Journal Series 4 Number 4

Note that this is a re-print of the original publication, based on a scanned copy. During the process of converting the original paper copy to this electronic version, the original formatting, page layout and page numbers have been lost. All diagrams and surveys have been scanned from the original and are consequently of poor quality.

 

Contents

Lundy 1967 by MT Mills

'Fibron' Tapes for Cave Surveys by BM Ellis

Review: Expedition '67 to Gouffre Berger

Pen Park Hole, Bristol in 1669 by S Sturmy

 

Journal published by the Shepton Mallet Caving Club

The Mineries, Wells Road, Priddy, Wells, Somerset, BA5 3AU

http://www.shepton.org.uk

 

Editorial

It is disappointing to note that only the 'regulars' have provided material for this number of the journal. I do not believe that this is because other members have nothing to contribute. Indeed, I have heard that a new cave has been discovered in South Wales by one of our members, but I have received no information in writing, even though the cave was discovered during the Summer; but perhaps I will receive an article for the next number.

The recent foot and mouth epidemic has had little effect on this issue, but the June issue may be seriously affected if caving is banned for a few more months.

In this issue every known cave on Lundy is described in detail, giving an historical account, with surveys accompanying many of the descriptions. Another article outlines the use of 'Fibron' tapes in cave surveys. Finally an account of Pen Park hole in 1669 is given.

Due to a typist's error in the last issue Ease Gill was misspelt East Gill. This should have been spotted before printing by the Editor, for which I apologise.

 

Lundy 1967

Abstract

The results are described of field and literary investigations carried out on the caves of Lundy since the previous article in this Journal. There are notes on a further thirteen features explored (including 11 surveys), additional notes on those previously described, and brief details of possible sites still to be investigated. There is a bibliography of 33 items.

Following the account of our visit to this island last year in this Journal 4, (2), pp3–9, (December 1966) Bill Tolfree and myself again visited the island early in June of this year, but this time our party numbered four persons through Bob Saunders and Dave Vickery joining us, and whose help was most welcome. Although perhaps the principal object of our second visit was a second taste of the rock climbing that the island offers, being endowed with undoubtedly the best week's weather of the year (temperatures in the middle eighties were recorded in the shade on several successive days) we were often only too pleased to vacate the soaring heat of the granite slabs and walls for the cool of the caves to continue our explorations.

At the conclusion of the previous article details had been given of five features which we were hoping to investigate on our next visit to the island, and it would seem opportune to commence by recounting our findings on these items.

Sentinel's Cave

It was stated at the conclusion of the article in this Journal 4, (2), that this year we were to investigate for signs of the continuation or other end of this cave. Mr FW Gade (the resident agent on the island) has kindly informed me that during the early days of his residence on the island he had attempted with a companion to get through the cave to the other side of the Lameter Peninsula, but he assures me that even at that time this was not possible. This confirms our observations in 4, (2), p5 that although the end of the cave does give the appearance of having collapsed we were not convinced that the cave continued beyond. Mr Gade also adds that there is no sign of a cave corresponding with Sentinel's Cave when the southward littoral of Lameter is examined, and this we ourselves confirmed during our visit.

In addition Mr Gade has kindly pointed out that this cave used to be known as Old Man's Cave, but this name has dropped out of use simply because to most people there is no cave at all, or at least not one into which it is easy to gain access. This information as to name is confirmed by a photograph forming the frontispiece to (1) which is entitled 'View from Old Man's Cave', but this photograph does appear to have been taken prior to the collapse of a large portion of the shale overhang over the entrance, which accounts for the boulder pile and slope shown on our survey 4, (2), p8, and helps to date this feature.

Our presumption therefore to naming the cave Sentinel's Cave has somewhat complicated matters, but further complications appear as (1), p50 states that the cave used to be known as Old Man's Cave or The Devil's Kitchen. This latter name is confirmed by (2), p67, but this does not make mention of the other name of Old Man's Cave. The name "The Devil's Kitchen" is shown on (3) in the proximity of the cave's position, whilst slightly to the east is shown Old Man's Cove, which would appear to be the derivation of one of its names. This cave therefore now has three names!

However, returning to (1), p50 this states that the cave may be followed for a considerable distance, but a large amount of debris has accumulated, making it very difficult to prove or disprove a tradition which holds that at one time a subterranean passage or staircase here connected the Marisco Castle above with the Landing Cove. This tradition has a similarity with the supposed continuation or connection of which we were informed last year, see 4 (2), p5, though differing slightly as to detail and both can now be considered as local tradition or legend only. This reference (1), p50 continues, "It is also said that far from the entrance is a bed of the finest sand and that this was found to be to some extant accessible at the time when the jetty was being built, a quantity of it actually being used in the construction of that very inadequate breakwater." A glance at our survey shows the distant part of the cave to have a floor of sand and shingle. Obviously there may well be some truth in the above statement, and whilst we are unable to comment as to the quality of the sand, the sand from the landing beach itself should not have been used for building purposes (unless washed) due to its saline content, which may wall explain the use of sand from the cave, which is probably above high water level.

Mermaid's Hole

This is to the south of the South Lighthouse, and on the opposite side of the Lameter Peninsula to the Landing Beach. At the conclusion of the previous article it was stated that we were hoping to instigate this feature. Our attention was brought to this item by its being shown on the OS map (4). We made a thorough search of the coastline around the Lameter Peninsula, and finding four caves of considerable size, were in a dilemma as to which was in fact Mermaid's Hole. Enquiry of Mr Gade revealed that this feature is in fact a curious rectangular shaped rock pool exposed at low tide, in which one can bathe, and which has an inlet for sea water at low level, the water in the hole rising and falling with the action of the waves outside. This feature is not therefore any form of cave.

