Fig. 1.

Linus Pauling and Robert Corey (A) and Herman Branson (B). Pauling's deep understanding of chemical structure and bonding, his retentive memory for details, and his creative flair were all factors in in the discovery of the α-helix. Robert Corey was a dignified and shy x-ray crystallographer with the know-how and patience to work out difficult structures, providing Pauling with the fundamental information he needed. Herman Branson was a physicist on leave at the California Institute of Technology, who was directed by Pauling to find all helices consistent with the rules of structural chemistry that he and Corey had determined. The wooden helix between Pauling and Corey has a scale of 1 inch per Å, an enlargement of 254,000,000 times. (A) Courtesy of the Archives, California Institute of Technology. (B) Courtesy of the Lincoln University of Pennsylvania Archives.