By means of these observations you may be sure that catalogue cube 2 is rightly placed. Catalogue cube 3 is just like number 1.
Having these cubes in what we may call their normal position, proceed to build up the three sets of blocks.
This is easily done in accordance with the colour scheme on the catalogue cubes.
The first block we already know. Build up the second block, beginning with a blue corner cube, placing a purple on it, and so on.
Having these three blocks we have the means of representing the appearances of a group of eighty-one tesseracts.
Let us consider a moment what the analogy in the case of the plane being is.
He has his three sets of nine slabs each. We have our three sets of twenty-seven cubes each.
Our cubes are like his slabs. As his slabs are not the things which they represent to him, so our cubes are not the things they represent to us.
The plane being’s slabs are to him the faces of cubes.
Our cubes then are the faces of tesseracts, the cubes by which they are in contact with our space.