Sir, – It is rather unfair to criticise Prof Michael O'Kelly's monumental work at Newgrange with the accusation that he built that roofbox ("Newgrange sun trap may be only 50 years old, says archaeologist", December 21st).
I want to point out that he did not change the direction of the passage, which points accurately to the rising position of the winter solstice on the local horizon. Neither did he carve the triple spiral in the end chamber where it could only be illuminated by the sun beam entering the end chamber, a phenomenon that does not occur today due to a change in the obliquity of the ecliptic since Newgrange was built, though the beam still enters the central chamber. Finally, he did not design the entrance stone with its triple spiral travelling in two directions, representing the reversal of the sun’s rising position on the horizon that is also played out in the central chamber over a few days.
I am convinced by the alignment of Newgrange and other sites such as the unreconstructed Cairn T at Loughcrew, and can I advise any sceptical archaeologist to visit Loughcrew on an equinox morning to see how our ancestors used these structures to provide a solar calender for an early farming community. – Yours, etc,
TIM O’BRIEN,
Castleknock,
Co Dublin.
Sir, – I suppose the next revelation in relation to Newgrange will be a pyrite problem, the site’s acquisition by Nama, its sale to a vulture fund, and its occupation by a group of celebrity musicians? – Yours, etc,
MIKE MORAN,
Clontarf,
Dublin 3.