Doubling the Cube/Historical Note/Mistake

Source Work

 * The Dictionary
 * $1 \cdotp 25992 \, 10498 \, 94873 \, 16476 \ldots$
 * $1 \cdotp 25992 \, 10498 \, 94873 \, 16476 \ldots$

Mistake

 * The legend was told that the Athenians send a deputation to the oracle at to inquire how they might save themselves from a plague that was ravaging the city. They were instructed to double the size of the altar of Apollo.

Other sources are consistent in that the plague (or whatever the cause of unrest) was in fact at itself, and the oracle was the famous.