Part 3

In a well that was digging in the neighbouring village of Sutton, a similar stratum of decayed wood and leaves had been cut through at the depth of sixteen feet, and, therefore, very nearly at the same level with that of the islets: it extends through all the eastern parts of Lincolnshire, and has been traced as far as Peterborough, more than fifty miles to the south-west of Sutton. The fisherman informed him that islets of the same kind are found as far north as Grimsby, on the Humber; so that this great subterraneous forest was nearly eighty miles in length; and as there can be little doubt of the woody islets along the coast having been a continuation of it, the breadth must also have been considerable.

Dr. Correa de Serra, who wrote this account, says that a most exact resemblance exists between maritime Flanders and the opposite low coast of England, both in elevation above the sea, and in the internal structure and arrangement of their soil. They contain similar organic remains of marine animals, as well as of tropical plants; and they each have a stratum of decayed trees and compressed vegetable matter below the present level of the sea. He, therefore, concludes that the two countries were once continuous; and instead of supposing that the sea is now higher than formerly, he gives it as his opinion, that this part of the earth’s surface has sunk below its ancient level. That the epoch at which this catastrophe took place, must have been in a very remote age, he thinks may be proved from the sixteen feet bed of soil, which now covers the submerged forest; and because it appears from historical records in the Academy of Brussels, that no change of that kind has happened in Flanders for more than two thousand years.

But the _uncovering_ of the woody stratum in the Sutton islets by the action of the sea, he refers to a comparatively recent date. The people have a tradition that their parish church once stood on the spot where those islets are now; and it is very probable that before the skilful embankments were made which at present restrain the stormy inundations of the North Sea, the soil was gradually washed away by the waves, and the trees were thus left exposed.

When we had done reading the above, my uncle told us that he had himself visited the little hamlet of Sutton. The tides unfortunately were not low enough to expose the islets, or rather the sandbanks, which the Doctor mentions; but he saw a great number of the stumps and roots of the trees, which the country people had obtained at favourable opportunities. One fine oak stem had just been drawn on shore: it measured forty feet in length, and five feet in circumference; and the wood, though rather soft on the outside, was sound within, though all black. He cut off a few chips with his knife, and was so good as to give me one of them. So, mamma, if the stratum of earth which now covers this submarine forest was deposited there by the deluge, it is clear that the tree my uncle saw was antediluvian; and that the oak chip in my possession was of the same growth of timber as that of which the Ark was constructed.

_16th, Sunday._--A question, that Wentworth asked, about the object and meaning of the prophecies contained in Deuteronomy, led to some observations of my uncle’s, which I will endeavour to give you.

“The prophecies of Moses increase in number and clearness towards the close of his writings. He appears to have discerned futurity with more exactness as he approached the end of his life. To be convinced of this, you have only to compare the records of history with his prediction of the successes as well as the dispersions and desolations of the Israelites; compare the rapid victories of the Romans, and the miseries sustained by his besieged countrymen, with his denunciations; and particularly compare his prophecies relative to the future condition of the Jewish nation, with their accomplishment which is still going on under your own observation, and which, indeed, may be called a standing miracle.”

“But are we certain that some of these distant prophecies have not been added in later times?” Wentworth said.

“I am glad that you have made that enquiry,” replied my uncle, “because it gives me an opportunity of shewing you how impossible it is that any such addition could have been made to the Pentateuch. In the fourth chapter of Deuteronomy are these words: ‘Ye shall not add unto the word which I command you, neither shall ye diminish aught from it.’

“This prohibition preserved these books from the slightest alteration; for it was considered so binding, that no copies were allowed to be made by any persons but the Scribes attached to the synagogue; and as the Jews were commanded to read portions of them every Sabbath day in their families, and as at certain times the whole ‘law’ was publicly read to the congregation, it is evident that any alteration must have been noticed. There is a remarkable proof of the fidelity with which that injunction was obeyed, in this fact; that the Samaritans have preserved the law of Moses to this day, as uncorrupted as the Jews themselves have done; although they were irreconcileable enemies, and though they have been exposed to all the changes and revolutions that can befall a nation during the long interval of two thousand four hundred years. No opportunity could have been more tempting than when the ten tribes separated from the house of David, and when each kingdom was zealously supported by a rival priesthood; yet both parties religiously preserved the books of the law, without changing a letter.

