Editorial

After the Christmas number, we are back in our usual goal
for another year.  As you will no doubt
notice, this consists of exactly the same cover and general arrangements as
last year.  Nevertheless, during the
course of the coming year, we are going to (we hope!) a fair amount of work –
mostly behind the scenes – with a view to further improving the B.B.

The main item for which we feel there is plenty of room for
improvement is the legibility of the printing. This is partly due to the machine, but could be improved by the use of a
thicker paper which would permit heavier inking.  We may try out a specimen page of this
soon.  We could recover the money by the
use of smaller type and hence less pages for the same amount of writing.  Again, we may serve up a sample.

A “fancy” cover has also been suggested by several
members.  If we go to this in 1960 –
which is the earliest we can – we shall be stuck with it for some time, so
during the course of this year, we should like to hear all your suggestions, so
that the club may enter its silver jubilee year in 1960 with the best possible
magazine.

 “Alfie”

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We Wish All Club
Members A Happy & Successful New Year

Notice

THE NEW STONE BELFRY will take an awful lot of man hours
before it is finished.  Anyone with a few
moments to spare when at the Belfry can help by carting stones from the pile
and stacking then round the building about three feet away from the outside of
the walls.  This will save the builder’s
time when laying masonry.  Also concrete
blocks can be usefully piled up inside the building.  Even a few minutes work on this will be
useful.

Committee Meeting

The December meeting of the committee discussed progress
being made on the new hut and the kitchen improvements.  It was agreed to buy a new projector for
slides at £3.  A long discussion on
ladders and tethers followed, after the recent failure of a club ladder down a
cave.  I was agreed to leave the purchase
of a suitable club tent to Frank Darbon. It was agreed to buy a copy of “Man’s Journey Through Time” by Prof.
Palmer.  Mo was authorized to buy a stock
of carbide lamp spares.  Bob Kitchen was
elected a member of the club.

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Congratulations to Roger and Daphne Stenner on the birth of
their son, Edwin.  Roger tells us that
his son has no beard as yet!

Angus and Maggie are back! Older members will remember these two who set out on the twenty first of
June, 1956 to travel round the world on a motorbike.  The bike in question – a triumph twin and box
sidecar – was to be seen outside the Belfry the weekend before they left for
furrin parts.  They arrived back in
Liverpool two days after Christmas having covered some 55,000 miles and after
visiting Norway, Central Europe, Greece, ‘Turkey, Egypt, Kenya (where they
worked packing oranges to save up enough for the next stage) Australia, New
Zealand, U.S.A. and Canada.  Intending
travellers please note that they are quoted as saying that they found
Turkey the most hospitable and the

U.S.A. the
least.

We understand that John Lamb will soon be with us again as
the latest rumours say that he will be back from

New Zealand in March.  Tony Rich still keeps in contact with club
members and is still in

Canada.

Caving Log

Membership List

(Continued from the Christmas B.B. with additions and
revisions)

The following new member has joined the club since the list
was published: –

And the following have changed their address since the list
was published: –

A.C.L. Rice is now at

13 Wades Road,
Filton,

Bristol

Mr and Mrs R. Stenner are now at
Ivy Cottage, 5 Beach Hill, Clevedon,

Somerset

Electromagnetic Surveying

By Norman Brooks

In was interested to notice the mention in the September
B.B. last year of the possibility of using a radio type service for cave
surveying and noted the editor’s reference to my equipment so an article on
what it was; what was accomplished with it, and how it came into the existence
would evidently be quite useful.

Whenever a cave system bends round and comes close to
another part or rises and comes close to the surface, surveyors have been
baffled by the fact that light will not penetrate the intervening rock, and
thus a closed loop cannot be obtained. Apart from digging through, there are three possibilities of overcoming
this difficulty based on the use of radio waves; electrostatic fields; or
electromagnetic fields.  The method least
affected by the nature of the rock is the magnetic one, using the field
produced by the passage of an audio frequency alternating current through a
large cell.  A radio method could be used
providing that a low enough frequency was used – 20 to 100 Kc/s would be
suitable – and would result in little loss of accuracy.  The radio method has one advantage in that
the signal falls off as the inverse square instead of the inverse cube in the
case of the electromagnetic field.

