"The imaginary horse isn't real, but your idea of it is real" (Marietta McCarty, Little Big Minds, 2006).  Photo as scanned by the Costică Acsinte Archive.

From Das Geschlecht der Pflanzen Betreffenden Versuchen und Beobachtungen by Joseph Gottlieb Kölreuter, 1761.

"Tough on flies," from Joseph Breck's Annual Descriptive Catalogue of Seeds, 1896.

From 1895.

From the Dr. Hess Stock Book, 1901.

From Annals of Horsemanship by Henry Willian Bunbury, 1792.

We're often asked how we relax after a long night of time traveling through old books.  Here's a hint: it involves the horse mask we acquired from Archie McPhee.  (As to the feline guardian also pictured, he somehow acquired us along the way.)

Before the "horse of many colors" in Oz, there was the rainbow horse of folklore that "delivered souls through the cosmos, avoiding wayward angels" (Max Evans, Animal Stories).

"Gutten med gullhornet" by Theodor Kittelsen, 1910.

From The Dover Road by Charles George Harper, 1922.

Good luck, from the late 1800s.

"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.

You've heard of putting the cart before the horse, but here's what it looks like.  From Beskrivelse over Finmarkens Lapper deres Tungemaal, 1767.

From The Hunter and the Trapper in North America or Romantic Adventures in the Field and Forest, 1875.

You've heard of putting the cart before the horse, but here's a dinghy before the swan boat.  From Happyland, Massachusetts.