Catholic Encyclopedia (1913)/Georg Hartmann
Mechanician and physicist; b. at Eckoltsheim, Bavaria, 9 Feb. 1489; d. at Nuremberg, 9 April, 1564. He studied theology and mathematics, probably with Glareanus and Melanchthon. After travelling in Italy he settled down in Nuremberg in 1518 as mechanician. There he constructed a great many globes, astrolabes, sundials, and similar instruments. To him is attributed the discovery, in 1544, of the so-called dip or inclination of the magnetic needle. If a steel needle is carefully balanced on a horizontal axis and is then magnetized, it will be found to take an inclined position, the angle of dip depending on the locality. Later he became vicar of St. Sebaldus's church in Nuremberg. He published a number of papers on astrological subjects.
WOLF, Geschichte der Astronomie (Munich, 1877).