Imágenes de páginas
PDF
EPUB

which this article embraces. An ac- As a sequel to the article Baromecount is given of the invention of the TER, we have, from the same pen, a air pump, by Güricke of Magdeburg, paper on BAROMETRICAL MEASUREabout the middle of the seventeenth MENTS. The decisive experiment by century,-of his statical balance, and which Pascal ascertained that the presa anemoscope: the introduction of ex- sure of the atmosphere diminished acperimental science into England, and cording to its elevation, naturally sugthe institution of the Royal Society gested to him the possibility of meaare next related ; this naturally leads suring by the barometer the relative to the mention of some of its most ce- heights of distant places on the surlebrated members, as Boyle and Hook, face of the globe. The first attempts, the latter of whom greatly improved however, were rude, as they proceedthe form of the air pump ; next come ed on the inaccurate supposition that the experiments of Huygens, who, the lower mass of air is a fluid of unia from the suspension of mercury in a form density. We regret that our glass tube exhausted of air, was led to limits prevent us from accompanying infer the existence of a more subtile Mr Leslie in tracing the successive fluid, which he called æther : the cis- steps by which the instruments and tern barometer is then described ; after the rules employed in barometrical which are detailed the various con- measurement have attained their pretrivances for enlarging the scale of the sent state of perfection. One interestvariations of the barometer ;- first in ing discovery, however, lately made order is the barometer of Descartes; by this mode of distant levelling, we then the double barometer of Huy- must, in justice to our readers, mengens, the advantages and disadvant- tion. Two Prussian travellers, Engalages of which are pointed out ; next, horde and Parrot, who proceeded, on the more accurate double barometer, the 13th July 1814, from the mouth of and the wheel barometer of Dr Hook; the Kuban, on the Black Sea, to the the inclined barometer, ascribed to Sir mouth of the Terek, on the Caspian, Samuel Moreland ; the square baro- ascertained, by a series of fifty-one acmeter of Cassini and Bernoulli ; the curate observations, that the Caspian conical barometer of Amontons; the is 334 English feet below the level of sectoral barometer proposed by Ma- the ocean ; and that, at the distance gellan ; the adaptation of the differen of 189 miles from the Caspian, the tial scale for measuring minute divi country is depressed to the level of sions, first proposed by Vernier, early the ocean—thus leaving an immense in the seventeenth century, but long basin, from which the waters are supafterwards strangely neglected the posed to have retired by a subterranearticle next proceeds to mention the ous percolation, formatges To circumstances which influence the va- In the article BATHING, the media, riations of the barometer, viz. the effect cal and physical effects of the various of moisture within the barometric kinds of baths, in various circumtube,-the effect of the width of the stances, as determined by the obsertube-the uniform convexity of the vations of Wright, Currie, Seguin, surface of pure mercury in properly Parr, Haygarth, Fourcroy, Marcard, constructed barometers,—the quantity and other able physicians, are minutely of depression in different tubes,-the and accurately detailed. vee application of a leather bag to the sy The article BEAUTY we opened with phon barometer,--the effect of heat on peculiar interest; and though we are the barometer, which leads to an ac- very far from agreeing to the theory count of the successive improvements proposed, and the reasoning by which of the thermometer ; marine barome that theory is supported, we are ready ters are next described, the most ap to do full homage to the abilities disproved kind of which, manufactured by played in the discussion. We cannot Mr Cary of London, is illustrated by a say, however, that we greatly admire figure, in a well executed plate the the style in which the article is comdifficulty of explaining the variations posed. It is distinguished, indeed, by of the barometer are adverted to, and great vigour of conception, and by a some hints are thrown out relative to command of language almost peculiar these causes. On the whole, we think to its celebrated author; but the vehethis a very able article, though, per- mence of its tone, and the dogmatical haps, a little too discursive.

confidence of its assertions, remind Vol. L

2 A

more of the manner of a pleader at wonderful ingenuity; whereas their the bar, anxious at all events to make expedients are few, obvious, and coarse. good his cause, than of the calm and of the methods proposed for supdispassionate style of a philosophical pressing begging, there seems to be inquirer--of which Mr Alison and dir none so deserving of approbation as the Stewart, in their treatises on the same scheme of the society at Edinburgh for subject, had given so pleasing speci- that laudable purpose. Nothing can be mens. We shall not at present at- more judicious than the principles on tempt any analysis of the contents of which the society, proceeds; and their this article, as we hope soon to have exertions have met with the success to a communication on the subject from which they are so well entitled. It is a correspondent.

