Abat-son

The term is commonly used to refer to angled louvers in a bell tower or belfry designed to redirect sound or to prevent ingress of water.

[4] The term comes from the French abat-sons, literally abat 'it strikes down' and sons 'sounds'.

[5][6] The slats, generally of the grid type and fixed to a carpentry frame, are usually made of wood or covered with metal, slate or lead; In addition to redirecting the sound of the bells towards the ground, they prevent rain or snow from penetrating the bell tower and allow the tower's carpentry to be ventilated.

«Beffroi», is an architectural technical Gallicism that appeared in the 19th century, replacing the popular name of «windscreen» (abat-vent).

Turntables developed especially from the 13th century, and were often already decorated with fretwork, serrated bottoms, or embossed in lead.