The Paris meridian 

Among the topics of research into Rennes-le-Château, there appears constantly a recurring theme. This is the theme concerning meridians which appear over and over.  Their stories also touch on fields such as alchemy, occultism or topographical alignments.

The Meridian 0 [zero], the Green Meridian, the Meridian of St. Sulpice, the Meridian of Bourges, the Paris meridian, these are all names for virtual lines scarcely known to the general public. These meridians,  or the so called meridians affair, because it is an affair in the enigma of Rennes, also touches upon the secret and sacred geography of France , a subject that receives little media attention.

    There are many errors in these Meridians which persist and are repeated over and over,  such as believing that the  Meridian 0 crosses the Pontils tomb exactly, or that Bourges Cathedral is located on the meridian of Saint-Sulpice Church in Paris.  These errors peddled by many authors inevitably lead to confusions that are difficult to correct over time. 

      The Paris meridian was for years the global geographic zero meridian used by navigators. It allowed later academics to bring to light another project, the cartography [or mapping] of France, a colossal project led by the Cassini dynasty. The work of updating the maps indeed became essential to carry out not only the political strategies of the royal power, but also for the knowledge of the territory and the world.

There is some mystery attached to this endeavour that has been directly associated with the affair at Rennes-le-Chateau. On the old Arcadia website under a thread for discussion i started [to discuss the novel CIRCUIT by Cherisey, a respondent by the name of Michel Montbard wrote the following: 

"I've searched for some references in CIRCUIT related to wells, and the contexts I've found them in are astonishing. First there is a connection made between MERIDIANS and TOMBS. Quote:

The Garoé affair took on cosmic proportions in 1637 when Louis XIII, the King of France, impatient with the disagreements amongst geographers regarding the placement of the 0 meridian, decreed that no map should be published in his kingdom which did not feature as a marker the lime tree of Valverde. An astonishing conflict broke out between the Spanish and the French regarding the nature of the marker. The fact that the King of France was going to situate the beginning of his world in a foreign land flattered the Spanish but made them wonder if by chance Louis XIII was using this to claim the Canary Islands. On the other hand, the French were wondering to what extent the ownership of the marker would bring about the domination of the polar vertical, if they had an interest in the material existence of the lime tree or in its abstract nature. Louis XIV who succeeded Louis XIII concluded the conflict in a threatening way. 

"The Pyrenees no longer exist!" 

Led by Thomas Corneille, French poets disputed the material existence of the lime tree, only seeing it as an abstract reference marker, while Spanish poets held to the conclusions of Monsignor Camara y Murgua and Father de Abreù Galindo. Politicians appeared just as perplexed as the poets, as shown by the decision of the Governor of the Canaries to pull out the last roots of Garoé and throw them into the wells of Temijiragua, also situated on the zero meridian and which were supposed to contain the sepulchre and the treasure of Sertorius, the happy rival of Pompey the Great. How to bring the 0 meridian to France without acting against his father wishes, posed a big problem for Louis XIV. Charles Perrault the poet architect solved it in a very ingenious manner by literally translating the Spanish Valverde into the French Vauvert. Well known to the Parisians, the cellars of 'the Devil Vauvert' served as the basement of the Paris Observatory which from then on marked the French nationalised 0 meridian. An additional advantage was that the cellars of the Devil Vauvert marked the placement of Robert le Forts' Castel, ancestor of the Capetians. As for the Observatory itself, it must not be considered simply as a place where the Earth contemplated the stars but a centre where the Sun king could shine over the Earth..

Now a quote from Wikipedia regarding El Hierro:


El Hierro was known in European history as the prime meridian in common use outside of the future British Empire. Already in the 2nd century A.D., Ptolemy considered a definition of the zero meridian based on the western-most position of the known world, giving maps with only positive (eastern) longitudes. In the year 1634, France ruled by Louis XIII and Richelieu decided that Ferro's meridian should be used as the reference on maps, since this island was considered the most western position of the Old World. (Flores Island lies further west, but the Azores were not discovered by Europeans until the early 15th century, and their identification as part of the Old World is uncertain.) It was thought to be exactly 20 degrees west of the Paris meridian, so indeed the exact position of Ferro was never considered. Old maps (outside of Anglo-America) often have a common grid with Paris degrees at the top and Ferro degrees offset by 20 at the bottom. Louis Feuillée also worked on this problem in 1724. Source:

In the Canary Islands we notice that the former 0 Meridian was marked by the tomb of Sertorius (from the Temijiragua well). Which strengthens the hypothesis that the true France Meridian is marked by a tomb. In this case, the tomb of the Grand Roman. The struggle for the monopoly over the line of the reference MERIDIAN was fierce between different countries like Spain-France and later Great Britain. Cherisey associates this dispute with the rivality between Pompey and Sertorius.