Old Copper Mine, Long Ruse

At the conclusion of the earlier article it was stated that we were hoping to investigate this feature. The mine is to be found at the rear of a small bay, which has a floor of granite boulders, some 400 yards south of the North Lighthouse on the west coast. Situated just above high water mark the mine consists of two parallel entrances driven into the granite cliff as shown on the accompanying survey. Some twenty feet above the entrance of the northern (larger) adit and in the same dyke, was noted a further small irregular opening some three feet wide, two feet high, above a vegetated ledge and ten feet back from the cliff line of the two entrances below. Access to this was not possible due to its position, scaling techniques would have to be employed to reach it. Due to position, size and shape this third opening would appear unlikely to be another adit, being either a natural opening or merely a mining probe.

We are informed (5), p115 that several copper samples were taken from the area where the vein of copper was found but the quantity was trivial, hence the abandonment of the mine. (5), p85 reveals that the area was originally called Long Roost by the Heaven family, who owned Lundy from 1836 to 1918, and has been mis-named Long Ruse on the Ordnance Survey maps.

Figure 1 – Survey of Old Copper Mine at Long Ruse

Seal's Hole

During our 1966 visit we had in fact located the entrance from the cliff above, but not having sufficient time, had contented ourselves with merely watching the seals in the sea below. At the conclusion of the article in this Journal 4, (2), it was stated that this year we were hoping to visit and survey Seal's Hole.

Descending the cliff directly from the Rocket Pole above the Rattles Anchorage we found ourselves once again above the entrance. Bill led the way to the bottom of the cliff by reversing a 60 foot V. Diff. rock climb. Traversing the base of the cliffs brought us to a point where we could see into the entrance, which is rectangular in shape, about twenty feet wide and some 40 to 50 feet high in granite, but a stretch of deep water at least twelve feet deep barred the way. A swim of 30 to 40 yards in this water with shear rock walls would have brought us to the entrance where the sea broke over boulders. Here the cave appeared to turn right and sounds of the water washing on to a pebble beach beyond could be heard.

A high level traverse along the left hand wall of the inlet leading to the entrance brought us to within ten or twenty yards of the entrance, but wet and steeper rock beyond prevented further progress. Laddering directly over the entrance would not have given access either, again due to the deep water. It would obviously be easier if we had had the advantages of spring tides which are lower; (6), p558 states the Admiralty charts give a rise of 27 feet on ordinary tides, 31 feet on spring tides and twenty feet on neaps; but even so we understand there is still always a deep pool in the entrance. Obviously next year we will either have to time our visit with spring tides or go suitably prepared to swim to the entrance.

There are several references in the literature to visits to Seal's Hole. (11), pp.38-42 is an interesting and extensive account of an early visit to the cave and states that the normal means of approach is by boat in calm weather, but it can also be reached at spring tides by descending the cliffs from Benjamin's Chair to the shore line of the Rattles Anchorage. It records the use of a ladder to span the water surging into the entrance, and the same technique was used to pass a pool seven to eight feet deep which blocked the passage a little way in. The entrance is stated to be 60 feet high and twelve feet wide, beyond which the floor was of sand and rising, and there is some detailed mention of the marine life on the walls of the cave. At the approach to the principal gallery the passage was only wide enough to squeeze along sideways. The leader of the party is stated to have held his candle aloft as he entered the chamber at the and of the passage, with his stout bludgeon grasped in his right hand; he was said to have previously killed no fewer than five seals on one occasion within the cavern. The chamber was of spacious area, and so lofty that the united light of their candles would not reach the roof. The walls were not particularly damp and a low and narrow hole at the farther end of the chamber is mentioned, which by creeping on hands and knees is believed to lead to another cavity.

Reference (7), p33-34 states the cave has a sandy floor near the entrance, rising and getting narrower until there is scarcely room to pass and then opening into a spacious and lofty chamber to which the seals resort, and this again opens into smaller chambers beyond. (5), p90-91 says the entrance is 50 feet high, twenty feet wide, and that the cave terminates in an enormous hall, the roof of which is estimated to rise to 100 feet or more, and would appear to have been formed in the same way as the Devil's Limekiln, by vertical faults in the granite.

Various issues of the Reports of the Lundy Field Society, (16) - (19), give details of visits to the cave by members of the Society during 1954-7 to count the seals present. (16), p35 states that as the calf of the Grey Seal is reported to spend the first fifteen to twenty seven days of its life on land, an examination was made of caves along the east coast as far north as Gannet's Rock and along the south coast. No other caves with beaches above high water mark were found. (17), p33 reports that exploration for further suitable breeding beaches or caves was continued, but nothing found. (18), p59 concludes that most of the permanent seal population is a maturing and not a breeding one, and this seems likely from the lack of any other breeding site but Seal's Hole, although further stretches of the coast have been explored for suitable caves and beaches. (20) includes a graph of the Grey Seal counts for 1954-7 with observations on the very minimal use of the island as a breeding ground and confirm that no caves or beaches for breeding were observed, despite a tour of the island on 10th September 1955 by motor boat. The heading of a brief article in the 1957 Report (19) is 'halichoorus grypus – grey seal', (21) states grey atlantic seal, whilst (7) and (22), p67 state common spotted seal – phoca vitulina. Some uncertainty and disagreement would appear to exist.

It is interesting to note that members of the Lundy Field Society found no other breeding caves as during our visit, whilst climbing on Needle Rock on the west coast we heard seal-like bellows coming from an opening which appeared to be a cave slightly north of the rock and at about NGR 132458. This may well repay investigation during our proposed visit next year.

Mousehole & Trap

Situated just north of Brazen Ward and south of Gannet's Bay on the east coast of the island.

At the conclusion of the previous article in this Journal it was stated that this year we were hoping to investigate this feature. Prior to our second visit I had learnt that this is no form of cave as (5), p82 describes this feature thus: "Looking northwards from Brazen Ward a curious natural rock formation called the Mousehole and Trap can be seen very clearly. This, standing on a projecting headland, consists of a large square of granite tilted upon a smaller piece, just as a brick was hold up by a stick in old-fashioned mousetraps; a few yards behind it is a natural hole through the rock." There is a sketch of this feature in (22), p45. The natural hole through the rock to which they refer is merely an eyehole through a rock wall some three or four feet thick.

