Description:

Leonardo’s notes contain numerous designs aiming to resolve the problems related to crossing water courses; the solutions he devised amaze one in their modernity and their genius. In Manuscript B folio 23r, Leonardo designed a bridge made up of two roadways, one on top of the other, so that a water course can be crossed at two different heights. The two roadways are connected to one another by inclined struts laid in X-shapes which meet at the extremities, forming a sort of network of vertical rhombi, strengthened by vertical struts following the vertical diagonal of the rhombi. The upper level is laid over traverses resting on the crossover point of the inclined struts. The thrust generated by the weight of the traverses makes the diagonal beams open slightly and so they can manage to carry the required load, making the bridge, as Leonardo wrote, truly “inrompibile” (unbreakable). .