[A second graduating class has now been instituted and is very largely attended. Each student attends three lectures and spends four hours in the laboratory each week. A higher class, in two divisions, is also held.] At an early date in his career as a professor Thomson called in the aid of his students for experimental research. In many directions the properties of matter still lay unexplored, and it was necessary to obtain exact data for the perfecting of the theories of elasticity, electricity and heat, which had been based on the researches of the first half of the nineteenth century. To the authors of these theories--Gauss, Green, Cauchy and others--he was a fit successor. Not knowing all that had been done by these men of genius, he reinvented, as we have seen, some of their great theorems, and in somewhat later work, notably in electricity and magnetism, set the theories on a new basis cleared of all extraneous and unnecessary matter, and reduced the hypotheses and assumptions to the smallest possible number, stated with the most careful precautions against misunderstanding. As this work was gradually accomplished the need for further experiment became more and more clearly apparent. Accordingly he established at the old College in the High Street, what he has justly claimed was the first physical laboratory for students.[15] An old wine-cellar in the basement adjoining the Natural Philosophy Class-room was first annexed, and was the scene of early researches, which were to lead to much of the best work of the present time. To this was added a little later the Blackstone Examination-room, which, disused and "left unprotected," was added to the wine-cellar, and gave space for the increasing corps of enthusiastic workers who came under the influence of the new teacher, and were eager to be associated with his work. A good many of the researches which were carried out in this meagre accommodation in the old College will be mentioned in what follows. [Illustration: INNER COURT OF THE OLD COLLEGE Showing Natural Philosophy Rooms] [In the view of the inner court of the Old College given opposite, the windows on the ground-floor to the right of the turret in front, are those of the Blackstone Examination-room, which formed a large part of the new Physical Laboratory. The windows above these, on the second floor, are those of the Apparatus-room of the Natural Philosophy Department. Between the turret on the right of the picture and the angle of the court are the windows of the Natural Philosophy Class-room. The attic above the Apparatus-room was at a later time occupied by the Engineering Department, under Professor Macquorn Rankine.] Here again we may quote from the Bangor address: