Jacoba della Porta's Contibution to the Piazza Colonna
Bernini decided it would be a good idea to move Trajan’s Column to this square, where the column of Marcus Aureleis already stood. The idea was to make a giant stage set. Bernini "limited himself to providing a sketch for a more modest pool at the foot of the column, with the figure of Ocean stretched out on the rocks". Bernini had to give up this idea, and put it somewhere else. The drawing at the bottom of the sketch was not Bernini’s invention, but Jacopo’s. The statue leaning against the pile of rocks has a likeness to Marforio. When the Piazza Colonna was built in 1575, the Marfario statue was still in its old home, and many artists had drawn the statue, complete with his mutilations.
The Marfario statue was assigned to the fountain on Capitoline hill, as was assigned to be restored by sculptor Ruggero Bescape. It is simply not possible that Bernini or Fontana would decide to put a statue on the piazza colonna that would reproduce the exact mutilations of a hundred years earlier. When looking closer at the sketch, a group of rocks with water spray, which is very similar to the one designer Jacopa placed in the center of the Moor fountain. The left side features a hand that has drawn out dolphins, one on each side of the mask. Right under Marfario that masked in flanked by dolphins.
Therefore the final conclusion is that the Piazza Colonna is by Jacoba della Porta and there were many designs for the Marforio Fountain. This fountain was originally sketched by Master Jacopa as well. Bernini has restored the fountain in Piazza Colonna, but was never a work of great importance. Under Pope Alexander VII it was suggested moving the fountain to Piazza Venzia, but it was simply moved back once the Monument to Victor Emmanuel II. The final restoration of this fountain came in 1702, ordered by Clement XI, where the eight point papal emblem was added to the fountain.