Lars Gislén
Retired, affiliated researcher
Four Instruments in Martín Cortés' Breve Compendio de la Sphera and a Rule for Finding the Age of the Moon
Author
Summary, in English
This paper investigates and discusses four instruments found in a sixteenth century Spanish book of navigation. The night clock is a rather standard application of similar instruments known since the fourteenth century in Europe. Cortés’ explanation of the causes of the deviation of the magnetic and geographical north is quite original. His instrument to correct for that the Polaris deviates from the North Celestial Pole is an original way of presenting the practical tradition of Spanish mariners. The general sundial is essentially a copy of the same instrument appearing in in Peter Apian’s books Cosmographia LIber and Ein kunstlich Instrument but with an addition for finding the azimuth of sunrise and sunset. The paper also investigates a simple rule for finding the age of the Moon for any date. Observations of the Moon and its phases were an important part of navigational art for predicting with the tides.
Department/s
- Particle and nuclear physics
Publishing year
2024
Language
English
Pages
53-62
Publication/Series
Journal of Astronomical History and Heritage
Volume
27
Issue
1
Links
Document type
Journal article
Publisher
National Astronomical Research Institute of Thailand
Topic
- Astronomy, Astrophysics and Cosmology
Status
Published
ISBN/ISSN/Other
- ISSN: 1440-2807