The Florence Court Caves:
Co. Fermanagh.
By Harold Brodrick.
Even though the accommodation at the average Irish hotel is not to be compared with that obtainable in Yorkshire, the beauty of the scenery and the cheerful nature of the inhabitants, to say nothing of the numerous unexplored caves, drive anyone who has commenced the ` work of cave-exploration in Ireland to cross the Channel again and again. In the last number of the Journal I gave an account of some explorations at Whitsuntide, 1907, in County Fermanagh, and stated that at least one more visit would be needed to work out the Marble Arch district fully. An opportunity luckily offered itself at Easter, 1908, when several, members of the 1907 party, together with others, visited the district. On this occasion we stopped at the Victoria Hotel, Black Lion, and so, although we still had a matter of four miles to drive to Marble Arch, We were saved the ten (Irish) miles drive from Boho which had considerably curtailed our time the year before. As on the occasion of our former visit, the Earl of Enniskillen kindly gave us permission to go into any part of the beautiful Florence Court demesne, and also gave instructions to his head keeper, Mr. Bowles, to give us all the assistance in his power.
As I stated in my former paper, three streams rise on the northern slopes of Cuilcagh Mountain, and sink at three points on the limestone plateau. There are three large springs on the low land below the plateau, and also numerous pot-holes on the plateau, some of which are indicated on the Ordnance Survey. Our intention on the occasion of our second visit was three-fold; we wished to complete the exploration and survey of the caves in the Florence Court demesne, to descend the various pot-holes, and thirdly, to trace, if possible, the flow of the underground waters in the district.
As the weather during the whole of our stay was perfect, we alternated between cave work and pot-holing, but for the sake of clearness I shall not describe our work in the order in which we did it, but will deal with the three streams and the pot-holes above them from E. to W.
The most easterly of the three streams sinks at Pollasumera, a cave which we partially explored in 1907; but still further to the E. are two pot-holes, both of which we have descended.
Although two Rattling Holes are marked on the Survey only that in Doneen townland is of any depth, and Mr. Bowles told us that it was reputed to be the deepest pot in the neighbourhood, so there seemed to be every prospect of good sport. This pot-hole is a long open fissure, surrounded by a wall and choked with vegetation. Some time elapsed before we could find a suitable lead for our ladders, as much of the rock was in a loose and rotten condition. The descent was somewhat awkward, owing to the extreme narrowness of the fissure in places, but nearing the bottom it widened considerably, and ended in a chamber 14ft. long and 7ft. wide. The floor, which was reached at a depth of 90 ft., consisted of of loose scree, sloping down in one corner to a depth of 6ft. From the N. end a very steep mud and rock slope ran up to the surface, and from this we attempted to take photographs of the party making the descent. This was a difficult operation, as the slope was so steep that it was necessary to secure both photographer and camera by ropes tied to trees on the surface. Looking upwards from the chamber, the shaft presented a very pretty appearance owing to the wealth of vegetation extending right over the opening and some way down the fissure. As in the other pots, there were the usual remains of sheep and lambs on the floor, a circumstance which impelled us to hurry to the surface as soon as our survey was completed. About a mile to the N., in the townland of Leefa, is a second Rattling Hole, but as we were informed that it was quite insignificant, we did not trouble to visit it. The last pot-hole we explored during the expedition is situated in the townland of Gortmaconnell, rather more than a quarter of a mile SW. of the Dooneen Rattlin Hole. It is represented on the Survey Map by a small circle, but is not named, and wc have called it “Gortmaconnell Pot,” as it lies in the townland of that name. The hole was bridged over with tree trunks, and trees had been planted all round the opening, evidently with the idea of preventing sheep falling into it, and this vegetation had flourished to such an extent that the mouth was completely covered. Our first business was to make a way for our ladders, and on plumbing we found the hole to be 68ft. deep, consisting of a fissure running N.E. and S.W., 48ft. long and only 3½ ft. wide. There was a small chamber at the bottom which showed signs of water action. The view from the bottom was very fine, as the sun was shining through the vegetation which blocks the mouth.
