Beschreibung
First Edition. [xxv], 299, [1] pp; 4 plates. Original cloth. Very Good. Contains a reprint of Jevons's 1870 article on his 'logical piano.' Jevons 'was able to devise a logic machine - a sort of motional form of the later diagrammatic scheme of John Venn. Jevons' 'logical piano' . . . was built for him by a Salford clockmaker. It resembled a small upright piano, with twenty-one keys for classes and operations in an equational logic. Four terms, A, B, C, and D, with their negations, in binary combinations, were displayed in slots in front and in back of the piano; and the mechanism allowed for classification, retention, or rejection, depending upon what the player fed in via the keyboard. The keyboard was arranged in an equational form, with all eight terms on both left and right and a 'copula' key between them. The remaining four keys were, on the extreme left, 'finis' (clearance) and the inclusive 'or', and, on the extreme right, 'full stop' (output) and the inclusive 'or again.' In all 216 (65,536) logical selections were possible. The machine earned much acclaim. . . . Although its principal value was as an aid to the teaching of the new logic of classes and propositions, it actually solved problems with superhuman speed and accuracy, and some of its features can be traced in modern computer designs' (D.S.B. VII: 105). Part I: Writings on the Theory of Logic. In addition to the above article, Part I reprints: 'Pure Logic or the Logic of Quality Apart from Quantity with Remarks on Boole's System and on the Relation of Logic and Mathematics' (1864); 'The Substitution of Similars' (1869); and 'On a General System of Numerically Definite Reasoning' (1870). Part II. John Stuart Mill's Philosophy Tested. Buchnummer des Verkäufers 08487