Mapping Mountains – Hill Reclassifications – The Fours

Lord’s Seat (NT 912 079) – 390m Sub-Four reclassified to 390m Double Sub-Four

There has been a reclassification to the listing of the The Fours – The 400m Hills of England, with the summit height, col height and their locations, the drop and status of the hill confirmed by LIDAR analysis.

This was initiated by Joe Nuttall who produced a summit analysis programme that used LIDAR with an alternative height map (DEM) allowing identification of summits and cols and thereby drops.  The resulting spreadsheet that Joe produced contains over 29600 hills.

This spreadsheet is being evaluated by DoBIH Editors and others, and for this particular hill it was Jim Bloomer who initially assessed its height and that of its adjacent peak via LIDAR analysis.

Myrddyn Phillips then evaluated this hill’s details via LIDAR analysis and confirmed its drop value and hence its reclassification.

LIDAR image of Lord's Seat (NT 912 079)

The criteria for the list that this reclassification applies to are:

The Fours – The 400m Hills of England.  English hills at or above 400m and below 500m in height that have 30m minimum drop, accompanying the main listing of The Fours are three categories of sub hills, with this hill being reclassified from the 390m Sub-Four category to the 390m Double Sub-Four category.  The criteria for 390m Sub-Four status being all English hills at or above 390m and below 400m in height that have 30m minimum drop and the criteria for 390m Double Sub-Four status being all English hills at or above 390m and below 400m in height that have 20m or more and below 30m of drop.  The list is co-authored by Myrddyn Phillips and Aled Williams and the 2nd edition of the booklet containing this list was published by Mapping Mountains Publications on the 24th April 2018.

The Fours - The 400m Hills of England by Myrddyn Phillips and Aled Williams

The name the hill is listed by is Lord’s Seat, and it is adjoined to The Cheviot group of hills, which are situated in the north-eastern part of England (Region 33 Scottish Border to the River Tyne), and it is positioned with a minor road to its south-east and farther afield has the A68 road to its south-west, the B6341 road to its south-east and the A697 road to its east, and has the town of Rothbury towards the east south-east.

When the 2^nd edition of the The Fours – The 400m Hills of England was published by Mapping Mountains Publications in April 2018, this hill was listed as a 390m Sub-Four with an estimated c 53m of drop, based on the 392m summit spot height and an estimated c 339m col height based on interpolation of 10m contouring between 330m – 340m that appear on the Ordnance Survey 1:50,000 Landranger and 1:25,000 Explorer map.

Extract from the Ordnance Survey 1:25,000 Explorer map

Approximately 1km to the south-west of the summit of Lord’s Seat is the triangulation pillar on the hill named Green Side.  The flush bracket adjoined to this trig pillar is given as 389.534m and positioned at NT 90299 07313 in the OS Trig Database, with its map height given as 389m.  As the map height of Green Side is lower than Lord’s Seat the former was unclassified with an estimated c 17m of drop and Lord’s Seat listed as the 390m Sub-Four.

However, it was not until LIDAR became available that the details for these two hills could be accurately re-assessed.  The LIDAR (Light Detection & Ranging) technique produced highly accurate height data that is now freely available for much of England and Wales.

LIDAR results for each summit:

Lord’s Seat:  392.2m at NT 91281 07968 and NT 91282 07966

Green Side:  395.5m at NT 90695 07602

As Green Side is higher than Lord’s Seat the respective cols are swapped and Green Side becomes the 390m Sub-Four.  However, the subsequent drop for Lord’s Seat is sufficient for it to be classified as a 390m Double Sub-Four.

LIDAR image of Lord's Seat and Green Side

Therefore, the reclassification of Lord’s Seat from 390m Sub-Four status is due to LIDAR analysis, resulting in a 392.2m summit height and a 370.9m col height, with these values giving this hill 21.3m of drop, which is insufficient for 390m Double Sub-Four status.

The full details for the hill are:

Group:  The Cheviot

Name:  Lord’s Seat

OS 1:50,000 map:  80

Summit Height:  392.2m (LIDAR)

Summit Grid Reference:  NT 91281 07968 and NT 91282 07966 (LIDAR)

Col Height:  370.9m (LIDAR)

Col Grid Reference:  NT 90985 07852 (LIDAR)

Drop:  21.3m (LIDAR)

For the additions, deletions and reclassifications to The Fours reported on Mapping Mountains since the December 2013 publication of the list by Europeaklist please consult the following Change Registers:

The Fours

The Fours – 400m Sub-Four

The Fours – 390m Sub-Four

The Fours – 390m Double Sub-Four

Our thanks to Joe Nuttall and Jim Bloomer for bringing the details of this hill to our attention.

