Two short treatises on the mathematical theory of music by Nicolaus Mercator, copied by Aubrey from MSS. apparently printed in 1672 (fol. 32) and 1673 (fol. 1). Of the first treatise Aubrey notes 'The original copie was lost at Paris'. begg. (after an explanation of hard words) 'Reasons and Concords are understood best by one another' (fol. 2), and 'Any string of a lute, violl, or other instrument' (fol. 33).