Mechanical Puzzle Collection

In 1893 professor Hoffman wrote a book called Puzzles; Old and New. It contained, amongst other things, more than 40 descriptions of puzzles with secret opening mechanisms. This book grew into a reference work for puzzle games and modern copies exist for those interested.
The beginning of the 20th century was a time in which puzzles were greatly fashionable and the first patents for puzzles were recorded. The puzzle shown in the picture, made of 12 identical pieces by W. Altekruse in the year 1890, was an example of this. With the invention of modern polymers manufacture of many puzzles became easier and cheaper.