Myrddyn Phillips and Aled Williams (July 2020)

Guest Contributor – Alan Dawson

Introduction

If readers would like to contribute an article for the Guest Contributor page heading please contact me, my email address appears on the About Me page heading.  The 0nly two things I ask is that the article should be hill related and importantly I should not end up in court through its publication!  Otherwise the choice of subject matter is down to the Guest Contributor.

About the Author; Alan Dawson

Alan has compiled some of the most important British hill lists, including the Marilyns, Grahams, Hewitts and Simms.  Many people consider him Britain's pre-eminent mountain surveyor and published hill list author.  With the Simms list he unified the 600m hills of Britain.  He is now busy working on his next publication.

How accurate was Munro?

by Alan Dawson

Hugh Munro's original list of hills has been described by eminent historian Robin Campbell as a "hurried stab in the dark".  The numerous subsequent revisions, extensively catalogued in Campbell's book The Munroist's Companion, support the impression that Munro's list was inaccurate and incomplete owing to the speed of his work and the inadequacy of Ordnance Survey maps available at the time.

The clarity and detail of OS maps have improved vastly in the past hundred years.  The accuracy of spot heights has not improved to the same extent, but current map heights are remarkably accurate considering that most of them have been obtained by taking photographs from a plane.  However, heights on OS maps are far surpassed in accuracy by heights obtained from surveying using GNSS (Global Navigation Satellite System).

In this article my aim is to use the scientific evidence now available to assess the accuracy and completeness of Munro's work.  My starting point for this analysis is the October 1921 issue of the Scottish Mountaineering Club Guide, pages 109 to 144.  The full title of this section is:

MUNRO'S TABLES
OF THE 3000-FEET MOUNTAINS OF SCOTLAND
(Revised by the Compiler, the late SIR HUGH T. MUNRO, BART., OF LINDERTIS,
and Re-arranged by Mr J. GALL INGLIS, F.R.S.E.)

This attribution makes it clear that it is Munro's work, so it is as close as we can get to his judgments.  In the introductory note, W. N. Ling wrote:

It is to be much regretted that Sir Hugh Munro did not live to carry through the press this revised edition of his Tables, for which he had been collecting material for many years.  As he always welcomed information on the subject, and had himself visited all the 3000-feet tops in Scotland except one or two, his knowledge of them was probably second to none.  Unfortunately, his revision was only partially completed at the time of his death, and no definite information has been found as to his views on many facts that had been brought to his notice.  In these circumstances, it has been thought desirable simply to reissue the Tables substantially as he left them, leaving the debatable questions of inserting additional tops, or of deleting old ones, to be settled when more complete information is available… The reclassifications of the new tops, cancelled tops, and separate mountains are all from Sir Hugh's card index, with only a few exceptions.

As Munro had 28 years available to work on his revisions, it is fair to assume he did not make them lightly.  In fact he removed only fifteen hills from his original list and added only twenty, taking the total from 538 to 543.  In order to assess Munro's work with clarity, I have cleared away the clutter by applying these rules:

–           The original 1891 list has been disregarded in favour of the 1921 list.

–           All updates to Munro's list since 1921 have been disregarded.

–           The distinction between tops and separate mountains has been disregarded.

–           Differences in hill names and spellings have been disregarded.

–           Heights are given in feet, as in 1921, with surveyed summit heights rounded to the nearest foot.

It is then simply a case of judging what Munro would have done if he had had more accurate information.

Summits under 3000 feet

Munro did not intend to include any hills under 3000 feet high.  Only five of the 543 hills are now known to be too low to qualify:

–           Am Bathaich near Kinloch Hourn, 2949 feet

–           Beinn an Lochain, south of Glen Kinglas, 2958 feet

–           Creag Dhubh, Beinn Eighe, 2976 feet

–           Faochag, south of Glen Shiel, 2982 feet

–           Glas Leathad Beag West Top, Ben Wyvis, 2986 feet

This leaves 538 hills, the same number as in the 1891 list.  Thanks to the initiative of The Munro Society, we now know that Beinn a' Chlaidheimh and Sgurr nan Ceannaichean are also under 3000 feet, but these were not listed by Munro and so can be excluded from this analysis.  We also know that Creag na Caillich, west of Meall nan Tarmachan, does not qualify.  It has been surveyed three times, twice by me in 2014 and once by GJ Surveys in 2015.  The result was 2999.7 feet on each occasion, so Munro was correct in omitting it.

