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Annual General Meeting.

A report of the 1950 Annual Genera1 Meeting will appear in the March BB.

Change of Address.

Members are asked to note that the Hon. Sec’s address has been changed.  Address all letters to Hon. Assist. Sec. if possible; failing this to T.H. Stanbury, c/o D.H. Hasell, 1, Stoke Hill Cottages, Chew  Stoke, Nr, Bristol.  The Telephone Number 77590 is now longer applicable.  This address is only temporary and any further change will be notified in the BB.

The Growth of Stalagmites and Stalactites. 

by R.M. Wallis.

Although stalagmites and stalactites are such a prominent feature in most caves, it is surprising how few cavers have any clear idea of how they are formed.  It is the intention of this article to remedy this as far as possible by setting out the processes involved in simple language.  No apology is offered for any wounded susceptibilities in the scientifically minded – they should have a good idea of the subject already and this account is not written for them.

It must be admitted at the outset that there is a fair amount of doubt about the actual processes involved, but current theories are described here and seem to deal with the matter satisfactorily.

All our caves of any importance are situated in Limestone, a rock which is composed almost entirely of Calcium carbonate.  In pure water, limestone, like all other rocks, is practically insoluble – it will dissolve to an extent of only one part in 30,000 of water.  However, water will dissolve carbon-dioxide, a gas which is exhaled in the breath and is produced in burning and so is found in the atmosphere.  It is therefore picked up by water which will then dissolve limestone much more easily, though still in small amounts -- about one part in 7,000.  (This is not strictly a true process of solution as a chemical reaction is involved, but it may be regarded as solution without affecting the argument).  This increase in the dissolving power of the water is an essential factor in the formation of dripstone.

Most people are aware that water dissolves the limestone, and jump to the conclusion that deposits are formed simply by the evaporation of water leaving the limestone behind.  A moment’s thought will shew that this can only very rarely be the only mechanism, and in fact is usually of negligible importance.  In most caves the air is very humid, as is shown by one's breath forming a mist.  The air already holds as much water vapour as it can.  This of course means that water vapour cannot evaporate, or at least only very, very slowly so that the water drops which are seen on the end of growing formations grow too big and drop off before they can deposit any of their load of limestone on the end of the stalactite.  It may be argued that if the water is saturated with limestone, any evaporation would cause a little addition to be made to the end of the formation and this would be generally true.  But is the water saturated?  It may be in some cases but unfortunately we have very little evidence on this point.

The presence of carbon dioxide in the water overcomes the difficulty of lack of evaporation.  Imagine that water laden with carbon-dioxide is trickling through tiny cracks in the limestone above a cave passage.  These cracks are completely filled with water so that the lower down in the rock we go, the higher is the pressure due to the head of water above.  Now there is a scientific law which states that the higher the pressure, the more gas will dissolve, so the solubility increases also.  But as soon as the excess pressure is removed the gas will come out of solution, as you can see happening when a beer bottle is opened.  Now the water cannot hold so much limestone, so this comes out of solution also, and without any evaporation having occurred.  The excess pressure will be released as soon as the drop appears on the roof of the cave as then the head of water is no longer acting upon it.

The limestone appears in the drop as minute particles evenly distributed through it.  These will tend to be drawn to the outside of the drop where it is touching the roof, so that a ring of particles will be formed on the roof.  The same will happen with the next drop and so on and so on, and in course of time a thin cylinder will appear – in other words, a straw stalactite will be formed.

It seems likely that all stalactites begin life as straws.  They grow by having successive layers built up on the outside and the central hole fills up, leaving only a very narrow tube down the centre.  If a cross-section is polished, the successive layers can be clearly seen by their slightly differing Colours due to the different amounts of impurities present.  What decides when a straw begins to thicken instead of continuing to lengthen, we do not know.  Some straws grow to great lengths, occasionally up to 10 or 12 feet, but these are likely to be broken before this (even if there are no cavers about) or the change comes upon them and they start to thicken.

Although the material of the formation s has been referred to as ‘limestone’ there is rather a difference between massive limestone rock and dripstone, although they are chemically similar.  Limestone has no particular structure, but dripstone is crystalline and is in fact calcite – the familiar ‘dog toothe’ Spar.  They may also accur as a different crystal structure, ‘Arragonite’ which is just another and rarer form.  Straws, even quite long ones, are often a single crystal.  Dripstone is usually purer than the original limestone as much of the impurity is not dissolved.  Small amounts do appear of colours from yellow to pinks and reds.  Manganese gives browns, and copper green.  Iron is widely distributed on Mendip as Ochre, and accounts for the prevailing rather dirty colour of the deposits.  Occasionally, however, they are very pure, and then show up a brilliant white – parts of Stoke Lane show outstanding pure dripstone.

