TYNDALL, JOHN (1820–1893), natural philosopher, son of John Tyndall and his wife Sarah (Macassey), was born at Leighlin Bridge, co. Carlow, on 2 Aug. 1820. The Tyndalls, who claimed relationship with the family of William Tyndale [q. v.] the martyr, had crossed from Gloucestershire to Ireland in the seventeenth century. The elder John Tyndall, son of a small landowner, although poor, was a man of superior intellect, and he gave his son the best education which his circumstances could afford. At the local national school young Tyndall acquired a thorough knowledge of elementary mathematics, which qualified him to enter as civil assistant (in 1839) the ordnance survey of Ireland. In 1842 he was selected, as one of the best draughtsmen in his department, for employment on the English survey. While quartered at Preston in Lancashire he joined the mechanics' institute and attended its lectures. He was at this time much impressed by Carlyle's ‘Past and Present,’ and to the stimulating influence of Carlyle's works was in part due his later resolve to follow a scientific career. On quitting the survey Tyndall was employed for three years as a railway engineer.
In 1847 he accepted an offer from George Edmondson [q. v.], principal of Queenwood College, Hampshire, to join the college staff as teacher of mathematics and surveying. Mr. (now Sir Edward) Frankland was lecturer on chemistry, and the two young men agreed respectively to instruct each other in chemistry and mathematics. But Queenwood did not yield all the opportunities they wished for, and they presently resolved to take advantage of the excellent instruction to be enjoyed at the university of Marburg in Hesse-Cassel. The decision was for Tyndall a momentous one. He had nothing but his own work and slender savings to depend on, and his friends thought him mad for abandoning the brilliant possibilities then open to a railway engineer.
In October 1848 Tyndall and Frankland settled at Marburg. Tyndall attended Bunsen's lectures on experimental and practical chemistry, and studied mathematics and physics in the classes and laboratories of Stegmann, Gerling, and Knoblauch. By intense application he accomplished in less than two years the work usually extended over three, and thus became doctor of philosophy early in 1850. Thenceforward he was free to devote himself entirely to original research.
His first scientific paper was a mathematical essay on screw surfaces—‘Die Schraubenfläche mit geneigter Erzeugungslinie und die Bedingungen des Gleichgewichts für solche Schrauben’—which formed his inaugural dissertation when he took his degree. His first physical paper, published in the ‘Philosophical Magazine’ for February 1851, was on the ‘Phenomena of a Water Jet’—a subject comparatively simple but not without scientific interest.
In conjunction with Knoblauch, Tyndall executed and published an important investigation ‘On the Magneto-optic Properties of Crystals and the relation of Magnetism and Diamagnetism to Molecular Arrangement’ (Phil. Mag. July 1850). They claimed to have discovered the existence of a relation between the density of matter and the manifestation of the magnetic force. Their fundamental idea was that the component molecules of crystals, and other substances, are not in every direction at the same distance from each other. The superior magnetic energy of a crystal in a given direction, when suspended between the poles, they attributed to the greater closeness of its molecules in that direction. In support