However during our visit we did inspect this natural feature and were most surprised to find a small cave through the granite to the north side of the actual Mousehole and Trap. The accompanying survey shows the position of the cave in relation to the Mousehole. Entrance to this short tunnel / burrow-like cave is from either end. The floor is of earth and we are firmly assured by Bob Saunders who gallantly did the through trip with the tape that animal droppings shows the cave to have been inhabited by birds, rabbits and sheep.

Figure 2 – Survey of cave adjacent to the Mousehole and Trap

Proceeding this year's return visit to the island, both Bill and myself had come across other references to caves, notably in (5), and I would like to continue by describing our findings on these, and other caves found whilst searching for caves rumoured and reported.

Cave Adjoining the Landing Quay

This cave was brought to our notice by (5), p70 which mentions its existence on the quay adjoining the Landing Beach, and comments that the mouth has been strengthened, and the cave is used for boat storage. This reference brought to mind the cave which we had in fact seen on our visit last year, but it had not at that time occurred to us to take a look at it. In addition the cave is sometimes used for storing cattle and livestock prior to loading them on to the supply vessel for transportation to the mainland to be sold.

The outline and details of this cave will be apparent from the accompanying survey. Like Benson's Cave it has been hacked out of shale, and the entrance has a surrounding stone arch to consolidate the shale cliff.

Figure 3 – Survey of cave adjacent to the Landing Quay

Cave Above the Rattles

A cave is indicated on the OS map (3) at a point on the cliffs some 500 feet south west of Benson's Cave and almost in direct line with the low water mark on the Lametry Beach. A thorough search of this area of the cliffs only produced two very small phreatic-type passages, too small to push more than a body's length. They are in shale with very shallow cover, which is subsiding at the entrance, and with evidence of habitation by rabbits. They might be more accurately described as burrows rather than a cave.

Subterranean Passage Under Rat Island

This feature is also indicated on the OS map (3), running under Rat Island and was readily identifiable on our approach to the island from the boat. We later visited this passage, which is in shale, at low tide and the accompanying survey shows its outline and details. At high tide the sea flows right through the passage.

In addition, we noted a further tunnel-like cave in the shale at the west end of Rat Island and adjoining Hell's Gates, the bar between Rat Island and the Lameter Peninsula. Upon investigation the cave was found to be about fifty feet long and basically triangular in cross-section. The floor is of pebbles, sloping upwards as one enters the cave. Magnetic bearing of the cave is 85° from the entrance, basically towards the westward branches of the Subterranean Passage, and at high tide the entrance is submerged. We did not survey this cave.

Figure 4 – Survey of Subterranean Passage under Rat Island

Queen Mab's Grotto

Situated in granite midway between Brazen Ward and the Mousehole and Trap on the east coast of the island. The whereabouts and existence of this cave was brought to our notice by (5), p82 which states the cave is thought to have been formed by the action of the sea many thousands of years ago before the levels of land and sea changed, and that this view is supported by the discovery of sea shells on the floor of the cave. During our visit we found no evidence of those shells. It is thought that the cave was used as an ammunition store for the battery at Brazen Ward, built at the time of the Napoleonic Wars. A footnote on p84 of (5) explains that Queen Mab in Celtic folk-lore is a fairy presiding over dreams, originally a Queen Maor of Connaught.

A further reference is found in (1), p58 to the existence of a cave in this vicinity and although no name is given for the cave the description of its entrance as a perfectly semi-circular opening can only refer to Queen Mab's Grotto, as will be seen from the accompanying survey of the cave. The floor of the cave is marshy and there is some fern vegetation to the walls as the cave is of insufficient length to have a dark zone, and such vegetation is undoubtedly encouraged by the water percolating from the walls.

Figure 5 – Survey of Queen Mab's Grotto

Whilst approaching Queen Mab's Grotto from the Brazen Ward, skirting the base of the granite cliffs at the rear of the bay known as Frenchman's Landing (immediately south and east of the Grotto) we came across a further cave. The accompanying survey of this cave shows it to be of rift-form and about sixty feet long.

Figure 6 – Survey of Rift Cave SE of Queen Mab's Grotto

Needle's Eye

The feature known as the Needle's Eye is a very large natural tunnel through one of the arms of the Lameter Peninsula and connects two inlets. This feature was located by us whilst traversing the base of the cliffs in search of Mermaid's Hole (prior to learning that this was not a cave). Passing through the Eye brought us into another bay which is almost immediately beneath the south lighthouse - metallic evidence of which fact is littered about the floor of the bay. Along the west side of the bay we found three caves which as far as we are aware are all unnamed. Surveys of these three caves and the Needles Eye, which are all in shale, are attached. The caves have merely been numbered commencing with the most northerly and working southwards. Cave 2 is about 100 feet west of Cave 1, and Cave 3 is about sixty feet west of Cave 2. While three members of our party were inside Cave 3 surveying, an aircraft passing overhead produced a sonic boom which shook the island and reverberated through the cave. Those inside believed the cave was falling in and made perhaps the fastest ever exit from a cave. This amusing incident offers an obvious name for this cave – if one is desirable.

Figure 7 – Survey of the Needle's Eye

Figure 8 – Survey of Needle's Eye Cave 1

Figure 9 – Survey of Needle's Eye Cave 2

Figure 10 – Survey of Needle's Eye Cave 3

Cave Adjoining Lametry Beach

While searching for a reported cave known as the Needle's Eye we abseiled down to this beach, attaching our rope to one of the balusters of the rails to the steps leading up to the South Lighthouse. After a short search we located almost directly beneath the Lighthouse a cave, which in form could be likened to the eye of a needle. Although we subsequently learnt that this cave was not in fact the Needle's Eye, and even though it is very small, its shape we consider warrants the inclusion of the accompanying survey. The cave has been formed in granite and clearly through the action of the sea.

Figure 11 – Survey of cave adjoining Lametry Beach

Subsequent to the article in this Journal 4, (2) much additional information has been found about the features reported in that article, most of the information coming from references in various books but a small amount has come to light in the course of correspondence, and it would seem relevant to include some of this information for the purpose of completeness.

