TED Talks
Ted: Ted Ed: Can You Solve the Leonardo Da Vinci Riddle?
You've found Leonardo da Vinci's secret vault, secured by a series of combination locks. Fortunately, your treasure map has three codes: 1210, 3211000, and, the last one appears to be missing. Can you figure out the last number and open...
Houghton Mifflin Harcourt
Harcourt: Biographies: Samuel F. B. Morse
An account of Samuel Morse's life and career, with links to related information. Uses popups for photos.