For overall simplicity of circuitry, however, a frequency of
between 300 and 500 c/s is desirable, and simplicity of circuits is a most
useful asset, considering that the amplifiers are likely to get hard
treatment.  The position of the
electronics in a device of this nature should be understood, for the transmitter
is no more than a surveyor’s assistant’s lamp and the receiver no more than the
surveyor’s eye.  The accuracy and
usefulness of the whole system depends on the mechanical side of the equipment
– that is, the accuracy with which the transmitting coil and the direction
finding coil can be set up and read.  On
the whole, the electronic side of the equipment is quite straightforward.

My work started about five years ago, when I decided it was
about time that someone found the easy way into August Hole as indicated by the
survey.  I do know whether anyone else
but me has noticed the similarity between August Hole and the river

Mississippi.  Mark Twain says in ‘Life on the

Mississippi’ that
‘measurements indicated that the river was lengthening by a certain number of
miles each year’.  From that data he was
able to calculate the distance that it would, after a few years, stick cut into
the
Atlantic ‘like a rod’.  Measurements on the published survey indicate
that August hole sticks out of the ground ‘like a rod’, and both calculations
have about the same degree of accuracy!

The first experiments showed the difficulties in making a
suitable piece if equipment were greater than had been anticipated, but after
two months a device consisting of a transmitter feeding a large flat
transmitting coil, and a receiver fed by a similar receiving coil, which could
be rotated about any axis, came into being. It was tried out in a 60 foot deep chalk mine at Northwood, Middlesex.  The test was not so very successful, but it
did serve to establish the design criteria and to point the way ahead.

One of the early experiments showed a fairly obvious snag
with an apparatus using an electromagnetic field.  The transmitter had been set up near the
local high street and the receiver taken further away in order to establish the
range of the device.  The range should
have been fifty yards, but this distance was reached and reception was still
good.  Further and further the receiver
was taken – into a minor road and on to a main road.  The local inhabitants must have been startled
to see someone carrying a square board and wearing earphones and an intent
expression walking down the street!  The
long range was due to the presence of an under ground pipe, which the apparatus
had detected with singular accuracy.

A month after the chalk mine experiment, in January 1954,
the equipment was tried out in Lamb Leer. It showed the position of the Beehive Chamber relative to the surface,
but could not determine its depth, as more work remained to be done on the
equipment.  There was no cheating about
the location of the chamber, for I was surprised to find that the equipment
pinpointed a spot not in the least where I should have expected it to be, yet a
subsequent check against the survey showed the spot to be correct.

After Lamb Leer things went slowly.  Many improvements had to be made before the
equipment could be used for cave measurements with any hope of success.  Because of a wet summer, it was not
convenient to use it in August Hole that year, and it was not until July 1955
that the first serious attempt to use the device was made.

The Wet Gallery of August Hole was tried.  The attempt to locate the position relative
to the surface and the depth was none too successful for a number of reasons,
not, the least being lack of skill in handling the new tool.  It was obvious that team work was essential
and Bryan Ellis became invaluable as the other member of the team.  In November 1955, the device was used
successfully for the first tine.  I am
sorry to say that the results firmly indicated that August Hole did not stick
out of the ground like a rod, and that any dig would be a big job.

In December l955, the equipment was used successfully used
to locate the position of Pillar Chamber in Ogof Ffynnm Ddu relative to the
surface.  From then on, it was decided
that the best course was to rebuild the equipment completely apart from the
receiver and amplifier as, now that the principle had been thoroughly
established, a proper instrument was required. So far this has not been done.