“From the Christian era down to this day, the Jews, though dispersed into every country of the globe, continue to read the books of Moses and the Prophets every Sabbath day, in the original Hebrew; and, however they may differ from us, or among themselves, in the _interpretation_ of various expressions, they have always considered the strict preservation of the original _text_ as the most important of their duties. Those books have now been translated into so many languages, and cited by so many authors, and have been the subject of so much discussion from the times of the Apostles, that it is absolutely impossible that any fraudulent change can have taken place since that period. I may add, that the books of the Old Testament were translated into Greek by the command of Ptolemy Philadelphus, about three centuries and a half before that period; and they have therefore been for upwards of two thousand years in the hands of heathens and sceptics, who would have been eager to detect any alteration that might have been attempted.

“It is, indeed, a most striking circumstance, that notwithstanding the many corruptions which the Israelites fell into while they had the sole custody of these books, no omissions should have been made in the copies, nor any attempts to suppress those parts of the law which bore directly on their misconduct; and I think we may safely infer, that it was the will of Him who had given the law, and who had inspired the prophecies, that they should remain an indestructible ‘memorial to all generations.’”

_17th._--The more I learn from my uncle’s kind geological conversations, the more I see the necessity of acquiring some knowledge of mineralogy, in order to understand them. In the mean time, Caroline and I find even the general views he gives us so interesting, that we seldom miss an opportunity of leading him to the subject. This morning he told us, that the _debris_ of the hills which accumulate in alluvial districts usually continue in the loose form of gravel or sand, or mud, or clay, in which they were deposited. “Their visible transformation,” he said, “into stone is of rare occurrence; in some circumstances, however, especially on the sea coast, we may perceive the consolidation of the sand and gravel into thin strata. If a stream, impregnated with _oxide of iron_, should empty itself on the beach, it acts as a cement, and the process goes on rapidly. The northern coast of Cornwall affords some examples of this sort of petrification at home; and abroad it may be seen on a much larger scale on the shores of Greece, Karamania, Sicily, and the West Indies. Abundance of sea shells and other organic remains are found in it; and at Guadaloupe a human skeleton was discovered in the beach, imbedded in a mass of that description.

“Some springs of water are so highly loaded with calcareous particles, that the sediment they deposit soon hardens into stone; and the _stalactites_ which I shewed you are formed in a similar manner, in the caverns and fissures of all limestone countries. Those were very small specimens, but in some places, for instance in the celebrated grotto of Antiparos, one of the Greek islands, they are found of enormous magnitude, forming rows and clusters of columns, that reach from the top to the bottom of that great cavern. The water in slowly dripping through the rock becomes saturated with lime; as the drops exude from the crevices, or trickle down the stalactites already formed, they are exposed to the air; the watery part then evaporates, and the lime forms a hard stony crust; in some cases assuming the shape of small crystals.”

When we reached home, my uncle obligingly laid M. De Choiseul Gouffier’s voyage on the table for us; and we all read with astonishment his description of that wonderful cavern, which is a thousand feet long, and full of these curious productions. The _stalagmites_ that grow upwards from the floor, are equally curious. My uncle explained to us, that when the quantity of water that trickles through the roof is more than can be evaporated from the surface of the stalactite, the remainder falls on the floor, where the same process occurs; and thus the upper and lower concretions proceed till they meet each other and form an entire column. In the middle of the widest part of the cavern there is a stalagmite of twenty feet in diameter and twenty-four in height; and on this superb natural altar, another French nobleman had mass celebrated by his chaplain to more than five hundred people who surrounded it. The cavern was lighted by a hundred large torches and four hundred lamps; and the splendour of this illumination, reflected by the concretions which hung from the roof, or which lined the sides, is described as producing a very magnificent effect.

_18th._--It will not be my uncle’s fault if I do not pick up some information in this delightful house, for every day he tells us something new. He has just been describing the method of casting plate glass; and I hope some day to see the whole operation myself.

The furnace for melting the materials is about eighteen feet long, and it is surrounded by ovens for _annealing_ the plates of glass when made, that is, for cooling them slowly. The pots in which the materials are melted, are made of a sort of tough clay that is found at Stourbridge, in Worcestershire, as it has the property of standing the most intense heat; and they contain about twenty hundred weight of melted glass, or metal, as it is called by the workmen. The _cuvettes_, or cisterns, which convey the liquid glass to the casting table, are made of the same clay.

When the metal is sufficiently fluid, refined, and settled, which happens in about thirty-six hours, it is put, by means of ladles, into the cisterns, which are left in the furnace about six hours longer, till the little bubbles formed by this disturbance of the glass have all disappeared. The door of the furnace is now opened, and by a chain the cistern is drawn out upon an iron carriage, and conducted to the casting table. Here it is raised, by means of a crane, against two iron bars, which are so contrived as to incline the cistern, and empty the fiery torrent on the table.

