MANUEL, a Greek writer on music, is supposed to have flourished under the elder Palaeologus, namely, about the year of Christ 1120. He wrote three books of harmonics, the first of which is a kind of commentary on Euclid, as the second and third are illustrative of Ptolemy. Meibomius had given the public expectations of a translation of this work, but not living to complete it, Dr Wallis undertook it; and it now forms part of the third volume of his works, published at Oxford in three volumes folio, 1699.