Editing Charles Sanders Peirce (section)

==== National Academy of Sciences ====
[[File:Peirce Quincuncial Projection 1879.jpg|thumb|upright=1.35|"The World on a [[Peirce quincuncial projection|Quincuncial Projection]]", 1879.<ref>{{cite journal |author-last=Peirce |author-first=Charles Sanders |date=1879 |title=A Quincuncial Projection of the Sphere |journal=American Journal of Mathematics |volume=2 |issue=4 |pages=394–397 |doi=10.2307/2369491 |jstor=2369491 |url=https://archive.org/details/sim_american-journal-of-mathematics_1879_2/page/n403/mode/2up}}</ref> Peirce's projection of a sphere onto a square [[conformal map|keeps angles true]] except at four isolated points on the equator, and has less scale variation than the [[Mercator projection]]. It can be [[Tessellation|tessellated]]; that is, multiple copies can be joined continuously edge-to-edge.]]
On April 20, 1877, he was elected a member of the [[National Academy of Sciences]].<ref>{{Harvnb|Brent|1998|p=367}}</ref> Also in 1877, he proposed measuring the meter as so many [[wavelength]]s of light of a certain [[frequency]],<ref>Fisch, Max (1983), "Peirce as Scientist, mathematician, historian, Logician, and Philosopher", ''[[#SIL|Studies in Logic]]'' (new edition), see p. x.</ref> the kind of definition employed [[Metre#Wavelength definition|from 1960 to 1983]].

In 1879 Peirce developed [[Peirce quincuncial projection]], having been inspired by [[Hermann Schwarz|H. A. Schwarz]]'s 1869 [[Schwarz–Christoffel mapping|conformal transformation of a circle onto a polygon of ''n'' sides]] (known as the Schwarz–Christoffel mapping).