Listed only by Bonavia-Hunt, who says: This title was first adopted by the author to mark the successful reproduction of the old XVIIth century diapasons in his organ at St. Peter's Mission, Uxbridge. Since then, several copies have been made by English voicers. . . . St. Barnabas's, Southfields . . . contains an early English diapason (labelled �small open diapason�).