Just down the block from that Federal style house I was taking about are some fancier-than-usual tenements. (Also, in the background, you’ve got a nice view of downtown about half a mile away, but that’s incidental to my point.) I want to talk about the one on the left, on the corner of the block. Let’s start with some basics: because it’s on the corner, the front facade at the ground floor is entirely reserved for the retail space, which in this case is a restaurant. The residential entrance is around the corner. There’s a big fire-escape on the long side, around the corner, and a tiny one on the front facade, to catch whichever rooms weren’t served by the big one.
Most of the brick is Flemish bond, which is more work to build than common bond and “fancier,” whatever that means for a mid-1800s tenement. The brick has recently been repointed except for a rectangular stripe at the second floor, centered over the restaurant entrance. It looks like there might have been a sign there that wasn’t removed when the pointing was going on. It’s possible that the storefront came later: the brick from the second-floor window sills down to the top of the storefront arches is common bond, so it may have been rebuilt. Or, maybe, it was meant to be hidden behind a larger storefront sign or canopy, and a few dollars were saved by using the cheaper bond pattern for this small area.
The most interesting question is exactly how the masonry is supported over the storefront. Despite appearances, those are not simply masonry arches. Even a short-span arch creates horizontal thrust at its ends and there is nothing at the corner to restrain the thrust from either of the two arches there (the one on the front facade and the one on the side facade). So it’s not the thing it looks like. It’s extremely unlikely that there are an ordinary I-beam lintels (in either steel or wrought iron) such as were used later in the 1800s, because building those brick arches around a lintel would be extremely difficult and pointless. There could be cast-iron lintels there, as some of them had an inverted fish belly profile (Ts with the flange at the bottom and the stem curved so that it’s deepest in the middle of the span) but that still would not explain why the arches were built. That brings us to cast-iron arches with wrought-iron ties. (I’ve talked about those a number of times. This post has links to the others.) Those iron arches had wide bottom flanges to support brick, and the tie rods at the bottom (which restrained the thrust) were usually hidden. The use of brick to hide the tie rods is not common, but not unheard of.
In short, a first guess as to how the wall is supported over the storefront has to be technologically feasible at the time of construction and has to make some kind of physical sense.