An exceptional nineteenth century French gilt bronze and Belgian black marble pendule cosmographique with equation of time of eight day duration by Mouret à Paris, signed with his name, with a globe made by Maison Delamarche and signed Globe adopté par le Conseil de l’Université Maison Delamarche Rue Serpente 25 Paris. The white enamel dial ring with Roman numerals and a pair of blued steel Breguet hands for the hours and minutes. The revolving terrestrial globe with coloured paper marked with the continents showing mountain ranges and national borders and the oceans showing warm and cold currents. The globe mounted on its axis above a mechanism geared to the clock’s going train, with a horizontal glass calendar ring with a bevelled edge marked with the names and days in each month within a plain gilt-brass meridian circle, with a calendar pointer to the front, the globe manually adjustable from the side. The single barrel movement with Brocot escapement, raised on adjustable feet above a base plate, the whole mounted on a stepped black marble dished bow in which the pendulum can freely swing

Paris, date circa 1876

Height c. 57 cm.

Of unique design, this clock was the brainchild of Louis-Jérôme-Napoléon Mouret (b c.1810) who in 1876 submitted a patent for this invention. Rather than a clockmaker, Mouret was a civil engineer who in 1874 was established at 13 rue Gaillon, Paris. Throughout his career, Mouret was constantly submitting patents for his many inventions. For instance, in 1874 he submitted one for ‘improvements in the arrangement and construction of model globes driven by clockwork for the purpose of demonstrating at all times all the astronomical phases of the earth with reference to the sun’ (“The Commission of Patents Journal”, 1874, p. 2483, patent no. 2699, of which an earlier patent for a similar mechanism was filed in August 1871). His patent for the present clock was submitted in June 1876 and from then one was described in detail in many of the scientific publications of the day, counting among a review by in “L’Année Scientifique et Industrielle” 1878, pp. 160-1 and also “La Nature Revue des Sciences et leurs Applications aux Arts et à l’Industrie”, 1877, where on p. 45 an almost identical clock is illustrated.

The clock and globe’s mechanisms are interactive, with the globe revolving every twenty four hours against a fixed pointer and a horizontal glass annual calendar ring below. A lever is fitted to allow disengagement from the clock movement to enable the globe and year calendar to be set correctly. The unique instrument also displays equation of time, i.e. the difference between solar and earth time. As the observed motion of the sun is not constant throughout the seasons, apparent solar time (sundial time) and mean solar time (clock time) only agree four times a year and can differ by up to sixteen minutes. Equation of time compensates for this differential.

When it came to selecting a globe maker, Mouret chose one of the leading cartographers of the day. This was Maison Delamarche based at rue Serpente, Paris. Their business dated back to the late eighteenth century when Charles-François Delamarche succeeded a concern run by Jean Fortin and the remaining studio belonging to the celebrated cartographer Robert de Vaugondy. Delamarche were the first French cartographers to produce affordable globes for the general public and pursue the educational market. The business continued in production for most of the nineteenth century, under the management of Charles-François Delamarche’s son Félix and the geographer Charles Dien, followed by Félix’s son Alexandre Delamarche.