The descent of the heavy body is not toward the centre through being drawn by it, nor because such a heavy body desires to join itself with that centre, but because the medium cannot sustain it. I say that the descent of the gravity of water is not caused by the centre of the world drawing it to itself, nor because such gravity desires to join with that centre, nor because its element draws it to itself by the shortest way. If the centre of the world drew it to itself, that water would always move toward that centre, and if it could not move, at least it would always weigh and press upon whatever obstacle impeded its descent. Of both of these the opposite is seen, because whoever lets water fall upon the earth, it immediately loses the weight and the desire to descend. And that it gives no heaviness upon its support is seen in the bottom of the water of marshes, where the mud is most light, almost of the thinness of water, floating like a mist between the ground and the water of the marsh. This would not be so if such water weighed upon that bottom. Again, one sees the tips of the most slender grasses spring up from the bottom of those marshes and penetrate through the water toward its surface, as if surrounded by air. If the water weighed upon its bottom, it would also weigh upon the tips of such grasses, and they could not be penetrated by them; rather it would hold them bent and flattened together with the condensed earth. Again, the gravity of great buildings does not weigh upon their supports, as is seen in the earth drawn out from under their foundations, which is no less rare than if it were situated under the air.

The descent of the pyramidal heavy body, made without impetus, will be at a right angle before it joins the centre of the world. Every pyramidal heavy body has 3 centres, of which the first is the centre of natural gravity a, the 2nd is the centre of accidental gravity, that is b, the 3rd is the centre of its magnitude, which is c. The centre of natural gravity b will move to find the centre of the world p along the line b p, always keeping 2 weights at equidistant height above itself, and when it will be joined to the centre of natural gravity.

The site of equality is that which holds the centres of the weights placed on the extremes of the balance at equal heights, above the centre of the world.

It is impossible to make the angles a, b equal upon one and the same base unless the pyramids are of equal length. When two triangles arise upon one and the same base, the proportion from angle to angle will be as that from one height to the other.

The water a will lose its weight in falling into the water n, even though it were very greatly distant from the sphere of its element b.