Related Clues:
- The Eisenhower years and others
- They're historical
- Times long gone?
- Champion immersed in unlimited calm for ages
- Important blocks of time
- Presidential administrations, e.g
- Figs. always expressed to two decimal places
- Geologic slices of time
- Schoolmaster assists only some of these characters in periods
- Parts of history books
- Different rooms in a museum, maybe
- Historical topics
- Royal reigns, e.g
- Geological timespans
- Periods for historians