is past all doubt, for they have not only British names for their little islands, tenements, and creeks, but there are many remains of circles of stones, erect rude stone pillars, cairns, &c. all monuments common in Cornwall and Wales, where the ancient Britons fled for refuge during the invasion of the Danes, Romans, and Saxons. How these ancient inhabitants disappeared has been matter of much speculation; to which it has been answered, the manifest encroachments of the sea, and as manifest a subsidence of some parts of the land, are the causes of this depopulation. The sea is the insatiable monster which devours these little islands, satiates itself with the earth, sand, clay, and all the yielding parts, and leaves nothing where it can reach, but the skeleton, the bared rocks. The continual advances the sea has made during the last thirty years is obvious. What is seen to happen every day, may be supposed to have happened in ancient times, and from the banks and sand giving way to the sea, and the breaches becoming still more open and irrecoverable, it appears that repeated tempests have occasioned a gradual dissolution of the solids, for many ages, and as gradual and progressive an ascendancy of the fluids.

"Again, the flats stretching from one island to another, are plain evidences of a former union subsisting between many now distinct islands. The flats between Trescow, Brehar, and Sanipson, are quite dry at a spring tide, and men easily cross them dry shod at such times; on the shifting of the sands, walls and ruins are frequently discovered, on those spots which at a full sea are covered with water ten or twelve feet deep. History confirms their former union. The isles Cassiterides,' says Strabo, are ten in number, close to one another; one of them is desert and unpeopled, the rest are inhabited.' But the sea has wonderfully multipied these ten islands, for there are now one hundred and forty; into so many fragments are they divided, and yet there are but six inhabited.

"But no circumstance can show the great alterations which have taken place in the number and extent of these islands, more than the following:-the Isle of Scilly from which the little cluster derives its name, is nothing more at present than a high rock, of about a furlong over, the summit of whose arid cliffs can hardly be attained but by

birds, and whose surface is so totally barren that it is inhabited by those birds only which feed upon fish.

"The land, or rather sands, between Sanipson and Trescow, which were formerly covered with dwellings, are now in many parts sunk sixteen feet below water; for we cannot suppose the ocean to have risen to that extraordinary height. This subsidence of the land must have been followed by an immense inundation, and this inundation is likely not only to have destroyed a great part of the inhabitants, but also to have terrified others into a total desertion of their shattered islands. This subsidence might have been caused by an earthquake very possibly, and thus is the extirpation of the Aborigines, or original inhabitants, who carried on so large a traffic with the Phoenicians, Greeks, and Romans, accounted for. There is one load or working of tin on Trescow, but this is so very trifling, and so lately worked, that except for the historical records upon that subject, no one would have supposed that these were the islands so fertile in tin, so much coveted by the Romans, and so long concealed by the Phoenicians."

Dr. Walker.—" You know the story of the Phoenician captain, who ran his vessel on shore purposely, and thus lost his ship rather than discover the trade of these islands to the Romans. That these mines are now sunk into the sea, there is but little doubt; for there is a tradition in Cornwall, that formerly there existed a large country between the Land's End and Scilly, now laid many fathoms under water. Now in all national traditions, however improbable they may seem, or however they may be enveloped in fable, there must have been originally some foundation from which they arose; invention and the love of the marvellous, may have adorned or even disfigured them, but to truth, though hard to be discovered, their origin must be attributed. Now although there is no evidence to be depended upon, of any ancient connection of the Land's End and Scilly, or at least of their proximity to each other, yet that the cause of that inundation, which destroyed much of these islands, might reach also to the Cornish shore, is extremely probable; there being several evidences of a like subsidence of the land in Mount's bay, where the principal anchoring place, formerly called a lake, is now a haven or open harbour. The Mount, from its Cornish name Guavas Lake, signifying, the grey rock in a wood, we must natu

rally imagine to have stood formerly in a wood; but now at full tide, it is half a mile in the sea, and not a tree near it." EDWARD." I wish my memory was as good as your's

Sir."

