Originally Posted by BBKing

It's a fascinating historical period, actually - the point was that prior to the Industrial Revolution the main architecture types could be built without advanced maths, as they were masonry gravity structures like walls, vaults, arches etc. which just happen to be the only ones where that idea is safe. As soon as you start doing beams and trusses you need calculus as a minimum.

One of Brunel's great contributions was legitimising the mathematical approach - being half-French he wasn't scared of algebra and effectively invented finite element analysis to do the Maidenhead Bridge. He wasn't quite the first, but as usual he was in the thick of progress.