake beds” in the western states were in large part fluviatile in origin.

Davis’ early fieldwork in geology, both in the West and in the northeastern states, coupled with his reading of the reports of the western surveys by Powell, Dutton, and Gilbert, served to develop his interest in the origin and description of landscape. Out of this interest grew his concept of the cycle of erosion and the demonstration of its use to describe the earth’s surface features and to decipher earth history. By 1883 Davis was discussing the origin of cross valleys, particularly in the folded belt of Pennsylvania and Virginia. He took exception to the work of Ferdinand Löwl (1882), which held that rivers now cutting across regional (or even local) structures could not maintain their courses by the action of antecedent (pre-existing) rivers flowing across a land slowly rising athwart their paths. Powell (1875, p. 163) had already introduced the idea of an antecedent stream and Davis argued, deductively, that such streams could in fact account for the drainage now cutting across the structures of the Appalachian Mountains.

In “The Rivers and Valleys of Pennsylvania” (1889) and its sequel, “The Rivers and Valleys of Northern New Jersey, With Notes on the Classification of Rivers in General” (1890), Davis firmly established his method of landscape analysis. The method involved assumptions from which he deduced a particular idealized landscape, a summation of the field data, a matching of the idealized form with the actual forms, and finally an explanation of the origin of the landscape.

The cycle of erosion was by far the most influential geographical concept introduced by Davis. For him the present-day landscape resulted from a long-continued and orderly development. To understand it, it was necessary to know the geological structures, the processes which operate on the surface, and the duration of their operation. He held that the present landscape could be understood only by understanding its past and, conversely, that an understanding of present-day landscape was a key to an interpretation of at least some earth history. Davis assumed that a river valley has progressed through one or more cycles, a complete cycle being marked by youth, maturity, and old age as the river valley is worn lower and lower into a landmass. In each stage the river and its valley displayed certain distinctive characteristics. Moreover, a cycle might be interrupted by uplift of the land, which would rejuvenate the river and allow it to impose the beginnings of a new cycle on the remains of an older one. The idea of youth, maturity, and old age in a valley, first presented in the “Rivers and Valleys of Pennsylvania,” was extended to embrace large landmasses. The cycle of erosion of a region was also seen as marked by youth, maturity, and old age. The end product of a complete cycle was a nearly featureless plain, called by Davis a peneplain. The regional cycle of erosion was also subject to interruption and rejuvenation; and various cycles, it was held, could be recognized by erosional surfaces of varying vertical and lateral extent.

Davis was among the vast majority of geologists who accepted uniformitarianism. Writing on the antecedent valleys in the Appalachians (1883, p. 357), he said that he “tests the past by the present” He began “The Rivers and Valleys of Pennsylvania” with “No one now regards a river and its valley as ready-made features of the earth’s surface. All are convinced that rivers have come to be what they are by slow processes of natural development…” (p. 215). Catastrophe as an explanation of a natural feature was avoided by the uniformitarian whenever another explanation could be offered. Thus Davis wrote: “Perhaps one reason why the explanation [for transverse valleys] has become so popular is that it furnishes an escape from the catastrophic idea that fractures control the location of valleys and is at the same time fully accordant with the ideas of the uniformitarian school that have become current in this half of our century” (ibid., p. 270). Long-continued action of observable processes were demanded by the Davisian approach to landscape, and in this his studies followed in the Hutton-Playfair-Lyell tradition.

Darwin had introduced the idea of organic evolution in 1859, and Davis extended the idea of development of one living form from a pre-existing form to the inorganic world of physical geography. Writing in 1883 about the antecedent streams of the Appalachians, he said, “It seems most probable, that the many pre-existent streams in each river-basin concentrated their water in a single channel of overflow, and that this one channel survives—a fine example of natural selection.”

Davis apparently was fully persuaded of the gradual and systematic evolution of topographical forms, and introduced the erosion cycle to “trace the development of… river systems… from their ancient beginning to the present time” (ibid., p. 183). The erosion cycle was developmental, evolutionary, and in step with the most exciting scientific idea of the time. I. C. Russell in 1904 noted that geomorphology was “vivified by evolution.”

