CHAPTER VII. IN THE LOGIC CHAIR: 1839-1844. WORK OF THE CLASS-RECORD OF HONOURS -MECHANICAL CONTRIVANCES IN CONNECTION WITH THE CLASS-RELATIONS WITH HIS FOR HONOURS COLLEAGUES-GRADUATION IN ARTS-EXAMINATION BESIDES carrying on the ordinary work of the class in the manner already described, Sir William gave special opportunities of prosecuting philosophical studies, which were entirely novel in the conduct of the Logic Class in Edinburgh. He instituted courses of Reading and prescribed subjects of Essay for the summer vacation. To eminence in these departments, the taking up of which was of course optional, he attributed great importance, as indicating a special and continued interest in the work on the part of the competitors. Prizes in the form of books were given in the three departments of ordinary class-work, summer reading, and essays. In a lecture on Academical Honours which Sir William delivered at the commencement of his first course, he thus explains the practice which he adopted in reference to the awarding of prizes in his own class:-"In the first place, I am convinced that excitement and rewards are principally required to promote a general and continued diligence in the ordinary business of the class. I mean, therefore, that the prizes should with us be awarded for general eminence, as shown in the examinations and exercises; and I am averse on principle from proposing any premium during the course of the sessional labours for single and detached efforts. The effect of this would naturally be to distract attention from what ought to be the principal and constant object of occupation; and if honour is to be gained by an irregular and transient spirit of activity, less encouragement will necessarily be afforded to regular and sedulous application. Prizes for individual essays, for written analyses of important books, and for oral examination on their contents, may, however, with great advantage, be proposed as occupation during the summer vacation; and this I shall do. But the honours of the winter session must belong to those who have regularly gone through its toils. "In the second place, the value of the prizes may be greatly enhanced by giving them greater and more permanent publicity. A very simple mode, and one which I mean to adopt, is to record upon a tablet each year the names of the successful competitors; this tablet to be permanently affixed to the walls of the class-room. "In the third place, the importance of the prizes for general eminence in the business of the class may be considerably raised by making the competitors the judges of merit among themselves. This, I am persuaded, is a measure of the very highest efficacy."* Sir William carried out the plan of memorial tablets here referred to. At the close of each session there was placed on the wall of the class-room, immediately behind the chair, a board painted green, on which were inscribed in golden letters the names of those students who, by the votes of their fellows, had been adjudged worthy of a place on the prizelist. These boards in course of time covered the entire line of wall behind the chair, and caught the eye of all in the class-room. The wall facing the chair displayed in a similar manner the names of those who had carried off the prizes for summer reading and essays, and also of those graduates who in mental philosophy had gained first or second class honours. Above the tablets behind the chair were inscribed the following mottoes, also on a green board, in golden letters: Lecture I., Appendix I. A. : "ON EARTH, THERE IS NOTHING GREAT BUT MAN ; IN MAN, THERE IS NOTHING GREAT BUT MIND." Πόνον ἡδὺν κάματόν τε εὐκαμάτον ἔχει ὅσα δὴ πρὸς ἅμιλλαν καὶ τιμὴν ἐπιχειρεῖται· Ἐρεθίζεται γὰρ, καὶ σφόδρα γε, ὑπὸ τοῦ φιλονίκου εἰς τὸ φιλόπονον ἡ ψυχή Κύριον ἄρ ̓ ἔστω τὸ Ἡσιόδου, περὶ μὲν ἀρετὴς ἁπλῶς, μάλιστα δὲ περὶ παιδείας, ̓Αγαθὴ ἔρις ἥδε βροτοῖσι. Altogether, as the tablets increased with the years of Sir William's occupancy of the chair, the class-room presented a unique and picturesque appearance, and afforded a complete retrospect of those students who during the period had achieved distinction in the study of Intellectual Philosophy. It is to be presumed that the heart of young ambition was frequently fired by the sight of the names thus conspicuously emblazoned; and that the tyro in Logic was incited to hope that his name too might be elevated to a place in this sphere of the Dii dialectici ! These devices for recording the names were entirely Sir William's own. His power of mechanical contrivance was also shown by certain black boards that