The author's knowledge and positions, Rodrigo Zamorano, declaring on the title page of this issue of the editio princeps of this work: Astrologer and Mathematician, and Felipe II’s Cosmographer, and Professor of Cosmography in the House of Trade of the Indies in Seville City.
Also in this issue we look at his portrait at the age of 39 years. He was born in Medina de Río Seco and died in Seville around 1612.
The appointment of Professor occurred in 1571, in 1579 received the appointment of cartographer and instrument and charts maker, but without salary, but when in 1586 achieved the position of Chief Pilot, although his knowledge was theoretical and not practical, multiplied allegations against him, but despite this he confirmed in office in 1605. It was fought because of the controversy with some competitors, as the Neapolitan Domingo Villarroel.
The success of the Compendio, the first edition is dedicated to the President of the Royal Council of the Indies, Diego Gasca de Salazar, put him well clear and repeated successive editions: 1582, 1586, 1588 and 1591.
Add also that the edition of 1588, also in Seville, in the workshop of Juan de León, was translated into English and published as an appendix to a work of enormous popularity, the mathematician Edward Wright: Certaine errors in navigation detected and corrected…
Both, in this Compendio as its Cronología y repertorio de la razón de los tiempos, the author achieves a clear and modern presentation. The purpose was to provide a text for teaching and was fully achieved.
Regarding its content has two parts: the first, theoretical, about the globe, the movements of the sky and the distribution of elements on earth, and the second, practical, which examines the manufacture and use of nautical instruments, i.e. dealing with employment of the astrolabe and the height of the sun, of the declination and its boards, the ballestilla, compass...