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Beach Rambles in search of Seaside Pebbles and Crystals

Beach Rambles in search of Seaside Pebbles and Crystals
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Title: Beach Rambles in search of Seaside Pebbles and Crystals
Release Date: 2018-11-05
Type book: Text
Copyright Status: Public domain in the USA.
Date added: 27 March 2019
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[i]

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BEACH RAMBLES
IN SEARCH OF
SEASIDE PEBBLES
AND
CRYSTALS.

WITH SOME OBSERVATIONS ON THE ORIGIN OF THE
DIAMOND AND OTHER PRECIOUS STONES.

BY
J. G. FRANCIS.

LONDON:
ROUTLEDGE, WARNE, AND ROUTLEDGE,
FARRINGDON STREET;
AND 56, WALKER STREET, NEW YORK.
1859.


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INTRODUCTION.

There is a pleasure to an intelligent mind in discoveringthe origin, or tracing the past history, of any naturalobject as revealed in its structure and growth. It is thusthat the study of trees and plants, ferns and field flowers,occupies and delights us. And a similar interest wouldbe found to attach to Seaside Pebbles, as one branch ofmineralogy, if we could once come to observe and understandthem.

But while the marine shells of England have been allnumbered and classified, and even the seaweeds areemerging out of dim confusion into the order of botanicalarrangement, there is no popular work extant on thesubject of our pebbles.

Dr. Mantell, indeed, published an elegant little volume,entitled “Thoughts on a Pebble;” but he therein treatsof a single species, the Choanite; whereas, we have otherfossil creatures beside Choanites preserved in the heartof siliceous pebbles; and our shores yield from time to[iii]time varieties of agate and jasper, differing from theoriental, and some of them of great beauty.

In the present treatise, an attempt has been made tocommend this subject to more general attention, bygrouping together many scattered facts and methodizingthe results. Learned disquisitions and technical termshave been as much as possible avoided; but in the concludingchapters, sundry interesting points in naturalphilosophy bearing upon the subject are handled rathermore scientifically; and here, some original matter willbe found.

The coloured plates are after drawings by a well-knownand ingenious artist;[1] the original specimens being in myown collection. They have been carefully and faithfullyexecuted, and are on the same scale as the pebbles themselves.

If this essay of mine should induce any one possessedof ampler leisure and more adequate powers to entermore largely upon the merits of the theme, I shall beindeed gratified.

J. G. FRANCIS.

Isle of Wight, 1859.

[1] M. W. S. Coleman.


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BEACH RAMBLES, ETC., ETC.

CHAPTER I.

ASPECT OF A BEACH, AND ITS PROBABLE ORIGIN.—TRUENATURE OF THE PEBBLES WHICH COMPOSE IT.

I know of few things more pleasant than to ramble for amile along one of our southern beaches in the early daysof autumn. We get the sniff of the sea-breeze; we seeprismatic colours dappling the water, or curiously reflectedfrom capes of wet sand; solemn, beetling cliffs, brokenhere and there by a green slope, rise on one side of us;while, on the other, we are enchanted by the wild musicof the waves, as they dash noisily upon the shingle atour feet, and then trickle back with faint, lisping murmursinto the azure gulf.

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Alpine scenery is majestic, and river-lit landscapes aredelicious; but they seem as pictures of still life comparedwith the stir and resonance of the shore and the ocean.The breeze which bends the standing corn does not impartso much pleasure as that which dimples the bay atthe foot of our rustic garden; the thunder-cloud restingon a mountain is not so impressive as that huge wall ofinky blackness, which seems as if it would choke thevery light and air while it gathers on the horizon, butwill presently rend asunder and purify the overchargedatmosphere by launching a tempest upon the face of thedeep.

There are few persons who, after spending one or twoconsecutive summers at Eastbourne, or in the Isle ofWight, can repress an ardent longing to visit similarscenes from time to time.