Beyond these points Davis approached the explanation of landscape with the eyes of a geologist. His earlier training, in both Montana and the East, and his association with Pumpelly and Shaler stood him in good stead. The cycle of erosion covered long periods of time. He agreed with Powell (1876, p. 196) that mountains cannot remain long as mountains; they are ephemeral topographical forms but, assuming the long perspective of the geologist, he knew that “a complete cycle [of a river] is a long measure of time” (1889, pp. 203–204).

Davis advanced the cycle of erosion “tentatively,” not feeling “by any means absolutely persuaded of the results” (ibid., p. 219). Despite this disclaimer the cycle met with almost immediate acceptance. It appealed most strongly to geologists. This seems to have been true for two reasons. First, the cycle of erosion was set in a framework of long periods of time. That earth history involved immense (if unspecified) amounts of time was inbred in every geologist. Second, geological history had been based on tangible objects, rocks. But what would serve as a basis for history if rocks were missing for a particular time unit? Davis provided a partial answer. In his system the form of the land could, if properly interpreted, provide a history even though no rock record was available.

The cycle of erosion influenced the work of many geologists. Almost immediately after the introduction of the concept, reports analyzing landscape and reconstructing earth history by use of the Davisian analysis of landforms began to appear in the geological journals. Such studies continued to appear throughout Davis’ lifetime and until the 1940’s.

Davis argued that in the cycle of erosion, uplift of the land was rapid and initiated the erosional process. The land then went through a much longer period in which there was little or no movement and during which erosion wore the land down toward base level and a peneplain. A corollary of this sequence was that erosion was rapid and then slowed as the end of the cycle was approached. With this in mind, one wonders whether Chamberlin, an admiring colleague and close reader of Davis, did not draw some inspiration from the cycle of erosion for his very influential paper “Diastrophism as the Ultimate Basis of Correlation” (1909). The changing nature of the landscape must be reflected in the sedimentary record; and it was to the sedimentary record that Chamberlin appealed, arguing that, the diastrophism was not only rapid but worldwide and was part of the sedimentary record. Long periods of stillstand of the land and its accompanying erosion were reflected in the slowly changing nature of the resulting rock types in the sequence of sedimentary rocks, from initially coarse elastics to finer and finer particles and finally to chemical deposits. The Chamberlin model focused on the positive record in depositional basins of the cycle of erosion envisaged by Davis for the continental masses.

When Davis came to the task of the description of landscape, physical geography was an unordered agglomeration of facts and figures. There was no adequate way to describe a landscape in brief, concise, memorable terms. Elevations of mountains, lengths of rivers, angles of slope might represent a landscape; but these facts were not easily retained, nor were the forms they represented impressed upon the mind. Davis came to view the cycle of erosion as representing a series of generalized or idealized landform types. These forms, first deductively arrived at, must be checked against nature and modified accordingly. He sought to develop a store of ideal landscape types correlated with “structure, process, and time” that “shall imitate nature’s products” (1902, p. 246). He saw his system as a technique of geographical description, feeling that

… comparing the partial view of the landscape, as seen by the outer sight, with the complete view as seen by the inner sight, [the geographer] determines, with great saving of time and effort just where the next observations should be made in order to decide whether the ideal type he has provisionally selected fully agrees with the actual landscape before him. When the proper type is thus selected, the observed landscape is concisely and effectively named in accordance with it, and description is thus greatly abbreviated [ibid., p. 247].

Davis thought of himself primarily as a geographer, although his influence was probably more profound among geologists. His professional work was in physical geography, which he shortened to “physiography.” This he viewed as a description of the land. If the element of time was emphasized—and thus the study became geological—Davis would have used the term “geomorphography.” Today the discipline is called “geomorphology.” The term generally includes that which Davis called “physiography.”

The cycle of erosion was Davis’ most important contribution. He at first conceived of it as occurring in a temperate climate—a climate he called “normal.” In later years, however, he extended it to the arid and glacial climates.

After his retirement from Harvard, Davis turned his attention to the development of coral reefs and coralline islands. His long monograph The Coral Reef Problem (1928) was the culmination of long study during the course of which he traveled to the south-western Pacific and to the Lesser Antilles. The volume stands as an exhaustive summary of the facts then known, the several hypotheses up to then advanced to explain them, and his own views on the role of ocean floor subsidence and the shifting sea levels of the Pleistocene in the origin of the coral reefs.

In 1930 Davis’ paper “Origin of Limestone Caverns” developed the still-accepted interpretation that caves as we now see them have passed through two stages in their development.

