Terrestrial Globe.

The other objects on the lower shelf relate to three of the mathematical sciences of the Quadrivium:

Arithmetic:

Peter Apian, Eyn Newe unnd wohlgegründte underweysung aller Kauffmanns Rechnung (A new and reliable instruction book of calculation for merchants) (Ingolstadt: G. Apianum, 1527).

Geometry:

Square holding the Arithmetic Book open, and the compass in the background.

Music:

Lute with broken string.

Lutheran Hymnbook: Johannes Walther's Geistlich Gesangbuhli (Holy Hymnbook) 1st ed (Wittenberg, 1524) and a case of flutes.