Quote:Although earlier researchers theorized about a "Midnight Minter" clandestinely clashing dies (perhaps night watchman Theodore Eckfeldt), later research points to denomination changeovers and the relative position of dies in the "hammer" and "anvil" positions as the likely culprit. The
Flying Eagle cent reverse was customarily used in the "hammer" die position, while the reverses of the
Seated Liberty quarter, half, and the Coronet double eagle were customarily used in the "anvil" die position. When the coinage press was being changed from one denomination to another to meet the changing coinage requirements, the collar would have to be removed as well as the dies and the press cycled to adjust the die spacing. This could lead to a die from one denomination in the "hammer" position clashing with a die from another denomination in the "anvil" position. This possibility is further borne out by the die clashes being aligned right-side up, rather than rotated 180 degrees as seen on normally clashed dies.
I don't know why you'd deliberately install the wrong die just to clash them without making any coins. I'm thinking the latter explanation quoted is more likely, and they never struck any planchets with it set up wrong.