Stop 5: Mercantile Trust & Deposit Company Building - 222 Redwood Street

Continue walking east along Redwood Street, crossing Calvert Street, to Stop 5. This dark red brick building, located at the northeast corner of Calvert and Redwood Streets, was constructed in 1885-1886 (Figure 5a) .

The building has extensive trim made of “Seneca Red” sandstone. The sandstone is of Late Triassic age, about 210 to 230 million years old, and was quarried in either Montgomery or Frederick County, Maryland. This is the first sandstone encountered on the tour (Figure 5b). It is a sedimentary rock formed by the cementation of sand-sized grains of quartz (silica). Sandstones can usually be recognized by their “sandpaper feel.” The chief minerals in this rock are quartz, feldspar (microcline and plagioclase), and white mica (muscovite). The red color is largely due to iron oxide in the rock, mainly in the cementing material.

Since construction of the Mercantile Trust & Deposit Company building, however, weathering has had an effect on the building stone. Weathering is obvious on the stairs where spalling (flaking) is occurring.

An interesting architectural design for the time was the placement of “spy steps” (Dorsey and Dilts, 1981) in the front of the building. This would allow police officers to step up and peer into the bank while on patrol (Figure 5c). A brass ring at shoulder level was used to balance them on the step.

Seneca sandstone was a popular building stone in Baltimore and Washington, D.C. due to its accessibility and ease of transport. The sandstone was also popular because it is easy to cut and carve for decorative stone when first quarried, but then hardens over time. Seneca Red sandstone was used in the building of the original Smithsonian Institution (“castle”) building in Washington D.C. (constructed between 1848 and 1859) (Merrill and Matthews, 1989).