The Earthquake

In my previous article it was stated that this feature is of volcanic origin and dates back to the early days of the island's evolution. However, Chanter (7), pp30-33 states its origin to be evidently due to some vast and deep-seated movement of the earth's crust; and continues that judging by the solidity of the underlying cliffs at this point and the distance from the edge it is difficult to explain this dislocation as a mere result of a landslip or sinkage by undermining. Local tradition confidently assigns its first appearance to the same date as the great earthquake at Lisbon in 1755. A competent judge has stated that as the rocks are fractured at right angles to their line of strike and nothing peculiar exists in the structure of the granite, as the clefts also extend in the same direction through the clay shale and are visible near the castle, might be attributed to some still greater disturbance in prehistoric times and that the subsequent earthquake of 1755 might have caused a further displacement of the rock masses already loosened and ready to fall; thus affording a not unreasonable ground on which to establish the tradition of the place. Etherton and Barlow, (2), pp60-1, explain that during the morning of November 1st, 1755 a violent shock threw down the greater part of the city of Lisbon; sixty thousand people were killed. The earthquake was felt in the West Indies and the waters of Loch Lomond heaved and splashed to a height of two feet along the shores. Ramifications were world-wide and probably embraced Lundy. TH Hall, (23), pp617-8, states that similar cracks, though on a smaller scale, have been observed by him on the mainland of North Cornwall. Fractured at right angles to the line of strike and in positions which show that they must not be attributed to the effects of any ordinary landslip. There is scarcely an instance in which it can be found (even after the most careful investigation) that a local tradition is totally devoid of foundation. But in this case it may fairly be questioned whether it is possible that any severe earthquake, capable of causing fissures of such magnitude, can have taken place in the West of England during the last eight centuries; since analogous examples would lead us to believe that it must also have inevitably destroyed, or at least shattered, every building within a considerable radius. We remember the numerous fine specimens of Norman and Early English architecture in North Devon and Cornwall - churches with their arches perfect, and their towers without a trace of a rent.

The 'Home Friend', (14), p102-3, records that a large and beautiful amethyst was discovered embedded in the rock some distance down one of the fissures, but was smashed into pieces by a clumsy plunderer trying to beat the finder to the removal of the stone. Subsequently a smaller stone was successfully removed and others are, we are told, still to be seen.

Contrary to what was said in the previous article in this Journal, Chanter (7) gives the extent as about two miles and says that it is most noticeable just north of the Quarter Wall. Two distinct lines of fissures lie seventy to eighty feet apart, with many minor fissures. (14) states the fissures go down to 100 feet depth.

Benson's Cave

In the previous article in 4, (2), 4, this cave was stated to have been constructed by Thomas Benson around 1750, and also that the cave is hacked out of granite. It has been pointed out to me by Mr Gade that of course the cave is hacked out of shale with a possible dyke of dolerite. Incidentally there is attached to (24) a very useful geological map and north / south section of the island showing the distribution of the upper and lower granites, in which the SE corner of the island is shown as consisting of Upper Devonian Slate, Grit and Limestone and including the positions and bearing of dykes around the coastline. Anyone particularly interested in the geology of the island is referred to the bibliography in the 10th Annual Report of the Lundy Field Society (18).

As to the age of the cave and the reason for its construction, Chantor (7), p36, states that it is called Benson's Cave, having been formerly used by him as a storehouse, but it bears marks of great antiquity. On page 65 it is suggested the caves and subterranean passages in the neighbourhood of the castle as being probably relics of the sway of the pirate nobles and illustrative of the bold lawlessness of the time, as well as of the natural strength and importance of the island. Etherton and Barlow (2), p124 state the cave to have existed undoubtedly before the time on Benson. (25), p55, and (5), pp44-5 both refer to the 'Journal of 1787', being a narrative of a visit to the island in 1752 in which the cave is referred to as being occasionally locked. Chanter (6), p566, reports this, referring to 'Mr Clevelands' Journal of 1787. Langham (5), p58, refers to the cave as being situated within the castle fortification, used as a repository, store-room, or magazine for the garrison, and adds that its form shows its great antiquity. (2) opposite page 49, and (1), opposite page 136, are photographs of the entrance.

Langham (5), p97, gives further suggestions as to the reason for its construction and states that the cave itself shows signs of considerable age, as the cement used in the construction is said to be identical with that used in the older sections of the castle. The most interesting thing about the cave is not so much its construction or the remains of cobbles on its floor, but the original purpose for which it was planned. If, as seems almost certain, it was originally built at the same time as the castle, it may have been an incomplete escape passage abandoned after the roof or shale fell in or for other reasons; although against this theory must be considered the futility of building such a tunnel on an island where escape to the mainland can present equally as many difficulties as assault. It could have been constructed as a sewer or drain, though this is unlikely in view of its large size. It could have been used to house horses [see (8), p486.] or prisoners, but unless it took advantage of some natural formation in the rock, it is surely unlikely that this cave would have been excavated in preference to an extra building in the castle grounds unless a secret hiding place was the prime object. A more likely possibility is that it was constructed by Bushell, who was after all a mining engineer, and if he did in fact rebuild the castle it would account for the similarity in cement. That it was used as a storehouse in later years is certain for Grose shows a capstan mounted at the mouth of the cave, the only possible use for which could have been the haulage of goods from the Landing Beach. A few years previously it was most probably one of the 'divers caves' in which Benson's contraband had been discovered. Just outside the mouth of the cave there are two recesses, one on each side, and these are shown on Grose's plan of 1775 (26). At some time since then a brick facing and doorway have been built to turn them into two small chambers.

The details in the latter part of the above reference in (5) are confirmed by Hall (23), a plan of the castle showing a subterranean vault with a capstan outside and two paths approaching it, one from either side, and a recess each side of the entrance is indicated. The 'Home Friend' (8) states the cave bore indubitable proof of its being a work of art. The grey shale of which this end of the isle is composed, is friable and easily removed; and time and labour alone would be needed to form such a cavern as this. This reference attributes its construction to Benson for the express purpose of housing the linen and pewter landed from the ship 'Nightingale' – see the account of this in (30).