The most easterly of the three streams usually sinks into its bed a quarter of a mile above Pollasumera Cave, and even at the time of our visit contained such a slight flow of water that we considered colouring it would be of no use; but we were informed by Mr. Bowles that he had seen his father put chaff into the stream and it had come out at the point marked ” Springs ” in the Cladagh Glen, where there was, at the time of our visit, a considerable outflow of water. This is to be expected, as the line through Pollasumera, Pollthanacarra and Pollnagollum would point to the same conclusion. In my former description of Pollasumera I stated that it was impossible to get beyond the lake which we found in it; on our second visit we carefully surveyed the cave and, as usual, found that we had greatly overestimated its length, as the main passage is only 92 yards long. When we had surveyed the part which we had explored before, we carefully inspected the lake and floated candles across it, and these revealed a pebble beach at its further end, and also the fact that along one side the water was not more than three feet deep.
We had not time that day to do anything further, but, on our last day, two members of the party hurried over to complete the exploration. To wade in three feet of water, with a bottom of rough boulders, and only twelve inches between water surface and roof, is not easy. One’s head is fairly between Scylla and Charybdis, and wettings and bumps alternate as one advances, while the frequent extinguishing of candles complicates the business. This ordeal safely over, the two explorers advanced over a descending floor of boulders, hoping that a long and new passage might reward them. The going was of the roughest, as the rubbly, marbled rock was excessively rugged. A curving passage, evidently in normal weather occupied by a torrent of water, led slightly downward for about 50 ft. Then ensued a series of great curtains of solid rock, descending to within 3 ft. of the floor, with a steep rise both of floor and ceiling beyond each. The second rise was formed, not of rock, but of solid peat, brought down from the mountains and deposited here. When we saw this we knew we were approaching some upward shaft through which the flood-water could rise, leaving below its burden of detritus, and our hopes fell. Another curtain, then a dense bank of peat and ancient branches of trees, and then the cave gave out, and the water evidently continued its course through narrower fissures and cracks. We had, however, done all there was to be done. We had penetrated more than 120 feet beyond the lake, and shown that in this direction further progress was definitely barred.
Close to the most westerly of the two Pollasumera caves we found a low opening at the base of the cliff, which led into a series of very narrow parallel fissures, but all of them became, in a short distance, too narrow for passage.
To the N. of Pollasumera, and in a direct line towards the Springs, is a large open pot-hole called Polldownlog, full of trees, with a f’loor of loose boulders through which no opening could be found.
Further N. still are two other pots – Pollthanacarra and Pollnagullum – lying close to one another. At Pollthanacarra we found that a ladder was required for the descent, but before we could obtain a satisfactory lead it was necessary to remove a considerable portion of the wall surrounding the pot. The fissure runs N. and S., and is 40ft. long and 20ft. wide. We fixed the ladder at the N. end and sent one man down. He reported that the fissure ran a short distance to the North, and was then choked with loose rock. The floor is 40ft. below the surface, and to judge by the articles found in various parts of the pot it is used as a general rubbish heap for the neighbourhood.
Meanwhile the rest of the party had been exploring Pollnagullum, a hole obviously in the same fissure. The S. side is almost vertical, and runs down 54ft. It was possible to climb down the N. side, which consisted of loose boulders covered with vegetation. At the bottom the fissure runs S. towards Pollthanacarra, and we followed it for about 20 ft. through loose boulders, but beyond this point the floor and roof are so unstable that we decided to retreat.
There is no doubt that before the fall of the rock which choked up the fissure there was a passage communicating with Pollthanacarra. The most striking feature of Pollnagullum is the wealth and beauty of its vegetation. The sides were covered with ferns, and festoons of creepers stretched from rock to rock. Practically every pot we explored in this part of Ireland was roofed over with trees and shrubs, in striking contrast to the majority of English pot-holes, which are often simply bare holes in the moors high above the tree limit.