So far as we have accounted for pendant stalactites.  We will go on to stalagmites, helictites, and other phenomena in another article.

 (Part 2 of this very interesting article will appear in next month's B.B. Ed.)

Climbing Section Reports.

New Year’s Weekend – Dec. 30/31st. 1950.
Climbing at Blaenant Farm.

Attending: -

J.V. Morris; J.R. Crabtree; R.W.G. Cantle; P. Ifold; R.H. Newman; Miss J. Treble.

Saturday 30th. Dec.  Weather: - Thick snow, cold and windy.

J.V. Morris, P. Ifold & R. Cantle set off for Llanberis to climb Castle Gully on Dinas Cromlech.  The snow was very thick at the P.Y.G. and it was quite an effort getting the car up to Pen-y-pass.  The car was left at the top of the pass and the party tramped off down the Llanberis Pass.  Crossing the scree we slogged up the snow slopes to the foot of the climb.  The Cave Pitch was climbed. R.W.G. Cantle leading, followed by P. Ifold and then J. Morris.  J. Morris led through a flake on the side of the chimney where a belay was found.  R. Cantle then led up to within 6 feet of the check stone with only 50ft. or so of the climb to complete.

Here the climb had to be turned, the going had been extremely hard, the leader having to dig his way up the chimney all the time.  Here the leader dropped his axe (on purpose).  The cold was terrific, and for the second week running, an honourable defeat.  A rapid abseil to the belay below.

A further abseil over the cave, and the climbers were off.  A rapid search for the axe, a rapid boulder hop, and a poor scree run saw us off the rock and on to the road.  It was by now snowing fiercely and it was with relief we arrived at Pen-y-pass to drive by car to Capel for a first class meal and a good night at the Royal Hotel.

Sunday December 31st.  1950

Weather still uncertain – snow, wet and slushy.

R. Crabtree, J. Morris, R Cantle climbed Wall Climb. R. Crabtree doing a very fine lead on the first pitch.  This climb is a V.D., and under these conditions was very fierce.  The rock was cold and wet and it was not advisable not linger on holds.  J. Morris led the Traverse and the climb was finished.  This climb is short but very strenuous.  We then traversed on to the Milestone Ordinary Route and finished that.  We climbed off the N.W. Face down a badly iced gully and this was only done by roping down.  Altogether a good day’s climbing and a weekend well spent.

R.W.G.C. 4/1/51

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John Ifold is now Club Librarian.  He was elected at the A.G.M. to replace Angus Innes now in the forces.  Thanks are due to Hal Perry, who, as acting Librarian has been looking after the library since Angus’ call-up.

There are a number of books that are outstanding.  Members having any such books in their possession are asked to return them as soon as possible, either to Club on Thursday evening or direct to John Ifold at Leigh House, Nempnet, Chew Stoke, Nr. Bristol. (Telephone Blagdon 432).

Johnny has asked that any member who is willing to loan or give books to the Club Library to either bring books to Thursday meeting or to contact him at the above address.

A new Library list is in the process of being made and a copy will be circulated to every member as soon as it is ready.

Archaeological Section

Bulletin No.3.  Belfry Site.

Since the last report no further news has been received by me regarding the Belfry Site, except that a new Map Tracing has been received from Geoff Ridyard, to replace the one that was mislaid.  As soon as I get the date for the starting of the Trial Trench, I will inform you.

K.S. Hawkins,
Archaeo. Corres. Sec.

London Section Dinner.

On Saturday 3rd, March 1951 the London Section are holding a Dinner.  The cost not more than 10/- each.  All members are invited to this Dinner the first to be held by the section.  Further details will be circulated to those interested as soon as available.  Will all persons who contemplate attending please let Johnny Shorthose know as soon as possible so accommodation etc. can be arranged.  (His address will be found at the end of this bulletin).

Account of a visit to Derelict Lead Mine in Swaledale, nr. Richmond, Yorks. 

by Jack Whaddon.

The Moors to the S.W. of Richmond, Yorks, have been mined extensively for both lead and coal in the years gone by.

