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PRESERVATION OF THE COPPER SHEATHING OF SHIPS.

THI
NHERE is scarcely any single de- per, and that the rapid decay of copper on

partment of practical science so certain ships was owing to its impurity. pregnant with interest to a maritime On trying, however, the action of sea-water

on two specimens of copper, sent by J, nation like Great Britain, as the re: Vivian, Esq. to Mr. Faraday for analysis, I cent discoveries made by that illustri- found the specimen which appeared absoous chemist Sir Humphrey Davy, ap- lutely pure, was acted upon even more plicable to the preservation of the cop- alloy: and on pursuing the inquiry with

rapidly than the specimen which contained per-sheathing of vessels from corrosion. specimens of various kinds of copper The expenditure, occasioned by the which had been collected by the Navy rapid destruction of the sheathing of Board and sent to the Royal Society, and his Majesty's ships, alone forms a very markable for their durability, and others

some of which had been considered as reconsiderable item in the naval depart. for their rapid decay, I found that they ofment of the public service. But the fered only very inconsiderable differences loss to the country from their decay on their action upon sea-water; and conbears but a small proportion, during sequently the changes they had undergone

must have depended upon other causes than time of peace, to the aggregate loss sus

the absolute quality of the metal. tained by the mercantile interests, from similar causes. Indeed the very con

Sir Humphrey then describes the siderable expense

of
copper sheathing,

chemical

agency

between sea-water added to its rapid decay, serves to pro

and a sheet of copper as follows: hibit its use in numerous instances, not When a piece of polished copper is sufwithstanding the additional security it fered to remain in sea-water, the first effects gives to a ship, by preventing the open- observed are a yellow tarnish upon the ing of her planks, and consequent which takes place in a few hours. The hue

copper, and a cloudiness in the water, leakage, in bad weather. But in spite of the cloudiness is at first white, it then of this expense and sacrifice, every changes to green. Within a day a blueish ship destined for navigating the tropi- green precipitate appears at the bottom of cal

the vessel, which constantly accumulates, if not protected by sheathing, seas,

at the same time the surface of the copper in a very short period becomes perfor- corrodes, appearing red in the water, and ated through the bottom by the innu- grass-green where it is in contact with the merable marine animalculæ which air. Carbonate of soda gradually forms abound in the warmer latitudes. It upon this grass-green matter, and these would perhaps be an interesting inqui- much less saline. The green precipitate,

changes continue until the water becomes ry to many persons concerned, to com when examined by the action of the solupute the annual loss which the ship- tion of ammonia and other tests, appears to owners of this great maritime nation consist of an insoluble compound of copper sustain, from the corrosion and destruc- (which may be called a hydrated sub-muri

ate) and hydrate of magnesia. tion of copper-sheathing; but although

According to the views which I developthe amount must be obviously very ed fourteen years ago, of the nature of the . great, it would encroach too much compound of chlorine, and which are now upon your miscellaneous columns to generally adopted, it is evident that soda

and magnesia cannot appear in sea-water enter into such investigation. I shall by the action of a metal, unless in consetherefore proceed to give your readers quence of an absorption or transfer of oxyan abstract of the valuable researches gen. It was therefore necessary, in order of Sir H. Davy, which promise to

to produce these changes, that water should

be decomposed, or that oxygen should be lead to the most important results in absorbed from the atmosphere. I found the preservation of shipping. The that no hydrogen was disengaged, and conpresident, in the communication of his sequently no water was decomposed ; the important researches on this subject, oxygen of the air must therefore have been

the agent concerned, as appeared subseto the Royal Society, after alluding to quently by numerous experiments. the rapid decay of the sheathing of the Copper placed in sea-water, deprived of ships in his Majesty's service, ob- air by boiling or exhaustion, and exposed

in an exhausted receiver, or in an atmos

phere of hydrogen gas, underwent no It has been generally supposed that sea change whatever. But an absorption of water had little or no action on pure cop- atmospheric air was shown, when copper

serves:

serves :

water.

extreme case.

and sea-water were exposed to its agency such a manner as to form seven divisions, in close vessels.

connected only by the smallest filaments

that could be left; and a slip of zinc, one. Sir Humphrey, after referring to the fifth of an inch wide, was soldered io the principles of chemical and electrical upper edge. The whole, after being imagency, which he developed twelve or mersed for a month in sea-water, left the fourteen years ago by his beautiful ex

copper in a bright polished state, as at first.