Rather more to the W. is another pot-hole not shown on the Survey, consisting of an open fissure running N. and S. From the surface we could see a wide ledge about 25ft. below, on which lay a dead lamb, so for the time being we call the place ” Lamb Pot.” From measurements we found that the fissure was 20ft. long by 7ft. wide. We descended to the ledge and discovered very quickly that the name was thoroughly justified, as there were three or four carcases of lambs in various parts of the hole, and the surface of the floor was almost entirely composed of bones and skulls, rendering exploration a distinctly gruesome business. At the N. end of the ledge was a second shaft, 25ft. deep. There were other holes in the floor, 10 to 15 ft. deep, but nothing of further interest, so we ascended, rather relieved to escape from the remains of lamb and sheep. We have since named this pot-hole Legnabrocky Pot, from the townland in which it is situated.
By far the most interesting of the three streams is the central one, which goes by the name of the Monastir River. In my former paper I described Templebawn and Monastir Cave, so I need not say anything further about them. There are several pot-holes marked on the Survey to the S. of Pollnagapple and not far from the Monastir Cliff. Pollawaddy proved to be a large opening, 80 feet deep, filled with trees. It is possible to walk down, but apart from its size it is without interest. The same may be said of Pollreagh and Pollagaria, and after a rapid inspection we turned our attention to Pollbwee.
M. Martel mentions a pot-hole close to the Monastir Cliff and marks it on his map as 22 métres deep, but he did not descend it. Mr. Bowles told us that its local name was Pollbwee, (The Yellow Cave).
The surface opening is a fissure running N. and S., the northern end being formed of a mud slope, down which it is possible to climb for a few yards. The fissure was bridged over in the middle by a boulder, and about 30 ft. down a small ledge was visible from the surface. On plumbing the shaft, we found that the vertical depth was 67 ft., but when stones were thrown down they appeared to roll on and finally to strike water. We had no difficulty in fixing our ladders and very soon all was ready for the descent.
The Irish member of our party was the first to reach the bottom and he reported that the shaft opened into a large chamber, the floor of which consisted of a steep mud slope. He remained tied on to the rope and worked his way down this slope, by the aid of very precarious footholds, until he reached a side fissure where there was firm rock on which to stand. The mud slope ended in a deep pool of water, from which the opposite wall rose vertically to the roof of the chamber. After ascertaining that his position was secure, he untied the rope and sent it up to the next man, and in this way four members of the party made the descent. We then started to explore the side fissure, but found our way blocked at the outset by a huge boulder, which completely filled the lower part of the entrance. But once over it, further progress was fairly easy, and we found ourselves in a long, narrow passage, which seemed to have been formed by the wearing away of a vein of calcite. We continued along the passage, over jammed boulders, for about 60 ft., after which the floor began to slope steeply downwards and, turning slightly to the right, ended in a small pool.
On the left was a side passage, ending in a steep slope of waterworn limestone, running up into darkness. One of the party climbed up this slope to a considerable height, but the holds were so bad that he decidedto descend. As far as we could judge by the aid of magnesium wire, the slope reached a height of about 30 ft., after which the passage narrowed so much that further exploration would have been impossible.
After measuring up the passage and its branches, we retraced our steps, and three of us reached the large boulder in safety, but the fourth member of the party had a narrow escape from a serious accident, as the false floor of loose rock behind the boulder gave way beneath him. Fortunately it only fell a few feet, and he escaped with a bad cut on the hand.
