Note:  Do not rely on this information. It is very old.

Fan Tracery

Fan Tracery, in Architecture, a kind of vaulting in which all the ribs that rise from the spring of the vault have the same curve and extend equally in every direction, the interstices being filled with lace-like ornament, so that the effect is like that of a fan. It is a peculiarly English kind of work: Henry VII.'s chapel at Westminster, King's College, Cambridge, and St. George's Chapel, Windsor. It is peculiar to the late Perpendicular style.