Uncertain summit locations

We can assume that Munro would have listed the highest point of a hill if he had known exactly where it was.  The following hills had incorrect summit locations in 1921:

–           Carn Ballach, Monadhliath

–           Beinn a' Chaorainn, Glen Spean

–           Slioch, Loch Maree

Assessing these is not simply a question of changing a grid reference, because we also have to consider whether there should be one or more separate tops.  Slioch is the simplest case, for Munro listed it as only one summit.  Its location is now the northern top (3219 feet), which I have confirmed is higher than the base of the trig pillar.

In 1891 Munro listed two tops on Carn Ballach but in 1921 the wrong one was removed.  In line with the 1921 list, only one summit should be included but it is the SW one, now known to be 3018 feet.  In 2014 I surveyed six points on this inconspicuous hill and found five of them to be within two and a half feet of each other in height, so confusion was inevitable.

In 2019 I was finally able to settle the longstanding uncertainty about Beinn a' Chaorainn.  The central summit is the highest, at 3442 feet, but it is only two feet higher than the South Top, not ten feet higher as shown on current OS maps.  Munro listed both in 1891 but for 1921 he removed the one now known to be the highest point.  As the North Top has always been listed, Munro evidently judged that Beinn a' Chaorainn warranted only two summits, not three.  However, he probably would have retained the South Top for balance if he had known it was lower, because he liked to include summits near the end of ridges or plateaus, as on Ben Avon and elsewhere.  In the case of Beinn a' Chaorainn, the location of the highest point determined whether the hill merited two or three listed summits.

Another hill that has caused uncertainty is An Riabhachan, north of Loch Mullardoch.  Munro listed two tops but appeared to change the location of the highest one with a note in the 1921 list.  As I have not surveyed this hill, there is still uncertainty about its highest point, but we can assume that Munro intended to list the highest one, wherever it is.  Further north, beyond Loch Monar, lie Maoile Lunndaidh and Creag Toll a' Choin.  Munro listed both these summits but changed the highest point to Creag Toll a' Choin for the 1921 revision.  He was right again.

The only change to the number of hills from this analysis is the extra one on Beinn a' Chaorainn, taking the total to 539.  Other hills with variable summit locations include Beinn Eibhinn and Meall Garbh by Glen Lyon, but these have only had one point listed and so minor relocations do not affect the total of summits.

Summits over 3000 feet

To assess these summits it is necessary to incorporate the concept variously known as dip, drop, prominence, re-ascent and relative height.  All mean the same thing.  It is an important measurement for assessing the separation of one hill from another.  Only four of the hills omitted from the 1921 list can be regarded as separate mountains according to Munro's undefined but inferred criteria.  There are three obvious additions:

Beinn Teallach, Glen Spean, height 3001 feet, drop 998 feet

Beinn Tarsuinn, Fisherfield, height 3064 feet, drop 679 feet

Ruadh Stac Mor, Fisherfield, height 3014 feet, drop 557 feet

Munro could not have known these hills were over 3000 feet and would undoubtedly have included them.  The fourth omission is Mullach na Dheiragain, located SW of Loch Mullardoch.  Its current mapped height is 3222 feet, making it 26 feet higher than nearby Mullach an Sithidh and 49 feet higher than Carn na Corn Dhu, both of which were listed.  I have not surveyed any of these summits so we have to assume that current OS figures are reasonably accurate.  These height differences are fairly small, but Mullach na Dheiragain can be regarded as one of Munro's few errors, for he omitted a significant summit.  It is over two and a half miles from a higher peak and has a drop of about 470 feet, so it can be assumed that Munro would have regarded Mullach na Dheiragain as a separate mountain.

