302. Boundaries, horizontal and vertical.

Ordinarily, land is divided either horizontally1 or vertically, but the division may be made in any other way2. Where the division is vertical, the imaginary line of division extends up to the sky, so that the surface carries with it the superincumbent column of air3, and down to the centre of the earth4, unless the minerals or other strata have been severed5, on the principle cujus est solum, ejus est usque ad coelum et ad inferos6.

In the case of a lease or conveyance of a building or flat forming part of a building, the external walls enclosing the property