Belfry Bulletin Number 172

B

No 172 June 1962

Monthly Journal Of The Bristol Exploration Club

B Vol. XVI No. 6

Keeping a balance.

Every now and then, we get a little worried about the contents of the B.B. Sometimes it is because nobody seems to be writing any articles of a serious nature: at other times it may be because there has been no climbing or archaeological news for some time, and so on.

The B.B. should, ideally, have something in it to interest every club member. Obviously, this cannot occur in every issue as there is not enough space for a diversity of articles, even if the Editor had a supply of them to use - which he certainly hasn't!

However, if such a supply of articles was possessed by the editor, some attempt would be made to avoid a preponderance of any one type, unless a definite preference was expressed by a sufficient number of readers.

All of which is leading up to the fact that a lot more articles of a scientific nature type are on the way.

This, we think, will please most members. Others, whose tastes do not run in his direction, are invited to rectify the situation by sending in other types of article. If this occurs, we may even reach a stage of being able to select the best of what is submitted for publication.

“Alfie“ _______________________________________________________________________________________ If you haven't paid your sub this year, and have been sent this B.B., it is only because your name has not yet been removed from the list. DON' T LET THIS HAPPEN TO YOU!!!! _______________________________________________________________________________________ BOOK REVIEW By Jim Giles, Shepton Mallet Caving Club Journal Series 1 Number 3 In this third journal of the present series, the Rhodamine ‘B’ water tracing technique devised by members of the Bradford Pothole Club is discussed by B.M. Ellis. He explains the intricacies of using this revolutionary spelaeo - aid and describes at length the results of experiments in St, Cuthbert's Swallet and Swildons Hole. The author makes an interesting comparison between this and other water tracing methods and concludes with an outline of further applications on Mendip. _______________________________________________________________________________________ Archaeological Note As most members will be aware, the field north of the Belfry is the site of a Roman settlement, presumably connected with lead mining. Excavations were carried out there some years ago under the direction of Ted Mason and work is now in progress on the preparation of a report which will be published as a B.E.C. paper. Much pottery has been recovered from this field since the excavation from ploughed soil and from the drainage trenches which from time to time are cut across the lower slopes. If any member gets a chance to check the field again, and finds any pottery or other small find, I would be interested to see it.

Keith S. Gardner - Archaeological Secretary

Page 2

June 1962

LUMINESCENCE

by M. Luckwill A recent article in the B.B. No. 170, noted the fact that the stal in Balch's Hole was phosphorescent. This article is intended to provide a simple explanation of the physics of the phenomenon in order that the reader will be familiar with the terms used in future articles which will doubtless appear.

For those who have never seen phosphorescence, a short description of what happens will not be out of place. A flash bulb is fired close to the stal and when the light from the bulb has died down, the stal can be seen to glow a bright apple green for a few seconds. Several people are investigating substances which show this phenomenon, using ultra violet light as a means of illumination. The process of light emission during and after illumination is known as Luminescence.

For practical considerations, Luminescence is divided into fluorescence and phosphorescence. Figure 1 shows the amount of light emitted in relation to time......

Figure 1.

The portion AB represents light emitted during the illumination and together with any light emitted for 10 seconds after illumination is called fluorescence. The portion BC is the light emitted after illumination and is called phosphorescence.

Phosphorescence may last only for a period of 10-7 seconds, or for several hours. We are mostly interested in periods of from 1 to 5 seconds.

There are three aspects of luminescence: (1) Absorption of energy of primary bombarding photons - due to the incident light.

(2) Transfer and storage of this energy.

(3) Conversion of this stored energy into light.

A crystal consists of a regular array of ions. (You can imagine a large box filled with billiard balls which have been packed in a regular and tidy fashion). In the case of calcite; these balls represent calcium and carbonate ions.

Naturally occurring crystals are rarely pure, however, and an impurity will cause a local disturbance in the array (you can imagine this time a larger ball such as a tennis ball in the middle of your box of billiard balls). Such an ion is called an interstitial ion and plays an important part in luminescence.

Now let us look a little further into the structure of these ions. For our purposes, the ion can be considered to be a nucleus surrounded by a number of mobile electrons. If an electron gains some energy, it will tend to move away from the nucleus and become less stable. In general, if an electron gets the chance, it likes to lose energy and become more stable. The electrons, however, cannot be at any distance they like from the nucleus, but must go round it at one of a number of fixed radii which thus divide the electrons into a number of shells representing different energy levels. We shall consider two of these outer shells or bands

Number 172

Page 3

which are‌.

(1) The Valency band, which is the highest normally filled band, and...

