<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 torquetum is a medieval instrument, thought to have first been built in the twelfth or thirteenth century, for making and converting measurements in three different coordinate systems. The operation of the torquetum relied on certain parts of the instrument being aligned with particular features of the sphere. For example, the lowermost dial-bearing plate had to be aligned with the celestial equator, and the two bottom plates were hinged together so that this could be achieved. The figure clearly shows this and a label makes it explicit that the instrument must be raised up to the elevation of the pole. Although this woodcut is rather crude, then, it successfully shows the parts of the instrument in relation to each other. It is interesting to note that one of the labels mentions another instrument, the astrolabe, as a source to be referred to in the marking out of the scales on the torquetum.</p>
