During my travels I gathered information and took pictures of anything and everything I came across that was related to mathematics, mathematicians and the history of mathematics. Most of these images found their way into full-length posts on the many individual mathematicians I've written about, but in some instances I don't have enough material to support a full post on a specific topic or person. I don't want these extra images and visits to go unused, however, so in this post I present additional images relating to mathematicians, the history of mathematics and mathematical objects, hoping that my students may find them to be interesting and to be helpful resources - and that others might simply enjoy the images taken of places and objects in the USA, the UK, France and Germany.

**Rene Descartes**

The great Rene Descartes (1596-1650) - a towering figure in philosophy as well as in mathematics - is one of the mathematicians for whom I was not able to get to a large number of relevant sites. I did get to visit the church where he is buried, St. Germain de Pres in Paris, and I also happened across a Parisian University named for him.

The picture heading this post, and the next eight pictures are of the Abbey of St. Germain de Pres; the original church at this site was conceived in 512 AD and completed and dedicated in 558 AD, making it the oldest church in Paris. It's bell tower is one of the oldest in all of France. Descartes' tomb is located in one of the side chapels near the altar; sadly, I could not view the actual tomb because significant construction is currently taking place at the eastern end of the church.

The picture heading this post, and the next eight pictures are of the Abbey of St. Germain de Pres; the original church at this site was conceived in 512 AD and completed and dedicated in 558 AD, making it the oldest church in Paris. It's bell tower is one of the oldest in all of France. Descartes' tomb is located in one of the side chapels near the altar; sadly, I could not view the actual tomb because significant construction is currently taking place at the eastern end of the church.

The following two pictures are of the University of Rene Descartes in Paris.

**Henri Poincare**

Henri Poincare (1854-1912) was the most prominent French mathematician of his time. Along with David Hilbert (1862-1943) he was one of the two most prominent mathematicians in Europe of the time. I was thankful that Montparnasse Cemetery in Paris included Henri Poincare on their map of celebrities buried here. During my travels it was the case that finding the graves of mathematicians was rather a hit or miss proposition and quite the treasure hunt in most cases - sometimes successful, sometimes not.

**W. W. Rouse Ball**

Walter William Rouse Ball (1850-1925) entered Trinity College, Cambridge in 1874, earned the spot of Second Wrangler in the Tripos, became a fellow of Trinity in 1875 and remained one the rest of his life. In 1927 he established chairs at both Cambridge and Oxford. Among those who have held the Rouse Ball Professorship of Mathematics are J. E. Littlewood and Abram Besicovitch (both at Cambridge) and Sir Roger Penrose (at Oxford). Plaques commemorating Rouse Ball, Littlewood and Besicovitch can be seen in the chapel of Trinity College Cambridge. Penrose is currently Emeritus Rouse Ball Professor of Mathematics at Oxford, and his famous tiles can be seen outside Oxford's Mathematical Institute.

When I expressed surprise to the professor hosting me at Cambridge at finding the name of Besicovitch here (I knew he was from eastern Europe), he replied, "Oh, yes, Besi was here!"

Penrose Tiling outside Oxford's Institute of Mathematics |

**Sir Isaac Barrow**

Sir Isaac Barrow (1630-1677) held the Lucasian Chair of Mathematics just prior to Sir Isaac Newton (1642-1726). This professorship was founded in 1663 by Henry Lucas and was recently held by famed physicist Stephen Hawking from 1979 to 2009.

Isaac Barrow resigned the chair in 1669 and was appointed chaplain to King Charles II in 1670. Three years later, Charles II appointed Barrow to the Mastership of Trinity College, Cambridge, stating that he was the best scholar in England. He is buried in Westminster Abbey and memorialized with a statue in the chapel at Trinity College, Cambridge.

I'd always heard that it was Barrow who came up with the Fundamental Theorem of Calculus (before Newton) and that he was Newton's teacher, but during my time in Cambridge I learned in no uncertain terms that this was not the case and that Barrow was nowhere near existing in the same intellectual universe as Newton. I have that on good authority! That said, he clearly made contributions and was recognized for those contributions by the king at the time and is worthy of remembrance - as we see in Trinity College and at Westminster Abbey.

Sir Isaac Barrow - Chapel of Trinity College, Cambridge |

Westminster Abbey, London - burial place of Sir Isaac Barrow |

**Mathematical Shapes and Objects**

As well as taking pictures of places and things related to specific mathematicians I always had my eyes open for mathematical objects wherever they might be. The first two pictures are of a sculpture in the grounds of Holyrood Palace, Edinburgh, Scotland. I think it's pretty cool that the monarch has an icosahedron in her garden. The pictures following those are of labyrinths whose locations are given in the photo captions.

Location - London Tube Station |

Location - Paris - on the bank of the Seine |

Location - Paris - on the bank of the Siene |

Seattle - near the Space Needle - taken at the JMM Conference before I left for the European part of my sabbatical |

In London, after visiting the Royal Society I was walking back toward Westminster Pier along the east side of St. James's Park. As I was looking across toward Buckingham Palace, a conversation caught my attention. Someone in a group of people approached another group and asked, "What do you call a seven-sided shape?" Discussion ensued regarding "heptagon" vs. "septagon." It caught my attention because this is something I talk about in certain classes I teach, but I'd never heard such a conversation just out and about before. I thought, "Why on earth are people who are just walking down the street conversing about names of polygons?"

It struck me later in the day that this must have had to do with British currency, for which, though most coins are circular, two of them are seven-sided polygons.