(2) The conduction band, which is the lowest normally empty band.

The difference in energy between these two bands is called the gap energy and is written Eg. Now, if a photon with energy hv, being greater than Eg is incident upon the valency band, it can transfer its energy to an electron, which can then jump into the conduction band, leaving behind a hole in the valency band, as in figure 2.

Figure 2.

Remembering that an electron likes to be stable, we should not be surprised to find that the hole rises to the top of the valency band, as it is displaced by electrons above it - rather like an air bubble rising to the top of your beer (not if you drink draught: -Ed). The electron-hole pair is called an Exciton. The exciton cannot conduct energy, but it can transfer energy because it is mobile. This excitation is therefore different from the excited state of an impurity ion which is fixed.

Figure, 3 shows the life of an exciton as it wanders about the crystal‌‌.

Figure 3.

Now and again the electron will fall into a trap. This is an interstitial ion which, you will remember, has produced a local disturbance in the energy levels present. Then, by chance, the electron will gain enough energy to jump back into the conduction band and continue its wandering. Eventually, it will be trapped in the excited state of an interstitial ion, which acts as an activator, or luminescent centre.

Recombination now takes place. The electron is first trapped and then the hole is trapped (an electron from the impurity fills up the hole) and the interstitial ion regains its ground state. In the process, a photon is emitted.

The nature of the impurity affects the time for which the exciton remains trapped and also the colour of the emitted light, which is always of a greater wavelength than the incident light. It is known that Strontiamite, SrCO3; Magnesite; MgCO3; Dolomite CaMg(CO3) and some forms of calcite luminesce under ultra violet light. Further work may discover the impurities which produce this phenomenon and hence throw some light on the formation of these crystals.

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June 1962

CAVING LOG 1962 13.1.62. Swildons.

14.1.62. Eastwater.

14.1.62. Eastwater.

15.1.62. Eastwater.

3.2.62. Eastwater.

3.2.63. Swildons.

3.2.62. Cuthbert’s.

3.2.62. Cuthbert’s.

4.2.62. Cuthbert’s 4.2.62. Balch’s Hole.

10.2.62. Cuthbert’s.

11.2.62. Balch’s Hole.

11.2.63. Cuthbert’s 11.2.62. Cuthbert’s.

17.2.62. Cuthbert’s 17.2.62. Cuthbert’s 18.2.62. Lamb Leer.

18.2.62. Balch’s Hole.

24.2.62. Heale Slocker.

25.2.62. Cuthbert’s

25.2.62. G.B.

25.2.62. Heale Slocker.

3.3.62. Cuthbert’s 3.3.62. Swildons.

4.3.62. Cuthbert’s 4.3.62. Cuthbert’s 4.3.62. Cuthbert’s

Mike Luckwill + 3 from Cardiff. Long Dry to sump.

Mike Luckwill, G.Dell, J. Cornwell + 3 from Cardiff. Camera descended second vertical under its own initiative.

Mike Palmer, Mike Weadon. Followed 'clothes line' all the way. Fings definitely ain't wot they used t'be!

M. Luckwill, J. Giles. Trip to retrieve camera.

Dell and J. Cornwill.

Mike Boone, Ron Wyncoll.

P.M. Giles + 11 Cambridge Spelaeos. Tourist.

Mo Marriott, John Eatough and John Attwood. 11 Derbyshire types. Tourist trip.

Mikes Wheadon and Palmer, Albert and. 4 Exeter University bods. Tourist trip, attention Mr. M. Baker. There is water in Lake Chamber!

B. Prewer, P.M. Giles, M. Baker, G. Pointing, D. Berry, M. Boone, G. Selby and several M.N.R.C., and Cerberus types. Photographic.

Bryan Ellis and Chris Falshaw + 9 from Nottingham. Tourist trip.

Mike Baker, Alfie Collins and Jill. Photography in Maypole and Pool Passages.

Mem. Collins must take alternative means of illumination. Survey trip in Cerberus Series, closed traverse almost completed. Damaged tripod stopped further surveying. Keith Franklyn, J. Eatough, N. Petty and Mo. John Attwood and Eatough started to take the latter's maypole down, but two lengths were, too long. Photographic trip instead. Taped the drip pockets in Curtain Chamber.

P.M. Giles, Mike Holland, L. Holland and 5 Swansea types. Transported two lengths of maypole from Upper Traverse to September Chamber. Same party toured Cerberus Series and found Lake Chamber very full (Mike Baker please note).

J.M. Calvert, J.Ransome, G. Tilley, G. Owen, R. Roberts, A. Leysham, C. Peters, H. Rowley.