This table is covered with a thick copper plate made very smooth on the surface; and it is supported on wheels, so that it can be moved from one annealing furnace to another. To regulate the thickness of the glass, two iron rulers are placed along the table, and on these rest the extremes of a very heavy roller, or cylinder of copper, which, as it moves along, drives the superfluous matter before it, and renders the two faces of the glass parallel. The iron rulers being moveable, serve also to determine the width of the glass plate, and to prevent the matter from running over the sides; the waste metal falls into a trough of water at the end of the table, and is reserved for the next melting.

As soon as the glass has cooled to a proper consistence it is examined; and if any bubbles or flaws are found, it is broken up and returned to the melting pot: but if it has a sound appearance, the table is rolled to the mouth of the annealing furnace, and the plate is carefully deposited there. The heat of this furnace is at first very great, but it is diminished every day for a fortnight, by which time the glass is sufficiently annealed. This process renders the glass less brittle; for, if suddenly cooled, my uncle says, it would fly into pieces when touched.

_19th._--Much as we were all interested by the manufacture of plate glass, my uncle steadily refused to carry us any further yesterday than the annealing furnace: this evening, therefore, as soon as we were comfortably collected round the fire, after dinner, we reminded him that he was to describe both the grinding and polishing operations; and the following is the substance of what he said.

The annealing furnace generally contains six plates of glass; when they are withdrawn, they are cut square by a large diamond, which moves in a wooden frame, and they are then carried to the grinding room. There each plate is laid on a table, covered with a large slate or flag; and to keep the glass steady it is bedded on the slate in wet plaster of Paris, which you know has the property of _setting_, or becoming hard, in a few minutes. A smaller plate of glass is then laid on the larger one, and being properly loaded and drawn forwards and backwards, with a constant supply of fine sharp sand and water, the two glasses grind each other to a smooth even surface. A ledge round the lower glass prevents the sand and water from running off; and the upper or moveable glass has a strong plank cemented to it on which the weights are laid. An upright pin is fixed to this plank, to which a handle, like a coach wheel, is attached for the workmen to give motion to the glass, and much skill is required to vary this motion in every possible direction; for if they were frequently to repeat the same stroke, the glasses would grind each other into furrows. But no matter what pains are taken to vary this motion, the two surfaces have always a tendency to become slightly spherical, one convex and the other concave; and to prevent this, the upper glasses of the different grinding tables are occasionally changed, so that two convex or two concave plates mutually correct each other.

When by these means a true surface has been obtained, finer sand is used, and then emery of increasing degrees of fineness, till the business of grinding is finished, and the plate is given to the polisher, whose operations my uncle was obliged to reserve for another evening.

_20th._--Within the last few days the swallow has returned to us; I remember seeing it last autumn, but I did not notice it much.

I have observed that its motions are very rapid, and that it sometimes perches on the house, where it makes an odd little twittering noise.--It is a very pretty bird; the back and wings are black, glossed with purple; and the breast white, with a spot of dull red upon it. I have often read of swallows in poetry, and I shall be glad to watch this little summer guest, as it sports in the sunshine, or skims along the surface of the water. This species is, I find, the house or chimney swallow, and is distinguished from the rest of the tribe by a small white spot on each feather of the tail, which is more forked than any other species.

Mary tells me that these birds generally appear in England about the middle of April, though some few may be seen a little earlier; and that they remain to the end of September. Their arrival, she says, is always considered to be the harbinger of summer, as they come here from warmer climates.

See from bright regions, borne on odorous gales, The swallow, herald of the summer, sails.

There is a remarkable conformity, my uncle says, between the vegetation of certain plants and the arrival of particular birds of passage. Linnæus remarked, that in Sweden the wood anemone blows on the arrival of the swallow, and the marsh marygold when the cuckoo sings; and a similar fact appears to have been observed in other countries also, for the same Greek word signifies both a cuckoo and a young fig, from their appearing at the same time.

These house swallows are the earliest of all the various species, as well as the most common. They build in barns, out-houses, and even in chimneys, the warmth of which they like; and they are said to pass with surprising address up and down the narrowest flues, to the depth of perhaps six feet, without soiling their wings.

All kinds of swallows, as they skim along the surface of the water, sip without stopping; but the common swallow only washes while on the wing; gliding through the pools many times together without seeming to stop.

_21st._--After some little conversation about the alluvial alterations of the coast, and the changes produced in the interior by the different causes which my uncle had already mentioned, he said to us this morning, “Those alterations are so gradual that years are required to detect their operations, or to measure the rate of their progress; but the gigantic changes effected by volcanoes and earthquakes carry their desolation at once over whole districts. You have, no doubt, read an account of some of the destructive eruptions of mount Vesuvius, by which you know the city of Herculaneum was overflown with a torrent of melted lava, and Pompeii was buried, and remained concealed for many centuries under the ashes that were ejected from the crater.

