Suspect for a good brood mare sire: Grand dam was the ENGINEER MARE (f 1770 ENGINEER) who was full sister to the ENGINEER MARE (f 1771 ENGINEER). The 1771 mare was grand dam to two Derby Stakes winners in:
SPREAD EAGLE (b c 1792 VOLUNTEER)
DIDELOT (b c 1793 TRUMPATOR)
SPREAD EAGLE had A full brother that come down as noted to us and may have been good brood mare sires:
EAGLE (b c 1796 VOLUNTEER)
and a full sister:
Y.EAGLE (b f 1800 VOLUNTEER)?