IX. NOTES. THE COMPLICATION PENDULUM. In a brief note upon an article by C. D. Pflauin, published in Wundt's Philosophisch? Studien, xv., 1, p. 139 ff., it was remarked (MiND, 1899, p. 564) that the author, who worked with the complication pendulum, had said nothing of the defects of the instrument. " The present writer," it was added, "has never seen an instrument in which the pendulum did not kick at the moment of complication." Prof. Wundt has penned a reply to this criticism, which appears in the Studien, xv., 4, p. 579 ff. He first of all notes the ambiguity of the reviewer's phrase "at the moment of complication". As, however, he himself, and every one who has actually used the instrument, know perfectly well what is meant, no words need be wasted on this score. Prof. Wundt then proceeds to the charge of incompetency, and gives full directions for the use of the pendulum. The reviewer's experience lias been so similar, that it may be briefly stated. In 1802 the reviewer assigned to a graduate student an investigation into the temporal relations of the " apperception of simultaneous stimuli ". The work was to be carried on by aid of a complication pendulum of Krille's make. After a little time, the student reported that he could not make the instrument work. The reviewer impressed on him the import- ance of the Balancirhebel H, and gave him directions for setting the pendulum : Prof. Wxindt's sentences on page 582 might be a German translation of them. In a little while the complaint was renewed. The reviewer knowing full well, what every director of a laboratory knows, that there are instruments which ' won't work ' for students, but which will work beautifully when the head of the laboratory comes and looks at them took the machine in hand himself. Then a 7iiechanician took it in hand. Then it went back to Krille, who apologised and sent another in its place. This other has also refused to work for anybody. It has travelled, despairingly, to three mechanicians, one after the other ; and each has proposed to rebuild it, at something over its original cost. It now rests in a cabinet, and possesses only an ' historical value '. The reviewer has a passing acquaintance with another pendulum, which also kicked when friendly advances were made to it. This need not be insisted on. To make the criticism more objective, he sent inquiries concerning the instrument to nine of the principal American laboratories, all of which have replied. Five do not own the pendulum. The remain- ing four speak as follows : Instrument I. Pendulum of Krille's make, in use '91-'92. "We soon discarded it for apparatus of our own construction : partly because it did not, in our opinion, furnish the conditions supposed by Wundt and von Tschisch ; partly because of the noise it made, owing to indifferent work- manship in fashioning the gear wheels, . . ." etc., etc. [A long technical criticism follows.] Instrument II. "I used it in [name of laboratory], and was not iin-
