Glossary/Lépine
Lépine Calibre
Prior to the late 18th century, nearly all watches used pillar movements and had their balance wheels outside the two circular plates, separated by pillars, that comprised the frame of the watch.
Around 1770, Antoine Lepine began making watches with one plate and a number of cocks or bridges, instead of two plates separated by pillars. A further distinguishing feature of this style of movement is that the balance is housed entirely within the frame of the watch, rather than on top of it. By also doing away with the fusée (or stackfried), the end result was a much thinner watch movement and heralded a new generation of portable, mechanical timekeepers.
French makers were quick to adopt this new style. English watchmakers, however, continued to build watches in the previous style for about a century.
Further Meaning
In a pocket watch, the Lépine or open-face style refers to a pocket watch that does not have a hinged cover to protect the face of the watch and whose seconds hand is inline with the winding stem of the watch. This is in contrast with the hunter style, in which the seconds hand is positioned perpendicularly to the winding stem, originally to facilitate easier reading of the seconds when the hinged cover, used to protect the glass front of a hunter's watch, was opened to read the time.