Correspondence with Mr KS Gardner of Long Ashton who was directing archaeological excavations on the island on behalf of the Lundy Field Society during the summer of 1966 [for reports of their findings see (31), (32), and (33)] when a short trench was excavated through the doorway of the cave, states that apart from showing that one could walk upright through the entrance it showed little, as stratification had been disturbed by 'treasure-seekers'. Pottery, food remains, iron, coal, etc found were from the 17th to 19th centuries. Graffiti dated from 1726, ie. pre-Benson. (27) repeats these details. Mr Gardner suggests that whoever dug the cave must have had a) necessity and b) skill. The Civil War Governor (1643-?) Thomas Bushell was Royal Mintmaster in control of the Royalist Bullion when all England had fallen to Cromwell. He was also a mining engineer, and could have quarried out the cave to store the bullion. With regard to the reference by Langham (5), p97, to remains of cobbles on the floor of the cave, Mr Gardner has confirmed that no signs of these were found during the excavation, although the somewhat 'wavy' effect of the hard earth floor may have given this impression. No sign of the cobbles were noted during our own visit to the cave.

Devil's Limekiln

Etherton and Barlow (2) give a double page photograph of the surface chasm between pages 56 & 57. Chanter (7) and Hall (23) state that the Limekiln appears to have been in some measure caused by the same great convulsion of nature as the Earthquake clefts, aided and directed probably by the decomposition of two small parallel trap dykes and the granite included between them. Depth stated from upper (landward) side to bottom to be, according to Mr Hudson Heaven, about 370 feet. Loyd (1) states quite a number of tunnels connect the bottom of the Limekiln with the sea, and the accumulation of wreckage at the bottom (and indeed in many of the larger caves) bears eloquent testimony to the toll taken of vessels during bad weather. I would comment that our visits and survey of the bottom of the Limekiln revealed only two tunnels connecting to the sea, and with regard to wreckage we noted none in the Limekiln and little elsewhere (apart from debris below the Lighthouses) though the case may well have been different when this work was written. Reference (10) suggests that the Limekiln's being attributable to the Devil probably dates from the darkness of the Middle Ages when mankind was ready to attribute to Satan operations with which he had nought to do.

In addition to the features investigated this year, and additional information brought to light on the features mentioned in this Journal earlier, details of other possible features of which we have found note but as yet have not successfully investigated, might not be out of place at this juncture.

Cave on Goat Island

Lawder and Pyatt (28) refer to a rock climbing route being put up on Goat Island, close to the SW corner of the island, and which ran down through an open cave. In all probability this is a ‘climber's cave’ (ie. any opening in a rock face) but we have not investigated same and are not therefore able to confirm whether this is so.

Cave Between Tibbett's and Gull Rock

Whilst in correspondence with Mr Gardner, mention was made of a cave half-way down the cliff between Tibbett's and Gull Rock below and off the east coast of Lundy. Despite a search of the cliffs in this area, but bearing in mind the waist-high bracken, we were unable to locate same. Unfortunately in order to be able to abseil down into the entrance we had to know on which side of the promontory leading down to Gull Rock the cave was situated. Upon enquiry of the resident Lundy Field Society warden we were informed that the opening was in the zawn south of the promontory but that it was only about six feet deep. Subsequent correspondence with Mr Gardner shows the cave he mentioned is in the zawn to the north, in which case there may well be two or more openings in this area. Mr Gardner had been told by a Mr T Saunt that the cave went in some sixty or seventy feet, and suggests that if it is mining adit one might expect to find several around the same spot. Investigation is obviously necessary.

Double-Decker Cave

Langham (5) states this to be a little to the north of the Devil's Slide on the west coast, the lower one being at sea level and the upper at approximately the level of Queen Mab's Grotto, suggesting sea erosion on two planes at different eras. Following our successful ascent of the Devil's Slide, Bill and myself endeavoured to locate this cave. Descending on foot and by rope we managed to get within thirty feet of the base of the cliffs only to be halted by an overhang. Had we reached the base of the cliffs by abseiling down, retreat might have been impossible and therefore we had to give up our attempt to locate this cave. A further search will be necessary not only to find a way to reach the base of the cliffs but also to locate the cave.

Copper Mine Above Rattles Anchorage

Langham (5), p115 states this to be just east of Benjamin's Chair and a shaft was opened in the mid nineteenth century. Chanter (7), p126 and Langham (5), p115 state that copper ore was found at the point of the junction of the slate and granite at the SE end of the island. A shaft was opened but the quantity was too trivial and it was abandoned. (11), p38 reports that the erections over the shaft were visible around 1853. We descended the cliff in search of this feature but were unable to locate the shaft, and a further search will be necessary. Mr Gade informed us that to the best of his recollection the mine consisted of two adits driven into the cliff half-way down, but that they were only about fifteen feet long.

Virgin's Spring and Subterranean Passage

The map (3) shows both these features adjoining the North West Point and the North Lighthouse whilst (4) only shows the Virgin's Spring which is clearly shown adjoining the eastern side of the Point. Chanter (7), p29 describes the subterranean passage as sixty feet high and 800 feet in length, through which it is said a boat can sail at high water. It is stated that a spring of fresh water rises in its centre, bubbling up through the sea water, and this is called Virgin's Well. (6), p562 states similarly. Etherton and Barlow (2), p29, state the subterranean passage to be 300 feet long and add that local tradition insistingly, but unconvincingly suggests that the Virgin's Spring connects with springs on Dartmoor by devious under sea and land channels. Langham (5), p83, states the passage to be 200 feet long and forty feet high, whilst Loyd (1), p51 states 800 feet long and sixty feet high. (9) states the entrance to be sixty feet high, thirty feet wide and the passage perhaps 800 feet in length. This reference points out that a boat can go right through but only at high water because there is a rock in the midst of the course which at any other state of the tide leaves too narrow a channel on either side. With regard to the spring it is stated that Mr Heaven could not vouch for this on personal observation, but the well-known occurrence of similar phenomena refers credence in this case no great difficulty.