Davis’ courses in meteorology and physiography were reputed to have been carefully and logically presented. Most American physical geographers and geologists adopted the Davisian approach as it developed in his classroom and was presented in his published papers. He had a strong effect as well on many of the French workers. There was indeed a “Davis” school. Despite this, surprisingly few of his own students carried on directly in his footsteps. Douglas Johnson, as a young instructor at the Massachusetts Institute of Technology, spent much time with Davis and became his most distinguished disciple. He extended Davis’ analysis of the landscape history of the northern Appalachians and described the cycle of shoreline development. In meteorology, his student Robert DeCourcy Ward succeeded him as a professor of meteorology and climatology at Harvard and became director of the Blue Hill Observatory, a research institution for meteorology at Harvard.

The cycle of erosion was soon introduced into college and university teaching. Albrecht Penck, in his Morphologie de Erdoberfiāche (1894), introduced the Davis system of stream classification and discussed the peneplain. Albert de Lapparent did not quote Davis in his third edition of Traité de géologie (1897), but he did discuss “aplanissement,” which corresponded to peneplanation, and described incised meanders as the inheritance of a stream course through uplift. The same book in its fourth edition (1900) leaned heavily on Davis’ physiographical writings, and the Leçons de géographie physique (1896) was still more indebted to Davis. In the United States, William Berryman Scott’s Introduction to Geology (1897) firmly established the Davisian system in American textbooks. Thereafter all American textbooks in introductory geology and physical geography relied upon the Davisian description of landforms. This influence on textbook writers persisted to the mid-twentieth century.

BIBLIOGRAPHY

I. Original Works. Publications by Davis are listed in Reginald A. Daly, “Biographical Memoir of William Morris Davis,” in Biographical Memoirs. National Academy of Sciences, 23 (1945), 263–303. A bibliography of meteorological papers compiled and annotated by Lylyan H. Block appears in Bulletin of the American Meteorological Society, 15 (1934), 57–61. Twenty-six essays by Davis were collected and edited by Douglas W. Johnson under the title Geographical Essays (Boston, 1909; repub. New York, 1954).

Original works by Davis cited in the text are “Origin of Cross Valleys,” in Science, 1 (1883), 325–327, 356–357; “The Rivers and Valleys of Pennsylvania,” in National Geographic Magazine, 1 (1889), 183–253; “The Rivers of Northern New Jersey With Notes on the Classification of Rivers in General,” ibid., 2 (1890), 81–110; Elementary Meteorology (Boston, 1894); “The Triassic Formation of Connecticut,” in U.S. Geological Survey, Annual Report, 1896–1897, 18, pt. 2 (1898), 1–192; Physical Geography (Boston, 1898), written with W. H. Snyder; “Systematic Geography,” in Proceedings of the American Philosophical Society, 41 (1902), 235–259; The Coral Reef Problem, American Geographical Society Special Publication no. 9 (New York, 1928); and “Origin of Limestone Caverns,” in Bulletin of the Geological Society of America, 41 (1930), 475–628.

II. Secondary Literature. Works relevant to the work of Davis cited in the text are: T. C. Chamberlin, “Diastrophism as the Ultimate Basis of Correlation,” in Journal of Geology, 17 (1909), 685–693; Albert de Lapparent, Traité de géologie (3rd ed., Paris, 1893; 4th ed., 1900); Leçons de géographie physique (Paris, 1896); Ferdinand Löwl, “Die Enstehung der Durchbruchsthäaumal;ler,” in Petermanns Mitteilungen aus J. Perthes Geographischer Anstalt, 28 (1882), 408–416; Albrecht Penck, Morphologie der Erdoberfläche (Stuttgart, 1894); J. W. Powell, Exploration of the Colorado River of the West and Its Tributaries (Washington, D.C., 1875); Report on the Geology of the Eastern Portion of the Uinta Mountains and a Region of Country Adjacent Thereto (Washington, D.C., 1876); I. C. Russell, “Physiographic Problems of Today,” in Journal of Geology, 12 (1904), 524–550: and William Berryman Scott, An Introduction to Geology (New York, 1897).

Accounts of Davis’ life and work are given in Daly (see above); Kirk Bryan, “William Morris Davis—Leader in Geomorphology and Geography,” in Annals of the Association of American Geographers, 25 (1935), 23–31; and Sheldon Judson, “William Morris Davis—an Appraisal,” in Zeitschrift für Geomorphologie, 4 , no. 3/4 (1960), 193–201.

