Introduction
I
have approached a number of people to write articles, but if readers would like
to contribute an article please contact me. The only two stipulations I make
are that the article has to be hill related and that I don't end up in court
through its publication! Otherwise the choice of subject matter is down to the
Guest Contributor.
Guest Contributor – Robin N
Campbell
 |
Robin Campbell, a few years ago, with two good friends
|
Originally published in The Munro Society Journal No 2 2010
(Photos: copyright SMC image collection)
Corbett’s Criterion
Robin N Campbell
John Rooke Corbett died in 1949 after
years of illness dating back to 1943, when he had suffered a heart attack. His
sister Catherine subsequently passed over a list of Scottish hills 2,500 ft.
and under 3,000 ft. in height to the Scottish Mountaineering Club, and of
course it is these hills that have come to be known as the Corbetts. The list
contained no information about the criteria for inclusion, beyond the obvious
one specified by the title. Indeed John Dow, in his introduction of the first
publication of Corbett’s list, seemed somewhat baffled. He described the list
as ‘incomplete’ and commented that ‘numerous heights of equal merit to those
listed have not been shown’. He argued, however, for publication in this
incomplete form ‘as a memorial to a personality genuine and likeable, rather
than as an authoritative document’. ‘Perhaps,’ he added, ‘at some later date,
we may see a revised Edition, comprehensive of every 2,500-foot summit.’ So Dow
was unable to understand at that time why some 2,500 hills had been included
while others were left out.
 |
| Corbett, on right, on the summit of Cona Mheall, 1938 |
However, when Corbett’s list was
published as part of Munro’s Tables, Dow wrote, ‘There was no indication in
Corbett’s papers as to the criterion he adopted in listing the heights
included, but it seems clear that his only test was a re-ascent of 500 feet on
all sides to every point admitted, no account being taken of distance or
difficulty. No detailed check has been made, but the 500 feet qualification has
obviously been exhaustively applied and rigidly adhered to’. Dow’s inferred
criterion ‘with a re-ascent of 500 feet on all sides’ was then, and henceforth,
added to the list’s title.
‘Seems clear’, and ‘no detailed check was
made’ are phrases that are apt to excite the scholar, so there is some room
here to wonder whether Dow’s inference was the correct one. Certainly the
current list of Corbetts results from the exhaustive and rigid application of
the 500-foot rule, but there have been many changes in the list of Corbetts
since 1952. Had the SMC perhaps changed Corbetts’s criterion as well as his
List? I believe that it did.
Short of a detailed examination of every
2,500 hill on and off Corbett’s list, there are quicker methods of putting the
500-foot rule to the test. Six hills were removed from the list in 1981 and two
more in 1984 on the grounds of inadequate drop. These are shown in Table 1
below.
Name
|
Location
|
GridRef
|
D&H
|
Year
|
Map
|
Cont.
|
Ht.
|
Drop
|
Beinn a’ Chumhain
|
S. of Ben Alder
|
NN462710
|
4B
|
1981
|
48
|
10
|
2958
|
482
|
Sgor Mor
|
NE. of An Socach, Glen Clunie
|
NO115825
|
6B
|
1981
|
49
|
11
|
2908
|
|
Meall Uaine
|
S. of Spital of Glenshee
|
|
6B
|
1981
|
49
|
10
|
2600
|
476
|
Carn Easgann Bana
|
E. of Fort Augustus
|
NH485063
|
9B
|
1981
|
42
|
10
|
2554
|
463
|
Druim Garbh
|
W. of Sgurr Domhnuill
|
NM881683
|
18B
|
1981
|
47
|
10
|
2637
|
466
|
Beinn an Tuim
|
N. of Glenfinnan
|
NM929835
|
10D
|
1981
|
47
|
10
|
2656
|
472
|
Kirriereoch Hill
|
N. of Merrick
|
NX420870
|
27B
|
1984
|
83, 87
|
10
|
2565
|
|
Cramallt Craig
|
S. of Broad Law
|
NT168247
|
28B
|
1984
|
80
|
11
|
2723
|
|
|
|
|
|
|
|
|
|
|
|
Table 1. Corbetts removed since 1952 because of drop < 500 ft. Final column shows drop
[= re-ascent] computed from Six-inch spot heights where these are available.
