Gaudi's models
Gaudi invented his own way of building a model out of ropes and suspended sand bags filled with gun pellets so that he could test the support system of the proposed church. The weights were added proportionally to ropes hung from a flat surface, then Gaudi took a photo of the structure and inverted it to get an idea of how the structure would look and function in real life. Don't worry. We don't really understand it either.