After its first publication in 1524, Peter Apian's work next appeared in 1529 in an improved edition by his student, Gemma Frisius. Providing a layman's introduction to astronomy, geography, cartography, surveying, navigation and mathematical instruments, it became one of the most popular texts of its day, and acted as an outstanding advertisement for the wares in Gemma's instrument shop. Importantly, it described America in part 2, dating the discovery 1497 and stating that Amerigo Vespucci gave the continent his name. In this edition, Gemma's account of Peru and the expedition of 1530 follows. Two further tracts by him, on triangulation methods and the uses of astronomy, are dated Antwerp, 1533. After 1544 an important worldmap was added to the editions. First description of Lunar Distance as a method for finding the longitude; and the use of trigonometry for surveying and mapmaking.