Wilson Bentley: The Man Who Studied Snowflakes
This Vermont-based farmer spent his career in the late 19th and early 20th centuries transforming the study of snowflakes into an art as well as a science.
Published June 1, 2005
By Fred Moreno
Academy Contributor
For centuries, humans have been fascinated by the endless variety of snowflakes and their six-fold symmetry. Scientists have sought to better understand how they are formed from single crystals of ice and why complex patterns arise spontaneously in such simple physical systems. According to Kenneth Libbrecht, a physicist at the California Institute of Technology, “snowflakes are the product of a rich synthesis of physics, mathematics, and chemistry.”
The oldest observation of snow crystals* on record appears in China around 135 BC, but the 17th century seemed to witness the dawn of their serious scientific consideration. A treatise by Johannes Kepler raised questions about the genesis of their hexagonal symmetry, while the French philosopher and mathematician René Descartes wrote detailed accounts of the geometrical perfection of snow-crystal structure.
Later in that century, English scientist Robert Hooke was the first to draw snowflakes through a microscope. Many others – including the 19th century Arctic explorer William Scoresby and the great Japanese scientist Ukichiro Nakaya in the mid-20th century – have made important contributions to understanding the science of snow and ice.
But if there is one person who transformed snowflake study into an art as well as a science, it was Wilson A. Bentley, a farmer from Jericho, Vermont, who spent a lifetime (1865-1931) studying snow crystals. He became interested in the structure of snow crystals as a teenager in the 1880s and tried sketching them through an old microscope his mother had given him. But he found this a frustrating task since he had to work very rapidly in order to capture a complex phenomenon.
Much Trial and Error
Eventually Bentley devised a means of attaching a bellows camera to a compound microscope, and after much trial and error, he finally succeeded in photographing his first snow crystal on January 15, 1885. Over the next 46 years, he took more than 5,000 snow-crystal images on glass photographic plates – as well as pictures of frost, pond ice, dew, and clouds. A little known fact about Bentley is that he also studied rainfall and was the first American to make measurements of raindrop size. His work in this area is one reason he is considered a pioneer in the science known today as cloud physics.
Keeping fragile things like crystals frozen and unspoiled meant Bentley had to work in temperatures below freezing. He caught the crystals on a blackboard and would transfer them to a microscope slide, taking care not to breathe on them.
“The utmost haste must be used, for a snow crystal is often exceedingly tiny, and frequently not thicker than heavy paper,” Bentley wrote. “Furthermore…evaporation (not melting) soon wears them away, so that, even in zero weather, they last but a very few minutes.”
The Treasures of the Snow
In the late 1890s, the world outside Jericho began to notice Bentley’s work. Some of his photomicrographs were acquired by the Harvard Mineralogical Museum and he published an article with George Henry Perkins, a natural history professor at the University of Vermont. It was in this article that he first outlined the notion that no two snowflakes are alike. In the coming years, many other academic institutions throughout the world – as well as the American Museum of Natural History and the British Museum – acquired samples of Bentley’s work, and he published articles in such magazines as Scientific American, National Geographic, Nature, and Popular Science.
Finally, in 1931, he collaborated with William J. Humphreys, chief physicist for the U.S. Weather Bureau, on a book, Snow Crystals, that would be the culmination of Bentley’s life’s work. It was illustrated with 2,500 snowflake photographs. Just a few weeks later, on a cold December day, Bentley died of pneumonia at his Jericho farm at the age of 66.
In the Old Testament, God asks of Job, “Hast thou entered into the treasures of the snow?” Wilson “Snowflake” Bentley surely would have answered, “Yes!”
*To most people, there is no difference between snowflakes and snow crystals. But there is a meteorological difference. A snow crystal refers to a single crystal of ice while a snowflake can mean an individual crystal or a cluster of them formed together. In short, a snowflake is always a snow crystal, but a snow crystal is not always a snowflake.
