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such a multitude of ancient monuments that at the first approach, one might imagine oneself entering a petrified town.'

Chambers. Proceeding along the foot of the hill, on the side facing the sea, there is a pagoda rising out of the ground of one solid stone, which seems to have been cut upon the spot out of a detached rock.'

Haafner. •At the foot of the hill, near to the sea, there is a very handsome pagoda cut, both as to its pillars and its ornaments, vul of the solid rock.'

Chambers. From hence a winding stair leads to a kind of temple, cut out of the solid rock, with some figures of idols in high relief upon its walls, very well finished and perfectly fresh, as it faces the west, and is therefore sheltered from the sea air. From this temple again there are flights of steps that seem to have led to some edifice formerly standing upon the hill.

Haafner. On the west side is a temple cut out of the rock, whose walls are covered with sculptured figures, which have suffered little from the hand of time, because they are not exposed to the salt air of the sea. From this temple many steps lead to the top of the mountain.'

Chambers. 'In descending there is an excavation that seems to have been intended for a place of worship, and contains various sculptures of Hindoo deities. The most remarkable of these is a gigantic figure of Vishnow asleep on a kind of bed, with a huge snake wound about in many coils by way of pillow for his head ; and these figures are all of one piece hewn from the body of the rock.

Haafner. 'Descending on the south is another excavation, supported by a great number of columns. Judging from the altars, and the quantity of statues of gods and goddesses which appear, one may conclude that it once served as a temple. Among the statues a colossal figure of Vischnow is remarkable. He reposes on a kind of bed, and his pillow is a serpent coiled round upon itself. This statue is hewn out of the rock to which it is attached by the lower extremity.'

The plagiarism stinks to heaven. Chambers visited the ruins in 1772 and 1776, but did not write his account of them until 1784. Haafner says that he visited them frequently while he resided at Madras, in 1780-82, and he publishes his book in 1806. Our own opinion is, that Chambers's account is vague and inaccurate; and that Haafner knows no more of them than what appears in the Asiatic Researches: hitherto nothing like a correct description has been given of those ruins, which, as monuments of ancient magnificence, far exceed the caverns of Salsette and Elephanta, and are surpassed only by those unparalleled examples of buman labour, the excavations of Ellora. It is not much to the credit of our countrymen, that, though within the distance of 16 or 18 miles of Madras, no resident, since the time of Mr. Chambers, has thought it worth his pains to visit them? The situation may be remote,' as Chambers says, ' from the high road which leads to the different European settlements;' and the coast,

MS

as Haafner subjoins, may be dangerous for vessels ;' yet the latter, if he may be trusted, found no difficulty in approaching the place in a crazy open boat, in the worst season, though we are taught, that

never traveller comes near These awful ruins of the days of yore, Nor fisher's bark, nor venturous mariner

Approach the sacred shore.' In conclusion, if Jacob Haafner be a real character, he is a man totally destitute of every principle of honour and truth; if a mere nom de guerre, the book may be considered as having been got up by the French government for the mean and odious purpose of creating a false and unfavourable impression of the British character on the continent, and fixing an unmerited stigma on the British name in India. This must be our apology for noticing it at all; and this, we trust, our readers will admit to be sufficiently valid.

ART. VII. Traité Elémentaire d’Astronomie Physique, par J. B.

Biot, Membre de l'Institut de France, 8c. Avec des Additions relatives à l’Astronomie Nautique, par M. de Rossel, ancien Capitaine de Vaisseau, Rédacteur et Co-opérateur du Voyage de d'Entrecasteuux. Seconde Edition, destinée à l'Enseignement dans les Lycées impériaux et les Ecoles secondaires, An Elementary Treatise on Physical Astronomy, &c, Paris. 1810 3 vols. 8vo. pp. xxxvi. 1727. and 41 Plates.

tion of a work of no superlative merit, yet it has many claims on our attention. In magnitude it nearly triples the former edition, and may, therefore, be considered rather as a new than an improved work. Since its first appearance, the author has received many suggestions for modification and improvement, from Laplace, Delambre, Pictet, Prevost, Maurice, Arago, Chaix, Rodrigues, Berrouer, Mathieu, Bouvard, and Rossel, his performance, therefore, may be contemplated as a fair specimen of the maximum of producible talent in France on this interesting subject. It coutains, besides, many striking instances of the prevailing wish among Frenchmen of science to extirpate from the continent the notion that any such beings as philosophers now exist in Great Britain. And it developes some of the arts to which even a man of respectable talents will have recourse, in order to derive all possible pecu, piary advantage from his character, by swelling out his work to double its requisite size,

M. Biot,

: M. Biot, in his prefatory sketch of the object of his treatise, supposes the student to possess no absolute knowledge of astronomy, or even of cosmography. He farther supposes the existence of all the prejudices respecting the figure of the earth and the celestial motions which spring from the uncorrected testimony of the senses ; and he endeavours to lead his pupil, by a gradual process of observation and reasoning, to the true mechanism of the system of the world, including, of course, the motion of the earth, the laws of Kepler, and the explication of the various phenomena which depend upon attraction. The work is divided into four books, of which we shall speak in their order.

