Reply from the Cambridge Observatory
- The festivities over, Barbicane hunkers down and starts planning. He starts by writing a letter to the fine folks at the Cambridge Observatory, asking if the task is even feasible.
- The answer, more or less, is yes. They have a few tips: He should fire the cannon from an area near the equator on exactly the "1st of December of next year" (4.30) because the Earth and the Moon will be closest on that day.