objected to their plan, by the writer of Under the article Bes, the many this article, that it is not calculated curious and interesting facts relative for permanent or general use. Let to the physiology and economy of their example be generally followed, these remarkable insects, which have and there can be little doubt that it been discovered by the researches of will be found generally beneficial. Swammerdam, Maraldi, Reaumur, The article on BENEFIT SOCIETIES Schirach, and Huber, are detailed in proceeds from the same pen, and is a clear and systematic manner : but as marked by the same prepossessions, as these facts are now so generally known, the article on Banks for Savings. It we think it unnecessary to give any is unnecessary, therefore, to say any analysis of the article.

thing of it at present, as another opBEGGAR is the next subject that portunity will offer of examining the claims our attention. The informa- doctrines and the principles which it tion contained in this article is chiefly contains. drawn from the report of a committee Besides the articles to which we of the Honse of Commons, appointed, have already adverted, this part of the in 1815, to inquire into the state of Encyclopædia contains some good biomendicity in the metropolis. Beggars graphical sketches of Joel Barlow, are classed into those who beg from Barry, Barthez, Basedow, Beattie, necessity, and those who beg from Beaumarchais, Beccaria, Beckmann, choice. With regard to the relative and Beddoes. munbers of these classes, the information of the coinmittee was quite contradictory. Two of the witnesses exa

EDINBURGH ENCYCLOPÆDIA, Vol. mined, whose experience was equal or

XI. Part I. superior to that of all the rest taken Two different plans have been adopttogether, asserted, that a proportion as ed by the Editors of Encyclopædias, large as one half were beggars from which may be distinguished by the epi. necessity, and some of them extremely thets of alphabetical and scientific. In worthy objects of compassion; while the Cyclopædia edited by Dr Rees, there others asserted, that all beggars, with is indeed a vast treasure of valuable hardly any exception, were beggars knowledge ; but the plan of that work from choice. One fact, extremely hon- appears to us, in several respects, esourable to the working part of the sentially faulty. One grand objection coinmunity, seems to be well ascer- to it is its extent, which places it far tained. Of the journeyinen in the out of the reach of ordinary readers; metropolis, no one is ever known to another objection, the consequence, beg, though thousands of them, in indeed, of the former, is the enormous the fluctuations of trade, have been length of most of the articles, which, recluced to the most cruel privations; instead of being compendious treatises, and not a few of them actually starve, are prolix and ill digested compilaunpitied and unknown! The number tions, apparently intended to contain of beggars in the metropolis the com- every thing that seems to bear, how. mittee have been unable to ascertain ; ever remotely, on the subject; but a but it appears to be certain that it is still more important objection is the gradually diminishing. Of the decep- want of unity, occasioned by dividing tions practised by beggars very erro- a subject into separate derartments, neous notions have been entertained. which are discussed in different, and In the number and variety of their con- often distant, parts of the work. The trivances they are supposed to exercise Edinburgh Encyclopædia, on the other hand, by a judicious plan of selection, meleons, geckos, anoles, lizards, taky. reservés a due space for the discussion droine, scinks, efts, and chalcides. The of important subjects, while it is over- third order comprehends the hylæ or loaded with no useless and lumber- tree frogs, rana or common frog, bufo some matter. Its plan is sufficiently or toad ;-these constitute one family, extensive to embrace every thing use- called the batracians, without tails ; ful in history, literature, and science; the other family (or tailed batracians) but not so extensive, and herein lies consists of the salamander, proteus, its excellence, as to admit of the te- and siren. In treating or the anadious and perplexing tautology, which tomy and physiology of these reptiles, is unavoidable when the same subject the author gives a clear and coinpre. is brought under the view of the read hensive account of their motions, suner, in different articles, and in various sation, digestion, circulation and ab. forms. The respectable names which sorption, respiration and voice, secreappear in the list of its contributors tion and excretion, integumation, gewere, froin the first, a pretty sure neration, and hybernation. pledge of the ability with which it History is the next article of imwould be conducted; and the pledge portance. The plan proposed is, has been fully redeemed. Many of first, to point out and explain the its leading articles may be held forth various advantages of the study of as the best treatises which have ap- history; secondly, to enumerate those peared on their respective subjects; branches of study which ought to and the plan very properly adopted be entered upon, previous to, or conof having every article an original com temporary with, the study of hismunication, marked by the signature tory; thirdly, to give a brief and rapef its author, has excited among the id sketch of the order in which ancontributors a very benefieial emula- cient and modern histories may most tion, and conferred on the work a uni- conveniently and advantageously be formity of excellence of which none of read; fourthly, to point out the order its rivals can boast.

