There is another important element of the Four Rivers Fountain. There was an unpublished drawing of the Barberini Triton and a copy of the two tritons and the four fishes in the Lanciano collection held in the Library of Archeology and Art History. This sketch, minus a few details, is identical to the one by Bernini in the Windsor collection. The only difference is that the figures are reversed. Both sketches feature a shallow pool where two identical water spouts, which happen to be dolphins, hold up identical shell basins. On the rocks sit two figures; one sketch has the men as young, and the other as old, with their legs and arms in identical positions. In the first sketch, the other arm of both figures is raised to support the arched basin resting on top of the rocks. The Windsor sketch has the arm holding the coat of arms. The first sketch shows the forceful spout of water shooting down the rocks. The difference may be a result of the addition of the obelisk, which meant the shell basins had to be removed and the arms lowered. The idea is then that this unpublished drawing was a lost copy of the original by Bernini showing the fountain at an earlier stage, than that of the drawing in the Windsor collection.
