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The labours of M. Laplace alone, care suflicient to justify our opinion: this illustrious mathematician in his Mecanique Celeste, a work inferior only to the Principin, has calculated from the effect of precession and nu. tation, the eccentricity of our earth, to be 33't, which agrees almost ex: actly with experiments made on the pendulum.
It was impossible to deny Mr. Laplace the justice of supplying, what is evidently a mere omission of our author ; the reader will therefore excuse this digression, and be issured that we have no wish to depreciate the value of operations, like those wäich are now under consideration ; on the contrary we view them as most useful and important. The inconsistencies which they betray, only serve, in our opinion, to render them more interesting, as these seem to indicate something, in the figure and conformation of our earth, not yet understood. It is therefore probable, that by repeating and comparing measurements of this kind, made in different and distant parts of the globe, we may at length be led to some curious and interesting discoveries. But to return—
Occultations of fixed stars by the moon, continues Mr. Svanberg, is ano. ther method, by which the figure of the earth may be determined. Mr. Treisnecker, after comparing a great number of these observations, concludes the eccentricity to be
Observations of this sort, however,
325 are liable to considerable errors, especially if made under different meridians.
Our author then gives the eccentricity of the earth, as derived from a comparison of different measurements, with those lately made in France, and points out their inconsistency. After which he concludes his instructive and entertaining preliminary discourse, with the following account of the journey of the Swedish mathematicians*.
• We set out from Stockholm about the end of April, 1801, in order to be at Tornea on the 24th of May following, to observe the tiansit of the moon over Spica Virginis. We arrived there on the 18th, buț were disappointed in our expectations. For after having made every preparation, and even begun to count the beats of the clock, suddenly, the sky became overcast, at the very moment of immersion. Our disappointment was aggravated by a recollection of the inconveniences we had encountered, in travelling, on purpose, over the great roads of Medelpad arid Angermania, which at this season of the year, when the thaw begins, are almost impassable. This unlucky circumstance deprived us of the opportunity of determining the longitude of Torneâ, and consequently of our whole meridian, with the greatest accuracy, which it was scarcely possible to do by any other means ; as will appear, from our not having been able to observe more than two eclipses of the first satellite of Jupiter, during our stay at Pahtavara, and in both these observations, the moment of dis
* The occasion of this journey, we have understood from good authority to be as follows. Bonaparte, at the suggestion of the National Institute, wrcte a letter personally to the King of Sweden, requesting permission for some members of that body to visit Lapland, in order to determine an are of the meridian, This high-spirited young monarch replied, that he would consult the Academy of Sciences at Stockholm, whether such an operation was desirable for the interests of science ; and if they were of this opinion, he would appoint Swedish mathematicians to undertake it. We are also informed that the National Institute has re, ceived the work now before us with great applause ; in consequence of which, Napoleon has presented Mr. Syanberg with a valuable snuff-box. Rev. appearance is marked as extremely doubtful, in consequence of the frost, which in Lapland is 80 excessively severe, as to freeze the exhalations from the eye, almost instantaneously, so that we were obliged to wipe the eye-glass of the telescope from time to time, with a handkerchief, to preFent iis being covered with vapour, which would occasion the satellite to disappear too soon.”
“ The principal object of our first journey, was to choose the points most proper for the trigonometrical operations, to fix the signals, and to de termine how far our meridian could be extended from North to South ; also to construct observatories, at the two extremities of the arc to be measured.”
“ These preparations being completed, before the autumn of 1801, we returned to Stockholm; where we waited the arrival of the repeating cirs. cle from Paris. It was made by Lenoir under the direction of M. Delambre, and arrived in the beginning of December following."
“ The Academy of Sciences, considering the niultiplicity of details, and the extreme delicacy required in performing every operation, now associ. ated with us Messrs. Holmquist aud Palander, so that from this time we must be considered, as consisting of four co-operators.
“ Accordingly in the beginning of January 1802, we all set out for Torneâ. Here we remained only time enough, to adjust the rods that were to be used in measuring the base, which was necessarily our first
operation, and was actually begun on the 22d February, when we left Niemis-by and advanced towards Poiki Torneâ. Here we arrived on the 11th of April, so that this part of the work took us nearly two entire months.
“ Having completed the measurement of the base, we returned to Tor nęã, there to wait the return of the fine summer weather, when we might 'observe the horizontal angles of the triangles, which were to connect Mal. lorn the most southern, with Pahtavara the most northern point of our meridian. These angles were taken in the months of June, July, and August, 80 that at the beginning of September, we were ready to commence the astronomical observations.
« We arrived at Niallorn on the 7th of that month, and on the same night made the first nine observations, of the meridian distance of the polestar, from the zenith, when above the pole. By repeating these observations as often as the weather would permit
, we obtained in the month of September, 260 repetitions of that distance.
