Q: This puzzle, a souvenir from the 1904 St. Louis World's Fair, has been in our family for many years. Can you tell us something about it?

 

A: Robert M. Shaffer patented this type of mechanical puzzle in 1900, then assigned the patent to the Copenhagen Puzzle Co. of Baltimore. Each letter is on a button that can be slid into place to spell a word. Your puzzle will spell the word "Exposition" when the letters are slid into place. Shaffer intended the puzzle to be used for advertising, with the letters forming the name of a particular company or brand. The St. Louis World's Fair, also called the Louisiana Purchase Exposition, commemorated the 100th anniversary of the U.S. purchase of the Louisiana territory from France. The fair was supposed to open in 1903 but was postponed until the summer of 1904 so more exhibitors could be lined up. The 1904 World's Fair Society, a club for collectors of souvenirs from this fair, hosts a website, www.1904worldsfairsociety.org. The value of your puzzle in fair shape is under $20.