Metrology at Mnajdra

I refer to Mario Vassallo's first of a three-part series, "The planning and layout of the Maltese neolithic temples" (The Sunday Times, May 11).

Mr Vassallo quoted Turnbull: "No work has been done on the metrology of the monuments, how the forms were generated, nor has a key question for science studies been addressed, that is the question of how the knowledge of the builders was moved and assembled..." (Turnbull, Vol. 19, 2002, 5-6, pp. 125-143).

This statement by Turnbull is incorrect since in a research article titled "Alignments along the main axes at Mnajdra temples" in Xjenza, the journal of the Malta Chamber of Scientists (December 2000), I had investigated the significance and determination of ellipse equations for Mnajdra complex.

It was established that the perimeter of the ellipses, in terms of whole number of units, was achieved for the high temple (larger ellipse and the lower (solar temple) in terms of the megalithic yard.

For the small trefoil, and the high temple (smaller ellipse), half a megalithic yard was used. For the major axis of the ellipse in terms of the megalithic yard, accurate results, in whole unit numbers were achieved for the small trefoil temple, and the larger ellipse of the high temple.

The same cannot be said for the smaller ellipse of the high temple and the solar temple and probably half a megalithic yard was used.

Quite accurate results were attained for the small trefoil temple, high temple and lower temple at Mnajdra when measurement in terms of the megalithic yard is considered for the major axis of the ellipses.

Another discrepancy is the distance between the foci for the lower temple ellipse. The error involved is 2.4% unless the megalithic builders used a quarter of a megalithic rod in their construction. Quite accurate results in terms of whole number of units were achieved for the ellipses of the high temple.

The results derived for the Mnajdra complex positively show that the distances between the foci and the major axis and the perimeters of the elliptical temples were achieved by means of some megalithic unit.

(The megalithic yard concept was put forward by the late Professor Alexander Thom of Oxford University where he conducted statistical research on more than 300 megalithic sites in the British Isles. He had concluded that one megalithic yard is 0.829 metres and one megalithic rod equals 2.073 metres.)