une crapaudine carrée

18:00 Dec 20, 2013 

I agree that friction would be a significant problem --especially with a *stone* door swinging on a stone pivot stone.

Perhaps stone+stone doors of that type were more "ceremonial" and/or symbolic than functional.

However, even a wooden door --even a relatively small wooden door-- "hung" in this fashion would have presented significant issues of wear, as the wooden pin at the top and (especially) bottom of the inner stile would have degraded rather quickly, rotating in the hole in its stone frog with the whole weight of the door bearing down on that single point of contact.

And, as you point out, moisture/rot would be an issue --a compromise between having the pivot stone flush with the ground (so that the space under the door wouldn't be so wide as to admit all sorts of unwanted critters into the house) and having it significantly raised, to keep it dry(er). It would seem that, in a rainy climate, the pivot hole would be full of water most of the time, and the pin at the base of the stile would rot rather quickly (depending upon the wood used).

It's a shame, really, since there is an elegant simplicity to this solution for hanging a door.

09:56 Dec 20, 2013 

According to "Dictionnaire Historique de la Langue Française" by Alain Rey (Edition du Robert), "crapaudine" is the shape of the head of the crapaud (my understanding is English calls frog both a grenouille that we eat and a crapaud that we do not eat).

I have seen some ornated such stones, they used to stand proud from the ground at their time and protect the wooden door from rot but they are now often flush or below ground.

By the way French has some misleading uses, one of the examples you found
http://www.foussierquincaillerie.fr/quincaillerie/poignees-d...
is in fact male when the original crapaudine described by Dicobat is female, an iron spigot inserted into it supports the wooden door

For Sumerian pivot stones, I wonder how this could work without considerable effort, friction between stones is rather high.

In French barn doors there is a crapaudine with friction of iron on stone at the bottom for reasonable ease of use, and a tourillon (rounded vertical part of the frame) in a hole at top for dampening.