to4 THE POPULAR SCIENCE MONTHLY. 



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 descend- 

 ants are still scattered. Among these was John Tyndall, the Pro- 

 fessor'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 " dif- 

 ference " with his grandfather, which cost him the inheritance that 

 he would have otherwise received as the eldest son. He was there- 

 fore left to struggle without means, and learned a trade, but sub- 

 sequently 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 con- 

 troversy, 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 contro- 

 versy, 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 Stillingfieet. 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 cour- 

 age, 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 Leigh- 

 lin 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 18.39 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 ids investiga- 

 tions 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 



