Note how "Hard Sky" and "Watery Sun" are two of the conditions in this weather chart from A Directory for the North Atlantic Ocean, Comprising Instructions General and Particular for its Navigation, 1918.

Geneticists have found DNA markers associated with mathematical ability.  And here's a precursor to that: Sudoku in embryo, from Die Stoffliche Grundlage der Vererbung, 1921.

You've heard of The Importance of Being Earnest.  Here's how Ernest came to be drawn more fully than some other characters.  From Biology and Man by Benjamin Gruenberg, 1944.

Above and below, from the Arthur and Fritz Kahn Collection, courtesy of the Leo Baeck Institute Archives.

From the Annual Report of the American Institute of the City of New York, 1862.

From the Smithsonian Institution's Bureau of American Ethnology's Bulletin 64, 1918.

Here's the so-called turkey dance of the Utes.  Dancers sit along the circle (A).  Drummers with their drums are seated at B.  The leader begins the dance at C and traces the arrowed path, followed by the dancees.  "The erratic motion is continued indefinitely."  From the Smithsonian Institution's Bureau of American Ethnology's Bulletin 75, 1922.

"'Too low they build, who build beneath the stars.' —Young.  From A Practical Grammar by Stephen Watkins Clark, 1847.

This is the symbol left in the crib after the Lindbergh baby was famously taken away.  "There has been no genuinely convincing analytic work done on [this symbol] with respect to the Lindberg story" (Jerry Kroth, The Lindbergh Kidnapping, 2011).  [Note that the three black rectangles are actually holes that were punched in the paper and are not technically part of the design.]  The shaded object in the center is, of course, the "black egg" of alchemy, symbolizing the nigredo (a stage of putrefaction; the final step toward the "philosopher's stone" of enlightenment) and expressing "the precarious balance of the hermaphrodite, exalted by a [threatened] equilibrium" (Johannes Fabricius, Alchemy: The Medieval Alchemists and Their Royal Art, 1994).

From Africa, Viajes y Trabajos de la Asociaeion Euskara La Exploradora, 1887.

"I had to make my getaway between two suns.  There was no other horse nor time," said Billy the Kid (The West of Billy the Kid by Frederick Nolan).  Here's what a horse of two suns looks like, from Archiv für Physiologie, 1877.

"Left alone," from Advances in the Study of Mammalian Behavior, 1983.

From Mental Philosophy by Thomas Wirgman, 1838.

Don't ask which came first when it comes to the cycle of infection.  From Diseases of Poultry, 1915.

From Science in Story by Edward B. Foote, 1874.

Climate science hasn't come very far from 1920, when 90% of thermometer readings were inaccurate.  The more things change, the more they're misinterpreted.  From the Bulletin of the Southern California Academy of Sciences, 1920.

Hermetic Library comments: "I thought this was something about my reading habits; and it seemed meaningful enough at first blush I started to contemplate my life."