What material is typically used for vertical dowels called empolia?

Empolia, which are vertical dowels used in various architectural contexts, are typically made of wood and iron. Wood provides the flexibility and ease of shaping required for these structural elements, while iron adds necessary strength and durability, allowing the empolia to support loads effectively without compromising the integrity of the structure. This combination is particularly useful in traditional construction practices where both materials were readily available and widely used.

Other options such as wood and concrete, or iron and stone, do not represent the traditional practice for empolia. While concrete can be used for dowels in certain modern contexts, it is not the primary material historically associated with empolia. Similarly, although iron can be combined with stone in various architectural elements, this does not apply to the specific function and construction of empolia, which necessitates the particular properties offered by the wood and iron pairing.