‘D&H’ gives hill sections in Corbett
Tops and Corbetteers. Alan Dawson & Dave Hewitt. TACit Press, 1999. ‘Year’
refers to the edition of Munro’s Tables
in which the hill was removed. ‘Map’ is the Popular One-Inch sheet. ‘Cont.’ is
the number of contour lines crossed from defining col to summit on the
identified map, and ‘Ht.’ is the height given on that map.
It
is obviously important, here and elsewhere in this article, to consider only
map data which was available to Corbett. I have used the ‘zoomable’ digital map
of Scotland accessible through the National Library website. Very conveniently,
the zoom passes through the ‘Popular’ One-Inch Survey to the Six-Inch, and
these are the same maps available to Corbett. I presume that I have to thank
Ordnance Survey copyright restrictions for this splendid historian’s tool, as
well as the National Library.
What
is immediately noticeable is that for six of these hills only ten contour lines
intervene between col and summit. Ten contour lines enclose only 450 feet. If
Corbett intended to include only hills with a 500-foot drop, then further data
was needed for such hills, especially since five of them had ‘surpluses’ over
the top contour of only a few feet. In fact, such data was available to him
from the Six-Inch maps in five cases, and this data shows (final column of
Table 1) that each of the five had drops comfortably below 500 feet. Even without the Six-Inch data,
contour-interpolated col estimates may be taken from the One-Inch map. Since
this adds only 25 feet to the summit surplus, we can see that we still have
five hills with estimated drops comfortably below
500 feet. So these hills were removed by SMC not because of revised O.S.
measurements, but because they didn’t meet the criterion of 500 feet of drop,
which Dow and perhaps Jim Donaldson had ‘deduced’ on Corbett’s behalf.
If Corbett consulted the Six-Inch maps,
or made use of col estimates from One-Inch contours, then we may safely
conclude that the SMC wise men were in error, and that Corbett intended as
criterion ‘drop > 450 feet’. If Corbett didn’t consult the Six-Inch maps or
use estimated col heights, then he was obviously content to include any hill
with 10 intervening contour lines. In either case, regardless of what Corbett
may or may not have had in mind, the criterion that defined his list of hills
in its original form was ‘drop > 450 feet’.
 |
| SMC New Year meet 1932, Newtonmore. Corbett 2nd from right. Front row from the left: Archie Robertson, James Gall Inglis, John Dow |
Cook’s Cairn (Glenfiddich) was removed in
1981 on the grounds of inadequate height. Corbett’s One-Inch map indicated a
summit at 2541ft. However, this was based on a mistranscription of a Six-Inch
spot height of 2341ft, situated 200m. SSW of the actual summit of 2478ft. So,
we have some evidence that Corbett didn’t look systematically at Six-Inch data.
However, before considering the question of whether Corbett consulted any data
other than the count of contours, it is essential to settle a more basic
question. We need to know (a) whether he included all hills with 10 or more intervening contours, and (b) whether he
left out all hills with less than 10
intervening contours. As to (a), if that was his criterion, then clearly they
should all be included. As to (b) if he included any hills with just 9, then
‘10 intervening contours’ was obviously not his criterion.
To see whether he included all hills with
10 intervening contours it is necessary to examine
those hills with substantial drops which were not included either by Corbett or
by succeeding editors of his List. Dawson & Hewitt’s excellent booklet
(page 27) provides a list of suitable candidates in descending order of drop. I
have examined the 27 hills in their list with drops in excess of 134m.
(440ft.). None have drops with more than 9 intervening contours.
The
second of these 27 hills, Marg na Craige (Laggan), deserves comment. The Marg
is of course interesting in every way: any sensible classification system would
grant it independent status, since it is the summit (2731ft.) of an extensive
range. But there's a puzzle about the Popular map markings. There's a spot
height of 2255ft. at the col, giving a drop of 476ft. But the contour lines
imply that the col is between 2300 and 2350 feet, hence there are only 8
intervening contours. The Marg's surplus over the last contour is 31, leaving a
drop of 445ft. to find to the spot height, which is just short of 10 contours.
So even if we take the 2255ft. spot height as definitive data, it's still a 9
contour hill.