These four additions take the total back to 543 hills.  Next in line for assessment are summits that were not listed by Munro but are now known to have a drop of between 100 and 400 feet.  There are twelve of these:

Name	Area	Height	Drop
Sgurr nan Saighead	North Glen Shiel	3048	353
Toman Coinnich	Fannich Forest	3068	236
Stob Choire a' Mhail	Mamores	3248	217
Stob an Duine Ruaidh	Loch Etive	3012	217
Sgurr Dubh	Fisherfield	3003	160
Druim Shionnach West Top	South Glen Shiel	3077	138
Stob Coire na Cloiche	Sgurr nan Ceathramhnan	3002	128
Mullach nan Coirean East Top	Mamores	3007	127
Stuc Fraoch Choire	Sgurr nan Ceathramhnan	3012	118
Meall nan Tarmachan South Top	Tarmachan ridge	3024	106
Meall Buidhe East Top	Knoydart	3086	103
Carn na Caim South Top	Drumochter	3001	100

Most of these summits are not much over 3000 feet.  We cannot be certain about Stob Coire na Cloiche, Stuc Fraoch Choire and Stob an Duine Ruaidh because they have not been surveyed using GNSS.  Munro's omission of Stob Choire a' Mhail is puzzling because its height was probably known at the time.  Perhaps he disliked the somewhat exposed narrow ridge south of Sgurr a' Mhaim or perhaps it was a rare oversight.

Munro did not have accurate information about relative height so he could not have used it as a basis for selection even if he had wanted to.  However, we can draw conclusions from the revisions he made to his original list.  Carn Ballach and Beinn a' Chaorainn were removed on the basis of summit location, but the other thirteen were removed on the basis of subjective judgment.  All thirteen have less than 100 feet drop.  As he did not remove any summits with over 100 feet drop, it is reasonable to infer that he would have included the twelve summits shown above had he known their height.

What about summits with less than 100 feet drop?  Munro included lots of these, 118 of them, so it is worth reviewing those he left out to assess whether there are any he would have included if he had known their height.  Starting with the most prominent summits, there are only nine with 80-100 feet drop that were not included in Munro's 1921 list:

Name	Area	Height	Drop
Mullach Coire Mhic Fhearchair East Top	Fisherfield	3208	96
Blabheinn South Top	Skye	3040	92
Meall Dearg East Top	Glen Coe (Aonach Eagach)	3028	90
Beinn Bhrotain East Top	Cairngorms	3641	89
Glas Mheall Mor West Top	An Teallach	3011	87
Ceum na h-Aon-choise	Kintail	3034	86
Ben Oss North Top	Strath Fillan	3088	84
Ben More Assynt West Top	Assynt	3195	83
Luinne Bheinn East Top	Knoydart	3071	81

This is an interesting and varied set.  I have surveyed all of them so the figures are certainly accurate to the nearest foot.  If it were not for summit cairns, I could claim accuracy to within three inches.  The GNSS technology really is that good.

We know that maps of the Fisherfield area were inaccurate at the time, which is why Munro missed Beinn Tarsuinn and Ruadh Stac Mor.  There was no contour ring shown for Mullach Coire Mhic Fhearchair East Top, but Munro would probably have included it if he had known its height and drop.  Even now, heights on OS maps of Fisherfield are not very accurate.  Beinn Tarsuinn, Sgurr Dubh, Mullach Coire Mhic Fhearchair and its East Top are all at least nine feet lower than their mapped heights.  Perhaps OS is over-compensating for earlier errors.

Blabheinn South Top is an odd anomaly in Munro's work, because he included it in 1891 but removed it during his revisions.  There is no topographic reason for removing it, so it is tempting to speculate that Munro did not like the awkward ridge between the main summit of Blabheinn and its South Top.  Whatever the reason, the fact that he removed Blabheinn South Top shows we should be cautious about summits with a drop of 90 feet or less.  They have to have a strong case for inclusion on other grounds.  Two of the remaining seven do have such a case.

Beinn Bhrotain East Top stands out from the rest owing to its height, which gives it a strong case for inclusion.  However, if Munro knew about it, that makes its case for inclusion weak, because it suggests he considered it and rejected it.  The fact is, we don't know why he omitted it.