From our landing-place at the entrance to the fissure we could see a glimmer of daylight coming through the roof at a point directly over the pool, and we heard the voices of those left on the surface quite distinctly. We measured the length of the slope, and found it to be 43ft., while the fall was about 1 in 1, so that the surface of the pool is about 100ft. from the surface. We were not able to ascertain the depth of the water in the pool but there was no perceptible flow in it. Our ascent of the ladder gave rise to considerable amusement amongst those on the surface, as a projecting rock about half-way up succeeded, in nearly every case, in removing our headgear, and a return to the pool, with a spare rope for fishing operations, was twice necessary. Before leaving the pot we found, close to it, the small hole through which we had seen daylight from below.
In a direct line between the Monastir Cave and the outflow of the water at Marble Arch are three openings in the moor; the first is Pollbwee, which I have just described, the second is Pollnagapple, of which I gave an account in the earlier paper, the third is Cradle Hole, which consists of a wide opening about 80 yards in » diameter, its floor being covered with a mass of boulders coated with vegetation of all kinds, while the whole pot is shrouded by tall trees. The N. and S. walls of this pot are composed of vertical limestone cliffs, some 110 ft. high, at the base of each of which are caves through which the stream from Monastir Hows; the other two , sides consist of steep slopes.
Although we had been into the Lower or Northern Cradle Hole Cave on the occasion of our former visit, we had not surveyed it; and our time had been so much taken up on _our second visit with the survey of the Great Cave and the exploration of the various pot-holes, that we did not survey the Cradle Hole Cave until our last day. We were due to catch the 4-49 p.m. boat train, at Enniskillen, a distance of some ten miles, so an early start was made, and after a quick drive on a car from Black Lion, we made our way up the glen for the last time. Two members of the party made at once for Pollasumera to complete the survey there, while the third stopped at Cradle Hole.
The solitary member first entered the Lower Cradle Hole Cave which lies at the foot of the southern cliff. The opening consists of a wide arch about 4 ft. high, leading into the Lower Cave. Inside this arch a drop of 20 ft. has to be negotiated. From here is a passage some 15 ft. wide and 3 ft. high, which at a distance of 30 yards opens into a straight passage some 50 ft. wide, and ranging from 10 to 30 ft. in height. The main stream flows in from the left, having worked its way from the Upper Cave under the boulders of which the floor of Cradle Hole is composed. At a distance of 104 yards from the entrance the stream spreads out and fills the whole width of the cave, which is here 30 ft. wide and about 7 ft. high.
Surveying single-handed is naturally slow and tiring work so the solitary member sat on the edge of this pool for a while, to rest. An empty match-box with a candle stuck on it formed an excellent fire-ship, which slowly floated down the stream. Although, at first, it seemed that the roof came down to the surface of the pool, the candle floated on, and showed that there was still at least 6 inches of head room above the water. Time and the danger of solitary exploring did not permit of anything further being done here, but on working out the surveys of Marble Arch and Cradle Hole afterwards, and plotting them out on the Six-inch Survey, it was interesting to discover that the lower end of Cradle Hole was within about 30 ft. of the upper end of the Grand Gallery in Marble Arch, so that it is probable that, if one did not object to a thorough wetting, a way through could be found. This discovery is naturally one of great interest, and could not have been made except from a careful survey.
The solitary member then made for the open again, and met the others returning from Pollasumera. As a short time was still at our disposal, we decided on a hurried look at the Upper Cradle Hole Cave. This lies at the base of the other of the two cliffs, and like the Lower Cradle Hole Cave is entered by descending a 20ft. drop under a low arch. We at once found ourselves in a fine water passage, with the stream flowing from left to right. Exploration was impossible down-stream, as the river soon flowed under the big boulders which entirely filled the passage. Up-stream, the cave – here 30ft. high and 15ft. wide – turned sharply to the right, the floor being entirely occupied by a deep pool of water. One member quickly stripped, and, taking a measuring cord with him, hurried through the water, which was about 4 ft. deep. He soon got clear of the pool, and continued along a fine, straight cave for a distance of 55 yards up-stream. At this point, although he could still see the cave going straight forward, he decided to return.
