Home
Solomon Brown, First African American
Mary Henry William H. Dall, Alaskan Explorer
The Wright Brothers, Robert H. James Smithson, Founder of the Smithsonian
James Renwick, Jr., Architect of William
Temple Hornaday
Employee at the Smithsonian
Diaries,
Eyewitness to the Civil
War
Pioneers in Aviation
Goddard,
American Rocket
Pioneer
the
Smithsonian
Building
Saving America's Bison
Wilson
A. Bentley Primary Source Document
Pioneering
Photographer
of Snowflakes
Exercise
Institutional
History Division
Snowflake Exercise
~ Return
to Wilson A. Bentley Home ~
What are snowflakes?
What are Snowflakes? Snowflakes start as ice crystals that freeze around small pieces of dust in the air. As they fall to the earth, the ice crystals join together to form snow flakes. The shape of each snowflake is determined by temperature, wind, the amount of time it takes to fall to the ground, and the amount of water vapor in the air.
What are the seven basic shapes of snow crystals?There are many types of snow crystals, but here are the most well known: the Star Crystal, the Dendrite Star, Columns, Plates, Capped Columns, Needles, and Irregular Forms. Snowflakes are six-sided because water molecules have six sides and tend to grow in six directions.
Columns
|
Star Crystal
|
Dendrite Star  |
Plates
|
Capped Columns
|
Needles  |
Irregular Forms  |
Photomicrographs of the seven types of snowflakes taken from Wilson A. Bentley's Studies among the snow crystals during the winter of 1901-2 with additional data collected during previous winters and twenty-two half-tone plates. Reprinted from the Annual Summary of the Monthly Weather Review for 1902. Washington, D. C.: Government Printing Office, 1903. |
|
Test your observational skills!
Can you identify the snowflake types in Wilson A. Bentley's photographs on the following page?
Resources
- LaCapelle, E. R. Field Guide to Snow Crystals. Seattle University of Washington Press, 1969.
- Ukichiro, N. Snow Crystals, Natural and Artificial. Cambridge: Harvard University Press, 1954.
- Snow Crystals.com -
An online guide to snowflakes, snow crystals, and other ice phenomenon,
created by Kenneth Libbrecht, Professor
of Physics at Caltech (California Institute of Technology)