Equation of Time Mantel Regulator with Remontoire and Calendar

Robert Robin was renowned for these excellent precision mantel regulators. The dial is signed Robin Hlger. du Roi, and the outer edge at 6 o'clock signed Dubuisson. It displays the annular calendar with signs of the zodiac, equation of time, hours, minutes, and center seconds. The high quality movement has a Graham-type escapement, remontoire, spring driven strike train striking bell above, and gridiron pendulum temperature-compensating pendulum. The rectangular mahogany case has the ebeniste 's signature F. J. Papst, with glazed panels that showcase the remontoire mechanism, and with ormolu leaf tip borders and moldings, and an ormolu tasseled drape below the dial.

Robin invented the endless chain remontoire, which provides a constant secondary source of power to eliminate the differences between a fully wound spring and one that has almost wound down. This clock also calculates and displays the equation of time, or the difference between mean (clock) time and solar (sun) time. These two times differ by as much as sixteen minutes throughout the year. Thus, the clock has two minute hands—one showing solar minutes and the other showing meantime minutes.