« The reason why these observations were not afterwards made use of, was, that on leaving Torneâ, we forgot to bring with us pendulum B; nevertheless, as we hoped to do without it, we began our work. But a very few trials with pendulum A, convinced us of the extreme irregularity of its motion, which was so great, as to make it not worth the trouble of reducing the observations. This being the case, it was necessary to dispatch M. Palander to Torneâ, to fetch pendulum B, which being arrived on the 5th October, we began to make all our observations, with that pendulum alone."
The work is divided into four sections. The first contains a Description of the methode made use of for measuring the base ; the second, An Account of the Trigonometrical Operations; the third, An Account of the Astronomical Observations, and the fourth, The Theory of the Spheroid. After which is an Appendix, containing observations mentioned in the course of the work, but which on account of some inaccuracy or other, it has been thought proper to reject.
Article 50 presents us with a summary of the principal results of these operations ;-whence it appears, That the base measured, extended to 47,427 feet; that the distance between the parallels of Mallorn and Pahtavara is 593,461 feet; the latitude of Malloro 65° 31' 30''. N. and of rahtavara 67° 8' 50." N. So that the whole arc measured, was 1° 37' 20". Consequently the length of a degree of the meridian, in latitude 66' 20' 10' (the centre of that arc) is 365,360 feet, or 69.291 miles English measure*.
From a comparison of these results with those obtained from the measurements made in Peru, the East Indies, and France, M. Svanberg deduces, as the most probable conclusion, zzjons for the eccentricity, and 3963.26 miles for the radius, of our earth, at the equator.
The operations, in general, appear to have been conducted with ability and accuracy; and the account given of them by Mr. Svanberg, bears every mark of the most scrupulous fidelity. The insertion of faulty obsertations, adds, in our opinion, to the intrinsic value of the work, as it enables the reader to appreciate more justly, the degree of confidence due to the observations obtained from them.
The contraction of the metallic rods used in the admeasurement of the base, must have been very great, in a climate, so different in temperature from that in which they were manufactured : we are induced to wish, that they had been made of Platina, like those used by the French mathematicians in the late survey of France, with a pyrometrical thermometer attached to them.
The precaution of measuring the deviation of every base from the true level, is much to be applauded.
We are not expressiy informed in any part of the work, what was the precise direction of the base. It appears, however, from Article 8. that it could not have been exactly in the meridian. The apparent alteration in the position of the signals, on receding from them, which occasioned so much embarrassment to the observers, is evidently nothing more, than the deviation of a rhumb line from a great circle, which in high latitudes is very apparent. This inconvenience would have been entirely avoided, had the direction of the base been North and South. We would not be understood to impute any blame to these gentlemen, for not doing what probably was impracticable, but we think the impediments to accomplishing so de sirable an object, ought to have been stated.
In so delicate an operation as this, the measurement of a single base is not sufficient. A base of verification ought certainly to have been traced out, and carefully compared with the original one. Perhaps, if the distance from Kalenkangas to Torneâ, could have been accurately measured, it might have served the purpose. It would also have possessed, from its direction, an additional advantage, affording the means of comparing the length of an arc of a great circle perpendicular to the meridian, with an arg of the meridian itself.
We perfectly agree with our author in the opinion, that the method of finding time by means of altitudes, in such high latitudes, is too uncertain to be much relied on. The method of obtaining the azimuth with the repeating
* M. Svanberg having written this memoir in French, every where makes use of the French metre ; we have reduced his numbers to English mea. sure, as more generally useful to our readers,
circle is good, but we think the circular instrument of Ramsden would have furnished one incomparably better. Throughout the work are interspersed a great number of very
useful aod elegant formulæ, used for reducing the observations. They present, however, nothing strikingly new. The observation in article 35 is worthy the attention of astronomers, as it seems to account sufficiently for certain small differences in the positions of the fixed stars, as given by different observers, which have hitherto been referred to errors of observation.
It must strike every one, as a very extraordinary circumstance, that the measurements now under consideration, should differ so materially from those taken in 1736. And it certainly would be very gratifying to the cultivators of this branch of science, could the difference have been satisfactorily explained. Praise therefore is due to Mr. Svanberg, for having bestowed „80 much pains upon the subject. The circumstance, however, which he mentions, of the French mathematicians having neglected to allow for difference of level in the measurement of their base, is quite sufficient. The omission of so necessary a precaution, must, in our opinion, destroy all .confidence in the operations of those gentlemen, and make it perfectly unnecessary to inquire any further, or to suppose, with Mr. Svanberg, that the -best instruments of those times, were liable to errors of half a minute. This is not only an improbable supposition in itself, but, if once admitted, must destroy the authority of every operation, antecedent to the improvement of instruments by Ramsden and De Borda.
