The annual season for form filling is now upon us!  In this issue of the B.B., you will find the
entry form for the 1962 photographic competition.  Next month will come the usual nomination
form for the 1963 committee and in September’s B.B. will be the voting form.

All of which goes to show that the A.G.M. and dinner is not
as far away as you might think.  Most
people reckoned that last year’s dinner was a good one.  We all hope to make this year’s an even
better one.  It’s at the

Cliff
Hotel,
Cheddar on Saturday, October 6th.

Although it is hoped that the general standard of the
entries for tie photographic competition will be even higher than last years,
don’t be kept from entering because you think that your slide or print is not
good enough.  It may be that your entry
has that something which catches the eye of the judges; but even if it hasn’t,
you may like to have the chance to have it compared with the best the club can
do.  Have a bash!

The song competition does not appeal to as large a section
of the club as the photographic competition. This year, we are going, to rehearse it beforehand and also arrange it
so that you don’t have to be afflicted with it if you don’t want to.  For those who like this sort of thing, we
hope that somewhere – in some sordid garret maybe – the winning song is even
now being written.

Finally,   DON’T
FORGET THE CLOSING DATES!!!

Caving Log

1st April.
St. Cuthbert’s.  Mikes Palmer &
Wheadon, and Albert to Cerberus Series & thence to Pyrolusite.

1st
April.  St. Cuthbert’s. J. Eatough,
M.Baker, R. Bennett, K.

Franklyn,
C.A.
Marriott.  Collected the Eatough maypole
from Upper Traverse Chamber and took it into Cerberus.  Both high level passages in Mud Ball Chamber
maypoled.  One on right proved to lead to

Lake
Chamber. Signs of a previous visit.  Rift
continues on far side of

Lake
Chamber and will be
maypoled at a later date.  Exploration
continued in Coral Series.  Passages
above the rift near Annexe Chamber were pushed without success.  Attention was switched to Coral Chamber and a
new pitch discovered by Mike.  This was
not descended as no ladder had been taken. A further hole was looked at but found to connect back to Coral
Chamber.  It is proposed to call the rift
“Fracture Rift” and the leaders will be informed of this proposal.

Coombe
Down Freestone Quarries.  2nd April (1
am).  M.R.O. Rescue.  M. Baker, M. Palmer, P. Buck, M. Wheadon, H.
Kenney, J. Hanwall.  A two hour search
for missing schoolboys.  An interesting
trip (if possible at 1 am) in a maze of mine workings that are in a rather
dangerous condition.  First time the
B.E.C. has gone caving with a bitch (police dog).  We never did see the boys!

7th
April.  Goatchurch.  Ray Chris, Phil and John from the
Midland association of Mountaineers, Pat Irwin, Gordon
Tilley and Jon “Rotten” Ransom. Full trip + drainpipe.

7th
April.  Swildons.  Four from M.A.M. as above and Pat.  The M.A.M. party cherishing the hope that
they could keep their feet dry.  This was
shattered at an early stage by one member getting his wet by water that entered
down his neck.  The 40 was found to be
laddered and the whole patty descended. The first man down was misguided enough to swing under the
waterfall.  The 20 was then encountered
and passed and a considerable length of passages traversed before a return was
decided upon.  A very damp but contented
party emerged from the hole only to find that it was raining.  Loud complaints.

Heale
Slocker 8th April.  M. Baker &
Alfie.  Digging continued at Alfie Speed
(what does this mean?)

Luminescence

by M. Luckwill.

In the last article (1) we looked at the mechanism of
photo-luminescence.  Two other forms of
luminescence might with convenience be noted here.  They are Thermoluminescence – light emission
caused by heat and Triboluminescence – light emission caused by crushing,
rubbing or scratching.

Table 1 shows the occurrence of luminescence noted by
several authors (2,3,4) and + indicates that some forms of the mineral
luminesce.  In the Mendip area, we are
mostly concerned with Calcite, Limestone, Arragonite and their various forms.

We remember that luminescence is caused by an impurity.  Very little of this impurity is necessary
however, and if too much is present, the energy is dissipated as heat rather
than, light.  The amount of impurity we
are concerned with will defy spectrographic analysis and requires neutron
diffraction techniques for tracing and identification.  I believe that stal from Balch’s Hole has
been analysed spectrographically and found to be free from trace elements
within these limits of accuracy.

Difficulties occur, therefore, when we wish to discover the
nature of the impurity.  Most research
has been stimulated by the recent advances in semiconductors and consequently,
although quite a lot is known about transition elements in host crystals – such
as germanium – little work has been done using limestone as a host
crystal.  However, of interest to us, is
a method of dating limestone by thermoluminescence.

The method is not reliable because of a variety of variable
factors, but briefly, the theory is as follows:-

Activation centres are caused by cosmic radiation. The
number of activation centres is related to the amount of radiation received,
which in turn is related to the age of the limestone.  When limestone is heated, luminescence occurs
and the light intensity is related to the number of luminescent centres
(5).  Hence the age of the limestone can
be found.  It has been found that
magnesium and strontium act as activators and that iron acts as an inhibitor.

