Friday, 14 December 2007

The Caverns of Bermuda

The Caverns of Bermuda

Story and Photos by A. Hyatt Verrill

From Tropical and Sub Tropical America, a monthly magazine, issue April 1908, digital capture December 2007 by Doug Frizzle

HUNDREDS of miles from the coast of the mainland, and surrounded by the restless surges of the great Atlantic, lies the little group of semitropical islands of Bermuda. Familiar as a winter resort, and intimately connected in the minds of most persons with early onions and potatoes, these islets have quite another claim to distinction in that they contain more caverns to the square mile than almost any other spot in the world. Indeed, it is no exaggeration to state that every cedar-clad hill encloses a cave.

This may seem strange to those accustomed to consider the Bermudas as “coral islands”, but in reality they are not of coral formation at all; for from beating surf to wind-swept hilltops they are composed entirely of drifted shore sand. This sand consists almost wholly of broken sea-shells with a few fragments of coral. Although in many places the sand has become solidified to the hardness and fineness of marble, the process of formation can readily be traced, step by step, from the loose shifting sand of the dunes and beaches to the hardest building stone. In many localities the layers of stone and sand grade into one another in such a manner that it is difficult to say where one begins and the other ends. The sand, when packed tightly by the wind and then left stationary for any considerable period, becomes saturated with rain water containing carbon dioxide, and the separate particles become, so to speak, cemented together.

A peculiarity of this formation, which has a direct bearing on the caves, is that in the hardest and oldest rock, and between layers formed centuries apart, are found strata or isolated accumulations of loose sand, which, for some reason as yet unknown, have remained unaffected by the percolating water. Overlying the surface of the sand-formed rocks, and especially in the valleys, is a layer of vegetable mould and insoluble residue of decomposed rock of a reddish brown color—the ''red-earth" of the natives, and the only fertile soil on the islands. As there are no springs or streams in Bermuda, and as the caves invariably occur in hills instead of valleys, their formation has proved a puzzle to many, and it is evident they could not have been carved from the rock by underground streams as is the case with Luray, Mammoth, and other well-known American caverns.

It is an established fact that the Bermudas in former geological periods covered an immensely larger area than at present; and what were valleys in that remote age, are now hills. Wherever in those ancient valleys a "sand-pocket," or sand-layer, existed, the surface water —and possibly long extinct brooks as well—was absorbed. Finding the loose sand but a slight impediment to its progress, the water worked slowly through it to cracks connecting with the sea, gradually washing out the sand until a cavity of greater or less size was formed. As Bermuda limestone hardens rapidly when exposed to the air, the walls of these former sand-pockets soon became harder than the surrounding rock, and, as the erosion of the following centuries took place, were left as domed or rounded hills standing above the softer limestone. Then, as the "red-earth" formed, and trees took root, and rain-water filtered through the cracks and crevices, the stalactite or dripstone formation was deposited, still further protecting the interiors and walls from the wear and tear of time and elements.

Unlike most other caverns, the Bermuda caves are all connected with the sea. In some only a few inches of water covers the floor at high tide; in others the tide rises and falls several feel within their gloomy recesses: while in yet others the floor is always submerged, and the visitor compelled to explore them in a boat. Although the water is clear and transparent, no fish are seen, notwithstanding the fact that there is easy ingress from the sea; but in the so called "grottos," which are merely caves whose roofs have fallen in, fish fairly swarm.

The Walsingham Caves are perhaps the most frequently visited of any in the islands, although they are by no means the largest or most beautiful. There are probably a dozen caverns in the Walsingham group, situated near the shores of Castle Harbour on the eastern part of the island. The entrances to most of these, as in nearly all Bermuda caves, are small and partially hidden by ferns, shrubs and drooping masses of convolvulus and jasmine. The largest of these caves is about two hundred feet long, and perhaps thirty feet from ceiling to floor, but for fully half the height is filled with water, through which stalagmites rise upwards to the surface. A narrow ledge, however, permits the visitor to enter dry-shod to its innermost recesses. The stalactites of the Walsingham caves are often ten or twelve feet in length, are sometimes from three to four feet diameter, and are grouped in bewildering array. A few join the stalagmites below and form columns rising from floor to roof. Unfortunately the stalactites and roofs of all the Walsingham caves have been blackened by the lack of care or interest of the owners, who allow visitors to light the interiors by flaming torches of palmetto.

