sentences:  The initial results were confusing because the unknown substance the British Museum had found across the whole map, effectively ignored by later researchers who were concentrating on the ink, turned out to be trapping tiny traces of fallout deep within the parchment from 1950s nuclear tests.Although there is none of this 1950s substance on top of the ink, further tests, starting with a detailed chemical analysis, are needed to confirm whether the lines were drawn after it soaked into the parchment.In 2008, Harbottle's attempt to explain a possible medieval origin for the ink was published, but he was shown by Towe and others to have misunderstood the significance of the various analyses, rendering his theory meaningless.