In the 1574 protrait of Mercator by Frans Hogenberg, Mercator aged, sixty two, is portrayed as “the man of magnetic declination”. He underlines in this way his continued, life-long interest in the subject. Magnetism was, in fact, not only a scientific and technical argument useful for navigation; it also symbolized Mercator’s cosmological principle of harmonia mundi. This work underlines Franciscus Monachus’s probable role in training young Mercator in hermetic studies, then shared with John Dee, which influenced Mercator’s cosmology (that he considered “scientifically Christian”). In this cosmology, the device of the pythagoric Y is central. It represents the profound structure of his world, as in the “typus universitatis” sent to Vivianus in 1573, but it is also connected, I propose, to magnetic declination and the correct, new representation of the “rhumb lines” for sailing, featured in Sixteenth-century nautical maps. It was also the model for drawing the other letters of the alphabet in Mercator’s 1540 monograph about italic humanist writing. Pythagoric Y was, in fact, a symbolic and cabalistic device, also employed by Dee in his astrological and alchemic works, which finally represented moral choice; human free will in the providential mechanisms of Creation.
Il rapporto di Mercatore con il magnetismo e la teoria della declinazione magnetica sono stati centrali nella storia del suo pensiero cosmologico. Dietro i suoi continui calcoli, il magnetismo continuò a rappresentare, per Mercatore, l’idea che il funzionamento dei corpi celesti era strutturalmente collegato con l’harmonia mundi, con la natura intima della materia e la presenza viva di Dio nel cosmo, secondo il rapporto di corrispondenza tra Alto e Basso teorizzato dalla tradizione ermetica. Per questo motivo la declinazione magnetica terrestre doveva avere una corrispondenza con la declinazione del centro del cielo (Medium coeli), chiamata da Cardano Cor coeli.
Rupes Nigra: Mercator und Magnetismus
MANGANI G
2015
Abstract
In the 1574 protrait of Mercator by Frans Hogenberg, Mercator aged, sixty two, is portrayed as “the man of magnetic declination”. He underlines in this way his continued, life-long interest in the subject. Magnetism was, in fact, not only a scientific and technical argument useful for navigation; it also symbolized Mercator’s cosmological principle of harmonia mundi. This work underlines Franciscus Monachus’s probable role in training young Mercator in hermetic studies, then shared with John Dee, which influenced Mercator’s cosmology (that he considered “scientifically Christian”). In this cosmology, the device of the pythagoric Y is central. It represents the profound structure of his world, as in the “typus universitatis” sent to Vivianus in 1573, but it is also connected, I propose, to magnetic declination and the correct, new representation of the “rhumb lines” for sailing, featured in Sixteenth-century nautical maps. It was also the model for drawing the other letters of the alphabet in Mercator’s 1540 monograph about italic humanist writing. Pythagoric Y was, in fact, a symbolic and cabalistic device, also employed by Dee in his astrological and alchemic works, which finally represented moral choice; human free will in the providential mechanisms of Creation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
