« PreviousContinue »
iron, with less difficulty ; I conceive who construct engines for the use of it to be a very difficult thing to make the Cornish miners.
When employs a wrought iron boiler so strong as we ed for that purpose, there appears to be can have it cast; we have some of a great saving, in point of economy, in our boilers made two inches thick; the use of high pressure engines. and to make a wrought iron boiler Without, however, supposing any bias equally strong as that, would be very from this cause, the two cases are difdifficult to be accomplished by work- ferent,
and different rules may apply men.
to them. It would seem, by the tes“Supposing the only object to be timony of those concerned in steamsafety to the lives or limbs of the per- boats, that the low pressure boilers sons who should be surrounding the burst almost as often as the high presengine, would you in that case prefer sure ; but, in bursting, they do no having the boiler of a high pressure injury; the fragments never explode. engine of wrought or of cast iron? The only danger is from the scalding -I would have cast iron, because of the steam ; but this seems never to it can certainly be made stronger have been experienced in boats, prothan wrought iron for the same ex- bably from the covered state of the enpence.”
gine ; it occurred only in mines or maMr. Thomas Lean.-" Have you nufactures, where the workmen were any choice, in point of safety onlý, exposed to the steam. It appears to between a boiler constructed of cast follow, therefore, that his Majesty's iron or of wrought iron ?-Were I to subjects may travel in boats using low have a boiler where I wished to have pressure engines, with perfect safety to the greatest strength, I would certain- life and limb. Moreover, these boats ly have it made of cast iron ; I have seem, in all common cases, capable of not one doubt that a cast iron boiler sailing with every degree of rapidity can be made much stronger than it is which can be wished for. The steampossible to make a wrought iron one; boats on the Clyde go, I believe, at in fact, the explosions that we have the rate of seven or eight miles an had in Cornwall have all been in hour, which is as rapid sailing as any wrought iron boilers, but I never had one could desire or choose. There one in cast iron boilers, nor have we seems no motive, therefore, for enhad an accident from high pressure countering the hazard of explosion, steam; all the accidents have been which probably can never be entirely from low pressure steam in Corn- prevented in high pressure engines, I pall.”
am not prepared to say, that the LeHaving thus extracted the substance gislature ought absolutely to prohibit of the examination, so far as relates to the use of boats with such engines ; these two leading questions, I shall because I share the feeling of the now beg leave to make a few obser- Committee, that as little restraint as Fations.
possible ought to be placed on the naThe Committee report, that the tural course of human industry. I persons examined «
generally agree, only conceive, that, unless in very pethough with some exceptions, that culiar and special cases, the use of high those called high pressure engines pressure engines in boats can serve no may be safely used, with the precauc purpose, and ought to be entirely distion of well constructed boilers, and couraged. The Committee also appear properly adapted safety valves.” Now, to me to be departing from their own I cannot exactly agree with the Com- principle, when they load all steammittee in this general inference. A boats indiscriminately with troublegreat majority, I think fully two- some and expensive regulations, which thirds, are decidedly against the high seem to be necessary or applicable only pressure engines. It is farther to be in the case of those using high presobserved, that these persons include sure engines. If the bursting of low almost all who have had any observa- pressure engines never produces any tion of, or concern with steam-boats ; damage, why require, before every while the advocates of high pressure voyage, an examination by an engiare almost all persons connected with neer, whose presence it may be diffithe application of steam to machinery cult and expensive to prooure ? used in manufactures. They are, in why also demand, that the boiler deed, almost exclusively the persons should be made capable of bcpring six
times the pressure which it is intend varieties of organized life, or the died to sustain ?