This passage led directly towards Pollnagapple so that there is little doubt that if we had had more time at our disposal we could have reached the point below that pot and it seems not unlikely that there may be passages and chambers here as fine as any in Marble Arch Cave.
The next point of interest on the moor below Cradle Hole is the Marble Arch Cave, but before describing our work there in 1908 some account of the known portion of the cave and of the earlier explorations will be necessary. One portion of the Marble Arch Cave seems to have been known for a very long period, but, until our first visit, only one exploration of the rest of the cave seems to have been attempted, that by M. Martel in 1895.
Walking up the beautiful Cladagh Glen from the main road, the Springs to which I have referred earlier are first passed on the left, and then, about a quarter of a mile further on, the Marble Arch itself is reached. This consists of a fine natural limestone arch rising some 30 ft. above the stream bed. There is a local tradition that a little girl once fell through the small hole in the arch on to the stream bed below and was not hurt at all. Some 25 yards further is a limestone cliff, from the foot of which flows the stream, and further progress in that direction is impossible; but on the plateau above are three open pot-holes, each about 60 ft. deep and some 50 yards apart, which, as they have no local names, we have designated by the letters D, C and E. All these pots, the floors of which are covered with great boulders, can be readily climbed down, and from the bottom of C an opening leads to a lake from whose shores light can be seen at D, and vice versa. From these two points practically all the lake can be seen, so that we did not attempt exploration there. At the bottom of C is another low opening which leads to a wide passage, some 20 ft. high, from which two branches run, one leading to an opening in pot-hole E, while the other, after a drop of 10ft., leads to the edge of the water where M. Martel launched his boat.
In the year 1895, M. Martel, in the course of what he calls his “British Campaign,” visited Marble Arch and, in company with Mr. H. Lyster Jameson, reached the end of the Grand Gallery by the aid of a collapsible boat; in the other direction, branching off from the Junction, he got as far as the point which we now call the Pool Chamber. In 1907 we explored the cave, but not having a boat, were compelled to wade through the deep water near the entrance. At the end of the first ” deep water,” a distance of some 80 yards, is the Junction, and beyond this we found that the conditions had materially changed since M. Martel’s visit, so that the Grand Gallery was no longer filled by a deep stream, but was floored with loose rocks between which the stream flowed, where it would have been quite impossible to float a boat.
The two members of the party who waded through the water in 1907 also explored the passage which runs in a north-easterly direction from the Junction. They found that this passage widened steadily for a distance of about 160 ft., while the floor to the left rose considerably, that to the right continuing at the same level.
At the upper end of the slope was a fine collection of stalactites, and beyond a low opening led, by a drop of 12ft., into a narrow fissure cave, some 30 ft. high and 40 ft. long. The floor of this fissure was composed of clay on which one of the explorers slipped and would g probably have had a serious fall if he had not been roped; at the lowest point was a small hole through which could be faintly heard the murmur of running water.
The continuation of the main passage to the right was found to end, at a distance of nearly 100 yards from the Junction, at the Pool Chamber, which consists of a cave 15 yards in diameter and about 20 ft. high, its floor being composed of a mass of boulders and sand, sloping steeply down to a still pool of water at its lowest point. The far end of this chamber, which was the extreme point reached by M. Martel in 1895, seemed to be entirely blocked by fallen rocks.