in which the history of particular Our notice of the articles which countries may be read, so that they this half volume contains must be ex- may be illustrative of one another; tremely brief; and this we are the fifthly, to notice the different species less disposed to regret, as there are not of history, besides what is emphatically many of them which can be supposed called history. Notwithstanding some to be very generally interesting. The defects, this article may be perused first in order is HERPETOLOGY, the with considerable advantage by those natural history of reptiles. Under the who wish to commence a regular course term reptiles, it is observed, naturalists of historical reading. have generally comprehended all those The account of the province of tribes of oviparous animals commonly HOLLAND is full of important and incalled amphibia, including both ovipa- teresting information. Indeed the georous quadrupeds and serpents; but in graphical articles of this Encyclopædia this article it is proposed to consider are distinguished in general by the ex. only the first order, reserying the his- tensive and accurate knowledge which tory of the serpent tribes for the arti- they display, and by a happy discricle OPHIOLOGY. The account which mination, which rejects all extraneous is given of these animals, and of the matter, without omitting any thing Iristory of the science, is methodical, that it is useful to know. The lanclear, and comprehensive; accompanied guishing state of manufactures and with a full list of references, which will commerce in that once flourishing be found very useful to those whose country, affords a striking exemplificaattention is directed to this department tion of the vicissitudes of national of zoology. The reptile tribes are disprosperity. We have no room for detributed into three orders, Chelonians, tails; but as a proof of the declining Saurians, and Batracians. The first condition of the country, we may state, order comprehends turtles, of which that, since the year 1732, the population there are six species, and tortoises, of of this province had, even previous to which there are fifty-two species. The 1796, decreased by one thirteenth of second order comprehends crocodiles, the whole; that, except the internal dragon, basilisk, tupinambis, guana, trade with Germany, its commerce is fying-dragon, agamas, stellios, cha- almost annihilated ; that many of its

principal manufactures have gone to pivot-holes; 5. machinery for going decay; and that the only one which is in time of working, invented by Haron the increase, is the distillation of rison-a contrivance of his own for ardent spirits.

this purpose is described by Mr Reid; The article New HOLLAND supplies 6. the dividing or cutting engine; 7. the information, which the publica- equation-clocks, an ingenious contriytion of Captain Flinders' discoveries ance to show both mean and apparent has put us in possession of respecting time, invented in London about 120 this island, since the article Australa- years since ; 8. repeating clocks and sia was written. The author of these watches; 9. compensation-pendulums, articles, however, seems to have known two kinds of which have been inventnothing of the journeys of Mr Evans ed by Mr Reid, the one with a zine and Governor Macquarrie into the in- tube and steel rods, the other with a terior-a deficiency which, we doubt glass tube ; 10. wooden pendulumnot, the attention of the Editor will rods, on which Mr Reid made some take the earliest opportunity of supply- experiments, which he details ; 11. on ing. In other respects the article is the sympathy or mutual action of the valuable ; containing an accurate and penduluins of clocks; 12. on turretwell-digested account of the coasts clocks; 13. on the method of fitting and bays, the mineralogy, botany, and up astronomical clocks; 14. on chimes zoology, of this immense island ; of and bells. its inhabitants, their arts, manners, and "To the amateurs of gardening, the customs.

article HORTICULTURE must prove an Our attention is next arrested by a exquisite treat ; while to the practical very long article on HOROLOGY. We gardener it will afford much valuable are told by the Editor, that he is in- instruction. It is evidently written debted for this article to Mr Thomas by a person who not only understands Reid ; and this may be regarded as a the subject in all its practical details, pretty sure pledge of its technical accu- but who has brought to that delightracy. On the whole, we consider it as ful study an elegant taste, and a phithe best account of horology that we losophical mind. We cannot afford, have seen, so far as the practical part of at present, to give any analysis of so it is concerned; and as many of the im- long an article, or even to mention the provements on various branches of the various topics which it comprehends. art were invented by Mr Reid hin- His own definition of HORTICULTURE, self, no person, surely, could be better however, will give some idea of the qualified to describe thein. The de- principal branches into which the subpartinents of this curious art we shall ject is divided. “By the term hortimerely mention, in the order in which culture," he observes, “ is to be unthey occur in Mr Reid's description. derstood the whole management of a 1. T'he escapement, or 'scapement, that garden, whether intended for the propart of a clock or watch connected duction of fruit, of culinary vegetawith their beats on this part of the bles, or of flowers. T'he formation of machinery Mr Reid has made several a garden may be included also, to a improvements ; connected with the certain extent, under this subject : escapement is the remontoir, the in- draining, enclosing, and the forming tention of which is, that the move- of screen plantations and hedges, may ment passing through the wheels be considered as parts of horticulture, should, at intervals, be made either to while the general situation of the fruit wind up a small weight, or to bend and the flower gardens, in regard to up a delicate spring, which alone the mansion-house, and the position should give its force to the 'scape- of some of their principal component ment; by which means the pendulum parts, as shrubberies, hot-houses, paror balance was supposed to be always terres, and walks, belong more proimpelled by an equal and uniform perly to landscape-gardening." force-Mr Reid has described & re- Thus we have adverted, in a very montoir which he appliet to the clock cursory manner, to the leading articles of St Andrew's Church in Edinburgh; in this half-voluine. It contains, be2. the compensation-balances, intend. sides, several excellent articles in bioed to counteract the effects of heat and graphy, geography, &c. On the whole, cold on time-keepers ; 3. balance or we think that this number supports podulum springs ; 4. jewellery of well the credit of its predecessors.