There would appear from these references to be considerable doubt as to the true length of the Passage, whether there is in fact a freshwater spring, and also some difference as to whether this latter feature is known as Virgin's Spring or Virgin's Well. From our own investigations we were readily able to locate the passage which is in granite, and descending towards the base of the cliffs below the Constable Rock one is able to see daylight through the headland via the entrance at the eastern end. Unfortunately, as in the case of our attempt to enter Seal's Hole, the state of the tides in June was insufficient even at low tide to permit access. However by clambering around the cliffs at the North West Point apart from ascertaining that the most southern entrances on either coast connect in approximately a straight line, in addition around the Point there are five other entrances running in to connect with the main passage. In two instances two adjoining passages combine some way in from the seawards ends and have large eyeholes above their junctions. These eyeholes revealed the passages below continuing in various directions, deep water rushing in and out with the tide and echoing. Descent from these eyeholes would be about a 120 feet pitch and finishing over deep water. The passages are generally up to sixty feet high and forty feet wide. Obviously siege tactics will have to be employed to enter and survey this complex and next year we hope to manage this using if necessary a rubber dinghy, wet suits etc. Once again spring tides would be of considerable assistance.

Miscellaneous

Langham (5), p. 99, states Lundy is not dependent entirely upon rainwater for fresh water for there are several small springs and four wells have been sunk south of the Lighthouse Wall, all of which were noted by Grose in 1775 (26), though not accurately. The most westerly of these, Parson's Well, is just south of Beacon Hill between the old churchyard and Friar's Garden - and thus aptly named, it is now dry and covered by a stone slab to prevent accidents. St. Helen's Well is in the field of the same name to the east of High Street. Golden Well is about 100 yards SSE of the modern church and probably derives its name from the colour of the sediment found there. St. John's Well is close by at the head of the St. John's valley.

(14), p. 101, refers to a cavern along the west coast, the entrance being of great height but it is comparatively narrow with the sides very nearly parallel and straight. This reference is repeated by Gross (22), p. 92 but in both cases there is a sketch of the entrance of the cavern though the entrance is not readily apparent in the sketch, nor is there any identifying landmark which suggests its location. Loyd (1), p. 73 refers to a translation from Latin of an inventory of the island made about 1325 by Sir Thomas de la More translated by Stow into English, in which it is stated that the island abounds in victuals, wines, etc. – this undoubtedly being a reference to the goods not produced from the soil of the island, but stored in the numerous caves and store-rooms in which it had been deposited – probably as pirated goods.

(29) lists photographs numbers 8435 and 8437 as being photographed by OD Kendall and being 'Lundy SE end - Cave in slaty series' and 'Lundy E coast – sea cave worn along joint in granite' respectively.

Finally I would like to make a few comments on the references below. Throughout my searches in literature relating to the island there has been considerable similarity in detail which tends to suggest that a proportion of the literature is merely based on previous writings, and rewritten.

An article entitled 'The Early Maps of Lundy' by AF Langham, in Lundy Field Society 13th Annual Report 1959/60 on page 46 reveals that Chanter, responsible for references (6) and (7) – considerable works about the island – never in fact visited Lundy but that his writings were probably compiled with the help of Rev. HG Heaven.

The references in the 'Home Friend', (8) to (15) contain perhaps the earliest comprehensive details of the island and its features, but the writings are attributed to no author. Reference (22) is a repeat almost word for word of the text of (8) to (12) except for a few minor corrections, mainly Latin botanical names, and the inclusion of the sketch of the cave entrance on p. 85. In the preface to (22) the author attributes the details in the work to accounts of his own experiences. It may well of course be that Gosse was also responsible for the 'Home Friend' articles.

Bibliography

Page numbers indicate references to caves, mines, etc.

  1. LOYD, LRW – Lundy; its History and Natural History (Longmans Green) 1925. Frontispience, pp 26-7, 50-1, 58, 61-4, 68-9, 73, 87, 135–6.
  2. ETHERTON, PT and BARLOW, W – Tempestuous Isle; the Story of Lundy (Lutterworth) 1925. pp 17, 29, opp 49, between 56-7, 60-5, 67, 76, 86, 109, 124.
  3. ORDNANCE SURVEY – 6" Map, Parts of Devonshire Sheets SS 14 NW and SS 14 SW (Provisional Edition) 1963.
  4. ORDNANCE SURVEY – 2½" Map, sheet SS 14 (Provisional Edition) 1960.
  5. LANGHAM, A and M – Lundy, Bristol Channel (Broadacre Books) 1960. pp 4-5, 70, 82, 83, 85, 86, 90, 91, 95, 97, 99-100, 115.
  6. CHANTER, JR – A History of Lundy Island. Report & Trans Devonshire Association, 4 (1871) pp 553-611; particularly pp 555, 560, 562-4, 566, 576, 587, 588, 589, 598-600.
  7. CHANTER, JR – Lundy Island: A Monograph Descriptive and Historical (Cassell, Potter & Galpin) 1877. Preface, pp 10, 28-37, 65, 94, 96, 126, 132.
  8. ANON – Home Friend; a Weekly Miscellany of Amusement & Instruction (Society for Promoting Christian Knowledge), 2 (47), pp 485-6 (1853).
  9. Ibid, 2 (49), pp 550-1 (1853).
  10. Ibid, 3 (53), pp 8, 9-11 (1853).
  11. Ibid, 3 (54), pp 38-42 (1853).
  12. Ibid, 3 (55), pp 54-5 (1853).
  13. Ibid, 3 (56), p 82 (1853).
  14. Ibid, 3 (57), pp 100-3 (1853).
  15. Ibid, 3 (58), p 125 (1853).
  16. ANON – 8th Annual Report, Lundy Field Society (1954), p 35.
  17. ANON – 9th Annual Report, Lundy Field Society (1955), pp 32-3.
  18. ANON – 10th Annual Report, Lundy Field Society (1956), pp 58-9.
  19. ANON – 11th Annual Report, Lundy Field Society (1957), p 30.
  20. ANON – 16h Annual Report, Lundy Field Society (1963-4), pp 24-5.
  21. GADE, FW – Lundy, Bristol Channel: The Official Guide (Gazette Printing Service, Bideford) n.d. pp 3, 4, 10-1, 15, 17.
  22. GOSSE, PH – Sea and Land (Nisbet) 1865. pp 12-4, 39, 45, 47-9, 51, 52-6, 64, 65, 67, 73, 85, 90-2, 95-7.
  23. HALL, TM – Notes on the Geology and Mineralogy of the Island of Lundy: with Some Remarks on its Relation to the Mainland. Trans Devonshire Association, 4, (1871), pp 612- 24; particularly pp 617-9.
  24. DOLLAR, ATJ – The Lundy Complex: Petrology and Tectonics. Quarterly Jnl Geological Society, 97 (1), (1941), pp 39-77.
  25. ANON – The Lundy Review. The North Devon Magazine, 1 (1824), pp 55, 58.
  26. GROSE, F – The Antiquities of England & Wales (Hooper) 1776, pages not numbered.
  27.  Archaeological Review, for 1966, (1), (Bristol University), 1967, p 42.
  28. LAWDER, KM and PYATT, EC – A Reconnaissance of Lundy. Jnl Climbers Club, for 1962, pp 313-7; particularly p 316.
  29. ANON – Geological Photographs taken and added to the Collection of the British Association. Report British Association, for 1935, p 309.
  30. THOMAS, S – The Nightingale Scandal (Gazette Printing Service, Bideford) 1959, pp 15, 26.
  31. 17th Annual Report, Lundy Field Society (1965-6). Due to be published Autumn 1967.
  32. Jnl of Medieval Archaeology, 11. Due to be published May 1968.
  33. Jnl of Post-Medieval Archaeology, 1. Due to be published February 1968.

