The illustration shows how to measure the height of a building with the help of astrolabe

German universal scientist, mathematician and astronomer, book publisher, artist and engraver’s Jacob Köbel‘s (1470–1533) treatise *Explanation* of *Astrolabe* issued together with another German scientist, Tubingen University rofessor of mathematics Johann Stöffl‘s (1452–1531) book *Elucidation of astrolabe construction and use.* Both books provide details of construction of astrolabe and its usage possibilities

** Astrolabe (a small calculation machine or in modern language – GPS) **–

Examples of disks - two separate constituents of astrolabe

Examples of two other astrolabe disks

two already sewn small models of astrolabe inset at the end of the book