Influences on 19th-Century Science

masthead saying 'We Proceeded On'
Reprinted from We Proceeded On1

A "blank spot" in their thinking: conventional views of L&C as field geologists

"[Lewis] paid little attention to potential mineral deposits, especially after leaving the Mandans. . . . [W]hen he entered the Rockies he hardly ever commented on rocks or minerals."

"There was no reason during those drab weeks [descending the Columbia River] to ponder geology, about which they knew little."

"The forbidding mountains, what forces made them, how the great canyons were cut, what ingredients were fused to make the craggy skyline—of these things Lewis and Clark had little to say. At the beginning of the expedition their journals had contained random observations on potentially useful mineral deposits, and a collection of rocks and minerals had been sent back with the keelboat. . . . But even here in the Rockies, where observations about the earth might have crowded the pages of the journals, they concentrated on plants and animals. It was a blank spot in Lewis's thinking that he almost surely acquired from Jefferson."

"As Lewis and Clark moved on up the Missouri they had less and less to say about minerals. The discovery of an increasing number of new and extraordinary plants and animals and stirring experiences with Indians diverted their attention from such lackluster objects as coal, limestone, and lead ore."

"[B]eing vitally interested in ethnology, they [Lewis and Clark] forget geology altogether. From the Great Divide to the Pacific their journal entries contain virtually no geological descriptions. Those that do appear are worthless."

Historical commentary like the examples here fail to take into account the state of geological science in 1803. Geology as we know it was just emerging as a separate physical science, and it was decades away from the first discoveries of the astonishing processes behind the formation of a vast array of geological phenomena, from angular unconformities (unimaginably long gaps in the rock record) to volcanoes to the uplift of mountain chains whose summits are imbedded with marine fossils. Lewis could write at great length about the taxonomy of plants and animals because the relatively advanced state of botany and zoology gave him the intellectual framework and vocabulary to do so. It was the nascent state of geology, not deficiencies in the captains' dedication or attention, that precluded similar efforts in the science of rocks and minerals.

Despite the survival of so few Lewis and Clark mineral specimens, we can say for certain that some of them wound up in Philadelphia and that for a time they were displayed in the celebrated museum of Charles Willson Peale.2 The museum had other rock and mineral specimens besides those collected by the captains. John C. Greene and John G. Burke, two historians of Jeffersonian era mineralogy, argue that the collection as a whole "must have done much to stimulate public interest in mineralogy and geology" and may have been used by Benjamin Smith Barton, perhaps the preeminent naturalist of the day, in his lectures on natural history.3

Most of the information on natural history in the Lewis and Clark journals lay dormant for a century, a result of the failure to produce the proposed scientific volume containing, as a prospectus put it, "the information acquired by Captains Lewis and Clarke in the several departments of botany, mineralogy and zoology."4 By 1905, when the journals were at last published in a definitive scholarly version edited by Reuben Gold Thwaites, virtually all of what the captains had discovered had been subsequently rediscovered by others.

Still, it's reasonable to believe that the rock, mineral, and fossil specimens collected by Lewis and Clark may have positively influenced scientific inquiry; perhaps they were used to illustrate points in Barton's lectures or motivated additional research while on display at the A.N.S.

Whatever their impact on nineteenth-century science, it is certain that Adam Seybert thought highly of them. Seybert had more than thirty Lewis and Clark specimens in his possession and attempted to identify them all. Patrick Gass's fossil fish jaw, Saurocephalus lanciformis, was described and illustrated by natural historian and physician Richard Harlan in 1824,5 and it is evident from Samuel George Morton's publications that the purported Lewis and Clark specimens stimulated other fossil collecting in the geographic areas where they were supposedly found. I believe that the expedition specimens played a small but consequential role in facilitating the emergence of mineralogy as a useful science. They also help validate the expedition's role as a model for the later U.S. geological surveys of the American West.6

  • 1. John W. Jengo, "'Specimine of the Stone': The Fate of Lewis and Clark's Mineralogical Specimens," We Proceeded On, August 2005, Volume 31, No. 3, the quarterly journal of the Lewis and Clark Trail Heritage Foundation. Editorial additions include page titles, side headings, and graphics to assist the web-based reader. The original format is provided at
  • 2. The only known surviving mineral specimens collected by Lewis and Clark are among the essential expedition artifacts in Lewis & Clark: The National Bicentennial Exhibition, now touring the U.S. (See for places and dates.)
  • 3. Greene and Burke, 37.
  • 4. Jackson, Vol. 2, 547–548.
  • 5. Richard Harlan, "On a new fossil genus, of the order Enalio Sauri, (of Conybeare)," Journal of the Academy of Natural Sciences of Philadelphia, Vol. 3, 1824, 331–337, plate 12. Harlan's paper begins, "About sixteen years ago, there was deposited, by Lewis and Clark, in the cabinet of the American Philosophical Society, a fossil organic remain of some unknown marine animal. During the expedition of these gentlemen up the river Missouri in the year 1804, this specimen was found in a cavern situate[d] a few miles south of the river, near a creek named Soldier's Run."
  • 6. John W. Jengo, "Geological Trailblazers: Observations of Western Geology in the Journals of Lewis and Clark," Geological Society of America Abstracts, Vol. 35, No. 6 (October 2003), 605.