The Georg Hartmann stamped on these nose spectacles may be the scientific instrument maker and physicist of the same name. After travelling in Italy, Hartmann (1489-1564) settled down in Nuremberg in 1518 as instrument maker. There he constructed a great many globes, astrolabes, sundials, and similar instruments and published a number of papers on astrological subjects. He is attributed with the discovery of the so-called dip or inclination of the magnetic needle. Later he became vicar of St. Sebaldus's church in Nuremberg. If indeed the spectacles offered here belonged to, or were made by Georg Hartmann the instrument maker, then they can be dated to circa 1518-1564.