CHAPTER VIII.
REPRESENTATION OF FOUR-SPACE BY NAME. STUDY OF TESSARACTS.
We have now surveyed all the preliminary ground, and can study the masses of tessaracts without obscurity.
We require a scaffold or framework for this purpose, which in three dimensions will consist of eight cubic spaces or octants assembled round one point, as in two dimensions it consisted of four squares or quadrants round a point.
These eight octants lie between the three axes Z, X, Y, which intersect at the given point, and can be named according to their positions between the positive and negative directions of those axes. Thus the octant Z, X, Y, is that which is contained by the positive portions of all three axes; the octant Z, X, Y, that which is to the left of Z, X, Y, and between the positive parts of Z and Y and the negative of X. To illustrate this quite clearly, let us take the eight cubes—Urna, Moles, Plebs, Frenum, Uncus, Pallor, Bidens, Ostrum—and place them in the eight octants. Let them be placed round the point of intersection of the axes; Pallor Corvus, Plebs Ilex, etc., will be at that point. Their positions will then be:—
| Urna | in the | Octant | Z | X | Y |
| Moles | „ | „ | Z | X | Y |
| Plebs | „ | „ | Z | X | Y |
| Frenum | „ | „ | Z | X | Y |
| Uncus | „ | „ | Z | X | Y |
| Pallor | „ | „ | Z | X | Y |
| Bidens | „ | „ | Z | X | Y |
| Ostrum | „ | „ | Z | X | Y |
The names used for the cubes, as they are before us, are as follows:—
| Third Block. | |||||
| Third Floor. | - | Arcus Mala | Ovis Mala | Portio Mala | |
| Laurus Mala | Tigris Mala | Segmen Mala | |||
| Axis Mala | Troja Mala | Aries Mala | |||
| Second Floor. | - | Postis Mala | Clipeus Mala | Tabula Mala | |
| Orcus Mala | Lacerta Mala | Testudo Mala | |||
| Verbum Mala | Luctus Mala | Anguis Mala | |||
| First Floor. | - | Telum Mala | Nepos Mala | Angusta Mala | |
| Polus Mala | Penates Mala | Vulcan Mala | |||
| Cervix Mala | Securis Mala | Vinculum Mala | |||
| Second Block. | |||||
| Third Floor. | - | Ara Mala | Vomer Mala | Pluma Mala | |
| Praeda Mala | Sacerdos Mala | Hydra Mala | |||
| Cortex Mala | Mica Mala | Flagellum Mala | |||
| Second Floor. | - | Pilum Mala | Glans Mala | Colus Mala | |
| Ocrea Mala | Tessera Mala | Domitor Mala | |||
| Cardo Mala | Cudo Mala | Malleus Mala | |||
| First Floor. | - | Agmen Mala | Lacus Mala | Arvus Mala | |
| Crates Mala | Cura Mala | Limen Mala | |||
| Thyrsus Mala | Vitta Mala | Sceptrum Mala | |||
| First Block. | |||||
| Third Floor. | - | Mars Mala | Merces Mala | Tyro Mala | |
| Spicula Mala | Mora Mala | Oliva Mala | |||
| Comes Mala | Tibicen Mala | Vestis Mala | |||
| Second Floor. | - | Ala Mala | Cortis Mala | Aer Mala | |
| Uncus Mala | Pallor Mala | Tergum Mala | |||
| Ostrum Mala | Bidens Mala | Scena Mala | |||
| First Floor. | - | Sector Mala | Hama Mala | Remus Mala | |
| Frenum Mala | Plebs Mala | Sypho Mala | |||
| Urna Mala | Moles Mala | Saltus Mala | |||
Their colours can be found by reference to the Models 1, 9, 2, which correspond respectively to the First, Second, and Third Blocks. Thus, Urna Mala is Gold; Moles, Orange; Saltus, Fawn; Thyrsus, Stone; Cervix, Silver. The cubes whose colours are not shown in the Models, are Pallor Mala, Tessera Mala, and Lacerta Mala, which are equivalent to the interiors of the Model cubes, and are respectively Light-buff, Wooden, and Sage-green. These 81 cubes are the cubic sides and sections of the tessaracts of an 81 tessaractic Set, which measures three inches in every direction. We suppose it to pass through our space. Let us call the positive unknown direction Ana (i.e., +W) and the negative unknown direction Kata (-W). Then, as the whole tessaract moves Kata at the rate of an inch a minute, we see first the First Block of 27 cubes for one minute, then the Second, and lastly the Third, each lasting one minute.
Now, when the First Block stands in the normal position, the edges of the tessaract that run from the Corvus corner of Urna Mala, are: Arctos in Z, Cuspis in X, Dos in Y, Ops in W. Hence, we denote this position by the following symbol:—
| Z | X | Y | W |
| a | c | d | o |