The same experiment succeeded with a periments on the alkalis, farther ob- slip of iron, soldered to the copper ;

whilst similar pieces of copper, undefended, Copper is a metal only weakly positive

were considerably corroded by the salt in the electro-chemical scale, and, according to my ideas, it could only act upon sea The importance of this discovery in water when in a positive state, and conse- the preservation of our shipping can at quently, if it could be rendered slightly present scarcely be appreciated; for negative, the corroding action of sea-water would be null; and whatever might be the there appears to be not a shade of differences of the kinds of copper sheathing doubt as to its complete efficacy when and their electrical action on each other, reduced to practice. Sir Humphrey still every effect of chemical action must be is still pursuing his researches on a prevented, if the whole surface were render- large scale; but his observations on a ed negative...

I rendered sea-water slight comparative experiment, made for the ly acidulous by sulphuric acid, and plunged purpose of demonstrating its practical into it a polished piece of copper, to which effects, is all I shall venture to extract a piece of tin was soldered equal to about from his late communication to the one-twentieth of the copper. Examined after three days, the copper remained per

Royal Society, fectly clean, whilst the tin was rapidly

As the ocean may be considered, in its corroded. No blueness appeared in the relation to the quantity of copper in a ship, liquor: though in a comparative experi

as an infinirely extended conductor, I enment, when copper alone and the same

deavoured to ascertain whether this circumfluid mixture were used, there was a con

stance would influence the results. By siderable corrosion of the copper and a dis- placing two very five copper wires, one untinct blue tint in the liquor. If one-twenti. defended, the other defended by a particle eth part of the surface of tin prevented the

of zinc, in a very large vessel of sea-water, action of sea-water, rendered slightly acid

which water may be considered as having ulous by sulphuric acid, I had no doubt a

the same relation to so minute a portion of much smaller quantity would neutralize the metal, as the sea to the copper-sheathing of action of sea-water, when depending only

a ship. The result of this experiment was on the oxygen contained in coinmon air. equally satisfactory with that of all the preAnd on trial, I found that one two-hun- ceding. The defended copper underwent dreth part of tin in proportion to the cop

no change whatever ; whilst the undefended per was sufficient to prevent the corrosion

wire tarnished, corroded, and deposited a of the latter.

In pursuing these experime and applying them in every

green powder. possible form and connexion, the results These electro-chemical researches were of the most satisfactory kind. piece bid fair to open a most extensive field of zinc as large as a pea, or the point of for investigation, and to prove of in 6a small iron nail, was found fully adequate nite value to the arts : for it seems not to preserve forty or fifty square inches of copper ; and the result was equally as sat. improbable that means will speedily be isfactory, in whatever part of the sheet of found, in almost every case, to prevent copper the other metal was placed. And that destruction, or at least injury, to even when the connexion between different which all metallic surfaces are liable. shrets of copper was completed by wires or thin filaments of the fiftieth of an inch di- from what is termed oxidation by the ameter, the effect was the same; every atmospheric air. I shall not fail to side, every surface or particle of the copper communicate to your readers, in the remained perfectly bright after being place ensuing numbers, such new facts as beed in sea-water for many weeks; while the iron or zinc was slightly corroded. come developed in this very interesting

A piece of thick sheet.copper was cut in department of science.

WASHINGTON IRVING'S NEW WORK.

MY DEAR SIR, I NEED not tell you how much your dizement, I must have, or I would

request flatters me, nor how will nearly as soon spend my time at a biling I am to comply with it. Having liard' table. Indeed altogether as reflected a good deal in the character soon; for a good game of billiards inof Washington Irving's writings, a very vigorates the body, whilst a novel, few hours have enabled me to adjust such as I speak of, debilitates the my ideas with respect to his last work. mind. The imagination being pam