versified appearances of the laws of The Committee also report, that nature, which are there presented. “ a great majority of opinions lean to The facts which I have to notice, are boilers of wrought iron or metal, in not, besides, very generally known, preference to cast iron;" and they and seem, on both these accounts, to therefore recommend as a regulation, be deserving of a place in your useful “ that all boilers belonging to the en- miscellany. gines by which such vessels shall 1. My first observation relates to be worked, should be composed of that species of marine animal which wrought iron or copper." Ĝenerally is known to naturalists by the name speaking, the same persons who re- of Medusa Capillata. It is a frequent commend low pressure engines, re- inhabitant of most of the shores of commend wrought iron ; and those this island, and may easily be distinwho advise high pressure engines, ad- guished from the other species of the vise cast iron. We do not exactly same' animal, by the remarkable transknow why the Committee has adhered parency of its whole mass; and more * to the former in the one case, and to particularly by some beautiful spots of the latter in the other. The general bright purple, which are placed near result seems to be, that cast iron boilers the centre of its disk. I ought, permay be made stronger than wrought haps, to remark, for the sake of some iron, and consequently less liable to of your readers, that the class of aniexplode; but, when they do explode, mals, of which that alluded to in the they occasion more damage. On these following observation is a species, is grounds, the preference between the commonly known in this country by two appears somewhat of a dubious the name of the sea-blubber, and is point. But, at all events, as the only remarkable for several striking proobject in the use of wrought iron is to perties, which characterize some of its diminish the injury produced by an species, such as that of occasioning a explosion, I can see no possible motive feeling of irritation in the skin when for compelling the adoption of it in touched, and of being phosphorescent low pressure engines, which never ex- in the dark. To a common observer, plode. The hardship of such a regu- all the varieties of this animal appear fation would also be very considerable, to be merely masses of a transparent as it would render useless all the low jelly, scarcely worthy of being rankpressure engines at present composed ed among the class of animals, and apof cast iron, and oblige the proprietors parently driven, without the power of to incur the expence of a new machine. directing their course, by the varying
Upon the whole, the result of the direction of the winds or the waves. evidence here collected appears to be, If, however, on a fine day, when the that there is no ground for giving any sea is calm, and when one of the speencouragement to the use of high pres- cies to which I now allude is swimsure engines in steam-boats. But, if ming near the shore, an attentive eye any proprietors choose to set such on be kept upon its movements, within' a foot, it is very proper that they should yard or two of the place of the animal, be made liable to the regulations pro- the following very beautiful and aposed by the Committee. To impose, musing appearance will be observed. however, the same regulations upon As the animal moves forward, it is all steam-boats, appears to be both un- constantly employed in forming its necessary and vexatious.
disk into a greater or less degree of convexity, while at every such change in the form of its mass, a fringe of most beautiful and apparently silky
filaments, all around the circumfe. MR EDITOR,
rence of the disk, is protruded into The following observations, though the water, and again withdrawn into unconnected by any other relation the body of the animal, as it resumes than that of having been made in the its ordinary and more flattened appearsame situation, may probably afford ance. These filaments proceed from an amusement to such of your readers the circumference of a circular space, as delight to wander, at this fine sea- · which is placed near the centre of the son, by the sea side, and to remark the animal, and may be distinctly seen
MISCELLANEOUS OBSERVATIONS ON
passing from thence, in the form of existence of which, in that situation, rays, to the extremity of the disk. the naturalist was very much puzzled The progress of this animal is there to account. A collection of observafore performed, as the reader will un- tions like the foregoing, would proderstand from the foregoing remarks, bably enable us to solve this difficulty. by a species of spinning; and the I have only further to remark on kind of organization by which this is this article, that, as the substance of effected, has always appeared to my-, the Medusa is gelatinous, and as this self to be one of the most pleasing in- matter is soluble in common water, stances of the wisdom of nature with any person may procure the filaments which I am acquainted, and adapted I before noticed, by placing one of the most happily to illustrate the remark, animals possessing them in a bason of that some of the finest specimens of river water during forty-eight hours. what is exquisite in structure, may be At the end of that time, the substance discovered in animals of the very low- of the animal will be found to have est order.
