The Curious Ring. GX1, Leitz Summicron 35mm v4

In 1986 I discovered this strange iron ring set into a granite curbstone in the neighborhood of Jamaica Plain. There is just one such ring and it has intrigued me for all these years as to what its purpose could be. Was the granite curbstone re-purposed from some former function and the ring left intact? Was the ring meant for tethering a horse? This is a Victorian neighborhood so that could make sense, but then, why only one? What about all the other horses?! As I was taking the photograph I noticed that the granite is hollowed out so that the ring will sit down flush. This supports the theory that the granite was always a curbstone and the masons didn't want that ring sticking up when it wasn't in use and tripping some Victorian lady. I haven't visited the ring for about 25 years and it took me a little while to find it. My memory was rusty and I was about 40 feet off. It took half an hour of walking around peering at the curbstones before I stumbled upon it. Nice to have old friends.