Louis the XIVth absolutely wanted the 0 Meridian to be on french soil, despite his fathers wishes, Louis the XIIIth, who would have prefered to leave the oficial Meridian on spanish soil:

Louis XIII, the King of France, impatient with the disagreements amongst geographers regarding the placement of the 0 meridian, decreed that no map should be published in his kingdom which did not feature as a marker the lime tree of Valverde. [...] Louis XIV who succeeded Louis XIII concluded the conflict in a threatening way. "The Pyrenees no longer exist!" […] How to bring the 0 meridian to France without acting against his father wishes, posed a big problem for Louis XIV. Charles Perrault the poet architect solved it in a very ingenious manner by literally translating the Spanish Valverde into the French Vauvert.  

It seems the conflict between geographers had something to do with the Pyrenees. As Louis's the XIVth had to decreed that the "The Pyrenees no longer exist!". 

If the 0 Meridien has to be marked by a tomb and not any tomb, then that tomb could have been in the Pyrenees. So Louis' the XIVth's problem was to bring the 0 Meridian to France without the reference TOMB or maybe to keep it hidden. For this reason Charles Perrault's great burden was to create a false Meridian, over the cellars of the Vauvert Devil (using the ressemblance between Valverde and Vauvert). Also from the CIRCUIT we find some references through which it is being suggested that the WELLS represent accesses but Cherisey is using different tricks (transpositions, intentional errors or time/space distorsions) to mix things up.

Quote: Valérien Ariès, the best French impresario, has his apartment on the sixth floor of a building without a lift in the Avenue Victor Hugo, where the cellars open to a well (shaft), through which it is possible to reach the 'drug-store' of the Champs-Elysées. Quote: VII VARIETY  It was was well expected of Louis XIII, known as “the just” to decide where the Zero Meridian was to be because he was born under the sign of Libra. The PERRAULT brothers. Suspected of having built the Paris Observatory according to cabalistic laws, to have fitted up an old well so that it communicated with the Catacombs, to have placed in the foundations a black virgin, patron of alchemists (Al Chimia black face) and called 'Notre Dame beneath the Earth”. Pun; coupole (dome) and coupe-pôle (cutting the pole).

This extract is even more interesting as we discover in it some elements connected to the story in the south of France. The black virgin – notre dame beneath the earth (in the north), is the reflection (the transposition on the MERIDIAN) of ISIS-VENUS/NOTRE DAME de CROSS (in the south). That detail with COUP-POLE, which Cherisey is adding here, is very interesting . Cupole de Chapiteau (Dome of the Big-Top)".

Please bare all this in mind as we follow the meridian [of if you prefer "following the sword"]!

The Paris meridian (or 0 meridian)

   The Paris meridian or 0 meridian is by definition the virtual line that crosses the North and South poles, and the Paris Observatory . Replaced today by the Greenwich meridian to serve as an international benchmark, the Paris meridian was the prestige of France and served as a world reference. It is still used today for all East-West coordinates on all topographic maps of France.

      In the middle of the XVII E century , after the death of Nicolas Poussin, some members of the scientific community worked out in 1665 the project of a " Company of Sciences and Arts ". The physicist astronomer Auzout even sent the King a dedication: " There goes, Sire, the Glory of Your Majesty ... the establishment of an astronomical observatory ... "

    Louis XIV and Colbert then took advantage of this request to launch a project, that of  the Royal Academy of Sciences The first session took place on December 22, 1666. But to make this birth a reality, a large-scale monument and above all a location were needed. Decision was taken to create the Royal Observatory This building, which will become the Paris Observatory, will serve as a meeting room for academics as well as a laboratory and shelter for astronomical instruments. 

    Colbert will then bring from the county of Nice, a certain Jean ‑ Dominique Cassini (1625‑1712) , one of the best astronomers of the time. Louis XIV will entrust him with the responsibility of the Observatory. It is the beginning of a real dynastic adventure since 4 Cassini generations will succeed one another at the head of the institution.

