according to the author,why the french and american revolutions did not turn out the same way?

Dickens saw the industrialization of Britain as a chasm between the rich and poor. "A Tale of Two Cities" was his wake-up call the the British people, a reminder of what had happened in France, and a warning not to let it happen again.

Both American and French Revolutions were launched out of a desire for political freedom. Unfortunately, the French Revolution came to embrace terror and violence. The rational thought of the American revolution was left behind, but you have to remember that the events leading to the revolutions were different. The French citizens were living in poverty and squalor, while their monarchs spent the taxes they collected from the poor recklessly and publicly. The peasants based their actions on vengeance rather than honor.