A great deal of data has now been obtained which would be
invaluable to anyone wishing to build something similar of their own.  By using this, they should be able to
guarantee success and save themselves three quarters or more of the work I had
to do.  It is not worth giving a
technical description of my device here, but if anyone is interested in
building a similar device, I shall be only too pleased to help them.

Norman Brooks.

Editor’s
Note:     There is a lot of work which
could be done on Mendip by a device of this kind.  The position of the end of the Maypole series
in Cuthbert’s for instance, or the relation of the end of the Black Hole series
in Swildons to the nearest part of Swildons I. I should imagine that there are members of the club who would also help
a constructor with advice on the use of transistors and assistance in getting
the circuitry “potted” in resin &c.  There appears to be a very interesting time
ahead of anyone who is prepared to take

Norman
up on his offer!

More Personal News

Congratulations to Sago and Ronnie Rice on the birth of
their son on Sunday, December 28th. He weighed in at 7½lbs and is to be named
David George.

Notices

The Southern General Meeting of the Cave Research Group of

Great Britain
will be held on 2nd May, 1959 at Wells. The hosts this year will be the U.B.S.S.

The B.E.C. Club Tent has now been purchased and may be hired
out by parties wishing to use it on climbing and other trips at a charge of
10/- per weekend.  Charges for longer
periods will be based on a rate of 10/- per three nights.  Thus a week plus the two weekends will cost
30/-.  The tent may be obtained en the
Thursday preceding the weekend or period required from the club room at
Redcliffe.  The tackle officer, Norman
Petty, is in charge of the tent and arrangements.

It is proposed to get mains water installed in the Belfry as
quickly as possible.  Owing to the cost
of this, it has been agreed to adopt the same procedure as was adopted to pay
for the calor gas installation originally. Thus, all Belfry charges will go UP BY 3d PER NIGHT from the time of the
installation of the water until the cost has been covered.  This will take about a year.

The committee have requested that a notice be put up in the
Belfry about the use of tackle.  This
will be done as soon as possible. Meanwhile, all tackle should be cleaned after use and stored in the
women’s room.  A tackle log will also be
re-started and members are asked to take it seriously.

Swildons

There will be a diving operation on the 17th January, in
which it is hoped to get five divers into Swildons VI, led by Oliver
Wells.  Four people will support them in
V, and a kitchen will be set up in IV.  A
sherpa party will be starting down the cave at 9.30 am on the Saturday and the
divers will follow at 10.30.  A second
party of sherpas, led by Oliver Lloyd, will go down at 3.30 pm carrying the
remainder of the 35 packs.

There will be a further operation on the 31st of January, in
which it is hoped to get 6 divers into VI.

ALL ABLE BODIED
CAVERS ARE ASKED TO SUPPORT THIS OPERATION.

Names  should be given
to Len Dawes, Ken Daw or Mike Holland. Even people who are only prepared to go to the 40 and back may come in
useful.  All people collaborating will
receive a copy of the official report of the operations in the cave.

This Month’s Sonnet

Exposure suits are now the thing
to wear.
No self respecting caver would be seen
Preparing for a trip on Priddy Green
Without one.  He’d regard himself as
bare!
Long year’s age, the gentlemen would dress
Correctly for a cave in bowler hats,
Plus fours and

Norfolk
jackets – maybe spats!,
And thus accoutred, downward they would press.
Then cavers, dressed in variegated rags,
Would bash through sumps, defying damp and cold.
Now supercavers, scorning ways of old,
Float gently through in suits like sleeping bats.
Do you suppose I think it all joke?
Not likely! They’d be just the job in Stoke.

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Tailpiece.  An
excellent barrel of beer was provided at the Hunter’s recently by Roger &
Daphne, who were celebrating the birth of their son, and by Norman Petty, who
was celebrating his tenth anniversary of caving’.  Mike Holland also dispensed free cider.  The usual time was had by all – and called
later by Ben!