The Penniston or Paynter’s Vale caves, although less than a mile from those at Walsingham, are almost unknown to tourists; they are carefully protected from vandalism and retain all their original beauty. The entrance to Penniston's cave is a mere crack, barely large enough to permit one to enter on hands and knees. It rapidly opens out, however, and a dozen feet from the entrance a person may easily stand erect. The descent is at first quite steep, and as the floor is strewn with large blocks and innumerable fragments of stalactites, walking is, of course, difficult. About fifty feet from the entrance the slope decreases, and the roof—which has hitherto been eight or ten feet from the floor— rises to twenty feet or more. In this portion of the cave are a number of curious formations of dripstone mixed with fine sand, which have the appearance of masses of stalactite covered with hoar-frost. About one hundred feet beyond this, and fully eighty feet below the surface, the lowest level is reached. Here the floor is covered to a depth of several feet with water, in which are masses of fallen stalactites of every size, while from its placid surface and from the edges, great fluted columns rise to the ceiling.

Throughout the cave the stalactite formation is wonderfully beautiful and varied. The ceiling is everywhere covered with the glistening pendants; some slender as knitting needles, others huge, fluted, gnarled and rough; while scattered among them are thin, transparent sheets of crinkled dripstone, hanging like silken draperies from roof and ledges. On the floor and on fallen stalactites new stalagmites have formed, and the "red-earth," washed in by heavy rains, is covered with a thin and icelike coating of the same material. Near the entrance, masses of roots, finding their way through cracks and crevices, have become coated with the dripstone, and the organic material, decaying, has left masses of hollow interlaced tubes. All is white; a glistening, frosted, creamy white, save where the "red-earth" shows dully through its glassy covering, or where masses of fossil snail-shells (an extinct species of Helix peculiar to Bermuda) rest, with their colors still bright, preserved for all time by the same stalactitic coating. In this cave the visitor may watch the stalactites in the very process of formation. Many of the smaller ones are so transparent that by holding a candle behind them, the internal tube, filled with water, and even the crystals of lime held in solution, are plainly visible; while at each point a drop of water ever glistens, ready to drip to the floor below and form an imperceptible deposit on the slowly growing stalagmite which it is building.

On Tucker's Island, in Hamilton Harbour, is still another large cave well worth a visit. This cavern is about three hundred feet long, from fifty to two hundred feet in width, and probably about sixty feet from roof to floor; but as the latter is completely covered with several fathoms of water, the cave's dimensions are difficult to determine. This cavern is navigated by a boat, on which visitors embark at a landing-stage just within the narrow entrance. The stalactites are remarkable for their size, many of them eight or ten feet in diameter; and also for the fact that the majority reach from the submerged floor to the vaulted roof, forming grotesque pillars, arches and columns, springing upward in myriad forms from the surface of the Stygian sea upon which the boat floats in profound silence. All the stalactites are dead, or, in other words, have ceased growing, and are mostly covered with a fine, slimy, dark green algae. This cave is lighted by acetylene gas from a generator outside the entrance, and is the only one so equipped on the islands. It is also one of the few caverns to which an admission fee is charged.

The Bermudians,—who are generally wide-awake in appreciating the importance of tourists,—have apparently remained insensible to the value of their caves as a means of revenue.

Rivaling the Tucker's Island cavern in size and importance, and in fact the largest known caverns on the islands, are the twin caves penetrating the high cliffs on the north shore near Bailey's Bay. These caves are partially submerged at high tide, and owing to the excessive violence of the waves in time of storm, have lost all but their largest stalactites.

At present they are mainly of interest because of their large size and the manner in which they serve to illustrate the transition from true caverns to “natural arches" and "bridges." As the surrounding rock is worn away by waves and weather, the stalactite-coated walls remain, and in the course of time stand out boldly from neighborly cliffs, presenting the appearance of the “Cathedral" or –“Church Rocks," in Somerset Parish, on the western end of the islands. But even the resistance of the hard dripstone gradually gives way before the elements; pillar after pillar is worn through, and finally only a small section of an arch remains, forming a structure like the "Natural Arch" at Tucker's Town, or the "Natural Bridge" on St. David Island. When situated further inland the caverns are frequently destroyed by the falling of the roofs. In the case of small caves the so-called "grottos" result, such as the "Devil's Hole," on Harrington Sound. If of large size, bays or lagoons may be formed, and many geologists affirm that Harrington Sound itself was once an enormous water-filled cave, whose roof, countless ages ago, collapsed. Doubtless many a large and beautiful cave still remains undiscovered in Bermuda; in fact, that such is the case is clearly proved by the report of the naval engineers, who, when excavating for the great floating dry dock at Ireland Island, discovered immense hidden cavers of wonderful beauty, which it was unfortunately necessary to entirely destroy in order to make room for the handiwork of man.

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As an armed forces brat, we lived in Rockcliff (Ottawa), Namao (Edmonton), Southport (Portage La Prairie), Manitoba, and Dad retired to St. Margaret's Bay, NS.
Working with the Federal Govenment for 25 years, Canadian Hydrographic Service, mostly. Now married to Gail Kelly, with two grown children, Luke and Denyse. Retired to my woodlot at Stillwater Lake, NS, on the rainy days I study the life and work of A. Hyatt Verrill 1871-1954.