Equation Marchante

Blancpain creates the first wristwatch with “Equation marchante”.

Blancpain once again distinguishes itself in the highest spheres of watchmaking by creating the Equation Marchante, the first wristwatch to feature a “running” equation. This means that the dial is fitted with two coaxial minute hands, one of which indicates mean solar time (that displayed on clocks) and the other real solar time (that shown on sundials). This original system, which is particularly functional, enables direct read-off of real solar time, without any mental arithmetic.

Equation of time

The dial of the new Blancpain “Equation Marchante” watch also features an equation of time display at 2 o’clock, with a slow retrograde hand moving over the arc of a circle graduated from –14 to + 16 minutes.

Moon phase

Blancpain has chosen a very original moon phase display: a retrograde hand sweeping over the arc of a circle located at 10 o’clock and pointing to tiny globes representing the new moon, the waxing crescent, the full moon and the waning crescent.

Real solar time

Another hand in yellow gold, adorned with a small sun, enables one to read off directly, and at any time, the real solar time as shown on sun dials, without having to perform any mental arithmetic. The user can thus visualise at a glance both mean time and real time, as well as the difference between them.

Equation cam

Variations in real solar time are mechanically reproduced by means of an equation cam – shaped like a figure-8 “analemma” – which completes one revolution around its axis in a year. The design of this cam called for extremely precise calculations based on the irregular path of the earth around the sun.
To celebrate this fascinating encounter between astronomy and Haute Horlogerie, and for the first time ever, a circular dial aperture at 6 o’clock allows one to contemplate the equation cam as well as the feeler-spindle in action. The seconds hand also turns in the centre of this opening.