Clementine Regnault is in the center of the field with similar-sized Stokes below it. Regnault straddles the rim of the much larger Volta, partially visible here on its right (east). The conspicuous craters on the left are Regnault C (at 11 o'clock) and Regnault W (at 8 o'clock).
- Depth data from Kurt Fisher database
- Westfall, 2000: 2.52 km
- Since Regnault's longitude places it essentially on the mean limb as seen from Earth, it is visible only when the Moon is favorably librated both in longitude and latitude. Under such circumstances it is fairly easily located, as it is more conspicuous than its neighbors.
- Named for Henri Victor Regnault (July 21, 1810 – January 19, 1878), a French chemist and physicist best known for his careful measurements of the thermal properties of gases.
- Regnault is listed as catalog entry 1727 in the original IAU nomenclature of Blagg and Müller, where it is described as a "ring plain" with a diameter of 0.028 of the lunar radius (49 km) situated at -0.586, +0.810 in the Xi-Eta system (54.1°N, 87.8°W), and corresponding to "Repsold" (#760) in Franz's catalog and "Repsold c" in Beer and Mädler. The IAU name is attribued to Schmidt.
- Kuiper attempted to "correct" Schmidt's spelling by adding an accent to the "e". This change was rejected by the IAU.
- According to Whitaker (p. 235), the name was moved to a new location in the Rectified Lunar Atlas, however the size and position listed in Named Lunar Formations are so similar to the present ones, that the comment is hard to understand. - Jim Mosher
- Also according to Whitaker (p. 93), the name Regnaultis, S.J. was used on maps published by Hell in the 1760's. This would appear to be a reference to the recently deceased Jesuit mathematician and philosopher Noël Regnault (1683—1762). Hell apparently used this name for a different feature, but it is hard to know if Schmidt was intending to honor the 19th century chemist identified by the BAA in Who's Who in the Moon, or meant to reinstate the older name from Hell's map. - Jim Mosher
- Rima Regnault (an unofficial name from D.Caes for the rille on the floor of Regnault, which is the westward continuation of one of the rilles on the floor of nearby Volta).