CATENARY ARCH

This is a picture from a Musgum village in Cameroon. These buildings are built entirely out of earth in the ideal mathematical form to bear a maximum weight with minimal material, the catenary arch.

"Catenary" is Latin for "chain", and the exact method of creating this form, is to hang a chain from two points to create a U-shape of sorts, then make a drawing of the curve, and turn it upside down to make an arch. The Catalonian architect Antoni Gaudí, famous for his characteristic organic architecture, especially the cathedral La Sagrada Familia in Barcelona, applied catenary arches widely, and used the technique of hanging strings and chains to create the designs for vaults, roofs and ceilings in his buildings.

I doubt these people are using the same technique, but the result is a catenary arch nonetheless. I think they may be using the principle of the corbel arch, which I've blogged about before, and that uses corbelling to create arches that are sometimes very reminiscent of the catenary arch.

Attention should also be paid to the surface of the buildings. Apart from being beautiful ornaments, the shapes covering them also function as a sort of stairs and platforms to stand on when climbing to the top of the buildings, and help leading rainwater away from the surface. More about these buildings at designboom.com.

By the way, tomorrow I'm travelling with my boyfriend to London, my favourite city! There will we pictures, I promise.