I have looked forward to the pub- pered, we have no energy of appetite lication of Geoffrey Crayon's new for the simple fare of reason and work with much greater anxiety than wisdom which other books set before to that of a new novel from the inde- us. That is a higher kind of writing fatigable pen of the Great Unknown. which, in however small a degree, Geoffrey (said I), does not write addresses the heart or the understand against time, as the novelist does. ing as well as the fancy. I do not, He pays his readers more respect however, mean to be taken as one and does himself more justice. "He who condemns romantic or imaginaloves fame as well as money. Be- tive works; I merely say that those sides, even when the G. U. was chary not wholly so are better. It would be of his reputation, and leaned but hard upon readers as well as writers to lightly on his feather, I do not know prohibit (were that possible in effect) that so much value (taking the utile all works of mere entertainment and the dulce together) was derivable there are many who can read only from

any of his works as from those such works, and some who can write of our transatlantic brother, Geoffrey. none other. Yet perhaps it is unjust At least, speaking for myself, who to say so: there are probably few always wish to combine in my read- readers who would not willingly iming profit with pleasure, the perpetual bibe the lessons of wisdom if they were insinuation of stories or passages sufficiently few and concise, if they where the strain of reflection is so were agreeably displayed and happily deep as to amount almost to philoso- illustrated; there are probably few phy,--the insinuation of such stories writers who could not impart such lesor passages amongst those of a more sons, if they took half the pains to depurely amusive kind, will ever render serve their own approbation that they such works as the Sketch Book much do to merit the applause of others. more acceptable to me than novels To instruct by delighting is a power like those of the Author of Waverley, seldom enjoyed by man, and still selwhich are wholly devoted to enter- domer exercised. It is in this respect tainment. I read the latter, as it that Homer may be called the second were, against my conscience. When of men, and Shakspeare the first. The I have finished one, and another, the wisdom of the Greek was not so uniquestion inevitably recurs-What have versal as that of the Briton, nor his I gained by such an expense of time genius so omnipotentin setting it forth and eyesight? Am I wiser ? Very attractively. From the several works little. Or better? Not much. What of the latter, a single work might be have I gained, then ? Why, so many compiled little less worthy of divine hours' amusement. And is this all? sanction than any other extant, and by All : what would you more ? --Instruc- the beauty of its nature, far more setion. I do not ask a sermon, or a cure of human attention. But Shakphilosophical essay ; but instruction speare has done so much in this way, of some kind or other, an accession to so nearly all that is sufficient,--he has my previous stock of knowledge, made the laws of the đecalogue and all something which can chew upon, their corollaries so familiar, he has digest, and turn to my own aggran exhibited the passions and propensi

35" ATHENEUM VOL. 2. 2d series..

I dare do all that may become a man,
Who dares do more is none.

ties, the feelings and emotions, inci- its morals. For one man on whom a dent to humanity, so freely, and as I moral lesson is impressed by a sermight say, graphically, that ano- mon, there are at least an hundred on ther such artist would be superfluous. whom it is much more deeply impressNature might create a second Shak- ed by a poem. No one who ever speare, but it would be bad economy. read can forget What the first has left undone, may be completed by a much less expense of Promethean fire than would go to the But we hear every Sabbath many creation of a second. We are there more maxims than we care to rememfore not to look for a similar being, at ber. A nation's poetry is then its imleast until we acquire new attributes, mediate Scripture, and the digest of its or are under a new moral dispensa- practical wisdom and morality. A tion. Spirits of an inferior order, a nation's poets are the best moral teachMilton, a Pope, or a Cowper, are po- ers of its people. In ancient times, tent enough to disseminate the remain- when the priesthood was not so sepaing or minor truths of natural morality rate an order as at present, the task of amongst the people, or rather to re- instructing the people devolved almost peat, illustrate, and impress them on wholly on the poets; especially on our hearts and memories. Writers of the dramatic writers. And hence we this class whom we may call the lay find the Greek and Roman dramas ministers of the Deity, to teach from so replete with maxims, precepts, the press instead of the pulpit, in the pious exhortations, and moral senticloset instead of the church, we may ments. expect; and with them should we be

But to combine the poet and the satisfied. Though we cannot reason- philosopher is not given to every one, ably hope for another high prophet of To instruct and delight at the same profane inspiration to re-communicate time is, as I before observed, not withto us the lessons of divine wisdom

in the power of every author; at which are already to be found in Shak- least, in this respect, there is a great speare, it is no presumption to hope difference in different authors. In the that the spirit of illumination will single province of amusing they are descend upon humbler poets, and more on a level both with each other, make them our secular guides in mo- and with the professors of many less rality. This is the office which should intellectual arts, the painter, the mube sought by every writer, and for sician, the actor, and the buffoon. which he ought to prepare himself, as But he who can, at once, improve our the will to become is (independent of hearts, expand our minds, and entergenius) one and the same with the tain our fancy, is a far superior genius power to be. In this case it is not to him who can do but one of these. God who chooses what priests shall It is in this general faculty that I think serve him, but the priests who choose Washington Irving excels his cotemwhether they will serve him or not. poraries. This is the age of “deep