      The estate which now houses the Paris Observatory originally had an area of 2.5 hectares . The perfectly clear terrain was pentagonal in shape and the north-south axis defined the future meridian. The site was purchased in the name of the King on March 7, 1667 for the sum of 6,604 pounds and its location was particularly well chosen. All around extended exclusively religious domains: to the north the abbey of Port-Royal in Paris; in the east, the Capuchin novitiate; in the west, the novitiate of the fathers of the Oratory; as to the south, the countryside with its windmills. The horizon was perfectly clear on all sides and therefore particularly suitable for celestial observations.

    To protect the site located outside Paris they quickly built an enclosure which cost three times the price of the land. Originally, the main entrance was in the Chemin du Faubourg Saint-Jacques, but in 1811 it moved to the Avenue de l'Observatoire. Two pavilions will frame the entrance and are still visible.

    On June 21, 1667 , the day of the summer solstice, the mathematicians and astronomers of the Academy plotted on the ground, at the current location of the building, the meridian and other directions necessary for the exact orientation of the building.

     The line thus defined became the meridian of Paris , the meridian origin for France and for the world. The 0 meridian was born. 

     The four faces of the building were oriented towards the cardinal points and the south face determines the latitude of Paris. The building was of course oriented with great precision.

     Built between 1668 and 1672 , the Observatory was designed according to the plans of a famous architect to the King: Claude Perrault and which must not be confused with Charles Perrault, his brother, the famous author of tales.   Claude Perrault, member of the Academy in the physical section, had a wooden model made beforehand which he presented to Louis XIV and to the academicians. The construction was rapid despite the consolidation work that had to be done in the basements. Indeed, Claude  Perrault very quickly discovered that old underground quarries were present and weakened the subsoil. They will later become the catacombs. These voids located about 28 m underground were consolidated to support construction. The depth of the quarry was equivalent to the height of the building, and a well with a height of 56m was even built with a spiral staircase in its lower part.

      This well enabled the astronomer Cassini in particular to observe the stars at the zenith and to carry out studies on the fall of bodies. The old quarries were also converted into an underground laboratory and became "  the caves of the Observatory " [Well known to the Parisians, the cellars of 'the Devil Vauvert' served as the basement of the Paris Observatory which from then on marked the French nationalised 0 meridian]   These very privileged places for scientific experiments because of the very great stability of the temperature, made it possible to establish all kinds of calibration including the calibration of thermometers.

    It is  through the titanic work carried out by geographers that the radius of the terrestrial globe could be measured very precisely. These measurements were able, among other things, to confirm the theories of Isaac Newton concerning gravitation, and to refine the value of his famous gravitational constantThe particularity of the meridian of Paris , like that of the Saint-Sulpice church, is that it is materialized by a copper line crossing the Observatory. This line is not intended to denote geographic location, but rather to serve as a gnomon.

A small opening is in fact placed in a window to the south of the Observatory allowing a ray of sun to cross the meridian line at solar noon very exactly .

In addition, the radius which depends on the height of the Sun allows it to function as a true astronomical calendar.  As in Saint-Sulpice, there are signs of the zodiac and the dates of the equinoxes, except that here they are engraved on the ground.

    It was in 1718 that the meridian line was finally completed thanks to Jean ‑ Dominique Cassini  (1625‑1712), first director of the Observatory, his son Jacques Cassini (1677‑1756), and Philippe de La Hire (1640-1718). This project required immense work because of the numerous extremely precise calculations that had to be carried out and the large number of territories covered. It is thanks to the technique of triangulation that the surveyors succeeded in reconstructing the geographical proportions and finally in drawing the map of France.

    To carry out this project, it was first necessary to triangulate around the 0 meridian. This line served as a support for the rest of the cartography and represents the spine of the French map.    The cultural influence created in the world by this new scientific and geographical reference was such that Paris became the capital of Precision Time and of the reference system. The capital was even associated with a new omphalos , that is to say " the center of the world

The meridian of Paris allowed to define the standard meter

    If France is at the origin of the metric system, the definition of the meter is linked to the length of the terrestrial meridian. It was therefore necessary to precisely determine its length.  In 1790 , there was no unit of measurement in France and it was in the midst of revolutionary turmoil that the universal standard meter was decided. For Condorcet, it was necessary for "A Universal measure for all times, for all men " ...  