B. Prewer, P.M. Giles, G. Pointing, D. Berry, J. Eastough, J. Cornwill. Maypole removed and replaced by chain and fixed ladder.

Coffee and occasional digging, very nearly in: M. Baker, M. Luckwill, P.M. Giles.

P.M. Giles, M. Luckwill, R. Pyke, P. Badcock. 24' of maypole transported to Upper Traverse Chamber and left at top of the pitch for use in Hanging Chamber.

This was followed up by a quick trip into September Series where a small hole at the lower end of the bedding plane which runs down the side of September Chamber was entered and found to join up via a large and rather well decorated fifth with the main chamber again at floor level.

Photographic trip to Gorge and Helictite Chamber by J. Attwood, J. Eatough, H. Phillpot, J. Cornwill. Noted with DISGUST the considerable deterioration in Helictite Chamber.

M. Baker, M. Luckwill, P.M. Giles, P. Scott, J. Hill. We are in! About thirty feet of passage ending in a choke, the floor of which is composed of large boulders and mud infill. Passage appears to be going steadily down the dip.

Bryan Ellis took a party of M.C.G. on a "Grand Traverse" down Pulpit Pitch and Main Stream to duck, out via Cerberus Series and Wire Rift.

Mike Luckwill, Bob Pyke. Surveying extension past Keith's Chamber.

Mike Baker, Bruce and 4 Redland Tourist trip which included LAKE CHAMBER (I have seen and I believe!) M. Baker.

N. Petty, B. Wilson, J. Williams, M. Rogers, S. Godwin, B. Hargill, B. Parrell.

Both Tourist trips.

M. Luckwill, Pat Irwin, plus 4 'Enterprise' bods

Number 172 Page 5 G. Tilley, J. Ransome. Quick trip to get rid of the Camera Pox. R. Roberts, R. Croft, C. Peters, H. Rowley. Finished the survey of September Series.

7.3.62. Eastwater.

M. Baker, R. Roberts plus six. “While on the above trip, I noticed a peculiar formation. It was about half an inch high and formed by spent carbide. Condensation had caused a water drip to form on the carbide which had produced a "stalagmite". The formation was very delicate and the walls were almost transparent.” M. Baker.

J. Hill, Peter Scott and 8 U.B.S.S. Tourist.

17.3.62. Cuthbert’s 18.3.62. Balch’s Hole Garth, Gordon and Roger.

18.3.62. Cuthbert’s P.M. Giles, M. Holland, M. Luckwill, J. Cornwell, J. Ransom, J. Williams, M. Calvert. Thirty six feet of maypole was assembled below the Maypole Pitch with a view to re-entering Hanging Chamber to recover the 20' of maypole therein, a lifeline was then run from the top of the Maypole pitch to a large boulder in Upper Traverse Chamber. The maypole was erected, but after three changes of position the attempt was abandoned and the may be disconnected and left at the bottom of Maypole Pitch. In order to retrieve the maypole in Hanging Chamber, the original method of maypoling seems to be the only solution, unless a less flexible method of joining maypole sections is devised which may just permit the direct route.

19.3.62. Nine Barrows Jim Giles and Mike Boone took a brief look at this dig and found that a partial collapse had occurred but that the shoring was still intact.

42.3.62. Swildons.

R. Stenner plus 2 boys to sump I. _______________________________________________________________________________________ 4.3.63. Goatchurch & Sidcot 4.3.62. Cuthbert’s

Song Competition 1. Competitors may submit any number of songs, the words of which must be the original work of the competitor.

2. Any songs submitted must, in the opinion of the organizer, be suitable for performing at the club dinner and must be connected with club activities.

3. Competitors should indicate how they wish their songs to be presented. If they do not wish to sing themselves, a suitable "choir" will be laid on, and various members of club who can perform on musical instruments will be available to act as accompanists if desired by the competitor.

4. There will be two closing dates. The earlier, for those who wish their songs to be sung and/or accompanied for them, will be SATURDAY, AUGUST 25TH to allow time for rehearsals. For those who wish to perform entirely by themselves, the closing date will be SATURDAY, SEPTEMBER 22ND to allow for elimination if this should become necessary.

5. If more than about half a dozen songs are received, it may be necessary to weed out some of the songs, so that people will not become, bored at the dinner by a long session. In that case, the organizer will arrange for an impartial judge to pick out the best songs. If this occurs, competitors who may have written their own tunes must arrange an audition with the judge between the last closing date and the dinner.

