## Casa Mila Design

Gaudi again! Casa Mila is a block of apartments further up Passeig de Gracia that Gaudi designed. I wasn't so impressed with the flats themselves - because you are allowed to look through some of them - but the exterior, the attic and the roof are very special.

Here we can see a model of Casa Mila in the attic. Notice the roof here is curved. Gaudi used "parabolic arches" a lot and used to hang chains to model the arches.

The mathematically aware amongst you, and that means me, will instantly realise that the curve of a suspended chain is not parabolic, but a catenary curve (given by the hyperbolic function cosh). This is only an approximation to a parabolic shape (the path that a thrown object traces out). Thank you. You may now resume your normal programming.