Foundations of geometry possible exception of the parallel postulate) that any theorem proved from them was deemed true in an absolute, often metaphysical, sense. Today, however, many other geometries which are not Euclidean are known, the first ones having been discovered in the early 19th century. Euclid's "Elements" is a mathematical and geometric treatise consisting of 13 books written by the ancient Greek mathematician Euclid in Alexandria c. 300 BC. It is a collection of definitions, postulates (axioms), propositions (theorems and constructions), and mathematical proofs of the propositions. The thirteen books cover Euclidean geometry and the ancient Greek version of elementary number theory.
Ptolemy II Philadelphus in the Library of Alexandria to the Capodimonte Palace by Gioacchino Murat and then in 1867 moved to the Palazzo Reale di Napoli, before being given to the Camera dei deputati in Palazzo Montecitorio in Rome. It later returned to Naples and since 1997 has hung in its original position in Room 31 of the Royal Apartments, also known as the Salone della Culla. Ptolemy II Philadelphus in the Library of Alexandria Ptolemy Philadelphus in the Library of Alexandria is an 1813 oil on canvas painting by Vincenzo Camuccini. It is now in the National Museum of Capodimonte in Naples. The work was commissioned by