The Lar position is more difficult to construct. To put the Lars of the Blocks in their natural position in our space, we must start with the original Mala Blocks, at least three inches above the table. The First Lar Block is made by taking the lowest floors of the three Mala Blocks, and placing them so that that of the Second is below that of the First, and that of the Third below that of the Second. The floor of cubes whose diagonal runs from Urna Lar to Remus Lar, will be at the top of the Block of Lars; and that whose diagonal goes from Cervix Lar to Angusta Lar, will be at the bottom. The next Block of Lars will be made by taking the middle horizontal floors of the three original Blocks, and placing them in a similar succession--the floor from Ostrum Lar to Aer Lar being at the top, that from Cardo Lar to Colus Lar in the middle, and Verbum Lar to Tabula Lar at the bottom. The Third Lar Block is composed of the top floor of the First Block on the top--that is, of Comes Lar to Tyro Lar, of Cortex Lar to Pluma Lar in the middle, and Axis Lar to Portio Lar at the bottom. CHAPTER X. CYCLICAL PROJECTIONS. Let us denote the original position of the cube, that wherein Arctos goes Z, Cuspis X, and Dos Y, by the expression, Z X Y (1) _a_ _c_ _d_ If the cube be turned round Cuspis, Dos goes [=Z], Cuspis remains unchanged, and Arctos goes Y, and we have the position, Z X Y _[=d]_ _c_ _a_ where Z _[=d]_ means that Dos runs in the negative direction of the Z axis from the point where the axes intersect. We might write [=Z] _d_ but it is preferable to write Z _[=d]_. If we next turn the cube round the line, which runs Y, that is, round Arctos, we obtain the position, Z X Y (2) _c_ _d_ _a_ and by means of this double turn we have put _c_ and _d_ in the places of _a_ and _c_. Moreover, we have no negative directions. This position we call simply _c d a_. If from it we turn the cube round _a_, which runs Y, we get Z X Y _d_ _[=c]_ _a_, and if, then, we turn it round Dos we get Z X Y _d_ _a_ _c_ or simply _d a c_. This last is another position in which all the lines are positive, and the projections, instead of lying in different quadrants, will be contained in one. The arrangement of cubes in _a c d_ we know. That in _c d a_ is: { Vestis Oliva Tyro Third { Scena Tergum Aer Floor. { Saltus Sypho Remus { Tibicen Mora Merces Second { Bidens Pallor Cortis Floor. { Moles Plebs Hama { Comes Spicula Mars First { Ostrum Uncus Ala Floor. { Urna Frenum Sector It will be found that learning the cubes in this position gives a great advantage, for thereby the axes of the cube become dissociated with particular directions in space. The _d a c_ position gives the following arrangement: