What type of piers did Eads use for the bridge design?

Eads used stone piers for his bridge design, specifically in reference to the Eads Bridge built over the Mississippi River in St. Louis. Stone was a preferred material during the time for constructing piers due to its durability, strength, and ability to withstand the forces of water and weather over long periods. Eads’ innovative use of stone also contributed to the bridge's stability and longevity, allowing it to support the heavy loads of trains that would cross it.

Other materials, while possibly viable for different types of construction, were not the primary choice for this specific application in Eads’ design. Wooden piers, for instance, are susceptible to rot and damage from water and pests, making them less suitable for such a crucial infrastructure project. Concrete was not yet widely used for major bridge support structures at that time, although it would become more popular in later years. Metal, while used in bridge construction, would have been utilized mainly for the superstructure rather than for the foundational piers that Eads selected.