For some time I have been keen to pin down the exact location and height of hill summits, and also cols (to determine drops). I have spent many happy hours in map libraries, and a few years ago I was given a Huger electronic altimeter to pursue these researches on the hill. This reads to a precision of one metre. Now I do not claim that it is accurate to that degree, and certainly absolute heights need care: for one thing, the change in pressure for a given change in altitude can vary with the temperature. So if it is set at a spot height at the start of a walk, then after climbing several hundred metres the reading may not be exactly correct even if the weather has remained stable. But if one measures several nearby points in quick succession it has usually proved reliable to within ±1m, unless the weather is unsettled or windy. This is confirmed by returning to a previously measured spot and taking a further reading. When I walk upstairs it always shows a gain in height of 3m or 4m. Lovers of Imperial units can set a Huger to read with a precision of one foot, but this is really asking too much of it, as the displayed value tends to flip about within a range of three or four feet even when held at one spot.
During 2005 I investigated two hills in section 34D, the newcomer Arnside Knott and Lambrigg Fell, which has been the subject of earlier discussion in Marhofn.
The Huger was set to 159m at the summit trig, then registered 9m on the railway north of Waterslack Bridge, at 4717 7635. In itself the recorded difference of exactly 150m is not sufficient to prove that AK is a Marilyn, but I took several readings in the vicinity, e.g. at the road junction at 4720 7597, where it read 12m each time, which is the same as the spot height there. So my provisional conclusion is that AK is indeed a Marilyn, though with the minimum possible drop. However there is one caveat. The railway track north of Waterslack Bridge appeared to be rising, though the rise (if any) was extremely slight and the observation was by no means certain. I have also studied the large-scale maps, which produced plenty of evidence to confirm this conclusion and none to conflict with it. A further visit should finally establish the true position but I do not expect a change of status. I remain, however, puzzled as to the location and height of the natural col, before the railway was built.
The 'official' summit of Lambrigg Fell was moved in 1997 by Alan Dawson from 338m at SD586943 to 339m at 586941. My observations supported this change (though I think the new grid reference should be 587942) but it was challenged by Jim Bloomer in Marhofn 93. I therefore visited the hill for a third time last year to take some Huger readings. Conditions were rather unsettled and so a firm conclusion could not be reached, but readings indicated that the E (current) top is most likely to be the highest but the N (original) top is of very similar height (probably not more than 1m lower), so we may have a case of twin tops. The third or S top is clearly lower.
Interestingly, the post-war 1:10560 map shows the N top as 1109ft (338m) and the E top as 1105ft (337m), but there is no way of telling whether the latter spot height was at the highest point of the E top. If I am in the vicinity on a day of settled high pressure I will have another attempt to nail this one once and for all! And next time I will take a GPS as well.