stood on either side of the chair, and were occasionally used for exhibiting propositional and syllogistic formulæ and diagrams. They have been thus described:-" One of these moves up and down in the ordinary way; another opens up, and is like a door on its hinges; and a third does neither, but stands out four-sided like a truncated pyramid on a tall pedestal of its own. This mysterious instrument, which is not unlike the trees seen in old sampler work, or the cropped yew and box of country gardens, is looked upon with a certain feeling of awe by casual lady visitors in the vacation, and timid students on first entering the class, as probably a novum organum of philosophy, a syllogistic machine, or perhaps a dwarfed and hodded specimen of Porphyry's tree."* Some years later than the period now referred to, a veritable logical machine, that would have delighted the heart even of the figurative Raymond Lully, occasionally appeared in the class-room before the wondering eyes of the students. This Edinburgh Essays': Sir William Hamilton." * was an ingenious apparatus, contrived by Sir William himself, for illustrating the doctrine of the comprehension and extension of notions or concepts-a favourite point with him in the Logic course. It consisted of a series of hollow wooden cylinders sliding into each other, and diminishing in depth as they increased in circumference. These cylinders were arranged round an upright rod, so that their upper faces formed a horizontal plane, and the whole presented the appearance of an inverted cone. The illustration was made by first of all exhibiting the upright rod, which represented the individual, standing naked on its pedestal, and then proceeding to clothe it with the cylinders, denoting such notions as say Greek, Man, Animal, Living Body, Body, Being, when the mere supraposition showed the increasing extension with the decreasing comprehension, and vice versa. "The vowels," says Sir William, "have been taken as affording a compendious order of subordination according to their priority and posteriority in the alphabet: A, of course, representing the summum genus; and z1, z2, z3, &c., denoting this or these individuals. The letters in general, or the consonants, would better approximate to the possible infinity of subordinate classes; but the vowels are more convenient, and quite sufficient in number to show the variety and relations of logical classes, concrete examples of which may in any variety be applied to the abstract symbols." The central rod was seven inches in height; the first or lowest inch was painted white, and bore the letters Z, and z1, z2, z3, z1, z3, z. Above the portion of the upright rod allotted to Z was a series of six similar divisions reaching to the top, and painted successively green, purple, yellow, blue, red, black, and lettered Y, U, O, I, E, A. These represented the attributes contained in the individual Z-that is, its comprehension; and as the colours reached to the top of the rod, comprehension was thus seen to be at its maximum in Z. Extension again was shown to be at its minimum there, seeing that Z stood at the inverted apex of the cone. Now let the first cylinder, the lowest inch of which was painted green and lettered Y, be slipped over the top of the stick, it would slide down so far as to take its place immediately above the white or Z division. It thus represented a notion (say Greek) wider or more extensive than the individual Z (say Socrates), for it included under it also the little zs-z1, z2, z3, zł, z3, z6 (say Alexander, Plato, &c.) As, however, it only reached from Z to the top of the stick, and bore the letters U, 0, I, E, A, its comprehension was seen to be less than that of Z by one division; viz., Z itself. The second cylinder, the lowest inch of which was painted purple and lettered U (say Man), was now slid down over the first cylinder, the whole of which it covered, except the part allotted to the letter Y, thus showing that its extension was greater than Y, but its comprehension less, for it had under it Y and Z, but on it upwards to the top only 0, 1, E, A. The third cylinder, the lowest inch of which was painted yellow, and lettered O (say Animal), was in a similar way let down on U, and it was at once seen that its extension was greater than U, for it embraced under it U, Y, Z, while its comprehension was less, for upwards to its top there were only I, E, A. The fourth cylinder, the lowest inch of which was painted blue and lettered I (say Living Body), was now let down on O, and it was seen that while its extension was increased, taking |