Calendars & Time

"An Election Entertainment, Plate I: Four Prints of an Election" by William Hogarth — https://commons.wikimedia.org/wiki/File:An_Election_Entertainment,_Plate_I-_Four_Prints_of_an_Election_MET_DP827052.jpg — CC0 1.0 (https://creativecommons.org/publicdomain/zero/1.0/)

"Atomic Clock017 (atomic clock NBS-1)" by National Institute of Standards and Technology — https://commons.wikimedia.org/wiki/File:Atomic_Clock017.jpg — Public domain (work of the U.S. federal government, 17 U.S.C. §105)

"George Washington (Gibbs-Channing-Avery Portrait)" by Gilbert Stuart — https://commons.wikimedia.org/wiki/File:George_Washington_MET_DT62.jpg — CC0 1.0 (https://creativecommons.org/publicdomain/zero/1.0/)

Illustration: The Yardstick Almanac. Generated schematic illustration — not a photograph or historical record. © The Yardstick Almanac, all rights reserved.