Mathematical Treasure: Guyot's Mathematical Recreations

Edmé-Gilles Guyot (1706-1786) was a Paris mail clerk who eventually worked his way up to Postmaster General (Directeur général des postes), but he was also experienced and talented in many other fields of knowledge. Among his special interests were optical illusions and magic. In 1769, he may have published the book of demonstrations and experiments, Nouvelles récréations physiques et mathématiques, which became very popular. Another possible author for this book is Guillaume-Germain Guyot (1724-1800), French abbé and author of scientific works. Whoever he was, author M[onsieur] Guyot provided an explanation of the “missing square puzzle," along with the solid geometry shown below. These images are from Volume II of the 1786 edition of the work:

Among the mathematical considerations can be found a discussion of regular solids:

Guyot also presented a technique for projecting points on the surface of a pyramid.

The images above are presented courtesy of the University of Toronto Library and can be viewed via Internet Archive.

Index to Mathematical Treasures