become entirely dissolved, and the I am not certain whether any other filaments will be obtained floating on of the species of this class possess the the surface. same organ to which I have now al- 2. My next observation relates to a luded. Indeed I think we have rea- remarkable appearance produced by son to believe, that most of the species the refraction of the rays of light. possess a power of locomotion, though If an observer is seated on a ledge of not apparently of so fine a construc- rock which has a gentle declivity totion, yet certainly capable of accelerat- wards the sea, and if the tide is in such ing their progress to a much greater a state that the wave, after having addegree. I remember, indeed, to have vanced upon the rock, rests precisely been once remarkably struck with this, at its margin when the water is at its faet, while bathing with a companion utmost retreat, the following amusing in one of those arms of the sea which appearance will be remarked. As the intersect the western shores of Ar- wave alternately advances and retires, gyllshire. We had been in use, dur- that part of the rock which is subject ing the greater part of the summer, to to the inundation, will appear to be bathe in the same spot. One day, alternately lifted and depressed with however, we were astonished on ad- something resembling a living movancing farther into the water, to per- tion.” The solid stone, in short, will cive myriads of the Medusa in rapid appear as if transformed into someprogress from the head of the loch, thing either endued with spontaneous apparently towards the open sea. They activity, or at least so light and movecontinued to float by us in countless able in its texture, as to be agitated numbers, during the whole of the with the same facility, and very
much time we continued in the water; and in the same way as the floating fuci though I was aware of the effect which which may happen to be attached some of the species are said to produce to it. upon the skin when handled, we yet There are few of your readers, I ventured, in youthful wantonness, and, dare say, of those at least who shall I dare say, to the no small annoyance actually observe the appearance, who of the “ emigrants,” to pelt one anę will find any difficulty in assigning other with them for a very consider- the cause of it. Every person knows, able time, without afterwards experi- that if a shilling be put into a bason, encing any disagreeable sensations. so as to be covered from the view of Next day, no appearance of the Me- an observer by its inargin, and if water dusa could be seen ; and I inferred at be then poured into the bason, the the time, that the animal was accus- piece of money is seen gradually to tomed, at certain seasons, to make rise in the water, so as to become long and rapid migrations, probably completely visible to the eye of the from the quiet and shelter of the in- spectator. It is evidently in precisely land bays, towards the open sea. Those the same way that the alternate apwho are acquainted with the late voy, pearance of elevation and depression age of Humboldt across the Atlantic, in the margin of the rock is produwill indeed recallect, that one part of ced. When the advancing wave grathat vast sea is completely covered by dually makes its way up the slopmany species of this animal, for the ing surface, that part of the stone
which is covered by the water, of the production of mist is chiefly decourse, appears to be affected with a pendent upon the agency of this fluid, gradual elevation ; as the wave retires, I am satisfied, among other considera a the rock necessarily sinks to its proper tions, from a fact which I have free level ; and if the ebb of the wave does quently noticed upon the sandy shores not go beyond the boundary of the of the Firth of Forth. When the air rock, the appearance of motion is of is in that state which is productive of course uninterrupted ; and when it mist, that is, when an east or northhas once attracted the notice of the east wind has been blowing for some observer, will be found to present a time, I have frequently remarked, that phenomenon which it is both amusing the water which was left upon the and instructive to contemplate. sands of the beach, and in every basin
3. I have now to direct the atten- and pool which was near the shore, tion of your readers to some particu- is carried off by evaporation, with a lars respecting the production and dif- celerity and power which gives to the fusion of fogs. It has been stated as whole coast the appearance of a vast being now decisively proved, that fogs smoking furnace. And that this is are not to be regarded merely as va- not merely the effect of the temperapour suspended in the air by the ture of the air at the time, must be simple circumstance of the inferior evident from this consideration, that, specific gravity of their particles, but on many of our most splendid and as moisture só combined with electric sultry days, when the wind happens city, as to assume that inferior gravi- to blow from any of the south or west ty by which its suspension is affected; points, no trace of evaporation can be and, as a proof of this, it is said, that, perceived, and the atmosphere is inon one occasion, a fog having been deed remarkable for a very peculiar carried very near a tree, the electrici- degree of transparency. ty of the fog was attracted by the tree, An east wind, in this climate, thereand the moisture thus deprived of its fore, I apprehend, is to be considered electricity was so immediately convert- as connected with important changes ed into snow, as actually to tear up, by in the electrical state of the atmoits overwhelming impulse, the roots of sphere, as might indeed have been long the tree upon whose branches it had ago suspected from the known increase rested. Now, although the fact, when of pressure in this fluid when the thusstated, certainly possesses noslight wind blows from any of the eastresemblance to some of those which ern points. These electrical changes, the renowned Munchausen observed which