1. The Bentley Snow Crystal Collection Jean M. Phillips, Librarian Space Science & Engineering Center University of Wisconsin-Madison November 2005

2. Discussion outline Wilson A. Bentley: History and work Professor Benjamin Snow What is snow? Snow crystal pictures (movie) Grow your own snow crystals Snow crystal classification Bentley Collection Other snow resources

3. Wilson Alwyn Bentley, 1865-1931 First photomicrograph of an ice crystal on 15 January 1885 Snowflakes are composed of many ice crystals that collide and stick together as they fall – Bentley, with persistence, was able to find and isolate individual ice crystals How Bentley took pictures: Adapted a microscope to a bellows camera What is a glass lantern slide? How many pictures did Bentley take and why did he take so many?

4. Bentley’s reputation and scientific contributions Early work ignored by scientists 1924, awarded first research grant by AMS Earliest attempts to classify crystals as a function of temperature Observations documented: temperature, cloud type and height (where possible), surface winds and direction, cloud movement, etc. First in U.S. to study raindrops and their sizes; insight into the origins of rain

5. Bentley with camera

6. Professor Benjamin Snow Taught physics at UW-Madison until 1925 with great enthusiasm: “no student should graduate from the College of Letters & Science without taking it [physics]” He learned about Bentley’s “snow pictures” long before 1920 Professor Snow gave “snowflake” lectures about two times per year to standing-room-only crowds Snow’s legacy: “two men on campus to whom we tipped our hats…one was Van Hise (president), the other was Snow” Later, ~1300 slides were given to meteorology department and then, to the library in 2001

7. What is snow? Snow is precipitation that freezes and collects in clouds When released, the crystals may join together or grow depending on the temperature of the atmosphere All snow crystals start as hexagons (each type of crystal has its own distinct shape) Why is it important to study snow crystals?

8. Environmental Temperature and Crystal Formation °C°FCrystal Form 0 to -432 to 25Thin plates -4 to -1025 to 14Columns -10 to -1214 to 10Plates -12 to -1610 to 3Dendrites -16 to -223 to -8Plates -22 to -50-8 to -58Hollow columns [From The Why Files: Know Snow ]

9. Snow crystal pictures

10. Grow your own crystals http://whyfiles.org/123snow/2.html

11. Snow Crystal Classification http://library.ssec.wisc.edu/bentley/abou t.html#classification http://library.ssec.wisc.edu/bentley/abou t.html#classification

12. http://library.ssec.wisc.edu/bentley

13. Snow Web Sites All about snow (NSIDC): http://www- nsidc.colorado.edu/snow/index.htmlhttp://www- nsidc.colorado.edu/snow/index.html Snow crystals (Kenneth Libbrecht, CALTECH): http://www.its.caltech.edu/%7eatomic/snowcrystals/ http://www.its.caltech.edu/%7eatomic/snowcrystals/ Secrets of crystal growth (LLNL): http://www.llnl.gov/str/DeYoreo.html http://www.llnl.gov/str/DeYoreo.html Wilson A. Bentley (Jericho Historical Society): http://snowflakebentley.com/ http://snowflakebentley.com/ Know Snow (The WhyFiles): http://whyfiles.org/123snow/index.html http://whyfiles.org/123snow/index.html

14. Snow Books Bentley, W.A. and Humphreys, W.J. Snow crystals. Dover Publications, 1962. (Includes many pictures of snow crystals) Blanchard, Duncan C. The Snowflake man: A biography of Wilson A. Bentley. McDonald & Woodward, 1998. LaChapelle, Edward R. Field guide to snow crystals. University of Washington Press, 1969. Libbrecht, Kenneth. The Snowflake: Winter’s secret beauty. Voyageur Press, 2003. Martin, Macqueline Briggs. Snowflake Bentley. Houghton Mifflin, 1998. (Children’s book) Major scientific publications of Bentley: http://library.ssec.wisc.edu/bentley/about.html#history http://library.ssec.wisc.edu/bentley/about.html#history