Munro is unlikely to have known the height of the other six hills.  The only one that I can confidently assert he would definitely have included is Ceum na h-Aon-choise.  Munro could not have known its height because no-one did until I surveyed it in 2017.  Current OS maps show it to be 891m, which is 2923 feet.  The map height is wrong by 111 feet, the greatest anomaly I have found anywhere.  I have informed OS of the correct height and expect their maps to be updated in due course.  I ought to have spotted the error sooner, because the 1:50000 map shows an 891m height within a 910m contour ring.  I had not noticed this and nor had anyone else.  The summit meets all the criteria known to be used by Munro.  It is almost two miles from its parent peak (Beinn Fhada), it is a distinctive and impressive-looking peak, it is at the end of a long undulating ridge and it is over 3000 feet high.  All boxes ticked, but the summit itself has not been ticked by many Munroists, unless they have approached Beinn Fhada via the steep direct climb from Glen Croe and over the equally rocky but lower summits of Faradh Nighean Fhearchair and Sgurr a' Choire Ghairbh.

West ridge of Beinn Fhada from slope above Morvich.  Ceum na h-Aon-choise is the highest point visible, to the right of the notch.  Photo: Alan Dawson

As usual, there are complications.  Munro did list a summit called Ceum na h-Aon-choise, but he was referring to the more rounded summit now known as Meall an Fhuarain Mhoir (3133 feet).  There is yet another peak in between the two, Ceum na h-Aon-choise South Top, which is 3025 feet with 68 feet drop. I have no idea what Munro would have made of that one if he had known its height.  Ronald Burn, the first person to climb all the hills in Munro's list, reckoned that Ceum na h-Aon-choise referred to a feature lower down the hill.  He may be right, but the map is clear about the name.  It translates rather charmingly as "step of the one foot".

Ceum na h-Aon-choise (right) from the path up to Bealach an Sgàirne.  Photo: Alan Dawson

Finally, there are those summits with less than 80 feet drop that Munro did not include.  There are hundreds of them, but the ones of most interest are those with 60-80 feet drop.  There are 38 of these and I have surveyed most of them.  The two that I find most notable are the pinnacles on An Teallach to the east of Bidean a' Ghlas Thuill.  One of these is 3421 feet (drop 74 feet) and the other is 3289 feet (drop 65 feet). These are striking summits, easier to climb than they look.  I do not know why they have been overlooked by Hugh Munro and all subsequent revisionists, considering that a nearby pointed peak south of Sgurr Fiona has similar credentials (3384 feet, drop 69 feet) and has always been a prized inclusion.

Seven of these 38 hills are currently classed as Munro Tops, for no apparent topographic or historical reason.  Two more have been added and then removed since 1921, and the other 29 have never been listed.  Munro would probably have included some of them if he had known their height, but there is no way of knowing so it seems best not to add any more.  In my opinion, any list that bears Munro's name should be as faithful to his work as possible, taking into account his judgments as well as survey findings.

Conclusions

The scientific evidence shows that Munro's list was remarkably comprehensive considering the maps and information available at the time.  His only significant omissions that could be regarded as errors are those of Mullach na Dheiragain and Stob Choire a' Mhail, while his removal of Blabheinn South Top is puzzling.

The amendments outlined above would bring Munro's work fully up to date with recent survey findings and current mapping, while remaining faithful to his judgments.  Removing the five hills under 3000 feet and adding five separate mountains over 3000 feet leaves his total at 543.  Adding the twelve summits with a drop of between 100 and 400 feet drop takes the total to 555.  Adding two more with a drop of over 80 feet – Mullach Coire Mhic Fhearchair East Top and Ceum na h-Aon-choise – takes the total to 557.  No further updating is needed, unless a survey shows one of the 557 to be under 3000 feet.  If Munro were around today I would argue the case for Blabheinn South Top, Beinn Bhrotain East Top and the pinnacles of Bidean a' Ghlas Thuill, and I would submit evidence about several of the tors on Ben Avon, but in view of his continued absence, I accept his final judgments on these summits.

It would be interesting to know how many people have climbed all 557 hills.  I am not one of them, as there are two or three in Munro's list that have so far eluded me – A' Chioch on Beinn a' Bhuird, the awkwardly located Creag a' Choire Aird East Top and possibly Stob Coire an Lochain, which I cannot be sure I visited on my way from Braeriach to Cairn Toul.  We know that Munro intended to climb all the hills in his list but had three remaining when he died.  If I do not quite manage the last couple then at least I will be in good company, and 555 would be a fine number to finish on.


Alan Dawson

Article originally published in The Munro Society Journal No. 5 2020