To return now to our experiences in 1908. On arriving the first day at Marble Arch Gate, which we had left with such reluctance twelve months before, we found the keeper, Mr. Bowles, waiting for us with a donkey car. Our wagonette could not go far up the glen, so we transferred our ladders, ropes, &c., to the donkey car, and worked our way up to the Marble Arch itself. The first item on our programme was the exploration of a pot-hole which had been pointed out to us by Mr. Bowles in the plantation the year before. This has a small opening some 10 ft. long by 3 ft. wide. A convenient tree gave us a safe belay for the rope ladder and this was soon lowered and the first man quickly descended the first pitch, which was only about 30 ft. deep. A second, and then a third, member of the party followed, and found themselves on a natural bridge of rock, with dimly discerned depths below. The first man, carefully roped, then climbed down one side of the bridge, to find himself, when 15 ft. lower down, in a vast confused mass of boulders, where it was easy to lose one’s way. This place was very similar to the upper portion of the Great Eastwater Cave in the Mendips. Three members, including two of the 1907 party, worked their way down through these boulders, and, after descending about 15 ft. in a sloping direction, arrived in a spacious chamber floored with boulders similar to those they had clambered through. Far above could be seen the dim light from the pot-hole by which they had entered, while a cheery shout from the man on the bridge shewed they were still within touch of the open air. The man on the bridge then tried to join them over the boulders, but this was found to be impossible without wings or a ladder. This “Great Boulder Chamber” was about 80 ft. high, as far as could be estimated, and had a diameter of about 60ft. There seemed to be no way forward, except through the boulders, and, by good luck, the first attempt led in the right direction – a vertical drop of about 8 ft. between the boulders, then a short scramble, and a further drop of 6 ft., leading us into the end of a low passage some 10ft. in width. This passage was formed entirely out of the solid rock, and was about 3 feet in height. A crawl of 40 ft. led the party into a fine chamber, 30 ft. in diameter. To the right the floor sloped steeply upwards, and led into several passages between boulders, which seemed as if they might lead back into the Great Boulder Chamber. To the left a steep sandy slope terminated in a still pool of water. The appearance of the pot-hole had not led us to anticipate anything very great, and only a very limited supply of candles had been brought, so when only two short bits of candle were left, two members remained where they were with the shorter bit, while the third went back for a further supply. Mr. Bowles and the man on the bridge came back with him into the Lower Cave with a plentiful supply of candles and the exploration was continued. On the far side of the Pool Chamber a passage was found, 15ft. high and 6ft. wide, which at a distance of about 40 yards became more or less blocked by big boulders. These proved only a slight obstacle, as, owing to their size, it was comparatively easy to climb either over or under them. After getting past this obstruction we found ourselves in a high chamber, with the floor composed of rocks cemented together by stalagmite and rising at a steep angle to the right, and after clambering over a few more boulders, a smooth stretch of sand was reached which led, in about 30 yards, to the shore of a large stream flowing in from the left and vanishing into a wide tunnel to the right.
The party had now been underground for about three hours, as the shortest way through the great mass of boulders had been bad to find and we had just decided to return to daylight for a meal, when one of the party, who had been there the year before, recognised a peculiarly-shaped rock, and it only needed a few minutes’ consideration to make it clear that a new way had been found into the Great Cave, which only involved a rope ladder descent and no wading, and a hurried return was made at once to the pot-hole.
Two members however followed more slowly, as they wished to explore the sides of the passage as much as possible. The Pool Chamber had evidently been the furthest point reached the year before – it was also the furthest point in that direction reached by M. Martel in 1895 – but the passage forward to the Great Boulder Chamber had been overlooked, as the entrance was hidden by several large rocks. After crawling along the low bedding cave, some difficulty was experienced in finding the way up into the Boulder Chamber; but, after two or three mistakes, the way through the boulders by which we had climbed down was found again. Clambering round part of the Great Boulder Chamber to see if any more passages led out of it, they were suddenly surprised to see a feeble glimmer of light in one corner. A short scramble over and under the boulders, 10 to 15 ft. in diameter, brought them to this light, which they found filtering in past large rocks, between which could be seen the waving branches of trees and ferns. About five minutes’ work sufficed them to widen the opening and climb out, to find themselves at the base of the wide open pot-hole marked by M. Martel as E, and within about 15 ft. of another opening into the generally known portion of the cave. A short scramble up the slope of the pot-hole brought them out quite close to the narrow pot down which the ladder had been lowered, and great was the astonishment of the rest of the party to find them waiting on the surface, the way through the boulders and up the ladder having taken much more time than the new exit.
