1. Tore Frängsmyr, J.L. Heilbron, and Robin E. Rider, Eds., The Quantifying Spirit of the Eighteenth Century (Berkeley: University of California Press, 1990).
2. Brian Ogilvie, The Science of Describing: Natural History in Renaissance Europe (Chicago: University of Chicago Press, 2006), 7, 99.
3. Gunnar Broberg, “The Broken Circle,” in Tore Frängsmyr, J.L. Heilbron, and Robin E. Rider, Eds., The Quantifying Spirit of the Eighteenth Century (Berkeley: University of California Press, 1990).
4. Robert Hamblyn, The Invention of Clouds: How an Amateur Meteorologist Forged the Language of the Skies (New York: Picador, 2001).
5. Stanley David Gedzelman, “Cloud Classification Before Luke Howard,” Bulletin of the American Meteorological Society 70:4 (April 1989), 381.