The sea-side stroll has, however, been accused of monotony.But this is either by really incompetent judges,or by inveterate sportsmen, to whom the neighbourhoodof the ocean suggests nothing more apposite than a meetwith harriers on the downs, or a raid upon puzzled rabbitsin some outlying warren, with the aid of a keeper,ferrets, and “varmint” dogs. To such, even a brief[3]sojourn on the simple-featured coast may, undoubtedly,prove wearisome; but the fault rests with themselves.For, all the while, others, who are better informed andmore awake to what lies around them, will be cheerfullyoccupied in kindred pursuits at the foot of the cliff, oraway on the beach, or far out, at low tide, among theweedy rocks and sand. Here they hunt the cockle andthe razor-shell, collect bright algæ and marvellous zoophytes,or search for agates and fossils among the endlessheaps of shingle.

The delicate actiniæ and the rarer sea-weeds cannot beobtained in winter; but the pebbles, which are intendedto form the subject of this little book, may always bemet with; and the changes induced by rough winds andsurging tides, yield them in even greater abundance.

The pleasure of collecting pebbles has been greatlyenhanced, to my mind, by considering how it is that wecome to have pebbly beaches at all. Inevitable as thesemay appear to some people, they are quite a phenomenonin their way, and to the full as deserving our attention asthe colony in a rabbit-warren.

Originally, the land alone possesses such materials; butit is the sea which finds them out; and these two facts,[4]put side by side, have sometimes reminded me of thearbitrary allotment of the sexes in the old mythology.Oceanus being an enterprising gentleman. Terra (alwaysfeminine) is the quiescent lady, to whom he pays hiscourt. She carries a prodigious number of these treasuresin her flinty bosom; but it is only he, and hisfriends the rivers, who can get at them and draw themforth. In our English Channel, Ocean is as fond ofdoing this, and of fringing his waterline with a brownpebbly border, as other gentlemen are, now-a-days, ofwearing, if possible, a beard like that of the Sophi. Noris this surprising, when we remember that all creaturesnaturally desire something which they have not got. Forthe bottom of the sea itself is no beach at all, but chalkor sand, and sometimes hardened sandstone, with, I daresay, many precipitous pits and hollows, and many pointedcrags. Here, gigantic fronds of the oar-weed wave toand fro among thousands of acres of dulse and bladderwrack;while porpoises and dog-fish dive, and limpetsand mussels crawl, and arrowy lobsters shoot throughthe cerulean gloom, and (if Mr. Tennyson may be believed)mermen and mermaids play at hide-and-seek.Wonderful things there must be, if we could only spy[5]them out; but I do not think many pebbles. Whereas,our mother Earth teems with these latter. There are jaspersin the conglomerate, and agates in the mountainrocks, and veins of porphyry and serpentine in the trapand basalt, and garnets and sapphires in the granite, andflint-nodules in the chalk, and quartz-crystals almosteverywhere. Probably these exist, also, in many of thesubmarine strata; but unless a volcanic eruption shouldoccur, there is no force in operation there to dislodgethem. The bed of the ocean, and all depths of it belowa hundred feet perpendicular,[2] as divers well know, remaincalm and still, even when a tempest is raging above.But on what we are pleased to call “terra firma,” thecase is reversed. Solid as the ground appears, all is subjectto elemental change and motion; and whenever thewaves of the sea or the strong current of a river canplough some crumbling chine, or wear away the face of acliff, down come the imbedded pebbles and crystals, andgradually form a beach upon the margin of the ocean.[6]And this beach is tossed up and down, and rolled to andfro, until most of the stones composing it have becomeas smooth as hazel-nuts.

The above may be rather a rough sketch of the sourceof a beach; but I believe it is correct in its leading features.In a subsequent chapter we may better note certainpeculiarities which are more than meet the eye.

But what are the pebbles themselves?

