Run on time

They say that Mussolini made the trains run on time.
Yes, it’s true. But not in the way you think.
Because coal, diesel, and wood were needed for the war effort, Mussolini hired physicist Enrico Fermi to build a train with an engine fueled by time.
Fermi worked day and night on the project until it was ready.
Mussolini was delighted… until he learned that Fermi’s wife was a Jew.
The Fermis fled Rome on the train, arriving in America.
Enrico worked on the Manhattan Project, thinking he was building another train.
He was just as surprised as the Japanese.