To conclude, we think this work a valuable acquisition to science ; and must observe, in justice to Messrs. Ofverboom and his associates, that it is -hardly possible to imagine a country, where the difficulty of conducting an operation of this kind, can be greater, than in Lapland. A high latitude,
severity of climate, thinness of population, and want of cultivation, all conspire to increase the hardships and bindrances of the undertaking, and to introduce sources of error unknown to
other region. FRENCH LITERATURE. Art. XXIX. Triomphe de l'Evangile, etc. The Triumph of the Gospel ;
or Memoirs of a Man of the World who has abandoned the Errors
of Modern Philosophy. 8vo. 4 vols. Paris, 1806. THE plan of this interesting work supposes a man of strong sense
and feeling, whose principles had been subverted, and whose morals of course had been ruined, by the delusions of modern philosophism, recovered from error and vice to a belief of Christianity, by the conTersation of an hospitable ecclesiastic, who afforded him a refuge from the misfortunes by which he was unexpectedly assail d. This plan naturally induces an explanation and refutation of various sceptical opinions: and : for this task the author has manifested a considerable degree of ability. He was a native of Spain, resident in France during the early stages of the Revolution ; his book, therefore, is rendered more interesting, by the occasional views which it gives of national character in the former country, and of events and principles in the latter. The volumes we review, are translated from the Spanish ; in which language, we are glad to perceive, the work has run through seven editions. A publication of this nature, much smaller in extent, and compiled by a person intimately acquainted with the true nature of Christianity, would indeed be a wel. cone sig at to us from the French or Spanish press.
ART. XXX. SELECT LITERARY INFORMATION.
* Gentlemen and Publishers who have works in the press, will oblige the Conductors of the Eclectic Review, by sending information (post paid) of the subject, extent, and probable price of such works ; which they may depend on being communicated to the public, if consistent with its plun.
octavo volumes, edited by Sir James Earle, Mr. P. Browne is engaged in an Ac- is in a state of forwardness, count and description of the Cathedral Mr. Miller has circulated proposals for Church of the Holy Trinity and its Pre- publishing in a series of one hundred cincts, Norwich. It will comprize a plates, drawn and etched by John Auguschronological table, containing a complete tus Atkinson, (author of the Russian list of the Bishops, Priors, and Deans, Costumes, in three volumes, folio) Pictuwith the dates of their respective appoint- resque Representation of the Naval, Miments, and remarks as to the several ad- litary, and Miscellaneous Costumes of ditions and improvements made by them Great Britain, with a description to each in the church, with other interesting plate in French and English. Dedicated particulars.
by his permission to His Imperial Majesty Dr. Smith, President of the Linnæan Alexander the first, Emperor and AutoSociety, will immediately publish a second crator of all the Russias. edition, with considerable additions, of The work is to be completed in three his very interesting Tour on the Continent. volumes, imperial folio.
The Travels of Mr. Heriot through The price of each volume, five guineas Upper and Lower' Canada, containing in boards. particulars of the new colonization of the The prints to be coloured to imitate the former of those important provinces, will original drawings. appear very shortly.
The first volume will be ready in March An octavo' edition of Sir John Carr's next, and the remaining two the spring Stranger in France, with twelve engra- following. vings in aqua-tinta, will appear in a few As there will be an equal number of weeks.
prints of each description, they may be A new edition of the Law of Evidence, bound in separate volumes, or mixed, as by Thomas Peake, Esq. of Lincoln's Inn, the purchaser may determine. Barrister at Law, is in the Press.
Mr. Grant, of Crouch End, near HighA treatise on the Law of Devises, by gate, hạs in the Press a work entitled, InJames Humphreys, Esq. of Lincoli's Inn, stitutes of Latin Grammar. This work Barrister at Law, will speedily appear. is chiefly designed for the higher classes
Edward Burtenshaw Sugden, of Lin- of an academy or grammar school. With coln's Inn, is engaged in a Practical Trea- this view the author has not only endeatise of Powers.
voured to supply the deficiencies and corThe Rev. G. S. Faber, author of a rect the errors of our common grammars, Dissertation on Prophecies, is prepa- but has likewise introduced a variety of ring for the press a work on the Restora- critical and explanatory observations. tion of Israel, and the Destruction of By exhibiting an ample and accurate din Antichrist.
gest of the rules and principles of the Another posthumous publication of the Latin language, and by a copious' enuvenerable Principal Campbell, of Aber- meration of anomalies and exceptions, deen, will shortly appear; it consists of he has endeavoured to furnish, not only his Lectures on Syematic Theology and the senior scholars, but also the master, on Pulpit Eloquense.
with a useful book of occasional reference. A third volume of Sermons by the Mr. Fraser, author of the Statistical Rev. John Hewlett, Morning preacher at Surveys of Devon and Cornwall, and of the Foundling Hospital, is in great for the county of Wicklow in Ireland, has wardness at press.
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