The kerplunk

A young man, Henry, wins a tour on a luxury cruise for two in the early 20th century, through a magazine contest. He is extremely excited and brings his best friend along with him. He takes a bus to the docks and when he sees the boat his jaw drops.
Never in his life had he seen such a magnificent boat. It seemed a kilometer long and at least 40 meters high. There was an Olympic sized pool on the deck and enough room for at least a thousand people aboard. Henry and his friend are shown their rooms and they are in awe. They each had a huge room with a large comfortable bed, A huge flatscreen television and a spacious bathroom with a shower and bath.
Henry's friend wants to nap but Henry is interested in exploring and meeting the people aboard. Everybody on the ship seems extremely posh and uninteresting to him except for one person. By the pool an old hairy man is fiddling with an extremely large machine. Henry approaches and introduces himself. The old man does the same. His name is Valentino and he lives on the ship permanently. In his head Henry wonders how he could afford permanent residence on this luxury cruise but he refrains from asking out loud. Henry is curious about the machine and asks about it. Valentino states that he had been working on it for almost 17 years and that it was almost complete and that it was called "The Kerplunk".
Henry asks what it does. Valentino simply replies with "wait and see". Henry questions no further and decides to take a swim. After a while it is late and Henry decides to sleep. The next day Henry takes his friend go to see Valentino. His friend asks again what the machine can do. He responds with "wait and see". This happens for a few more days until Valentino claims to have had a breakthrough and that his invention is finally complete.
All of the passengers and the entire crew of the ship gather around. He says that it is finally complete except for one thing. He claims that he needs a two dollar bill to put on top of the machine to work. Nobody on the ship seems to have one. Except for Henry's friend, a collector of odd coins and bills. Henry's friend does not want to part with the 2 dollar bill but Valentino tells him that this is the only thing that could make the machine work and he gradually acquiesces.
Valentino slowly takes the 2 dollar bill, and turns on the machine. A loud humming noise is heard. Suddenly Valentino rips up the two dollar bill, and then picks up the machine and throws it into the ocean and the machine goes "kerplunk".