WILLIAM GILBERT, AND TERRESTRIAL MAGNETISM IN THE TIME OF QUEEN ELIZABETH: A DISCOURSE BY SILVANUS P. THOMPSON, F.R.S. WILLIAM GILBERT AND TERRESTRIAL MAGNETISM IN THE TIME OF QUEEN ELIZABETH. William Gilbert, the father of electrical science, was born in Colchester in 1540. Educated at St. John's College, Cambridge, where he took his degree as Doctor of Medicine in 1569, he settled, after four years of foreign travel, in London in 1573, and was admitted to the Royal College of Physicians, of which he became Censor, Treasurer, and, in 1599, President. He was in February, 1601, appointed personal Physician to the Queen, whom he attended in her last illness. He came of a well-known East Anglian family, and held extensive landed estates in Essex and Suffolk. He survived the Queen only eight months, dying November 30th, 1603. Gilbert's monumental work, the _De Magnete_, published in 1600, marks an era in magnetic science. For some four hundred years the employment of the magnetic needle in navigation had been known both in Northern and Southern Europe. While it is possible that the primitive use of the loadstone may be ascribed to the Baltic, it is certain that the employment of a pivotted needle, and the addition of a rose of the winds as a compass card both originated in the Mediterranean. The pivotted needle is described in the Epistle of Peter Peregrinus, written in 1269; while the earliest known compass-card marked with the initials of the names of the winds is that ascribed to Jachobus Giraldis, of 1426, in the Biblioteca Marciana in Venice. The manner of use in Elizabethan times of the loadstone and of the compass may be gathered from Olaus Magnus (_Historia de Gentibus Septentrionalibus_, 1555), from Pedro de Medina (_Arte de Nauegar_, 1545), Martinus Cortes (_Breve compendio de la sphera_, 1556), Blundevile (_Exercises_, 1594), Norman (_Newe Attractive_, 1581), Borough (_A discours of the Variation of the Cumpas_, 1581), Pedro Nuñez (_Instrumenta Artis Navigandi_, 1592), Barlow (_The Navigators Supply_, 1597), Nautonier (_Mécometrie de l'Eyman_, 1602), and Stevin (_Die Havenvinding_, 1599).