Spherical Chalkboard
Purpose
A slate globe with writable chalkboard surface and pre-printed latitude/longitude grid lines. Use it to discuss spherical coordinates, great circle paths, and planetary axial tilt — the adjustable mounting bracket lets you set any axial tilt angle.
Figure 1:
Slate globe with writable chalkboard surface and pre-printed coordinate grid. The meridian bracket allows adjustment of the axial tilt angle.