6. Judging of the final selection of songs will be by popular acclaim at the dinner.

7. A suitable trophy will be awarded to the winner and runner-up. All competitors whose songs were presented at the dinner will receive a consolation prize - probably in the form of a drink.

The rules for the PHOTOGRAPHIC COMPETITION will be printed in next month’s B.B. the dinner is on Saturday, October 6th.

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June 1962

Climbing in Cornwall - Easter 1962 A large crowd of about thirty assorted members assembled on the Thursday evening after motoring down under incredible difficulties (cars travelling in the opposite direction on their correct side, etc.) The venue was Trevalgan farm near St, Ives where a choice was to be had between camping and staying in the excellent barn provided.

Good Friday dawned cold and clear and the entire expedition repaired to Porthmorna Cove on the North Coast, where the climbing members attacked Basigran Pinnacle. This is a long steep sided ridge jutting into the sea and almost cut off from the mainland at high tide. It may be traversed by first of all scrambling up to the foot of a gendorme, from whence an interesting crack and a long traverse descends to a small platform near sea level. The climb is not difficult and is rather more satisfying than the usual outcrop type of climb as it has a definite object, to reach the final platform accessible only by rock climbing. Three parties did the climb, returning by one of the lower West Pace traverse variations. Mossman and Sandall kept near the sea and found some wet, slimy rock; whilst Bennett and Miles, Tuck and Marriott climbed a chimney encrusted with the usual odiferous bird lime.

After this effort, Marriott, Bennett and Tuck ventured up Black Slab Climb on Bosigran face. The slab, which is a conspicuous feature of the face, looks F.N.I. from a distance, but on closer inspection is found to be liberally sprinkled with holds. According to the guide book, its colour (black) is due to a coating of 'schorl', a piece of information which appeared to produce no intelligent response from the climbing party. It was decided by a two to one vote that Mr. Marriott should lead the slab, which he did after surmounting an awkward pinnacle.

On Saturday morning, the intrepid explorers 'did' St. Ives and returned to Bosigran in the afternoon. This time, attention was directed to the Bosigran Ridges on the West side of the cove. These run down at a steep angle to the sea and were used for commando training during the war. When the climbers arrived at the seaward end, ready to do great things, a major setback was encountered. The climb - carefully selected from the guide book - could not be found.

After some argument agreement was reached as to where the climb ought to have started. Unfortunately, the rock at this point was in the form of a smooth vertical wall up which no climb of a reasonable standard could be found. After several unsuccessful attempts, the climbers retreated muttering darkly that 'it must have fallen into the sea' etc. Messrs Dunn, Turner and Malcolm departed up the ridge from a higher start while Marriott, Tuck and Bennett followed after roping a severe which proved much harder than it looked. By this time the weather had become warm and sunny and the climbers slowly meandered up the ridge, talking photographs and making private variations to the pitches. Further on, things became more serious and the final climb caused some misgivings. This was in the form of an almost horizontal knife edge, which is climbed to the detriment of certain parts of the climber's anatomy. The end of the ridge was so thin that it looked likely to cut the hands, and the whole thing was quite unlike anything that anybody present had previously climbed.

The next day was spent on the West Coast, starting with climbs on Chain Ladder. This is reckoned to be the finest of the Cornish sea cliffs, and the four climbers were quite anxious to visit it. It is best approached from the north, where a steep scramble leads to a deep inlet, bridged by a large boulder. This looks insecure and was crossed rapidly. As it was the first visit, two fairly easy chimneys were selected. Initial pitches proved quite straightforward but some confusion with route finding occurred higher up due to not reading the guide book properly. Several sea birds nests with eggs were found and Steve Tuck was nearly attacked by a bird which we think from its size must have been one of the last surviving Cornish ostriches. ________________________________________________________________________________________________ Cave preservation in a nutshell from the N.S.S. magazine..... "Take nothing but photographs - Leave nothing but footprints" ________________________________________________________________________________________________ THE CAVE DIVING GROUP REVIEW FOR 1961 IS NOW ON SALE! Containing reports and references to operations in Northern Pennines; Mendips; Derbyshire; South Wales; Ireland and Gibraltar. This is well worth having and, whether you are personally interested in diving or not, makes a worthwhile addition to any caving library. It is obtainable at 2/9 plus 6d postage from the Editor; - E-J. Waddon, 65 Raleigh Hall, Eccleshall, STAFFORD. It is issued free to C.D.G. members. Enquiries regarding membership of the C.D.G. should be made to J.S. Buxton, 38 Maulden Road, Flitwick, Bedfordshire.

_______________________________________________________________________________________ The Belfry Bulletin. Secretary. R.J. Bagshaw. Editor, S.J. Collins.