As we come to the end of our discussion, I have argued that the anonymous unpublished drawing is actually a copy of the lost original design for the Trevi Fountain by Bernini. We have also argued that Salvi was chosen to create the Trevi, over the more popular Vanvitelli, because his design was in line in form and spirit with that of Bernini. It is clear, when studying the sketch and what Nicola Salvi actually built, that this has to be why he was chosen for this task. Therefore, it is evident that Salvi owes much to the great Bernini, but there is another important factor to consider.
In Rome, in 1728, a double wedding between the royal families of Spain and Portugal took place, and Salvi was commissioned to create one the “firework engines” to honor the wedding. These fashionable features were built all over the city, full of pageantry, and often a waste of very good wood. These festive engines were lit up for the evening of the celebration, an evening full of joyous crowds, many of them drunk from the wine that was flowing through the fountains near the engines. The interesting part of the engines was that they were each designed especially for the celebration, alluding to the special event or the people being honored in the form of a mythological or philosophical idea, or even a risqué jokes.
The engine Salvi created was built right on top of the Barcaccia. This engine was enormous, resembling a skyscraper, being 47 meters high and 27 meters wide. It featured two tiers that both had columns. The lower tier features the kingdom of the god of marriage. Hymen was seated on with wide shell back throne, and in the large niche above was Mount Parnassus, Apollo and the nine muses around the base. This is important because it shows that Salvi was aware of Bernini’s famous design, or at least, aware of the sketch. The lower level is a blatant testament to Bernini’s design, with features taken directly from the design like the balustrade, architrave, two Corinthian columns on each side standing forward of the single column, and the large niche beneath a corbel with two festoons springing from a large mask.
Here is another fact, perhaps even more important that the above stated themes: the clouds that spread across the bottom of the engine actually correspond to the rocks of the fountain. The pyramidal arrangement of the engine surmounted with Hymen is the exact same arrangement in the fountain the features the muses culminating to Apollo. The final detail was the use of Parnassus. Salvi was unable to remove this from his mind and used it as the topper for the whole feature.