THIS WILL SOUND like a silly question, but does anyone have any thoughts as to where the top of Dumyat might be? No, it''s not been bulldozed, or bundled into a car and kidnapped - but there is uncertainty as to its precise location. Most people - at least 99% of those who run, stroll or stagger up Dumyat, I''m sure - regard the cluster of cemented cairn / Ordnance Survey triangulation pillar / memorials to various regiments as comprising the summit area. They flop down to eat their piece there or thereabouts entirely content that they''ve topped-out Dumyat. There''s no doubt that the cemented cairn with its fire-beacon brazier sits on a slightly higher piece of land than the trig point. So, for most people, the cairn counts as the top.
Note that the top of the brazier doesn''t count as the top of Dumyat, even though it has the highest elevation of anything on the hill. Ditto the top of the cairn or indeed the top of the trig. These are artificial objects and, by what tends to be known in hillwalking circles as the Ben Lawers Principle, they aren''t included in official height calculations. (Ben Lawers stands 1214m or 3984ft above sea level. Around a century ago some well-intentioned but misguided gentlemen built a 16ft cairn on top in an attempt to raise the hill to the elite 4000ft club occupied by Ben Nevis, Ben Macdui and a few others. This cairn has long since toppled, but its builders might as well have saved their energy. Even had they built a 25,045ft cairn and so made Ben Lawers one foot higher than Everest, it still wouldn''t have counted, as the height of a hill is derived from geology rather than built structures. Otherwise, after all, people wanting to reach the top of Burnfoot Hill would, for the next 18 months at least, be forced into shinning up a 50m mast.)
Anyway, I must have been up Dumyat 30 times before, when approaching one day along the little grassy ridge rather than the standard path, it struck me that the knuckle of rocks a few metres northwest of the cairn could well be the highest natural ground. There''s clearly not much in it: the rocks in question are only shin-high, and the dip between them and the cairn is minimal to say the least. But once noticed, such things have a habit of retaining the interest, and over subsequent visits I became more and more convinced that this little outcrop, and not the base of the cairn, was the highest bit of land on Dumyat, albeit only by a few centimetres.
Then, one day last summer, an esteemed denizen of Dollar by the name of Andrew Smith dropped by for a cuppa and handed over a lovely bit of kit: an Abney Level. This is a high-quality hand-held instrument comprising a kind of miniature brass telescope, a levelling bubble and a Vernier scale. Andrew is a retired mining surveyor, and his example of Captain Abney''s patent device had clearly seen much use over the years. It was just the thing for assessing the summit of Dumyat, so in October a crack surveying team comprising me, my partner Tessa and retired mathematician and FotO member Ken Stewart went up to see what was what.
Although skies were clear, our efforts were hindered somewhat by there being half a gale blowing (OK, 0.476 of a gale, since we''re being precise). But after much ungainly sprawling across the outcrop, awkward lying down alongside the big cairn and squinting through the miniature telescope, a series of both-ways readings was taken which appeared to suggest around half a degree of slope in favour of the outcrop. In other words, the Abney Level angled very slightly downwards from the outcrop to the base of the cairn, and so the outcrop appeared to be the higher of the two.
There are a couple of ifs and buts with regard to this, however. For a start, a second set of readings on a windless day would provide reassurance with regard to accuracy. Then there is the question of invisible ground. Who knows what lies under the big cairn? It could stand on flat ground, in which case the readings already taken might well be reliable. But what if the cairn was built over a big pointy rock that would very much count as natural ground? Does anyone know? Can any reader recall what the summit area looked like before the cairn was built? Does photographic evidence exist? This has echoes of another highest-point controversy, that relating to the Old Man of Coniston and Swirl How in the Lake District. Here the two rival points are well over 2km apart, with only a metre of difference in height terms, so it''s nigh on impossible to tell which is the higher. But the cairn on the Old Man stands on a large and extremely well-made slate platform, and again there could be all manner of up-jutting rocks lurking beneath to muddy attempts at measurement and calculation.
Of course, this is all pedantry, and in the grand scheme of things it doesn''t really matter exactly where the highest bit of Dumyat lies. But it would be nice to know, and if it does prove to be the quiet outcrop rather than the busy cairn, it would mean - amusingly - that almost everyone who purports to have climbed this fine hill hasn''t actually been to the top.