Most persons have occasionally handled specimens ofthe precious stones or “gems;” but few of them, perhaps,are aware that our pebbles of the road-side andsea-shore claim a common origin with these dazzlingcrystals. Such is, however, the fact. Chemical analysis,availing itself of the blow-pipe, the solvent acids, andthe voltaic battery, has succeeded in determining thebase of every known gem. And the earths which furnishsuch bases are chiefly two—ALUMINA, or clay, andSILICA, or pure flint. From these, with an admixtureof lime, and sometimes of iron, in small quantities, allthe native gems are derived, with the exception of thediamond, whose base is CARBON.

Intensely hard as these substances are, and apparentlynot susceptible of change if left to themselves, they have[7]probably passed through great chemical changes in thesilent laboratory of Nature. For it is supposed that ouroperations in analysis, if carefully conducted, merelybring back their subjects, by a kind of reversing process,to their several primitive bases.

Now it is evident that the commoner pebbles are derivedfrom these same earths, of clay or flint, albeit ina debased condition. For there is nothing else of whichthey could be made: neither do they exhibit any propertiesforeign to those which such substances possess.Yet, how vast is the difference between an oriental gemand the brightest production of clay-pits or granite rocks.Not greater, however, than that between Damascus steeland coarse pig-iron; or, between French lawn and sail-cloth.And if Art can work such distinctions, why notNature?

In fact, a perfect gem is a master-piece which chemistryand crystallization have combined to elaborate, and whichman has ransacked the corners of the earth to obtain. Thedeep has been made to surrender its treasures to the diveror the sunken net: the rock has been blasted, and its inmostvein searched: the rushing river filtered, and its sandsifted: and the contents of the jeweller’s caskets are the[8]result. Here may be seen diamonds from Golconda;and rubies from Samarcand and Pegu: sapphires, emeralds,and amethysts from Persia, Arabia, and Armenia:the topaz, blazing like fire, from the Indies or from theUral: the turquoise, with its delicious blue, from Arabiaand Palestine: the opal from Honduras: the blood-redgarnet and amandine from Bohemia, Ceylon, and Greenland:the jacinth and the chrysoprase, the chrysoliteand beryl, with pure pearls of globular form, all from theland of the rising sun, while a deep brown jasper, rayedwith stripes and rings as black as jet, has travelled like awandering palmer from sultry Egypt or the terrible desertof Sinai.

To form and perfect the finer crystals, extremes ofheat or cold appear to be necessary: whereas our climehas perhaps always been temperate. Beside this, it isprobable that the mother-earth is not found pure with us.There is a kind of white clay, called “kaolin,” obtained inone particular quarry near Meissen in Saxony, and metwith nowhere else. From this clay the exquisite Dresdenporcelain is baked, and this clay cannot be exactly imitated.A near approach to it has been made by mixinggood potter’s clay with pounded chalcedony-flints; but[9]still the biscuit so produced is never equal to that fromthe “kaolin.” In like manner, we may suppose that thepeculiar earth which exists in sapphires no longer occursin our post-tertiary clay-beds.

Moreover, we know that there are many different claysoccurring in our geological strata. We have the claysof the Lower Tertiary; the clay of the Wealden; and theKimmeridge and Oxford clays, both of which belong tothe Oolite. Also in these main divisions, sundry mineralogicalvarieties are comprised under a common name.But the great age of the granite formation renders it certainthat from none of these clays could those sapphireshave come (as to their base), which are born ofthe granite rock. Indeed, our existing beds of clay aremore or less mingled with felspar, and felspar is one ofthe “silicates;” whereas the blue sapphire is pure aluminafree from all admixture of silica.

However this may be, the great fields for gems arein India and the island of Ceylon, and in certain partsof the Russian dominions. No very valuable stones haveas yet been obtained from Australia; although the vicinityof gold-mines has always been held to be prolificin at least one kind: the “mother of ruby” being a[10]roseate substance embedded in the rock, and generallymet with alongside of a vein of gold. The topazes

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