Stretchers, headers, a few soldiers, and a few rowlocks:

Common bricks are rough rectangular prisms, nominally eight inches long by four inches wide by a little less than 2-3/8 inches high. (More on the “little less” below.) The actual dimensions are the nominal dimensions less 3/8 of an inch to allow for mortar joints. Since the three dimensions are not equal, there are six possible distinct orientations for a brick. Because brick use predates modern technology*, these different orientations used to matter more than they do now. We can stabilize masonry any way we choose using embedded steel anchors, but prior to the mid-1900s, masons had to do so by interlocking the bricks in a wall. That meant that the different orientations mattered a lot, and so each was given a name so that they could be easily distinguished.

If we call the 8-inch side the x-axis, the 4-inch side the y-axis, and the short side the z-axis, we have the following, roughly in order of decreasing frequency of use:

- stretchers: z-axis vertical, x-axis parallel to the plane of the wall,
- headers: z-axis vertical, y-axis parallel to the plane of the wall,
- soldiers**: x-axis vertical, z-axis parallel to the plane of the wall,
- rowlocks: y-axis vertical, z-axis parallel to the plane of the wall,
- shiners: y-axis vertical, x-axis parallel to the plane of the wall,
- sailors***: x-axis vertical, y-axis parallel to the plane of the wall.

To prove that a picture is worth 72 words, here are the orientations illustrated. If you look at the pictures closely or think about my awkward descriptions, a peculiarity of shiners and sailors can be seen: they mess up the through-the-wall coursing of the brick. The other four orientations are all nominally four or eight inches deep (measuring perpendicular to the face of the wall), while these two are nominally 2-3/8 inches deep. Brick walls are built up in wythes, meaning parallel planes of brick, with each plane 4 inches deep. Headers are used to tie together each wythe; in most brick patterns, the majority of each wythe consists of stretchers.

Remember when I saw the height of a brick is a little less than 2-3/8 inches? The exact height of a brick is 8 inches divided by three, minus 3/8 inches.**** That means that three bricks in an ordinary stretcher or header orientation, plus the three associated bed joints, add up to exactly 8 inches in height, which *just by coincidence* is the same height as a solider plus a joint. So if we use a solider course for ornament, it fits in nicely with the regular coursing of stretchers and headers. If we use a course of rowlocks it changes the rhythm of vertical coursing, but two courses of rowlocks add up to 8 inches and get us back on track.

The two oddballs, sailors and shiners, require either enormous amounts of geometric juggling or partial bricks to fit into regular coursing, which is why they were less commonly used. Now, with the use of metal ties, we can create one-wythe brick veneers that need bear no geometric relationship in coursing to anything else, and can therefore freely mix the different orientations. That makes the construction of modern cavity walls easier, but does nothing to help with repairs to old walls. For those we need designers and masons who understand the way these things fit together.

This complex of geometry and funny names didn’t just appear one day and wasn’t developed as a unified system. It developed over hundreds, maybe thousands, of years as people played around with bricks to see what they could do to create attractive patterns. It’s ambient technology, almost invisible because it is everywhere around us and has been, effectively, forever.

* Without exaggeration, brick use predates written history.

** Apparently the etymology of the name is that the bricks are standing at attention like a line of soldiers.

*** Apparently the etymology of the name is that sailors are more broad-shouldered and/or fatter than soldiers.

**** 2.29 inches, if anyone cares.