“Large tracts of country seem to have been produced by volcanoes, and after the lapse of ages the decomposed lava has become a fertile soil. But even within the reach of history new volcanic mountains have been elevated, and new islands have sprung out of the ocean. Pliny and Seneca describe two marine volcanoes that raised themselves out of the water in the Grecian archipelago; and in the beginning of the last century the same thing again happened in the same place. In 1720, a small volcanic island rose out of the sea near Terceira, one of the Azores; and in 1811, among the same group of islands, another violent eruption of lava produced an island of considerable altitude; but in the following year it sunk into the ocean. In the sixteenth century the Lucrine Lake near Naples disappeared, and Monte Nuovo, a volcanic hill six hundred feet high, and four miles in circumference, rose out of the place it had occupied.

“Perhaps the most wonderful example I can give you of volcanic action, is the elevation of Mount Jorullo, near the city of Mexico, in 1759. Alarming sounds and repeated earthquakes, which continued for three months, had prepared the inhabitants for some dreadful convulsion; when at length a tract of ground, from three to four miles in extent, swelled up in the shape of a bladder to the height of 500 feet. The terrified natives, who witnessed this extraordinary scene from the neighbouring mountains, asserted that flames burst from the ground; that red-hot rocks were thrown to a prodigious height; and that the surface of the earth was seen to heave like an agitated sea. The surrounding district is covered by hundreds of small cones called _hornitos_, or ovens, by the inhabitants; they are about ten feet high, and from each a thick smoke ascends. From among these ovens six large masses arose from the plain, some of them upwards of 1200 feet; and the volcano of Jorullo, which has never ceased to burn, is now 1700 feet high. The place where this extraordinary convulsion took place was forty leagues from any volcano; and what renders this remarkable is, that Jorullo appears to be in the exact line of continuation of a chain of distant volcanoes, as if there were a subterranean communication. Though the fire is now much less violent, and though the plain and even the great volcano begin to be covered with vegetation, yet Humboldt found the air dreadfully heated by the small ovens, and the thermometer rose to 202° on being plunged into the aqueous vapour emitted by every fissure in the ground.

“It is said, that two rivers fall into the burning chasm, and that at some miles distance they emerge from the ground in a heated state. You may recollect Colonel Travers told you that he had seen the thermometer at 200° in a subterraneous spring called Nero’s baths, at Solfaterra, near Naples; and that he had eaten an egg which it had completely boiled in a few minutes.

“It is computed that there are at present nearly a thousand volcanoes known to exist, and yet there is no doubt that, in a former state of the globe, they must have been more numerous, and far more active and extensive in their operations. Remains of extinct volcanoes of great size are scattered in almost every country, and geologists are every day discovering large tracts of rocks and earths, which there is every reason to ascribe to volcanic agency.

“Several have been found in Europe, which for many centuries must have been at rest. Great part of Italy and Sicily are clearly volcanic. Near Coblentz, in Germany, are the remains of several craters, and large masses of lava are seen strewed over the surrounding country. Along the Rhine entire chains of volcanic hills are found; and near Spa there are traces of some very large volcanoes, with deep craters half full of water. Great part of Languedoc and Provence in France are volcanic; and Auvergne presents an astonishing example of the activity of its ancient volcanoes, for the whole country consists of lava. In the East Indian islands there are great numbers; Sumatra, Java, and the Molucca islands, possess some of the finest volcanoes now existing. You know, from Humboldt, how numerous they are on the western side of South America and Mexico; and Nootka Sound, in the 50th degree of north latitude, was observed by Captain Cook to be entirely volcanic. In the Pacific Ocean, Easter Island is a mere mass of lava and basalt; and I need scarcely mention the Sandwich Islands, as you have been lately so much interested by Mr. Ellis’s account of the great volcano in Owhyhee, with its sublime gulf of boiling lava, seven or eight miles in circumference.”

_23rd, Sunday._--My uncle continued the subject of the prophecies of Moses, this morning.

“There are different kinds of prophecies in the books of Moses, some of which were fulfilled soon after the prediction, such as the conquest of the land of Canaan; and others the accomplishment of which was not to follow till after a long interval of time, such as those that relate to the coming of the Messiah, and the dispersion of the Jewish nation; but in all there is the same clearness and consistency, the same tone of inspiration and authority, and the same internal proofs of their truth. The Jews have always looked on him as by far the greatest of all their prophets. They assert, that the others received the divine communications by dreams and visions; whereas they were given to Moses by an immediate revelation from God.