Open AccessPreliminary report on a survey of magnetic declination near the Royal Alfred Observatory, Mauritius
Publication year - 1905
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1905.0057
Subject(s) - theodolite , declination , observatory , magnetic declination , geodesy , chart , geology , earth's magnetic field , physics , mathematics , astronomy , magnetic field , statistics , quantum mechanics
The accompanying chart is a graphic representation of the results of a survey of magnetic declination over a portion of the grounds of the Royal Alfred Observatory, Mauritius, which originated as follows:— Absolute determinations of the magnetic elements have been made with instruments of the Kew pattern since the year 1875, and in the year 1903 it was decided to utilise the 12-inch theodolite for more refined observations of declination. For this purpose its vertical pillar was removed and a brass one substituted. Suitable experiments showed that the small steel screws in various parts of the instrument had no sensible effect on the declination magnet when at a distance of 4 feet from the theodolite.