Parallel (geometry) as a pair of straight lines in a plane which do not meet appears as Definition 23 in Book I of Euclid's Elements. Alternative definitions were discussed by other Greeks, often as part of an attempt to prove the parallel postulate. Proclus attributes a definition of parallel lines as equidistant lines to Posidonius and quotes Geminus in a similar vein. Simplicius also mentions Posidonius' definition as well as its modification by the philosopher Aganis. At the end of the nineteenth century, in England, Euclid's Elements was still the standard textbook in secondary schools. The traditional treatment of geometry was being
Serapeum of Alexandria Serapeum of Alexandria The Serapeum of Alexandria in the Ptolemaic Kingdom was an ancient Greek temple built by Ptolemy III Euergetes (reigned 246–222 BCE) and dedicated to Serapis, who was made the protector of Alexandria. There are also signs of Harpocrates. It has been referred to as the daughter of the Library of Alexandria. The site has been heavily plundered. The site is located on a rocky plateau, overlooking land and sea. By all detailed accounts, the Serapeum was the largest and most magnificent of all temples in the Greek quarter of Alexandria. Besides the image of the god, the