Working "Celtic Cross"

Older than history and the obvious mariners instrument for navigation

Versions from 5000BC-to 500AD

Stamped out by the expansion of the Roman Empire, this archetypal instrument goes back to times when nomadic peoples sailed the planets oceans by the stars.It was last seen surviving in the hands of the "Celtic" peoples in the Western seaboards of Europe up to 500AD although there is evidence of the design existing amongst the Amerindian civilisations in the America's until they were destroyed and their knowledge obliterated by the Conquistador in the 16th Century AD

The Egyptian Cross and plumb line

Derivative of the principles of the older Celtic cross?

?-2170BC

This version of the cross has been identified by the author as the device that was used by the architect,astrologer to align the Great Pyramid of Giza to the circumpolar stars.

It could also the instrument of wisdom belonging to the Egyptian God of measurement and recording, known as Thoth.

In this particular device or instrument of observation an exponential measuring rod has replaced the circle of the earlier Celtic design.

With a rod measuring 90 centimeters, this device is accurate to 3 minutes of arc or 3 nautical miles.

It is the only type of inclinometer device that could logically design and survey the pyramids.The Author has discovered one in the Great Pyramid of Giza.

Never before recognised, it could be the most important treasure of knowledge to come from the Egyptian complex answering many questions and dispelling many myths

The Antikethera Mechanism

?-64BC

Found in the early twentieth Century,

The instrument was discovered in a ship wreck by diver's off the Greek island of Antikethera.

It was dated by the pottery found along with it in the ships hold.

Archaeologists have designated it to be a mechanism for predicting astronomical movements.

It is as complex mechanically as a Victorian clock and is made of brass/bronze intermeshing movements of superb accuracy and workmanship

It was enclosed in a wooden box and is a historical anomoly.

What is missed by the casual reader is that no such instrument comes about as a one off , but is an evolution and conglomeration of diverse long term skills to manufacture it and to use it to its full potential

A Mariners Astrolabe

500BC-1700AD

This instrument was used by the Greeks,Muslims and later Europeans as an astronomical observational device for astronomy/astrology and navigation.

The one in the picture was hung in the rigging of a ship.

The holes in this mariners astrolabe were to reduce windage.

Quadrant

500BC-1600AD

A quadrant is a device for measuring angles used by the Greeks, Muslims and early Europeans for astronomy/astrology and navigation.

Its name is derived from a fouth part or quarter of a circle.

The Celtic cross is a complete circle, earlier and more efficient.

Octant

18th Century

The octant was devised from the earlier quadrant in the 17th Century and was used for navigation.

It was the first instrument to use mirrors to reduce a stellar body to the horizon, dispensing with the plumbline.

Its name is derived from octagon, or eigth part of a circle.

It is mostly restricted to measuring verticle inclines and is unable to directly find the horizon on land.

The Sextant

With Vernier

18th Century to present but being replaced with GPS

The sextant is similar to the octant in that it uses mirrors and reduces a sighted body to the horizon.

When combined with Harrisons chronometer 1764 the problem of longitude was solved for European navigators.

Its vernier acts as a sixth part of a circle.

The Celtic cross was a complete circle allowing it greater flexibility