Sheldon Judson

Davis, William Morris (1850-1934)

American geologist

William Morris Davis was a geographer, meteorologist, and geologist who devised a relative method of determining the age of a river system. Davis' method of landscape analysis considered the cyclical nature of erosion and the subsequent uplift of the surrounding land in order to determine the age of the river in relation to its surroundings.

Davis was born in Philadelphia, Pennsylvania into the city's social elite. His grandmother was Lucretia Mott, the famous abolitionist. William Morris Davis bore the name of his uncle, a congressman. Davis spent many of his childhood summers in the farmlands of Pennsylvania, which instilled in him a deep interest in natural history. This interest spurred Davis to study at the Lawrence Scientific School of Harvard University. After his graduation in 1869, he pursued a master's degree in mining engineering, also at Harvard. Davis embarked on a tour of the mining districts of the Lake Superior region with Raphael Pumpelly during the summer of 1869. Later in the same summer, Davis helped Josiah Dwight Whitney conduct fieldwork in the Rocky Mountains. In 1870, Davis accompanied one of his former teachers, Benjamin Gould, to Argentina for the purpose of organizing an astronomical observatory. Davis remained in Cordoba for two and a half years assisting Gould with the observatory and undertaking meteorological work. Davis then returned to Philadelphia after experiencing differences with Gould.

Davis later became an instructor at Harvard, but initially struggled to interest his students. He commenced a lifelong career in research and writing in 1882. In the 1880s, Davis received notice for his work in geology and meteorology , but was internationally known for his research in physical geography . Davis turned out many articles on the Triassic formation of the Connecticut River Valley and on meteorological topics. In 1889, Davis wrote a paper on "The Rivers and Valleys of Pennsylvania." In this paper, Davis introduced the cycle for river system formations that was reiterated in many more of his works. Davis believed that running water is the single most important agent in creating landscapes. At the beginning of his erosion cycle, rivers are small, shallow streams, the result of imperfect drainage of the surrounding topography . With time, the streams carve out deeper channels, widen, and contributing tributaries form. These tributaries, in turn, bring in more and more water creating larger, more powerful waterways. Waterfalls are caused by the contrast of hardness of the rocks as they are worn back. Side-streams then form their own valleys and the valley slopes increase as more soil is carried downstream. At maturity, the river has a system of headwater branches that gnaw at the uplands, which in turn widen the rivers. The surrounding mountains then slowly erode over time. This erosion deposits a large amount of sediment into the rivers. This causes the rivers to become increasingly sluggish and the tributaries dwindle as the flow of water slows. The cycle then begins again when another episode of uplift rejuvenates the river systems. Davis, who was influenced by the English scientist Charles Darwin's organic evolutionary theories, determined the relative age of the river system by discerning its place in the erosion cycle and thus, proposed a cyclical nature to the evolution of the landscape.

Davis published the textbook, Elementary Meteorology (1894), which was widely used in colleges. Other relevant scientific literature published by Davis includes: Elementary Physical Geography (1902), Geographical Essays (1909), The Lesser Antilles (1926), and The Coral Reef Problem (1928). In The Coral Reef Problem, Davis endorsed both James Dwight Dana's and Darwin's belief that barriers such as atolls and reefs are the result from the slow subsidence of the ocean bottom under the upward growing formations of islands.

Davis was appointed Sturgis-Hooper Professor of geology at Harvard in 1898. He retained this position until his retirement in 1912. Davis founded the Association of American Geographers in 1904. He also played a major role in the Geological Society of America. In 1928, Davis, a widower, married his third wife and settled in Pasadena, California where he peacefully lived out his final years until his death in 1934.

See also Landscape evolution

Davis, William Morris

American Geomorphologist
1850–1934

William Morris Davis is a major historical figure in geomorphology, the scientific study of landforms. Davis is especially known for his theory of landscape development—called the geographical cycle—that was the leading geomorphic theory from 1890 to 1950. He is also considered the father of American academic geography because of his role in establishing geography as an independent professional field. Today, geomorphology constitutes part of the subject matter of both geography and geology , and this dual affiliation exists largely because throughout his career Davis maintained strong ties to both disciplines.