To see whether Corbett excluded all hills
with less than 10 intervening contours, it is first of all necessary to examine
those hills in his List with low drops. Leaving aside the hills of Table 1,
which are already established as having 10 or more contours of drop, it is not
too difficult to examine relevant others, since surprisingly few Corbetts have
drops in the vicinity of 500 feet. I looked at Cam Chreag (Lyon), Meallan nan
Uan (Strathconon), Geal Charn (Lochy), Carn Ealasaid (Cock Road) and Morrone
(Braemar): all have at least 10 intervening contours. Secondly, there are a few
hills added since 1952 for various reasons. Table 2 below shows those hills
added to Corbett’s List by SMC since 1952, on account of having a drop > 500
feet. Since Corbett didn’t include these hills, none should have 10 or more
contours of drop.
Name
|
Location
|
GridRef
|
D&H
|
Year
|
Map
|
Cont.
|
Ht.
|
Drop
|
Beinn
Each
|
S.
of Stuc a’ Chroin
|
NN602158
|
1A
|
1984
|
62
|
9
|
2660
|
|
Sron
a' Choire Chnapanich
|
W.
of Stuchd an Lochain
|
NN456453
|
2A
|
1984
|
55
|
4
|
2250c.
|
|
Meall
na Meoig (Beinn Pharlagain)
|
S.
of Sgor Gaibhre
|
NN448642
|
4B
|
1981
|
48
|
9
|
2836
|
|
Cam
Chreag
|
W.
of Creag Mhor, Glen Lochay
|
NN375346
|
2B
|
1981
|
55
|
9
|
2887
|
485
|
The
Sow of Atholl
|
W.
of Drumochter
|
NN624741
|
5A
|
1981
|
48
|
7
|
2500c.
|
|
Sgurr
Cos na Breachd-Laoigh
|
N.
of Upper Glendessary
|
NM948946
|
10B
|
1981
|
41
|
8
|
2600c.
|
|
Sgurr
Gaorsaic
|
W.
of Sgurr nan Ceathramhnan
|
NH036219
|
11A
|
1981
|
36
|
8
|
2600c.
|
|
Sail
Ghorm
|
W.
peak of Quinag
|
NC198304
|
16E
|
1981
|
15
|
6
|
2551
|
|
Table 2. Corbetts added
since 1952 because drop > 500 feet. For column headings, see Table 1
Clearly
no hill in Table 2 had more than 9 intervening contours in 1952, so if
Corbett’s rule was ’10 intervening contours’, he should have left these hills
out, and he did. On the other hand if his rule was ‘drop > 450’ and he had
consulted other data, then he would have included Meall na Meoig
(contour-interpolated col estimate of 2375ft.) and Cam Chreag (Six-Inch col
spot of 2402ft.; or contour-interpolated col estimate of 2425ft.), and he
didn’t. Sron a’ Choire Chnapanich deserves a mention as being possibly the
worst-mapped Scottish mountain. Its summit is almost 500 feet higher than the
1952 height.
I
believe that all relevant hills have now been considered and it can be stated
with confidence that Corbett’s criterion for inclusion in his List was, besides
the height criterion, a drop criterion of at least 10 contour lines intervening
between col and summit. That is, his List was a list of Scottish 2,500 foot
hills with a re-ascent of 450 feet on all sides. There is no evidence that he
consulted other available map data, and considerable indirect evidence that he
didn’t look at Six-Inch maps or use contour-interpreted col heights. Had he
done so, his List would have been a different one, regardless of whether he had
a criterion of 450 or 500 feet of drop in mind, since either there would have
been some 9-contour hills that met the 450 foot drop criterion, and were
therefore included, or there would have been some10-contour hills that failed
to meet the 500 foot drop criterion, and were therefore left out. It is
surprising that he ignored such data: he was a mathematician and land tax
assessor and thoroughly familiar with the use of such data by Munro and others.
Perhaps he had intended to, but failing health prevented it.
As
a consequence of the observations in this article, and if it is desired to keep
faith with Corbett’s intentions, the List of Corbetts should be revised to
include the 21 new and reinstated hills with current drops between 500 feet
(152.4m.) and 450 feet (137.2m.). These are the first 21 hills in the list on
page 27 of Dawson & Hewitt’s booklet.
