The white door on the lower right is the
entrance to the Vatican Library. While the library's collection
is centuries old, this particular wing of the Vatican dates only to the
1950s. The much smaller door at the bottom left is the entrance
to the "secret" collection. This photo was taken not far from the
entrance to the Sistine Chapel. Each year the Vatican receives
thousands of requests from scholars across the world asking for
permission to be a Reader.
Among the mathematical treasures, one especially appreciates the "P"
Euclid, confiscated by Napoleon (1808) and returned to Rome over a
century later. In addition, Paciolo's
"Summa" is a compilation - an encyclopepdia - of all mathematical
knowledge known as of 1494. His work is the first published
treatment of double-entry bookkeeping.