Landscape Evolution

Davis attended Harvard University, where he studied geology (bachelor of science in 1869) and mining engineering (master of science in 1870) at a time when geography was taught only as part of other subjects. In 1878, Davis was hired by Harvard's geology department to teach physical geography courses, including landforms and meteorology .

Combining field observations in Montana in the summer of 1883 with his knowledge of the geomorphic literature, Davis began developing his theory of landscape evolution. He theorized that the geomorphic appearance of a given landscape is controlled by the combination of the following three variables.

• Structure: Structure involves rock resistance to weathering and erosion, and whether strata (rock layers) have been deformed into relief elements (areas of variable elevation) like fault blocks or folds.
• Process: Landforming processes include weathering as well as erosion and deposition by such agents as gravity and streams.
• Stage: Youth, maturity, and old age constitute the principal stages of development, an indication of how long the processes have been acting.

Davis first developed his theory for stream-dominated, humid, midlatitude settings, but geographical cycles were eventually proposed for other environments. The great popularity of the geographical cycle propelled Davis into the forefront of landform studies and the emerging discipline of geography. Throughout his career Davis remained a professor in Harvard University's geology department and a tireless champion of geography.

see also Stream Erosion and Landscape Development.

Dorothy Sack

Bibliography

Chorley, Richard J., Robert P. Beckinsale, and Antony J. Dunn. "The Life and Work of William Morris Davis." London, U.K.: Methuen, 1973.

William Morris Davis

The American geographer and geologist William Morris Davis (1850-1934) formulated a concept of the cycle of erosion, but his theories of landscape evolution are now sharply contested.

Of Quaker stock, William M. Davis was born in Philadelphia, Pa., on Feb. 12, 1850. He graduated from Harvard in 1869. From 1870 to 1873 he was a meteorological assistant at the Córdoba observatory in Argentina. In 1878 he returned to Harvard to teach geology and geography. Warned by senior colleagues that it would be difficult to gain promotion without publication, Davis soon became known for his contributions to journals. In all he wrote some 500 papers, chiefly on physical geography but also on the teaching of geography in schools and universities. These included 42 papers on meteorology and a textbook, Elementary Meteorology (1894).

In 1890 Davis became professor of physical geography at Harvard, and 9 years later he was appointed professor of geology. He retired from Harvard in 1912.

In 1889, in the first volume of the National Geographic Magazine, Davis published a notable paper on the rivers and valleys of Pennsylvania, followed in 1890 by a study of the rivers of northern New Jersey. For 10 years he published papers in this journal, which was then austerely academic; his work also appeared in numerous American and European journals. Steadily he developed his theory of the cycle of erosion under humid, arid, glacial, and other conditions. It provided a wonderful framework for teaching and research, profitably used by his disciples, notably the geologist Douglas W. Johnson. Block diagrams and sketches of unique clarity helped readers to visualize landscapes in three dimensions. For a time Davis's ideas on the evolution of landscapes were the basis of most geomorphological teaching. But there were always dissenting voices that called attention to the large assumptions on which some of the Davisian views were based, and at present some geomorphologists regard his views as interesting period pieces.

Davis was always anxious to bring geographers together, and through his enterprise the Association of American Geographers was founded in 1904. In 1911 he ran a 9-week "geographical pilgrimage" from Wales to Italy. He also organized the 8-week transcontinental expedition of the American Geographical Society in 1912 for European and American geographers. He was an enthusiastic fieldworker, and several of his papers were based on his careful fieldwork in Europe.

Davis was professor of physiographic geology at the California Institute of Technology from 1930 to 1934. He died in Pasadena on Feb. 5, 1934.

Further Reading

Davis's Geographical Essays, edited by Douglas Wilson Johnson (1909), gives his most important papers. His work is discussed in Preston E. James and Clarence F. Jones, eds., American Geography: Inventory and Prospect (1954). □

William Morris Davis

1850-1934

American geoscientist whose career and scientific contributions spanned the disciplines of meteorology, geology, and physical geography. In the latter field Davis's interest in geology, landform processes, and rain effects led to his defining the science of geomorphology , based on his theory of a continuing, progressive cycle of terrestrial erosion. His meteorological teaching and study at Harvard (1876-1912) produced Elementary Meteorology (1894), a standard college text for over 30 years. Davis's research included comprehensive field work and publications on the origins of limestone caverns and coral reefs and islands.