From Mike Baker’s article we might draw the conclusion that
CaCO3 which has been dissolved and re-deposited luminesces more than the
original carbonate deposit.  This could
be due to trace elements being held in solution due to their small concentration,
thus deducing their concentration in the stal and enabling luminescence to
occur.

These trace elements play an important part in the crystal
formation, and a knowledge of their identity will give further insight into the
formation of cave deposits.  This
knowledge might well be gained by further analysis of luminescent materials.

Table I.

Photographic Competition.

There will be SIX classes this year.  Prizes will be awarded to the winner and
runner-up in every class EXCEPT class 6.

CLASS 1           CAVING            2″
x 2″  Colour Slide
CLASS 2           CLIMBING         2″ x 2″  Colour Slide
CLASS 3           CAVING/CLIMBING        “Two and a quarter square”
Colour slides.
CLASS 4           CAVING            Black & White print.
CLASS 5           CLIMBING         Black & White print.
CLASS 6           Best Special      Slide or print.

Rules

1.                  All entries must have been taken by the
competitor.

2.                  All competitors must be PAID UP members of the
B.E.C.

3.                  No professional photographers may take part.

4.                  No entry must have been previously entered in
any competition.

5.                  No more than TWO entries may be submitted in any
one class.

6.                  No competitor may win more than one FIRST prize.

7.                  A picture entered in one class may not be
entered as a print or slide in another.

8.                  Monochrome prints must be POSTCARD size or
larger.

9.                  The judges may not compete.

10.              No responsibility for loss or damage is to be
borne by the organiser or by the B.E.C.

11.              In any interpretation of these rules, the
decision of the organiser is final.

12.              THE CLOSING DATE FOR THE PHOTOGRAPHIC
COMPETITION IS ON FRIDAY,21ST  SEPTEMBER,
1962 AFTER WHICH DATE NO LATE ENTRIES WILL BE ALLOWED TO TAKE PART.

Readers will find an entry form with this B.B.  In any case of doubt, please get in touch
with the organiser    M.J. Baker,
“Morello”,

Ash Lane,
Wells,

Somerset.

Competitors who will not be at the dinner should make some
suitable arrangement with the organiser for having their entries returned.  If postage is necessary, please include cost
of return.

*****************************************

Apologies for the shortness of this B.B. – the first one of
only two thirds the number pages this year – and also for its lateness.  The editor has been afflicted with
“finger trouble” (literally) by getting his hand mixed up with an
empty beer glass – that’ll teach him to muck around with EMPTY beer glasses in
future.

*****************************************

DON’T FORGET THE DATE OP THE A.G.M. & DINNER – 6TH
OCTOBER

Kent’s
Cavern

by Jon Ransom.

On my way through Torquay, I saw a large sign reading ‘

KENT‘S
CAVERN’.  Following various arrows I
arrived at a small car park with an imposing modern building facing it.  I paid my 2/- and went into the waiting room,
all excited to think that I was going underground with about thirty other
weegees.

While waiting, I compared the general layout with the fronts
of Gough’s and Cox’s. 

Kent‘s seemed
to be cleaner and more informative about the caves.  At this stage the guide arrived, took our
little tickets (or tallies) swung open a massive oak door, and led us into the
unknown.

The cave is located on the side of a hill, which it
penetrates for about half a mile.  The
rock consists of the Devonian limestone and sandstone which, with the mineral
deposits from the soil above, give some very striking and colourful effects in
the cave.

Just inside the entrance and down to the left are the
remains of a hyena den, and the abode of prehistoric man.  The remains of mammals of that era have been
found in great number and include mammoth teeth and remains of fox, badger,
hyena etc.  There are also several
remains of bear, including an excellent skull and leg bone which may be seen
embedded in a false floor, which the guide then takes you underneath.

The main tourist section has been excavated in some places
to a depth of twenty feet and you can see, as you walk through, the line of the
original floor level high above your head.

Several of the formations are very good, and there are also
quite a few straws and helictites which can be seen in odd corners on the tour.  These do not occur very frequently
however.  Most of the passages and
chambers show good signs of the water which formed them and mud in the numerous
side passages is fairly thick and sticky. These passages shoot off in all directions and, when asked about them,
the guide said that a lot of them were unexplored.  He went on to relate how school kids often
went up these passages, to reappear with hundreds of bones.  I think that the guides of

Kent‘s are in
strong competition with those of Gough’s and Cox’s and that all guides go to a
special course in tall caving stories.

Apart from housing prehistoric man (and woman!) many
inscriptions found on the walls of the cave go back as far as the fifteenth
century.  One of these inscriptions is a
woman’s but many are difficult to decipher as they are covered with a thin
layer of calcite.

Although

Kent‘s
Cavern is a show cave, and has an imposing entrance and the guide builds up the
place as much as he can, it is worth a visit from any caver who finds himself
in the district even if you only go in to hear the guide’s tall stories!

*****************************************

The Belfry Bulletin. Secretary. R.J. Bagshaw, 699, Wells Rd,
Knowle, Bristol
Editor, S.J. Collins, 33, Richmond Terrace, Clifton, Bristol 8.
Postal Dept.
C.A. Marriott,
7’8, Muller Rd, Eastville,

Bristol.