As such a comparatively easy entrance had been found there was now no necessity for a ladder, and on another day we all quickly clambered down into the Great Boulder Chamber by 10a.m. and divided into three sections of two each, for exploration, survey and photography. Nothing new of any note was found, although one narrow fissure leading from near the Pool Chamber was explored for some distance. Making our way past the Pool Chamber, by the passage we had traversed a few days before, we reached the Great Chamber and found that it was even more impressive than our recollections of the year before had led us to expect. Now we were a party of six, with an unlimited supply of candles; then we were only two and had got into the cave by wading through deep water, and only reached this part after exploring all the other known parts of the cave. At the upper end of the steep slope which forms the floor of this chamber is a good collection of very fine stalactites, and near them, laid out on a clay bank, was the perfectly clean skeleton of a rabbit, which must have lost its way in the intricacies of the cave. From the condition of the bones they had quite possibly been there for centuries. We went forward to the Fissure Chamber, and on its muddy floor could see traces where one of the party had a nasty fall the year before.
We next surveyed the Grand Gallery, and found it to be an absolutely straight passage 123 yards in length. At the upper end was the same pool we had reached twelve months before, and where we turned back owing to the lowness of the roof. The floor had not altered materially, but our footmarks had been washed away, indicating that this portion of the cave floods considerably at times. We retraced our steps to the Junction, and sent a volunteer through the deep water down stream to the old entrance. This was necessary, as we required accurate measurements and compass bearings. We found it to be exactly 100 yards, while the actual deep water was 40 yards in length. The whole passage through which the river runs, from the upper end of the Grand Gallery past the Junction to daylight at pot-hole C, is a
magnificent tunnel about 20 ft. wide and ranging from 8 ft. to 25 ft. in height, while at the Junction the roof must be at least 50 ft. above the stream. One curious feature was noticed at this point. In all other parts of the cave, when the photographers burnt their flashlight powder, the heavy smoke remained hanging about the passages for a long time, but at the Junction it seemed to be drawn up at once through a dark hole which we could see high up in the roof. By this time we were all beginning to feel rather tired, and, as we had completed the survey of this part of the cave, we regretfully made our way out through the Great Boulder Chamber to daylight and tea, having spent altogether rather more than six hours in the cave. After tea we went through the passage, which is well known, from pot-hole C to E, and also took careful measurements of the surface features. As already explained, the new entrance is within 15 ft. of one previously known, so that we had now data for checking our survey. On getting home and working out the plan we were glad to find, that although the round journey from entrance to entrance is 270 yards, we had only made an error in position of less than 20 ft. – very slight, considering the difficulties of taking exact bearings by candlelight in such complicated passages.
In order to test the accuracy of the report that the Monastir River emerged at Marble Arch, we put half a pound of fluorescein into it at 11-30 a.m. in dry weather; it was clearly visible in the Upper Cradle Hole Cave at 10-45 a.m. the following day, and at 6-45 the same evening it began to emerge at the Marble Arch Spring, having taken thirty-one hours to travel a distance of slightly more than half a mile. By this test we have practically settled the courses of the three streams: the eastern one rises again at the Springs, the central or Monastir River appears again at Marble Arch, while the water which sinks at Cat’s Hole almost certainly rises at the spring near the road, as I explained in my last paper. These conclusions are what one expects from a consideration of the master-joints in the district.
During this excursion we inspected a large number of caves and pots marked on the Six-inch map of Co. Cavan, between Black Lion and the Source of the Shannon, but found none of any importance. One pot-hole, however, probably holds the record for size in the British Isles, as it consists of a vast basin, some 250 ft. deep, with a diameter of at least a quarter of a mile. All its slopes were covered with vegetation and at its lowest point a small stream drains away into a muddy sink.
The party consisted of H. Bassett, W. L. Hicks, Chas A. Hill, R. Lloyd Praeger and the writer.