Book I. contains twenty-three chapters, which treat of the heavens viewed astronomically; the roundness of the earth; the atmosphere; instruments necessary in astronomical observations; use of the transit instrument; equality of celestial revolutions, and their use in measuring time; determination of the meridian by the measure of time; direction of the axis of apparent

celestial rotation; mural quadrant, and its use in determining the height of the pole; exact determination of the laws of diurnal motion, including proofs of its uniformity; principal circles of the celestial sphere; terrestrial poles and equator; determination of the figure of the earth; with the exact measure of its magnitude; mode of fixing the position of the different points of the earth's surface; investigation of the physical consequences which result from the universality of the diurnal motion; physical consequences of the compression of the earth's polar axis, including the variations in the length of the second's pendulum; atmospherical refractions ; parallaxes; description and use.of the repeating circle; instruments used at sea ; sextant; reflecting circle; and mariner's compass. These subjects, with the notes, occupy the whole of the first volume.

In this volume we meet with some excellencies, and not a few peculiarities. Among the former, we must specify the note on the subject of refraction, and among the latter, the omission of the English measurers in the chapter on the determination of the earth's figure and magnitude. The progress of sentiment, and change of conduct, on this point, are somewhat curious. At first, the English measurers and the French academicians met at, Dover to adjust their plan of operations; they then kept up a friendly correspondence, and the French' liberally extolled the superior accuracy of the English operations; afterwards they praised the accuracy of the English measures, but with a saving clause in favour of their own; as was the case with Puissant in his 'Géodésie, who, after stating some remarkable intances of correctness in General Roy and Colonel Mudge, says, ' Neanmoins,

jusqu'à jusqu'à présent rien n'égale en exactitude les opérations géodésiques qui ont servi de fondement à notre système métrique; and, lastly, an elaborate chapter is written on the measure of the earth, in which there is no more notice taken of the most correct of all trigonometrical surveys, carried on uniformly with great science and skill, and extreme public benefit, for 27 years, than if it had never commenced. This is rendered still more extraordinary by M. Biot's commendation of Messrs. Mason and Dixon's measure of a degree in Pennsylvania, though we will venture to say there is no respectable mathematician in Europe who is not aware of the extreme inaccuracy of the American results. Dr. Maskelyne, in the Philosophical Transactions for 1768, (from which the French authors obtained their account of Mason and Dixon's belles opérations,') informs us, that Mr. Henry Cavendish

having mathematically investigated several rules for finding the attraction of the inequalities of the earth, has, upon probable suppositions of the distance and height of the Allegany mountains from the degree measured, and the depth and declivity of the Atlantic ocean, computed what alteration might be produced in the length of the degree, from the attraction of the said hills, and the defect of attraction of the Atlantic, and finds the degree may have been diminished from 60 to 100 toises from these causes. Yet this is the degree which our Gallic lovers of exactitude' prefer to any of those measured in England !

Our author has a diffuse though interesting chapter on atmospherical refractions, which is the more valuable as it is now known that M. Lambert's theory, hitherto almost generally received, is erroneous. In this he traces the cause of several curious phænomena which depend on variable refractions, and among others that which is known to their mariners under the name of mirage, and which the French army frequently observed in their expedition to Egypt.

• The surface of the ground of Lower Egypt is a vast plain, perfectly horizontal. Its uniformity is not otherwise broken than by some emi. nences, on which are situated the towns and villages, which, by such means, are secured from the inundations of the Nile. In the evening and morning the aspect of the country is such as comports with the real disposition and distance of objects, but when the surface of the earth becomes heated by the presence of the sun, the ground appears as though it were terminated at a certain distance by a general inunda. tion. The villages beyond it appear like islands situated in the midst of a great lake. Under each village is seen its inverted image as distinctly as it would appear in water. In proportion as this apparent inundation is approached, its limits recede, the imaginary lake, which seemed to surround the villages, retires; lastly, it disappears entirely, and the illusion is reproduced by another town or village more distant. Thus,

as

as M. Monge, from whom I have borrowed this description, remarks, every thing concurs to complete an illusion which is sometimes cruel, especially in the desert, because it presents the image of water, at the time when it is most needed.'

The second book of this treatise is devoted to what is technically called the theory of the sun,' and is divided into eighteen chapters, occupying 342 pages. The distribution and arrangement of subjects will appear from the following enuneration. Proper motions of the stars, and the means of determining them; application to the sun, with the theory of its circular motion; calendar; manner of referring the position of the stars to the plane of the ecliptic; progressive diminution of the obliquity of the ecliptic; precession of the equinoxes; nutation; second approximation to the sun's motion, with the theory of its apparent elliptical motion; mode of determining the exact position of the solar ellipse upon the plane of the ecliptic, with the origin of mean time, &c.; exact determination of eccentricity from observations of the equation of the centre; use of equations of condition for the simultaneous determination of the elements; construction of solar tables; inequality of solar days, and the equation of time; spots of the sun, their form, and rotation; inequality of days and seasons in different climates; temperature of the earth; hypothesis of the earth's annual motion; precession of the equinoxes considered as the effect of the displacing of the terrestrial equator ; use of the theory of the sun, and the motions of the equator, ecliptic, and equinoxes, in chronological researches, with some curious applications. This book contains much valuable matter, though not always exhibited in the best form.

In the fourth chapter there is a short but useful note on the method of determining the longitude and latitude of a heavenly body, the right ascension, declination, and obliquity of the ecliptic being given; as well as the method of solving the converse problem. Let w the obliquity of the ecliptic, d the declination of a star, or other body, a its right ascension, a its latitude, l its longitude; then the following formulæ are deduced from the principles of spherical astronomy : sin. a =

sin. w cos. d sin. a t cos. w sin.d. tan. d sin. fi sin. a cos. w

1 These two formulæ may be accommodated to the logarithmic calculus, by taking an auxiliary angle o such that tan.o =

tan. d then exterminating sin. a from the first and tan. d, by means of the usual expressions for sines and cosines of sums and differences, there result

tan.

COS, a

sin. a

: for

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