English Diapason is mentioned only by Irwin, who says: �The English Diapason, sometimes so labeled on a draw knob, inclines towards a silvery, ringing sound that must be head to be fully appreciated. It sometimes serves as the Choir Diapason.� Englisch Prinzipal is listed only by Maclean who says: �In E. F. Walcker's famous organ at St. Michael's, Hamburg, we find this German tribute to English Diapason-tone.� However, the Osiris specification for this instrument contains no such stop-name.
English Diapason 8', Swell; Holy Trinity Lutheran Church, Buffalo, New York, USA; Moller 1986.