he had been altogether unsuccessful. She then wrote to Sassi under date of 24th February 1811.

"I have received all your letters, and observe that the bad weather and contrary wind still keep you in the same spot. I must apprize you that your last two letters, one of 29th January, the other of 8th February, came to me sealed not with your ordinary seal, but with a small round seal without any impression. This circumstance makes me uneasy, and I beg you will inform me how it has happened. -I had yesterday a letter from Dieffembach, which gives me good hopes from Count Metternich: but hopes, you know, are all that have yet fallen to my lot."

The alteration of the seal was, no doubt, caused by the letters being opened and read by the secret agents of Bonaparte; who were thus enabled to watch the movements of Sassi, and safely to defer his arrest until he should be ready to embark for England, and until the evidence should thus have received every addition of which it was susceptible. His person being secured on the 15th April, Bonaparte ordered, two months afterward, that he and Chiffenti, who had been arrested at Leghorn, should be brought to trial, with some other persons indirectly concerned with them: while the Princess was watched with increased strictness in the castle near Nice, and was subsequently removed to Rome, where she was placed in a convent. At the trial, no witnesses appeared against the accused persons, the whole evidence consisting in the papers; and Chiffenti, it was found from his own admission, had been commissioned to the court of Sicily in 1809, to endeavour to arrange the means of the escape of the Princess from her confinement. The sentence of the court was that the persons connected with Sassi and Chiffenti were not participators to a criminal extent, and should consequently be acquitted; which, however, was not carried into effect by Bonaparte, as they remained in prison at Paris till the counterrevolution. Sassi and Chiffenti were capitally condemned, and the sentence was executed on the latter but, when the former was on the scaffold, a page with Bonaparte's livery arrived on horseback, with an order for a reprieve; which, however, availed him but little, as he expired, a few days afterward, in prison.

The latter part of this publication is occupied by an account of the trial of General Malet and his associates*, and a short notice of the proceedings in the case of the Duke D'Enghien: but we find nothing that either differs from or adds to our former

$tatements.

* For a report of this affair, see a subsequent article (No. XX.) in this Appendix.

ART.

._

ART. XIV. Astromy, thoughie Théorique et Pratique, &c.; i. e. Theore tical and Practi be totaal Astronomy. By M. DELAMBRE, Perpetual Secretary toxing, ththe Institute, &c. &c. 3 Vols. 4to. Paris.

1014. Imported by De Boffe. Price 51. 58.

A MONG all the physical sciences, not one displays the perseverance and genius of man to greater advantage than astronomy; since, though no subject seems more completely beyond the reach of human powers, no other has attained a nearer approach towards perfection. The improvements which, within the last half century, have been introduced into the construc tion of astronomical instruments, the consequent accuracy of observation, and the amazing extension that has been given to analysis during the same period, have raised astronomy, which was formerly founded almost entirely on hypothesis, to a rivalry with the most complete of the abstract sciences: while the limits of the solar system have been nearly doubled with regard both to number and to extension. As well might a critic now endeavour to refute the deductions drawn from the Euclidian axioms in geometry, as attempt to deny the universality of the laws of gravity, or the elliptic motions of the planetary bodies. Such having been the progress of astronomy, it is not surprizing that so many treatises on it have been presented to the public; some of them, it must be admitted, without adding much to our previous stock of information, but others highly honourable to the distinguished authors by whom they have been produced. Few men, however, seem to possess the requisite qualifications for writing a complete treatise of astronomy, in its present improved state, in so high a degree as the celebrated author of the present volumes; who has for thirty years devoted the most unremitting attention to his favourite science; and whose numerous papers in the Connaissance des Tems and the different volumes of the National Institute prove that this attention has not been uselessly bestowed.

Of a work of such importance, we are desirous of conveying. to our readers as correct an idea as we can include within the limits to which we must confine our observations: but, when it is considered that it occupies three large quarto volumes, the reader will be aware that much important matter must necessa◄ rily be passed over by us in silence. We shall begin, however, by giving a sketch of the general plan which the author has adopted; afterward offering a few observations on the most distinguishing features of the production, as compared with others of a similar kind by which it has been preceded.

In the first place, it is to be remarked that this publication is intended to form a complete treatise on theoretical and

L14

practical

practical astronomy; and one great diffice wrote to Sassi an undertaking is so to arrange and connect with each other, that a student may proceed 1 weather various chapters without being required to admit any thing to have place that has not been previously demonstrated, or satisfactorily determined from observation. The want of this logical arrangement is a great defect in many of our best treatises on astronomy, and has indeed generally been considered rather as appertaining to the subject itself than to the authors. who have written on it. All the theoretical results are drawn from observations, which require to be corrected for certain minute inequalities that cannot be understood by beginners. It is impossible, therefore, to take a student into an observatory, explain to him the method of making his observ ations, and, after they have been taken, teach him to apply them to calculation, without entering on the doctrines of parallaxes, refraction, precession, nutation, &c.; and these are subjects with which he must be supposed to be wholly unacquainted. Hence, it follows that the astronomical student must either first content himself with observing for a considerable time, without applying his observations to computation, or must first learn the method of computation; supposing the observations with which he is furnished to be correct, but without being himself able to ascertain whether they are so or not. According to the latter plan, which is most commonly adopted, the pupil must take much for granted which he has not the means of verifying; and, consequently, the subject thus arranged is deficient in that grand feature which characterizes the exact sciences, and with which we ought never to dispense in mathematical investigations.

