Oris Aquis Date 43 (733 7653 4155-07 8 26 01PEB)

Barely ten years in the business, the revived Louis Moinet brand faced an incredible challenge after the surprise discovery just two years ago that the famous watchmaker after whom the brand is named had actually invented the first chronograph in 1815, predating Adolphe Nicole's patent of 1862 by nearly a half a century. Not only had Moinet produced the stopwatch far ahead of its time, he had also created one that operated at a frequency that even today is unimaginable. The device was called a "compteur de tierce", since a "tierce" in the French of the time meant one sixtieth of a second. To measure this, the world's first chronograph operated at 216,000 vibrations per hour, or a frequency of 10 Hz.

But back to the challenge: The horological world, and Louis Moinet, celebrate the bi-centenary of the invention this year and in just two years the brand had to come up with something that would celebrate its tenth anniversary and do justice to its newly discovered watchmaking heritage. The result is the Memoris, the world's first "chronograph-watch". Put simply, it turns the usual chronograph movement configuration on its head: the chronograph functions are housed on top of the movement mainplate and the timekeeping elements effectively become a "complication" hidden beneath them.

The chronograph deconstructed
The fact that Louis Moinet has given pride of place to the chronograph mechanism means that its workings are laid bare and can be admired in all their detail, without any elements of the timekeeping functions obstructing them. At the heart of the chronograph is a column wheel, which is the most essential of the 147 components of the chronograph mechanism (which in turn account for almost half of the 302 components in the watch). The column wheel is the central processor of the mechanism, translating the movement from each press on the monopusher into a rotation that either blocks or releases the components interacting with it (minute hammer, brake and clutch).

Just as the column wheel is traditionally the sign of a superior chronograph, Louis Moinet believes that tradition also dictates that all three functions (stop, start and reset) should be activated by a single pushbutton, which is found at 2 o'clock on the case. Not wishing to push things to the extremes of the compteur des tierce and the headache that would cause for the power reserve, Louis Moinet has coupled its unique chronograph to a 4 Hz movement in its LM54 calibre, which offers 48 hours of power reserve and offers its own signature feature.

Energie Plus
Louis Moinet has devised its own automatic pawl winding system to get the most out of each swing of the oscillating mass. "Energie Plus" () consists of an excentric plate with two click levers in a "crab-claw" design and captures the movements of the oscillating mass in both directions to transmit 30% more energy to the barrel spring than a conventional self-winding system. Furthermore ultra-lightweight miniature ceramic ball bearings, each with a diameter of just 0.397mm, allow the bi-metallic oscillating mass to swing more freely and thus further improve the energy transmission.

From scratch
To house all 302 components of this movement, Louis Moinet redeveloped practically every element of what is known in French as the "habillage", in other words everything that "clothes" the movement. As such the case, hands, dial, oscillating weight and even the foldover clasp are new. The gold case alone consists of 52 individual components and includes a screw-on transparent case back, screwed-in black zircon settings on all four lugs and a patent pending crown protector.

Only 180 of the memorable Memoris chronograph-watches will be made, 60 in 18-carat red gold, 60 in 18-carat white gold with a rhodium-plated mainplate and 60 in 18-carat white gold with a blued mainplate.