Two of the four sides of the Cousolre baptistery are decorated with a series of arcatures. These two faces are opposite each other and feature the same composition: on each side is a series of six semicircular arches. The columns on which the arcades rest are composed of a bulbous base, a straight shaft and a truncated cone-shaped capital with a decoration created by two flat leaves. The spandrels of the arcatures are decorated with a trifoliate palmette.
The empty arcades were probably filled with painted decoration, perhaps with figures under the arcades, and one could imagine a college of apostles in each intercolumn.
This frieze pattern of empty arcades bears witness to influences from Tournai and Namur; it can be found on the vat of the church of Saint-Martin d'Antheit in the province of Liège, as well as on the baptismal font of Beauvechain, located in Walloon Brabant. In both cases, the arcades are composed in the same way as those on the Cousolre font.
Lexicon:
Spandrel: surface between the curve of an arch and its orthogonal frame.
Trifoliate palmette: ornament, stylized motif in the shape of an axially symmetrical palm (here with three leaves).