   In 1792 the Convention then decided to unify the units of measurement on French territory (each canton then had its own measuring rod, and the assembly abolished the privilege of "establishing the measure". The meter has just been born. It will be the 40 millionth of the Earth's meridian. The measurements will be renewed after Cassini from 1792 to 1798 by Jean Baptiste Delambre and Pierre Méchain. Sent with a letter of mission signed by Louis XVI , the scientists left, one to Dunkirk and the other to Barcelona to measure very precisely the length of a meridian arc. For this they used a technique based on angle measurements from points and marks located on the heights on either side of the Meridian. Their work was presented on July 3, 1799 after 7 years of measurements. This will be the yardstick and units like the gauge and the foot will be abandoned .

  Jean ‑ Baptiste Biot and François Arago will then be appointed by Napoleon to continue the work of Delambre and Méchain as far as the Balearics, in the south of Spain. On site, José Rodriguez, a faithful mathematician, will help them carry out the 17 triangulations necessary for the layout of the meridian.  François Arago is 9 years old and lives in Estagel when he is impressed by the passage of Pierre Méchain. In 1806, when he was 20 years old and graduated from polytechnic school, he asked and obtained to be able to extend the measurement of the meridian to the Balearic Islands. The work ended in 1809 and on his return he became a member of the Royal Academy, then Permanent Secretary of the Division of Mathematical and Physical Sciences in 1830 . Finally, he was Director of Observations at the Paris Observatory in 1834 .

   After the father-to-son dynasty of the Cassini  and after the Revolution, the Observatory was acquired by the Bureau des longitudes in 1795. This new organization worked on the definition of the metric system. The standard meter was defined in 1799 and became the basis of the decimal metric system created by the Convention in 1795 . The other units are based on the meter and become the international measurement system:

The lengths (the decimeter, the kilometer ...)
The surfaces (the square meter ...)
The volumes (the cubic meter, the cubic decimeter ...)
The capacities (the cubic decimeter corresponds to the liter)
The weights (the kilogram is the weight of a liter of pure water)


The Paris meridian loses its prestige and moves

      If for a long time the original meridian was that of Paris, this reputation ended up disappearing. While all navigation systems, French sailors, geographers and travelers, use this reference, it was in 1884 that an international convention decided under strong pressure from the British attached to maritime affairs, on a new meridian. It was that of Greenwich which won, not far from London. It was therefore in 1891 for the purposes of international navigation that this new meridian became the world geodetic reference and was used to calculate positions and universal time.

    In 1911 despite the efforts to impose its meridian, France will be obliged, under pressure from the rest of the international community, to adopt the English meridian of "Greenwich" as the meridian of origin used to calculate universal time. The clocks of all the French territory were thus delayed by 9 minutes and 21 seconds.  

    History sometimes reserves surprises since finally the red line (copper) of Paris (Roussillon) gave way to the green witch (Greenwich). The meridian line passing through the Paris Observatory is now defined in the NTF system (New Triangulation of France).

Map of France in the 19th century

   Following the Cassini cartography , the need to update this immense work became essential in the 19th century . This necessity arose from the soldiers who wanted to draw up precise and reliable staff maps of the territory as quickly as possible. Of obvious strategic importance, the staff map was the work of the war depot created in 1688 by Louvois . In 1887 , this depot was attached to the general staff under the name of geographical service of the army. The drawing of the map at 80,000 ° began in April 1818 and lasted more than 60 years, again representing enormous work and a very high cost. The maps were finally completed in 1880.

    To carry out this work, France is divided into quadrilaterals of approximately 200 km per side separated by the main chains of triangles, the first two being the Paris meridian , and the Strasbourg-Brest perpendicular (principle already adopted by Cassini). The triangulation was thus carried out according to the same principles as in the 17th century, but with much more precise instruments.

    From this triangulation carried out by the geographic engineers and on the definition of the ellipsoid of Plessis 1817 , the staff officers carried out the surveys at 1/40000. The reference meridian was that of Paris and the reference parallel 45 ° N. A tracing paper accompanied the minutes and received the outline of the contour lines intended to help the engraver in the representation of the relief using hatching.

   The leaves were then engraved on copper for editing.

    The complete map of France was not completed until around 1880 , the first published map being that of Paris, the last that of Corte.

    The projection used is that of Bonne, whose essential characteristic is to be equivalent, that is to say that a surface on the plane corresponds to the same surface on the terrestrial sphere. Its drawback is that it does not conform, that is to say that an angle on the plane does not correspond to an angle on the sphere.