The preceding exaltation of the po- feeling,” but of little else. Few auetic character into something of a sa- thors endeavour to merit the reputacred nature, the designating poets, as tion of being as wise as they are pasit were,-a temporal order of moral sionate. The author of Waverley is teachers,-may astonish those who certainly a more powerful writer than have been accustomed to degrade po- the author of the Sketch Book ; that etry into a mere collection of sounding is, his subjects are more lofty, his words and glittering images. But a imagery is more daring, and his langreat poet is always a philosopher and guage is, if I may so express myself, a moralist; such also, in some degree, much louder and more vehement. is every poet who is worthy of that But though a more powerful, he is not

The moral state of a nation a more effective writer. He agitates may be judged of by its poetry, and it the heart more, but he does not more is its poetry which chiefly influences forcibly persuade it towards his object.

name.

beneath any.

And he would as soon think of putting happiest example. The subject is inop band and cassock as of address- teresting to the inost insensible reaing the reason instead of the fancy of der ; the language is some of the his readers. I say not this to disparage sweetest I have ever met with; and the author of Waverley; by no means. the sentiments are of that deeply imHis line of writing may not admit of such pressive moral kind, pregnant with a proceeding. His talents may lie in feeling, simple, yet full of thought, another direction, and, powerful as composing a master-piece of its kind, they are, they may not be universal. which it is almost vain for me to recI merely wish to point out in what I ommend to imitation ; for it can conceive Washington Irving's superi- scarcely be imitated with success, perority to consist. He is certainly the haps by the author himself. The last only author I can now recollect, who, page or two where he speaks of the in the present day, largely intermin- sorrows for the dead," are worthy of gles moral reflection with the poetry perpetual study and eternal rememof composition. This is the consum- brance. They are at once beautiful mation devoutly to be wished by rea- and sublime ; instructive and delightders, and devotedly to be sought after ful. To them I would chiefly point by writers. The author of the Sketch my reader's attention, as exhibiting Book is, in my opinion, a model for that that degree of reflection, and that meaclass of writers to whose works the sure of instruction, which I am anxmultitude chiefly resorts for its mental ious to see all our general authors imrecreation, apprehensible by alnjost part to some portions of their writings. every age, sex, and condition, yet not I am not an admirer of didactic com

He unites much of the position ; but I confess it is not withsolid with more of the splendid ; a cer- out some compunction that I sacrifice tain degree of reftection with a greater my time to the perusal of works degree of imagination; considerable where the imagination alone is pampower and will to instruct, still more pered, and the reason altogether considerable power and will to de- starved. Idle meditation would be a light. But such unions are rare ; more profitable employment than such anions by which Nature sometimes reading. endeavours to make compensation for With these pre-dispositions in Mr. the myriads of fools whom she brings Irving’s favour, and with these expecevery day into the world.

tations from his forthcoming work, How beautifully, for instance, does you may judge, my dear sir, of my the story of “ The Widow and her disappointment, when instead of the Son,” in the Sketch Book, intervene qualities I have mentioned as raising between “ The Country Church," him so far above his cotemporaries, and 6 The Boar's Head Tavern!" I found little in his Tales of a Travel How much sweet and unobtrusive ler, but the style, to admire. Here is wisdom is inculcated by the sketch of scarcely a gleam of his playful and “ Westminster Abbey” and several Addisonian wit ; nothing of his vivid others in these volumes ! How fre- delineation of character. But this is quently does the author lead us unwa not the worst. The Tales of a Trava rily into a train of reflection! and in eller are a number of short stories the midst of his liveliest stories how comprised in two volumes of about the often do we meet with sentences and same size as his former works. Not passages of gentle admonition or in- one of these stories is of the reflective structive remark, a maxim or a moral, character. In not one of them does tending to make us better or wiser, the author indulge that fine strain of disclosing a new truth, or impressing sentiment and moral feeling which an old one !- but of this beautiful and makes his Sketch Book such a familymost praiseworthy introduction of treasure,-even for the space of an moral reflection into works of enter- ordinary paragraph. Some of the fainment, “Rural Funerals” is the tales are to be sure of a serious na

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