| Clue | Source | Date |
|---|---|---|
| Leon -, 19th-century French physicist credited with naming the gyroscope | Mirror Quiz | 17 Nov 2024 |
| Leon ___, French physicist who demonstrated the rotation of the earth on its axis by means of the pendulum named after him | ||
| Léon --, inventor of the gyroscope | The Telegraph General Knowledge | 03 Feb 2020 |
| Physicist's name inscribed on the Eiffel Tower | Newsday | 01 Apr 2017 |