It is a peculiar trait in the present work that the author has so arranged the several subjects, and has so blended observ. ations with deductions, that the student is never under the necessity of admitting any thing which has not been previously established; he is not required to adopt any hypothesis on any system; he is taught to reason only from incontestible facts, and thence to draw conclusions equally incontrovertible: so that, supposing him to possess the necessary instruments, he might, in the course of a few years, from his own observations only, produce a system of astronomy such as it now exists; and he would arrive at the same theories, and draw from them the same consequences; except that, for want of sufficient time, they would not, in course, possess the same degree of accuracy with those which rest on the observations of as many ages. Less than fifty years, however, would be sufficient, in the present state of the arts and of analysis, to bring astronomy again nearly to the same degree of perfection which it possesses

Anr. XIV. Astrowy, though every record and observation relating to it tical and Practi be totally destroyed. In describing this part of his unSecretary toxing, the author says:

We shall suppose, then, that a young man, struck with the regularity of the celestial motions, devotes for a year or two his nights to observations of the stars and planets; that in the day he takes the altitude of the sun and its transit over the meridian; and that he employs himself in investigating the rules for all the problems of spherical astronomy which present themselves to him. He will even have no occasion for supposing the earth to be a globe, because that knowlege will be for a long time useless to him; he will thus discover the degree of uniformity which the phænomena observe, and the small irregularities to which also they are subject; and, if he perceive not at first the causes of them, he will obtain at least their measure, and the calculus requisite for determining them with the greatest accuracy. His astronomy will be at first such as it was sixty years ago; and, with this approximative knowlege, he may find, by means of geometry, the small corrections that are necessary for it to become such as it is at present.'

If the reader have not the means of making the observations himself, the author in course supposes that he can consult the collections of those which have been published during the last fifty years; that he can take the rough observations in the state in which the observer has given them in his register; and that he will compare those of different astronomers, and thus convince himself that they have all the authenticity which he can desire. The tables best calculated for this purpose are those of La Caille, Bradley, and Maskelyne, the recent observations of Piazzi, and those which have been published in the Connaissance des Tems. After having made the above verifications, the student is supposed to admit the accuracy and legitimacy of the observ ations, and this is all that he is required to grant without a direct and accurate demonstration. The investigations commonly begin synthetically; for, as the author remarks, the analytical method is not always the most easy, nor the shortest; and therefore, when a problem admits of an easy construction, which speaks as it were to the eye, it is preferred, and employed to furnish the fundamental equation: but, if analysis can be afterward intro duced to simplify this formula, or to present it in a shape more commodious for calculation, or to facilitate the combinations which are necessary to render it more general and comprehensive, the author in no case fails to avail himself of the advantages which are thus offered.

This, again, is another distinguishing feature in the present treatise; and one which, from the example of so celebrated an author, we are willing to hope may produce considerablechange in the method of treating not only astronomy, but every other branch of mixed mathematics. Most other writers on

physics

physics have adopted, exclusively, the method either of synthesis or analysis, and have never allowed themselves afterward to deviate from it, whatever advantages that deviation might offer in certain cases. In astronomy, particularly, almost every author of the last century still followed the methods of Tycho and Kepler, with the trigonometry of Briggs and Gellibrand, and consequently rejected all analytical formulæ, in no case thinking of putting a problem into the form of an equation. La Grange was the first who undertook to investigate astronomical problems on principles purely analytical; and, without any other aid, he resolved the problem of rotation, calculated the effects of the parallaxes, and gave formulæ for finding directly the apparent place of a planet. He then employed the same principles in the calculation of eclipses and occultations, and in determining the geocentric place of a planet with reference both to the ecliptic and the equator; as well as in a variety of other intricate and difficult problems. Soon afterward, a complete revolution was effected in all the physical branches of mathematics; every thing was treated analytically; and even spherical trigonometry was reduced to one fundamental equation diagrams, however simple and illustrative, were proscribed from nearly all mathematical treatises; and, in short, simplicity was almost every where sacrificed to generalization. These remarks will, in course, be understood to be made almost exclusively with reference to modern French authors, and will apply to the most distinguished of them. English mathemati cians, on the contrary, (generally speaking,) having as pertinaciously adhered to old principles, have thus deprived themselves of the many advantages which analysis presents; and the consequence has been that the mathematical sciences have remained nearly stationary in this country, while they have been carried to their utmost limits by our continental neighbours.

That analysis possesses immense advantages in a great variety of intricate problems, it is impossible to deny: but that it has been pushed far beyond its natural limits is also not less certain. The French character, whether in politics or science, seems calculated to carry every thing to excess; and it is thus that analysis has been applied by them to a variety of problems which might have been much better resolved by other means. M. DELAMBRE is well aware of this species of scientific en thusiasm, and has too much fortitude and good sense to suffer himself to be carried away by the fashion of the day : he conse quently exhibits no partiality, but employs either method as it best suits the nature of the problem under discussion; and he has by these means rendered his work as simple and perspi cuous in its parts as it is complete in its concatenation.

Certain