countered on the Atlantic, and was burned at the stake for his opinions in 1536.
About the middle of the seventeenth century some of the offshoots of the martyr's family emigrated from Gloucestershire, England, to Ireland, on the eastern or Saxon fringe of which some of their descendants are still scattered. Among these was John Tyndall, the Professor's father, who, although unknown to the public, was a man of unusual intellectual power and force of character. The Tyndall blood seems to have been rather fiery, as Prof. Tyndall's father had a "difference" with his grandfather, which cost him the inheritance that he would have otherwise received as the eldest son. He was therefore left to struggle without means, and learned a trade, but subsequently took a position on the police force of Ireland. But, being denied the usual facilities of education, he taught himself upon various subjects, and especially he became an able student of history. Prof. Tyndall's father inherited from his ancestors a taste for religious controversy, and threw himself zealously as an anti-Romanist into the Protestant and Catholic warfare. The fathers of the English Church, Chillingworth, Tillotson, Faber, Poole, Jeremy Taylor, and a host of others, were at his finger's ends. Young Tyndall's early intellectual discipline consisted almost wholly of exercises in theological controversy, on the doctrines of infallibility, purgatory, transubstantiation, and invocation of the saints. The boy knew the Bible almost by heart, and, with reference to this knowledge, his father used to call him Stillingfleet. But he had also an early interest in natural things, and his father flattered this tendency by calling him Newton, and by teaching him lines concerning the great natural philosopher, before he was seven years old, that are still remembered. The father of Prof. Tyndall was not only intellectually gifted, but he was a man of courage, independence, mental delicacy, and scrupulous honor. By the silent influence of his character, by example as well as by precept, he inspired the intellect of his boy, and taught him to love a life of manly independence. He died in May, 1847, quoting to his son the words of Wolsey to Cromwell—"Be just and fear nothing."
The subject of our present sketch was born in the village of Leighlin Bridge, Ireland, in 1820, and his earliest education was received at a school in that neighborhood. Through the influence of one of his teachers, he acquired an early taste for geometry. In 1839 he quitted school and joined the Irish Ordnance Survey. He acquired a practical knowledge of every branch of it, becoming in turn a draughtsman, a computer, a surveyor, and trigonometrical observer. In subsequent years he turned this experience to admirable account in his investigations of alpine glaciers. In 1841 an incident occurred which, although apparently trivial, had a powerful effect upon the young man's career. One of the officials, who had become interested in Tyndall's work, asked him one day how his leisure hours were employed. The answer