Graphic representation of the periodic table of chemical elements organized as a series table with symmetrically divided short periods. This table was originated by chemists Arthur A. Blanchard and Frank B. Wade in 1914 and classified by chemist Edward G. Mazurs as Type IC2-3 in his seminal work Types of Graphic Representation of the Periodic System of Chemical Elements (1957). This illustration appears as Figure 28 on page 107 of Mazurs' 1957 publication.
Mazurs, Edward G., Frank Bertram Wade, and Blanchard, Arthur A. (Arthur Alphonzo). “Series Table with Symmetrically Divided Short Periods.” Glass, circa 1914–1957. Edward G. Mazurs Collection of Periodic Systems Images, Box 1. Science History Institute. Philadelphia. https://digital.sciencehistory.org/works/79407x754.