Navigation Construction


To study how an extension to the navigation system might be constructed in rugged terrain one pentacle (shown in turquoise) was selected.

This selection was not totally at random, as an alignment from this pentacle provides the intersection with the Brenac pentacle.

The Location

extension-location The pentacle is also situated between two alternative routes which the Visigoths might have used travelling south from Carcassonne.

Thus this area is typical of where the treasure might have been hidden.

construction-01_0 A little practical work soon showed that the use the pentacles as a navigation system was a very valid alternative to conventional triangulation.

A relatively simple methodology can be devised.

The two white pentacles are considered as “existing” pentacles. Both pentacles are in the departement of Aude, the one on the left could be associated with the village of Villefloure and the one on the left with Sainte Hilaire.

The Terrain

The turquoise pentacle is a new pentacle which it is desired to construct as an extension of the navigation system. The first stage would be to extend centre lines from the two existing pentacles to the point at which they intersected.

construction-02 This 3D view gives a good idea of the terrain and gives a feel for the difficulty of carrying out surveying work in this location. Both centre lines cross changes in level.

Elevation Profiles

elevation-profile-2 Initially I could not image how there could be any accuracy in constructing these extensions.

The elevation profiles provided by google earth are also very helpful in getting a feel for what is entailed.



elevation-profile-1 It can be seen from both this and the previous diagram that the cetre of the new pentacle is slightly over the top of the hilltop from the points from which the extrapolation is being made. There is an excellent website called Elementary Surveying Equipment which sets out how the extrapolation might be done.

In principle it requires lots of straight poles, fitted with flags, which can be reiteratively aligned for as far as is required. Measurements are then made with lightweight chain of only 20 metres in length with pegs being driven in to be inline with the poles.

build-2-1 It is clear from the web site that it is possible to carry out complex layouts. The North South lines (actually three degrees east of north) must be extended across the area to be occupied by the new pentacle. The North- South lines shown here running through this area run from Lille to Barcelona. As indicated under Navigation Solution many sets of these lines can be drawn along the main alignments of the pentacles. However in this example there is no need to consider the other orientations.

The most dangerous woman in the world

The Treasure of Trencavel

List of Characters

Table Of Contents



List of Places

Table of Contents

Pseudo History


Extract from The Prisoner of Foix--Chapter 43 -The EntranceNo need to buy a Kindle. Read it on your computer or tablet

John Stanley-26th April 1355


'Looks like we are going to see a bit of excitement, John. The Captain tried to get an agreement from the Prince that if there is surf running across the channel to Arcachon we will turn back to Bordeaux, but the Prince would hear none of it. Instead, he has offered to provide insurance for all three ships. If they are damaged or sunk, the owners will be compensated and every sailor who makes the passage will be given a bounty payment. What none of this seems to take into account is that if we sink in rough, fast-flowing waters we might all drown.'

John raised his eyebrows. 'But that is what we are going to do?'

'Yes, despite the fact that surf running accross the entrance is not uncommon and the deep water channel moves continually. In the end, the Prince attacked their captains on their weakest point, their professional pride! He threw down the gauntlet. He offered to take the Sally first through the channel, and to take control during the passage.' He raised his brow. 'We are going into the Bay of Arcachon, come what may! '

Extract from The Eagle of Carcassone -- Chapter 24-- A Real GoddessNo need to buy a Kindle. Read it on your computer or tablet

John Stanley - 22 July 1355

An hour later John walked with Ximene close to the river along the valley below St Feriole. It was the very essence of a summer’s day. The sun was fierce but in the shadow of the trees, it was cool and fragrant. The trees and shrubs along the riverbank hid their progress, from the Château, from St Feriole.

Eventually they reached a point where John thought it was safe to emerge from cover. To his satisfaction the stream extended into a pool with a sandy beach, shaded by trees. Where the stream entered the pool there was a flat grassy area, almost circular. Behind this, the bulk of two mountain ridges provided a splendid backdrop. He looked around once more ‘Not just a good training ground but a great training ground. If the Greek heroes knew about this they might be tempted to join me, to train with me’

Ximene laughed out loud. He turned to look at her. She had removed her outer clothes and was wearing a white chemise, cut short so that it barely reached her knees. Around her waist, she wore a plaited leather belt, obviously fashioned from the multitude of leather straps to be found in the tackle room.

She ran her hands down over her breasts. ‘When you were unconscious I heard you muttering about gods and goddesses, so  I have decided that from now on, for you, I will be the goddess.’

The Prisoner of FoixVol 1 of the series—The Treasure of Trencavel

Aquitaine, an English possession, is in crisis. It is under threat from neighbouring nations and internal dissension.

The Black Prince, King Edward III’s eldest son has been given the task of taking command in Aquitaine.

Suddenly there is an opportunity. Ximene Trencavel is the heiress to the lands of Occitan, to the east of Aquitaine: lands controlled by the Franks. Ximene wants independence, both for herself and for Occitan.

A union between Aquitaine and Occitan would be mutually beneficial. The Black Prince undertakes a secret journey to meet Ximene to negotiate a marriage contract. It is, however, a marriage neither of them really wants.

Meanwhile, the  Franks plot to murder Ximene to prevent ,not just the marriage, but any kind of union between England and Occitan.

The Eagle Of CarcassonneVol II of the series—The Treasure of Trencavel

The loose alliance between Ximene Trencavel and the Black Prince is under threat.

The Prince invades Occitan, to show his support for Ximene but it becomes an invasion which creates more problems than it solves.

The Prince has fallen hopelessly in love with Joan of Kent and Joan is now determined to marry him and become the next Queen of England.

Joan is therefore  determined to convince Ximene that she should not marry the Prince.

Part of her strategy is to encourage Ximene’s relationship with John Stanley—one of the Princes bodyguards—not an easy task as both John and Ximene have doubts about their compatibility.

However, John is grievously injured in a battle and Ximene commits herself to nurse him back to health.