During the second century AD, Ptolemy (circa 100 - 178 AD) made a number of important contributions to geography. Ptolemy's publicationGeographikehyphegesis or "Guide to Geography" compiled and summarize much of the Greek and Roman geographic information accumulated at that time. Some of his other important contributions include the creation of three different methods for projecting the Earth's surface on a map, the calculation of coordinate locations for some eight thousand places on the Earth, and development of the concepts of geographical latitude and longitude