When Tait became professor of physics at Edinburgh University, laboratory teaching of physics was unknown in Scotland. It had been Forbes' custom to allow now and then a promising pupil such as Maxwell the use of the lecture apparatus, and in this as in many other customs he was followed by Tait. About ten years later Prof. Tait, following the example of Prof. Sir William Thomson of Glasgow, instituted a practical class. It was his idea that each student, taking that class, should be instructed how to make a series of measurements, and then should try some real experimental problem. Prior to the founding of the Cavendish Laboratory at Cambridge, the facilities at Edinburgh and Glasgow for gaining an experimental knowledge of physics were the best in Great Britain and this was due to the circumstance that in these twin cities of the North, the chairs of physics were occupied by twin giants in physical science. At the Scottish Universities the academic classes meet only in the winter for six months; the medical and other professional classes have a summer session in addition. In the winter session Tait lectured five times a week to the academic students, about 200 in number, and endeavored to traverse the whole range of elementary physics. Every other Saturday there was a one-hour examination; at which, following a custom of his predecessor, he did not give out printed questions, nor write them on a board, but dictated them at uniform intervals of five minutes. Having propounded his problem Tait grinned with satisfaction; if a member of the class asked a question about it Tait reminded him that he had changed for the time being from a benevolent teacher into a relentless inquisitor. The papers were afterwards returned marked with i or o or ———, the length of the dash indicating the degree of imperfection.
To help those who wished to make a more thorough study of physics he instituted an advanced class; at this work he appeared to the greatest advantage. Before entering the lecture-room he glanced for a short time at his notes; thereafter he would write out mathematical equations for an hour without referring to any notes whatever. It was astonishing to see
