The burn was first spanned by a segmental arch (36 feet 6 inches wide and 36 feet high) of coursed rubble with deep spandrel walls and narrow voussoirs. On this foundation a superstructure has been erected composed firstly of two semicircular arches (28 feet across and 14 feet high) separated by an extremely wide spandrel in which, at a higher level, a fourth arch has been cut. This is segmental and measures 14 feet by 5 feet. Above these three tiers of arches rise the parapet in a curve in which is placed an empty niche. [1]