There is only one item in the index to the Historic American Building Survey and the Historic American Engineering Record listed as “dragons.” It’s this cast-iron fence at 1000 North Dearborn Street in Chicago, described as “late nineteenth century.” It is, in my opinion, a beauty. It’s also tiny – the graphic ruler tied to the rail is showing inches, so the dragon is about a foot high.
The first thing that jumps out is that cast iron, like any cast material, can be made into amazing shapes; like any metal, it’s reasonably strong even when thin. You could cast small-aggregate concrete into this shape, but the wings and neck would be quite vulnerable to cracking; you could make a shape something like this by cutting, bending, and welding metal, but you’d never get this complexity of detail. Using modern materials – GFRC, for example – you could get something equally detailed and as strong, but that was not an option 120 years ago.
The second thing that jumps out (at least for me) is that this is far stronger than it needs to be. You don’t really get regular handrail loads on a horizontal rail a foot off the ground, but even if you did, we’re talking about maybe 200 or 300 pounds of lateral or vertical force on the dragon’s mouth, converted by the curve of its neck to maybe 800 or 1200 pound-inches of bending moment. Even accounting for the low allowable flexural tension in cast iron, that’s nothing much. Ordinary use was never going to damage this little dragon, although I’ve got no doubt that a car mounting the curb and driving into it might.
The use of dragons as fence posts is arguably an extreme in both ornamentation and frivolity. There is no rationale for it – dragons, in myth, are not dogs who like to carry sticks in their mouths – other than aesthetics, and taste changes over time. Whatever the reverse of “form follows function” is, this is it. But…it looks good to me. Given that I’m not a victorian, no matter how much time I spend with my head stuck in the nineteenth century, I can’t say I really understand or expect a dragon to be a fence post (or, not the same thing, a fence post to be a dragon) but I like it. You could use a row of cast-metal dragons as fence posts today, or as bollards, or sidewalk lighting. (I really like the idea of reddish lighting coming from the dragons’ mouths, possibly combined with dry-ice vapor.) Why not?