LITERARY AND SCIENTIFIC INTELLIGENCE. :

A NEW instrument, called a Capillary easily increased from three to seven miles Hydrometer, for measuring the strength and an hour. The weight of the machinery specific gravity of spirituous liquors, has late will not be more than three tons, and the ly been invented by Dr Brewster. The space it will occupy is comparatively small. principle of the instrument is to determine Mr J. B. Emmett of Hull has published the specific gravity from the number of some experiments which he made during drops contained in a small glass bulb, so the suminer of last year, with the view. of that we have only to fill this bulb with any ascertaining whether a gas might not be obmixture of alcohol and water, and count tained from oil, equal to that obtained from the number of drops necessary to empty it. coal, so as to prevent the injury threatened When a bulb about 14 inch in diameter to the Greenland trade by the rapidly inwas filled with water, it yielded only 724 creasing use of the latter in the lighting of drops, whereas, with ordinary proof spirits, towns, &c. By distilling various oils, preit yielded 2117 drops, giving no fewer than viously mixed with dry sand or pulverized a scale of 1393 drops for measuring speci. clay, at a temperature little below ignition, fic grayities from 0.920 to 1.000. A cor. he obtained a gas which appeared to be a rection must be made for temperature as in mixture of carburetted hydrogen and superall other instruments.

carburetted hydrogen gases. This gas proA remarkable fossil has lately been disc duces a flame equally brilliant, and often covered in the parish of Alfold, in the coun. much more brilliant than that produced ty of Surrey, some miles east of Guildford, froin coal. It differed very little in quality, It was found about eight feet under the whether obtained from mere refuse, or from surface in a bed of clay. Above the clay, in good whale sperm, almond or olive oil, or that particular part, is a bed of gravel, which tallow. The gas, when burnt, produces no extends to a considerable distance east and smoke, and exhales no smell or unpleasant West, and varies in breadth from eleven vapour. Whatever oil is used, it evolves yards to about forty, and has the appear. much more light when burnt as gas than ance of having been the bed of a river when consumed as oil; in the latter case, The fossil consists of hard clay covered with the flame is obscured by a quantity of soot ; thin rectangular scales, lying in a regular in the former, the spot remains in the disorder, about of an inch long, and broad. tilling vessel, and the flame burns with a These scales have been analyzed by Dr clear light. Thomson, and found to consist of

The water of the ebbing and flowing Animal matter,

11.37 spring lately discovered in the harbour of Phosphate of lime,

65.61 Bridlington, Yorkshire, and described in Carbonate of lime,

119.65 the Philosophical Transactions for 1815, by 3.47 Dr Storer, has been found to possess many

. excellent properties, and becn administered

100.00 with decided benefit in numerous cases of This is nearly the composition of the scales chronic disease. It has been analyzed by of fishes as determined by Mr Hatchet., Mr Hume of Long-Acre, who finds that

A new mineral, consisting of sulphate of great purity is one of its most distinguishing barytes and carbonate of strontian, has been properties, in which it may vie with Mal. lately discovered at Stromness, in the Ork- verne well; that although this stream is so ney Islands, by Dr Thomas Traill of Liver- nearly connected with the sea, which covers pool. An account of the analysis of this its whole vicinity twice a-day, yet it is altomineral by Dr Traill was read at one of gether free from muriate of soda, every kind the late meetings of the Royal Society of of sulphate, and magnesia. It is little heaEdinburgh. He proposes to call it bary. vier than distilled water, and contains no strontianite from its composition, or strom other aëriform substance than carbonic acid. messite from its locality.- N.B. We have The solid contents of a wine gallon amount seen specimens of this mineral, and conjec. to 134 grains, consisting of carbonate of ture that it is a compound of the two known lime, 3.750; silex, and a little oxide of iron, species, carbonate of strontian and sulphate of about .125. barytes, and that with care the two ininerals The Rev. F.H. Wollaston has submitted might be separated from each other. to the Royal Society a description of a ther

A new artificial horizon has lately been mometer constructed by him, for deterinvented by Mr White of Kinross, of which mining the height of mountains, instead of an account will be found among our Ori the barometer. It is well known, that the ginal Communications.

temperature at which water boils diminishes Mr W. K. Northall, of Wolverhampton, as the height of the place increases at which announces that he has discovered a new the experiment is made ; and this diminumethod of propelling boats by steam. The tion was suggested, first by Fahrenheit, and Velocity of the boat may, by this plan, be afterwards by Mr Cavendish, as a ipediun

Loss,

« AnteriorContinuar »