nt space, it is worthwhile to
| spend some time with an example, that of the tangent space to the sphere.
| The information in the previous section concerning charts for the sphere
| allows charts to be constructed for this new space.  The atlas resulting
| from the construction is examined in the light of the earlier definitions
| to see that this tangent space forms a manifold.  The example is useful, too,
| for giving insight into such things as the dimensionality of a tangent space
| and the fact that i