Schubert, Hermann, 1848-1911, McCormack, Thomas J. (Thomas Joseph), 1865-1932 · Chicago, The Open Court Publishing Company; [etc., etc.] · leaf 100
ree points 3-4, 2-4, 2-3, also mustultimately lie in a straight line, consists in the simple fact that theplane of the three points 2, 3, 4, must cut the plane of the drawingin a straight line. The figure here considered consists of ten pointsof which sets of three so lie ten times in a straight… … Fig. 37- ties, may be obtained from the section of a figure of four-dimen-sioned space. Imagine six points, i, 2, 3, 4, 5, 6, situated inthis four-dimensioned space, and every three of them connected bya plane, and every four of them by a three-dimensioned space. Weshall obtain thus twenty planes…
