This is THE DISAPPEARING BICYCLIST puzzle by 18th Century mathematician Sam Loyd. In position 'A' 13 boys are visible, but in position 'B' - only 12. One is invited to determine which
Sam Loyd and His Puzzles (1928)" - Copyright J. A. Storer
Puzzle: Let's (Un)Do the Twist! – David Richeson: Division by Zero
Puzzle Sum 19 - Puzzle Prime
Sam Loyd's Archery Puzzle
Page:Cyclopedia of Puzzles by Samuel Loyd.pdf/22 - Wikisource, the free online library
Sam Loyd's Puzzles
Sam Loyd Collection - 6 Card Set | Paper Puzzles | Puzzle Master Inc
The Sam Loyd Company | Sam Loyd Puzzles Official Site
Sam Loyd - Can you solve this puzzle by the world's greatest puzzle creator Sam Loyd? You'll find this puzzle in our new Tom Tinker's Puzzles by Sam Loyd at the official
Sam Loyd - Linda Hall Library
Puzzle Sum 17 - Puzzle Prime
Sam Lloyd's Get-Off-the-Earth Puzzle
Famous Trick Donkeys - Wikipedia
Map, Novelty, Get Off the Earth Puzzle, Cartographic Curiosity, Antique, 1918 – George Glazer Gallery, Antiques
Sam Loyds Monkeys Puzzle - Solution
Sam Loyd's Puzzles
The Sam Loyd Company | Sam Loyd Puzzles Official Site
Sam Loyd Puzzles
Sam Loyds Puzzles | Book by Sam Loyd | Mr Puzzle
A picture of frustration: Sam Loyd's 15 puzzle – David Richeson: Division by Zero
Sam Loyd, Weight Problems, and Exercises | Math Munch