L’astronomie dans les Harmonica de Manuel Bryenne
There is not much about astronomy in Manuel Bryennius’ Harmonica, but it is not unimportant to the text. In two chapters we find a discussion about the harmony of the spheres, where the author tries to establish in which direction the planets move around the earth from the planet’s mean longitudinal motion. These observations are not sufficient, hence the author uses philosophical and analogical arguments that are strongly linked to the figures associated with the text. The last figure, a diagram connecting the musical scales with the moon phases, probably does not belong to Manuel Bryennius’ Harmonica, but it is taken from one branch of the text of Ptolemy’s Harmonica. This is important for a better understanding of the history of the textual tradition of Bryennius’ Harmonica.