Cadran solaire Rauba Capeu

Sommaire / Summary

The Rauba Capeu sundial measures a dozen meters in diameter and is painted horizontally on the ground. It is therefore located just a few metres from the #IloveNice sculpture. Users can find out what time it is by looking at the shadow of their head.

Sundial, quai Rauba Capeu

You can't miss it, it's just a few meters from the sculpture #IloveNice. The Sundial, quai Rauba Capeu is right at the foot of the Château hill, it was set up on June 21, 1981, the day of the summer solstice. It is inclined and has 24 branches indicating the hours. But only 12 are numbered from 7 to 18 and extend to the end of the dial. In addition, between lines 12 and 13, the North Pole is indicated. It uses the user's shadow to deliver the time. The 1.70 m tall person must stand on the rosette, the shadow of the head indicates solar time.

Plaques under the sundial, quai Rauba Capeu

As you can see from the photos, three metal plates beneath the sundial give us important indications.

The first indicates the date of its installation 21 06 1981, the position 43°41'22'' north latitude and 29 m 11 s. 29 being a time scale.
This sundial is the work of B Milet Cal, P Février Cog, and R Capron Fec.
The Société astronomique de France has found the meanings of the abbreviations Cal. Cog.Fec. Either:

Cal = Calculavit: "calculated... " from Latin calculare
Cog = Cogitavit: "was conceived by..." from the popular Latin cogitare
Fec = Fecit: "was made by ... " from classical Latin facere.

Bernard Milet , well-known astronomer, made the calculations (Cal). Roger Capron, a renowned ceramist, designed the dial artistically.
As for the second plate, it shows the operating instructions. It reads:
Solar Dial The solar time determined by the shadow of the head of a 1m70 observer, placed on the rosette, must be corrected according to the date by the number of minutes indicated on the graph.

The third is more complex.

You can read, at the bottom horizontally the months and at the left vertically the correction to be applied in minutes...

A correction is necessary because the inclination of the globe's axis of rotation is different in each season.

Solar time and GMT

The sun's path is always from east to west. To find the solar time of a town in France, you first need to locate the town in relation to the meridian that sets France's time zone, because fortunately there's only one.
This means knowing whether the city is east or west of the meridian, and then adding or subtracting minutes. For example, Strasbourg: add 31 minutes, Nice: add 29 minutes, Lyon: add 19 minutes, Amiens and Paris: add 9 minutes and Bordeaux: subtract 3 minutes.
Remember, of course, that solar time is different from Greenwich Mean Time.
GMT time was created to harmonize, quite useful when traveling to several cities and countries. In simple terms, it's the local mean time at the Royal Observatory in Greenwich, London, from midnight onwards.

Roger Torrenti and the Sundial, Quai Rauba Capeu

Roger Torrenti is an engineer at École centrale Paris and President of the Sundial Commission of the Société Astronomique de France since 2021.

Only someone 1.7 m tall can get the time right. Smaller or taller people will note an approximate time.
Many people wonder why this choice and design!
Roger Torrenti, on the other hand, performed the calculations and says it would be easy to add stars based on height.

He is also, the author of Les cadrans solaires : histoire, théorie et construction, it is free to download. The paper version can be purchased online.

In short, the time indicated by a sundial is solar time and is specific to its location. Your watch, on the other hand, indicates legal time, based on the Greenwich meridian.
The dial and the watch never give the same time.
In Nice, once you've discovered the time on the sundial on the Quai Rauba Capeu, you have to look up. And look, admire the magnificent scenery all around, including the view over the Baie des Anges.

Useful information

Sundial
Quai Rauba Capeu
near #ILoveNice
Nice

Please note that there are different spellings for Rauba Capeu, Rauba Capèu or Rauba Capeù...

Informations Côte d'Azur

Jean-Marc Foulquier