MT Mills

September 1967

 

'Fibron' Tapes for Cave Surveys

Abstract

A measuring tape of relatively new construction has been tested and the values of various physical properties obtained. From these values the probable accuracy of the tape is calculated for cave conditions and various recommendations are made.

Introduction

Within the last few years a measuring tape of new construction has been put on the market by Rabone, Chesterman Ltd., under the trade name of 'Fibron'. These have been found to be almost ideal for cave surveying as they lack most of the disadvantages of the earlier tapes; for example they are impervious to water, are non-magnetic and are easily cleaned. Unfortunately the makers have published little information on their physical properties and correspondence with them has shown that they were unable to supply figures for properties such as Young's Modulus and thermal coefficient of expansion. However, they did send a 2.5 metre length of tape which has been tested to obtain those values.

Construction of tape

Microscopic examination showed the tape to consist of many thousand very fine glass fibres (diameter approximately 0.03 mm) made up into 48 strands running longitudinally through the tape. These strands are 0.3 mm in diameter and are encased in plasticised polyvinyl chloride (PVC).

Figure 12 – Cross-section of 'Fibron' tape

Weight per unit length

The full length of the sample was weighed on a chemical balance and the value found to be 0.0067 lb/ft.

Thickness

Using a dial gauge marked to 0.0001 inches, the mean of 50 readings along and across the tape was found to be 0.017 inches. There was an appreciable difference in thickness between the two edges of the tape.

Width

This was more difficult to measure accurately but the mean of 25 readings along the length of the tape was 0.58 inches. A bench micrometer having a two inch diameter drum and calibrated to 0.0001 inches was used. Care was taken not to buckle the tape when taking measurements.

Cross-sectional area

The last two values above give a figure of 0.01 square inches. This value was checked by measuring one cross-section by means of a cathetometer.

Young's Modulus

Two samples five inches long each were stretched to give 1% elongation on an 'Instron' Tensile Tester. An average load of 105 lbf was required. After an initial curve, the stress-strain curve was a straight line from 5 to 110 lbf. Part of the curve is reproduced on the accompanying graph. From those figures, Young's Modulus was found to be approximately 1 x 106.

Thermal coefficient of linear expansion

The proper apparatus for measuring this value was not available. An approximate value was obtained by measuring the distance between two marks on the tape when it was at 3°C and 37°C. The distances were measured by means of a cathetometer reading to 0.001 cm. The linear coefficient of expansion was calculated to be 7 x 106 per °C. (Not too much faith is put in this value but it is similar to that for glass and therefore is probably reasonable.)

Using the formulas given in any manual on surveying, it will be found from these values that the change in length of the tape when used at an ambient cave temperature of 10°C is -0.0014 feet over a survey leg of twenty feet, an average leg length in cave survey. The stretch over this length at a pull of 10 lbf on the tape is +0.016 feet, and the effect of sag under these conditions will be 0.00015 feet. (Note: 'Fibron' tapes are 'standardised' at 20°C with a pull of 2 lbf when supported along their length.) These effects are seen better from the accompanying graphs where the stress-strain curve obtained experimentally is drawn, together with the effect of temperature correction to 10°C, and the effects of sag and stretch at various loads. The sum of these effects is also shown. The actual stress-strain curve is used because Young's Modulus assumes a straight line relationship which is not true for the low loads in which we are interested.

In order to determine the size of these effects under conditions of cave surveying it was necessary to measure the size of pull normally applied. A spring balance was taken on two surveying trips and the load measured under a variety of caving conditions. The readings obtained, with three people, ranged from 2 to 10 lbf. The principal conclusion reached was that there was less difference between the three people than between different caving conditions. Very generally it was found that under easy conditions with plenty of room, an average pull of 8 – 9 lbf was applied; in constricted passages a pull of 4 – 5 lbf was used. A pull of 10 – 12 lbf was found to be a definite effort, especially if the ring at the end of the tape is held on one finger only. Using this method of holding the tape, a pull of 8 – 10 lbf will probably be applied under good caving conditions.

Figure 13 – Effect of stretch on 'Fibron' tape

Conclusions

By far the most important factor is that of stretch. A pull of 3 lbf will give a correct reading of length but even with the maximum pull likely under cave conditions (12 lbf) the total error will be only 0.1%. It is better to apply only a gentle pull than to pull as hard as is possible. Even in the worst likely case, the measurement of distance with a 'Fibron' tape will be well within the accuracy of the remaining measurements made in cave surveying.

