The fourth dimension

128 THE FOURTH DIMENSION

are at a distance o from our space in the fourth dimension, the second showing all those that are at a distance 1, and so on.

These fizures will each be cubes. The first two are drawn shewing the front faces, the second two the rear faces. ‘We will mark the points 0, 1, 2, 3, putting points at those distances along each of these axes, and suppose

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2h Sh Fig. 71.

all the points thus determined to be contained in solid models of which our drawings in fig. 71 are representatives. Here we notice that as on the plane 0% meant the whole line from which the distances in the 7 direction was measured, and as in space 07 means the whole plane from which distances in the 2 direction are measured, so now Oh means the whole space in which the first cube stands—measuring away from that space by a distance of one we come to the second cute represented.