probably take place at the same in the course of his journeyings, I time in the atmosphere and in the have yet long been convinced that the earth, appear to be peculiarly favourtheory which it supposes is perfectly able to the elevation and suspension of correct. Indeed, considering how far vapour; and hence it happens, that, our knowledge of the properties of when the wind blows from the east, electricity has been extended, and are immediately plunged in a how certainly we are now informed of cloud of haze or fog, while those geits universal diffusion, it is not a little nial breezes, which have traversed the astonishing that philosophers should Atlantic, and which might have been persist, with such obstinacy, in exclud- expected to come to us with wings ing it from their explanations of those profusely bedewed with the moisture ordinary appearances, with which it of their way, pour only around us that cannot be doubted that it has the beautiful transparency, through which most intimate connection. Who, for all the hues of nature are seen to adinstance, can doubt that snow, and vantage. rain, and dew, in all their varieties, 4. I have one further remark to are not merely dependent, according make. It often happens, in very calma to the prevailing theory, upon the weather, that the sea has the appearmerting and intermixture of currents ance of being very beautifully varied, of air of different temperatures,-but, from portions of its surface being far more, upon changes taking place gently agitated, while other portions in that active fluid, which seems to are in a state of perfect repose ; and pervade and communicate their most these alternations are commonly so important properties to every thing gracefully disposed, as rather to reupon and around this globe. That semble the effect of some moving body
OF A REMARKABLE AU DIENCE OF A POLISH AMBASSADOR AT THE COURT OF QUEEN ELIZA
which had passed in a winding direc- you in the attainment of this object, tion over its surface, than of any so far as my ability may extend, I am, cause existing in nature itself. Nom Mr Editor, yours very respectfully, thing is more common, indeed, than
P. to hear this appearance ascribed to a variety of causes,--to the oily matter deposited by vessels which had sailed Account in the direction of the more placid portions,—to something in the bottom of the sea which rendered the surface BETH IN 1597. more easily agitated in some parts than The arrival in 1597 of an ambasa : in others,—to the influence of clouds sador from Sigismund the Third, exerting a composing energy on those King of Poland, at the Court of Elizatracts of water which liebeneath beth, is mentioned by all the historithem,-or to the effect of promonto ans of her reign. This ambassador, ries and other partial irregularities in whose name was Paul Dzialenski, was interrupting the natural direction of sent to complain of some interruption the wind. The simple account, how- of the Polish commerce by the Engever, of these appearances, seems to lish cruizers ; a measure to which, be, that, besides those greater and according to Carte, * his master was more extensive agitations to which the instigated by certain Jesuits at his atmosphere around us is constantly Court in the interest of the King of liable, its lowest stratum is also oc- Spain. Elizabeth granted him a pubcasionally subject, especially where it lic audience, at which he addresis in contact with the surface of the sed her in a harangue of uncommon sea, to a tremulous agitation of a far boldness and vehemence, to which she less perceptible character; which seems immediately made a suitable reply in to originate in causes somewhat dif- Latin, in which tongue the Pole had ferent from that by which wind is spoken. The substance of both their produced ; and the existence of which speeches is given in Camden's Ancould only be discovered by its effect nals, and in Čarte's History; but we upon a surface so easily agitated as
have procured an extract from the that which a very placid sea presents. Burghley Manuscripts, preserved in It is to this slight tremulous agitation the British Museum, of a letter from in the lower surface of the air, a mo- Sir Robert Cecil to the Earl of Estion, I may remark, which is probably sex, which, as it contains much more not very easily propagated, which minute details of the circumstances seems, as I have already said, to de- attending this remarkable audience pend upon causes of a peculiar nature, than are to be found in these histories, and not necessarily to be carried for- cannot fail, we should think, to prove ward like wind, in a continued stream, interesting to our readers. that I am disposed to attribute those
The letter is not a little curious in variations of the surface, by which several respects. Elizabeth's partialieven the calmest sea is commonly ty for handsome men is well known to marked ; and I am persuaded, that any all who are acquainted with her hise person who will take the trouble of tory and character; and it appears remarking the manner in which these from this letter, that she was induced agitated and calmer portions of the to grant the Polish ambassador a pube water are gradually varied and inter- lic and splendid audience, from the mingled with each other, will readily very favourable accounts she had ree acquiesce in this solution of the phe- ceived of the beauty and elegance of his nomenon.
and manners. She seems to have Whatever, Sir, may be the truth of been prepared to hear an address from these explanations, I apprehend, how: him, couched in those romantic terms ever, that your miscellany can seldom of love and admiration in which she was be better employed than in giving sometimes accosted by her courtiers; currency to such views of the appear- who, when they wished to ingratiate ances of Nature as may lead your themselves, always contrived to mingle readers to a more intelligent observation of the beauteous order which prerails around us; and, with assurances
• Carte's History of England, Vol. III. of my being always ready to assist