Astronomical Images : Definition of geometric shapes
Gregor Reisch
Astronomical Images
<p style='text-align: justify;'>The <i>Margarita philosophica</i> was a compendium, or 'Epitome' of university learning in the sixteenth century. It was written by the prior of the house of Carthusians at Freiburg, Gregor Reisch (d. 1525), and was first published in 1503 in Freiburg by Johannes Schott, a printer from Strasbourg. The work was illustrated amply with somewhat crude woodcuts, and was divided into twelve books, with one book each dealing with the trivium (grammar, dialectic and rhetoric) and quadrivium (arithmetic, music, geometry, astronomy), four books devoted to natural philosophy, and one book on moral philosophy. It was a popular work, reprinted numerous times during the sixteenth century, including the unauthorized, augmented editions by another printer at Strasbourg, Johann Grueninger. Oronce Fine edited and added to the Latin text of the 1535 edition. In the 1512 edition, Grueninger attached an appendix consisting of material not discussed extensively in the original Schott edition. This appendix included Greek and Hebrew alphabets, musical notation, perspective and architecture, and explanation of such instruments as the quadrant, astrolabe, and torquetum. The figures from the top show: straight line (<i>recta linea</i>), curved line (<i>linea curva</i>), square (<i>quadratus</i>) with its diagonal, circle (<i>circulus</i>) with diameter ('<i>diamita</i>'); the captions of hexagon (<i>hexagonus</i>) and a sphere (<i>sphaera</i>) should be reversed, with the hexagonal shape showing the side (<i>latus</i>) and diagonal (<i>diagonalis</i>) and the sphere its axis (<i>axis</i>); a cord (<i>corda</i>), semidiameter, side (<i>costa</i>) of a square (<i>quadratus</i>), a perpendicular or orthogonal line (<i>linea perpendicularis sive orthogonalis</i>), parallel lines (<i>lineae parallelae</i>), non-parallel lines (<i>lineae non parallelae</i>), a tangent (<i>linea contingentiae</i>). On the other side are woodcut figures of spiral lines and the base and hypotenuse of a right-angled triangle.</p>