What's the difference between ensphere and insphere?

Ensphere

Definition:

• (v. t.) To place in a sphere; to envelop.
• (v. t.) To form into a sphere.

Example Sentences:

Insphere

Definition:

• (v. t.) To place in, or as in, an orb a sphere. Cf. Ensphere.

Example Sentences:

• (1) The hexons are thus bounded by icosahedra with insphere radii of 336 A and 452 A.