"The earth is rude, silent, incomprehensible at first. . . .
Be not discouraged—keep on—there are divine things well enveloped,
I swear to you there are divine things more beautiful than word can tell!"

In faded sepia curves, Walt Whitman's words preface the timeworn leather-bound journal of a scientist as enthralled as the poet with the hidden treasures of the natural world.

Written in the elegant 19th century script of legendary UI natural sciences professor Samuel Calvin, those lines from Leaves of Grass stand as an epigram to the passion that animated Calvin's life and career.

Scottish-born Calvin taught geology at the UI from 1873 until his death in 1911. Whereas Whitman celebrated the divine things of the earth with words, Calvin honored them in pioneering photographs. The invention of mass-produced dry glass plates with light-sensitive gelatin made photography a popular hobby in the late-1800s—and a natural tool for scientists. Carrying the heavy equipment along on the field trips that were a mainstay of his teaching, Calvin took thousands of black-and-white images of scientific specimens, landscapes, and geological features—from geodes and bison bones to Colorado peaks and Iowa prairies. Rounding out his collection are portraits of family, colleagues, and students in the quaint dress and formal poses of the time, as well as records of university and Iowa City buildings, many of which have long since vanished.

Recognized as the best photographer in Iowa City, Calvin used this new technology to bring geology out of the field and into the lecture room. He created plate books to help students identify paleontological specimens, and 35mm copies of his photographs are still being used in UI classes today.

"Calvin had more than just a scientist's eye," says Julia Golden, curator of the UI's paleontological collection. "Rather than being utilitarian snapshots, his photos are beautifully composed and make lovely pictures. The light, shadows, and reflections are wonderful."

In the rare instances he was in front of the camera, Calvin can be distinguished by a gold watch and chain draped across his vest and a stern look that belies his popularity with students and fellow faculty. With his wide-ranging knowledge of the natural world, Calvin taught geology, botany, zoology, and other science courses at the UI before eventually becoming chair of the geology department and state geologist. For many years he was curator of the university cabinet, the forerunner of the natural history museum. To supplement the meager collection, Calvin sold his own collection of about 6,000 specimens to the university for a mere $150.

Almost a century after his death, Calvin's presence lingers within the UI's geoscience department. Calvin's wooden desk takes pride of place in Golden's office in Trowbridge Hall. His notebooks and cameras spill out of cupboards, and thousands of his heavy glass negatives fill metal filing cabinets.

Pulling on white cotton gloves, Golden carefully extracts a negative from its acid-free paper sleeve, exclaiming over its almost pristine condition. "Look, the emulsion is flaking a little around the edges," she says, "but otherwise, it's perfect."

Considering the fragile nature of the glass plates and the emulsion, the survival of Calvin's photographic collection is indeed remarkable. Apart from everyday handling over the decades, the collection also withstood two major relocations by the geoscience department, including the 1904 move (photographed by Calvin) in which Old Science Hall (now Calvin Hall) was rolled 150 feet across Jefferson Street and turned 90 degrees.

Leafing through the journals and photographs, Golden exclaims at her predecessor's pioneering work and scientific expertise. Even so long after his death, Calvin still inspires the admiration that led one of his students to state, "All who have sat in his classes have felt the striking personality of the man and the inspiration of his teaching."

Now, Calvin's work is inspiring another generation of students and natural history buffs. Since 1975, geoscience staff have worked to preserve Calvin's photographic collection and to make it more accessible. Some 800 images now make up the online exhibitions "Fixing the Image: Samuel Calvin's Vision of Iowa" and "Calvin's Scrapbook."

Thousands of people have logged onto the website (www.uiowa.edu/~calvin) to view Calvin's photographs, and many have e-mailed Golden and her staff to praise the virtual exhibitions.

"Maybe it's a person they knew, a campus building they studied in, or a scene from their home town," says Golden. "But each person who looks at Calvin's photos sees something special."