This one is a classic Technofiction nightmare. We have the mad scientist. We have huge in accuracties in dimensions such as machining to one hundred thousanth of a inch. We have either/or option in space travel: Either fly to the moon or fall back to Earth. His description of using a telescope as he follows the progress of the launched space ship is pure fantasy.
Its only virtues are the cute characterizations. Brown gets away with writing in English spoken with... mit zee theek German dialect, no? The ending is a cute twist, but the story really has nothing else going for it.