It is considered that 'Fibron' measuring tapes are the most suitable for cave survey purposes, particularly No. 271/3 which is marked in feet and twentieths of a foot, thus saving the conversion of inches into decimals of a foot for calculation. The current price of this tape, 50 feet long, is:

Refill (tape only) reference number 271/3 £1/ 0/ 3.

In open aluminium case reference number 271/3 £2/ 19/ 0.

Alternatively these tapes can be purchased marked in metres, centimetres and half centimetres when the reference number is 271/5.

BM Ellis

May 1967

 

Book Review: Expedition 67 to the Gouffre Berger

Report by P Watkinson and others

Published by the Pegasus Club, Nottingham at 10/-, plus postage

Available from BM Ellis, Knockauns, Combwich, Bridgwater, Somerset

This is an excellent report and this time there is not going to be any qualifying clause of "but ...". Even the price, which as usual appears high at first sight, is considered reasonable when everything is considered. There are 25 printed pages of text, three diagrams and 29 photographs, many of them excellent, and obviously the club are hoping to recover some of their costs from sales of this report.

The text consists of a fairly brief, factual account of the expedition which does not go into laborious and repetitive details, a fault of many other reports, and is unusual in that in only one place in the whole report is an individual name used. To find who was on the trip it is necessary to consult the list of members given at the end. It should be pointed out, perhaps, that the Pegasus Club was at the cave at the same time as the much more publicised expedition led by Ken Pearce. It appears nowhere in so many words but it does not require much effort to realise that there must have been a certain amount of friction between the two parties. The original plan was for Pearce's party to ladder the cave and for the Pegasus to detackle. It is probably well known by now that several members of Pearce's party became demoralised, left the cave and refused to go down again. In this report one keeps coming across phrases such as "and morale remained high" when talking of the Pegasus parties. Some of the members from the other expedition did join the Pegasus in their attempt, and later Pearce entered the cave and dived the sump. The bitterness shows through in this report in, "the first team met the Pearce team coming back … he had made a dive but would give no news". After all that had gone before, including Pegasus having to ladder the cave, such bitterness is understandable at such discourtesy though excuses have almost certainly been made.

The report also contains reports on the equipment, food, medical, communications and photography. All is concise and factual but there are sufficient anecdotes to prevent it being dry. The most disappointing, for me, was the communications report which while giving no details was still too technical for me to follow; but this is a very small criticism. It is a pity other expeditions have not prepared similar reports in such a readily available form; most are hidden away in club journals. This one is a good buy.

 

Pen Park Hole, Bristol in 1669

The following account of a visit to Pen Park Hole is by a Samuel Sturmy. It appears in a very rare book, 'Lectures de Potentia Restitutiva' by Robert Hooke, published in 1678. There is a photocopy of these pages in the club library.

[p 40]

Having thus delivered here somewhat of my own thoughts concerning Springs and Rivers, finding among some of my Papers a Relation, wherein a very strange subterraneous Cistern is mentioned, I have here subjoyned it as I received it from Mr. Thomas Alcock from Bristol who together with Sir Humphry Hooke was by whilst Captain Samuel Sturmy made this inquiry, and who by interrogatories made to him, penned this Relation for him as it follows verbatim.

 

In pursuance of His Majesties Commands to me at the presenting of my Mariners Magazine, I have with much diligence, some charge and peril endeavoured to discover that great Concavity in the earth in Gloucestershire, four miles from Kingrode, where His Majesties great Ships ride in the Severn. And I find by experience that what has been reported of that place is fabulous, whilst I thus describe it.

 

Upon the second of July 1669. I descended by Ropes affixt at the top of an old Lead Oare Pit, four Fathoms almost perpendicular, and from thence three Fathoms more obliquely, between two great Rocks, where I found the mouth of this spacious place, from which a Mineman and my self lowered our selves by Ropes twenty five Fathoms perpendicular, into a very large place indeed, resembling to us the form of a Horseshoe; for we stuck lighted Candles all the way we went, to discover what we could find remarkable; at length we came to a River or great water which I found to be twenty fathoms broad, and eight fathoms deep. The Mineman would have persuaded me, that this River Ebbed and Flowed, for that some ten fathoms above

 

[p 41]

the place we now were in we found the water had (sometime) been, but I proved the contrary by staying there from three hours Flood to two hours Ebb, in which time we found no alteration of this River; besides, it's waters were fresh, sweet, and cool, and the Surface of this water as it is now at eight fathom deep, lies lower than the bottom of any part of the Severn Sea near us, so that it can have no community with it, and consequently neither flux nor reflux, but in Winter and Summer, as all Stagna's, Lakes, and Loughs (which I take this to be) has. As we were walking by this River thirty two fathoms under ground, we discovered a groat hollowness in a Rock some thirty foot above us, so that I got a Ladder down to us, and the Mineman went up the Ladder to that place, and walked into it about three score and ten paces, till he just lost sight of me, and from thence cheerfully called to me, and told me, he had found what he looked for (a rich Mine;) but his joy was presently changed into amazement, and he returned affrighted by the sight of an evil Spirit, which we cannot persuade him but he saw, and for that reason will go thither no more.

 

Here are abundance of strange places, the flooring being a kind of a white stone, Enamelled with Lead Oara, and the Pendent Rocks were glazed with Salt-Peter which distilled upon them from above, and time had petrified.

 

After some hours stay there, we ascended without much hurt, other than scratching our selves in diverse places by climbing the sharp Rocks, but four days together after my return from thence I was troubled with an unusual and violent Headache, which I impute to my being in that Vault. This is a true account of that place so much talked of, described by me.

 

Samuel Stury.

Notes

The words underlined in the above quotation appear in italics in the original work.

A modern account of the reopening of Pen Park Hole, together with descriptions and a survey, was published as Publication No. 12 of the Cave Research Group of Great Britain (1963).

 

Attachment

 Journal Series 04 Number 4