The elastica theory is a theory of mechanics of solid materials developed by Leonhard Euler that allows for very large scale elastic deflections of structures. Euler (1744) and Jakob Bernoulli developed the theory for elastic lines (yielding the solution known as the elastica curve) and studied buckling. Certain situations can be solved exactly by elliptic functions. Later elastica theory was generalized together by the Cosserat brothers François and Eugene into a geometric theory with intrinsic directions at each point (1907).