So, on the afternoon of 25th. Nov, 1950, myself and another member of Catterick Rover Crew hiked along a rough track on the S. bank of the Swale.

This track was made of slabs of limestone laid end to end, stretching from the ruins of an old smelting works below Richmond Castle to one of the old lead mines upstream, which was our objective.

Two adits lead into the mine.  We entered by the lower one, which is about three feet above the river level, and was probably used to drain the workings.  It had been raining heavily during the previous week, and quite a stream of water was flowing out of the mine.

The mine itself consisted of several parallel passages which were at right angles to the mineral lodes.  Many of the tunnels contained up to two feet of water, whilst others came to a sudden end where the roof had collapsed.  Stalagmite coated the walls of many of the tunnels, and at one place (at the bottom of a shaft) several roots and twigs were ‘petrified’ by a coating of stalagmite.

There was fair amount of malachite (green carbonate of copper) in the lodes, and some of this had been dissolved by the water, tinting the stalagmite flow green.

It was dark when we emerged from the mine, so we headed up to the moors, where, after spending an evening holding up the bar of the local inn in the usual manner, we slept out in spite of the weather, which was extremely cold, even for Yorkshire.

“Pome”

by Holler.

  Stalactites – I think – grow up, not down,
Or have I got it the wrong way round?
  To avoid confusing appellations
I’ll refer to them merely as formations.

  And sandstone, limestone, O.R.S.,
Get me in a hell of a mess.
  And so – in case thee experts mock,
I’ll drop all names and talk of rock.

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T.H. Stanbury,                 c/o Stoke Hill Cottages, Chew Stoke, Nr. Bristol.
Miss D.S. Bowden-Lyle,   31, Highworth Road, St. Annes Park, Bristol. 4.
W.J. Shorthose,              Hon. Sec. London Section B.E.C. 26, Gateside Road, Upper Tooting, S.W. 17.
R. Cantle,                       Leader Climbing Section, 46, Cherrington Road, Henleaze, Bristol.
K.S. Hawkins,                 Sec. Archaeological Section, 9, Quarrington Road, Horfield, Bristol. 7.
J. Ifold,                            Hon. Librarian, Leigh House, Nempnett, Chew Stoke Nr. Bristol.

List of Publication’s available in the Library of the Bristol Exploration Club.

The address of the librarian is appended at the bottom of the back page of every Belfry Bulletin.

CAVING.

The British Caver. Vols,12; 13; 14; 15; 16; 18; 20; 21;
Cave Science (B.S.A.) Nos. 3; 4; 5 ; 6; 11; 12; 15; 14;
Transactions of the Cave Research Group. Vol.l.No3. ;Vol.l.No.4.
Caves and Caving (B.S.A.) Vol.l. Nos.1; 3; 4; 5;
C.R.G. Newslettes 1948, Nos 12 /20; 1949,Nos 21/26; 1950, No 27.
Belfry Bulletin (B.E.C.) Nos.5; 6; 7; 8; 10; 11; 12; 13;
Cave Surveying (C.R.C.)
Derbyshire Lead Mining Glossary (C. R.G.).
Cavern Guide
U.B.S.S. Proceedings Vol. 5, No.1; Vol. 5, No. 2.
My Caves                                        N. Casteret.
Ten Years Under the Earth                N. Casteret.
Au Fond des Gouffres,                      N. Casteret.
Dan-yr-Ogof Official Guide.
Pennine Underground,                      Thornber.
Caves and Caverns of Peakland.
The Falls and Caves of Ingleton,        J.L. Hamer.
The Story of Wookey Hole                Thornycroft.
Mendip Caves and Rock Shelters.     H.E. Balch.
Journal of the Craven Pothole Club Vol.1, Nos 1; 2;

CLIMBING AND MOUNTAINEERING.

Climbing Mount Everest                    G. Ingle Finch.
Climbing in                             J.E. Barford.
The Welsh Three Thousands             T. Fairbank
Snow on the Equator                        H.W. Tilman.
Mountains of the Moon                     Synge
The Ascent of Nanna Devi                 Tilman.
Epic of Mount Everest                       Sir F. Younghusband.
Rockclimbing and Mountaineering      C. Brunning

GEOLOGY

History of the Devonshire Scenery     Clayden
Bristol and Gloucester District Geological Survey
Geology in the Service of Man
Principles of Geology Vols 1 & 2       Lyell
Water Pollution Research 1933/45 & 1946.

(to be continued,)