Finally,
although I will not dwell on it here, I should state that it is my belief that
the identification of hills as outstanding in some way should always be made by
considering some function of distance and drop, as was done by Hugh Munro,
Percy Donald, William Docharty and Fiona Graham, and not by drop alone – as has
been done by Corbett and Alan Dawson, and by various tabulators of English and
Welsh hills. The use of drop alone has led to absurdities such as the vast
range south of Glen Lochsie and west of Glenshee – outstanding in every sense –
being treated as a mere appendage of Glas Tulaichean, and to the fine
outstanding mountains of Quinag and Sgurr Dhomhnuill being split into numerous
hills, each with tiny ‘footprints’. The method of Munro is required, and should
be insisted upon by all students of mountain form.
Originally published in the SMC Journal (Photos: copyright
SMC image collection)
The following article first appeared in the
Scottish Mountaineering Club
Journal (SMCJ, 202/41, 341–2) Copyright © 2011,
and is reproduced here
with permission.
Robin N Campbell
Since its appearance in Munro’s Tables in
1953, Corbett’s ‘List of Scottish Hills 2,500 and under 3,000 feet in Height’
has been announced as selected by the criterion that each listed hill has a
drop of 500 feet on all sides. However, this criterion was never stated by
Corbett.
Instead, the editors John Dow and Jim Donaldson deduced that this was Corbett’s
criterion, which ‘has obviously been exhaustively applied and rigidly adhered
to’, said Dow. I believe that this deduction was incorrect.
The
‘zoomable’ digital map of Scotland accessible through the National Library
website provides a convenient means of examining the hills included by Corbett,
and those left out, in relation to the map data available at the time. The zoom
passes through the ‘Popular’ One-Inch Survey to the Six-Inch Survey, and these
are the same maps that were available to Corbett. I presume that I have to
thank Ordnance Survey copyright restrictions, as well as the National Library,
for access to this useful historical tool.
An examination of the hills included in
the 1952 List in relation to the Popular Map shows that all of them had at
least 10 contour lines intervening between the drop-determining col and the
summit. An examination of those hills excluded from the 1952 List shows that
all of these had 9 or fewer contour lines between col and summit. Corbett’s
drop criterion was therefore ‘at least 10 contour lines intervening between
drop-determining col and summit’, and it is this criterion which was
‘exhaustively applied and rigidly adhered to’. The Popular Map plotted contour
lines at 50-foot intervals, and so 10 contour lines enclose 450 feet.
Effectively, then, Corbett’s drop criterion was ‘450 feet or more’.
 |
| SMC Easter Meet 1931, Tomdoun. Corbett centre in big hat |
Naturally, the application of this
criterion will result in the inclusion of some hills with between 450ft. and
500ft. of drop. Five 10-contour hills were removed from the List in 1981 and a
sixth in 1984, because they failed to meet the drop criterion of 500 feet. But
these deficiencies of drop did not
result from any relevant change in the mapping of these hills. Data was
available in 1952 (though it is unlikely that Corbett consulted it) to
associate these 6 hills with drops between 450ft. and 500ft. Dow and Donaldson,
had they noticed this in 1952, would have concluded that Corbett’s drop
criterion was 450 feet, rather than 500 feet. If Corbett had consulted Six-Inch
col heights, and/or contour-interpolated One-Inch col estimates, his list would
have been a different one, whatever height-specific drop criterion he had in
mind, if any. In fact, there is no evidence that he looked at any data except
the summit heights and the contour markings of the Popular Map.
If Corbett had consulted Six-Inch col
heights, and/or contour-interpolated One-Inch col estimates, his list would
have been a different one, whatever height-specific drop criterion he had in
mind, if any. In fact, there is no evidence that he looked at any data except
the summit heights and the contour markings of the Popular Map.
As
a consequence of these observations, and if it is desired to keep faith with
Corbett’s intentions, the List of Corbetts should be revised to include 21 new
or reinstated hills with current drops between 500 feet (152.4m.) and 450 feet
(137.2m.). These are the first 21 hills in the list on page 27 of Alan Dawson
& Dave Hewitt’s booklet Corbett Tops
and Corbetteers (TACit Press, 1999). A slightly different possibility, less
precise but perhaps more in keeping with Corbett’s actual criterion, would be
to add those Corbett Tops which exhibit at least 15 contour lines intervening
between drop-defining col and summit on current maps. Since 15 ten-metre lines
enclose 459ft., this is effectively a slightly more severe criterion than
Corbett’s. Its application would add only 19 new or reinstated Corbetts.
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