DR. WALKER.—" Nature has not been sparing of her gifts to you, and it remains with yourself, whether you chuse to wrap your talent in a napkin, or whether you chuse to make it ten. Sancho would tell you, Rome was not built in a day,' and it would be hard indeed, if at your time of life, you should be equal in information to me, who have been cultivating my talent for these last forty years, I may say with unwearied dilligence; but the same field is before you, and at my age you will, I hope, be a wiser man than your tutor. Having satisfied our curiosity with our imaginary trip to the Scilly Islands, you may now resume your book." EDWARD, (reading.)-" The tin works are of different sorts, on account of the different forms in which that metal appears, for in many places it so strongly resembles common stones, that it can be only distinguished from them by its superior weight. It sometimes appears mixed with earth, forming a substance as hard as stone, and this ore is always found in a continued stratum which the miners call load, running through the hardest rocks, beginning in small veins near the surface, perhaps not above half an inch or an inch wide, and gradually increasing in size, stretch out in extraordinary ramifications, and bending downwards in a position which generally lies east and west. These loads are sometimes white, very wide, and occasionally so thick that large lumps of the ore are drawn of more than twenty pounds weight. The loads of tin ore are not always continuous, but sometimes break off so abruptly that they appear to terminate. But the sagacious miner knows that by digging at a small distance, on one side he shall meet with a separated part of the load, appearing to tally so exactly with that which is so suddenly interrupted, that it appears as if it had been broken off by some violent shock of the rock. The miners of this country follow the load in all its meandering curves, through the bowels of the rocky earth. Sometimes the waters are drained from these mines by subterraneous passages, formed from the body of the mountain to the level of the country: these are called adits, and occasionally prove the labour of many years; but when effected, save the constant expence of large water works and fire engines.

"In order to convey the ore above ground, they sink a passage to the mine, from the surface of the earth, which they call a shaft, and over it place a large winch; but in greater works a wheel and axle, by which means they draw up large quantities of the mineral at a time, in vessels called kibbuls. This ore is thrown into heaps, which great numbers of poor people are employed in breaking to pieces, and fitting the ore for the stamping mills.

"A third form in which tin appears is that of crystals; for tin will, under proper circumstances, readily crystallize; and hence, in many parts of the mineral rocks, are found the most perfectly transparent and beautiful crystals of pure tin." DR. WALKER." Does it say nothing of its properties?" EDWARD." No, Sir, not a word."

DR. WALKER." Then I will give you a brief sketch of them. Tin is of a colour approaching to that of silver, but somewhat duller; next to lead, it is the softest and least elastic of all the metals. In tenacity it is superior to lead, and though not very ductile, it may be reduced to very thin leaves. It is less sonorous than copper, iron, or silver, and it is the lightest of all the metals, except cast-iron.

"The putty of tin is used for polishing mirrors, lenses, &c. and for rendering glass white and opaque, or converting it into enamel. It is soluble in sulphuric acid, and with muriatic acid it forms muriate of tin, which is of great use in dyeing. Tin combined with sulphur, forms aurum musicum, used by the japanners. It alloys with other metals forming solder. With lead and antimony it constitutes pewter; and with mercury, it is employed for silvering mirrors.

"Tin formed a part of the composition of the ancient bronze; for, according to Pliny, new copper was first melted, into which was poured a third of its weight of copper which had been long in use. To every hundred pounds weight of this mixture they added twelve pounds and a half of a mixture, composed of equal parts of lead and tin. Bell metal is also composed of tin and copper. And the best specula of the ancients were composed of these two metals, and made at Brundusium.

"The purity of tin in Cornwall is ascertained, before it is exposed to sale, by what is called its coinage; the tin, when smelted from the ore, is poured into quadrangular moulds of stone, containing about 320 pounds weight of metal, which, when hardened, is called a block of tin; each

block of the tin is coined in the following manner. The officers appointed by the Duke of Cornwall assay it, by taking off a piece of ore of the under corners of the block, partly by cutting, and partly by breaking, and if well purified, they stamp the face of the block with the seal of the duchy, which stamp is a permission for the owner to sell, and at the same time an assurance that the tin so marked has been properly examined and found merchantable.

"The Dutch tin founders have all these marks, so that this stamp is no security for foreigners, who purchase what they think assayed English tin in Holland.

"Our evening has not appeared very long," said the doctor, as he looked at his watch, "yet it is just upon the stroke of ten. But we will not order supper just now, as I have one more subject I wish to discuss; I mean the Eddystone Light-House, to which my imagination has wandered upon quitting the Scilly Isles."

SECTION IV.

THE EDDYSTONE LIGHT-HOUSE.

"LIGHT-HOUSES are a very ancient invention. Near Alexandria, in the island of Pharos, stood one particularly celebrated; it was ranked as one of the Seven Wonders of the World, and was a building of extraordinary beauty, as well as of incalculable utility. Sostratus, the Cnidian, was the architect, under the patronage of Ptolemy Philadelphus, who expended upon its erection, the sum of 180,000l. sterling. Ptolemy anxious to immortalize himself by so useful and magnificent a work, ordered his name to be placed upon it; but the architect, although he apparently obeyed the commands of his master, yet contrived to make his own name the more lasting of the two. Having engraved the following inscription upon it "Sostratus the Cnidian, son of Teziphanes, to the protecting deities, for the use of seafaring people." He then covered this sculpture with lime, upon which he traced the name of Ptolemy. In the course of a few years the lime wore away, and beneath it appeared the artist's own inscription. Amongst the modern light-houses Eddy