the autonomy of which had been guaranteed by both England and Persia. Dost Mohammed captured Herat on May 26th, but died three days later, May 29th. The governor of Herat, Ahmed Khan, took refuge in the Persian camp at Khourivan. It was expected that this would lead to a war between the Persians and Affghans, but up to the end of the year no hostile movements had taken place. The Affghans were masters of the whole province of Herat, and were even preparing to invade Khorassan.

The Sultan of Bokhara, a country in Central Asia, which has long been celebrated for the hostility of its rulers to all foreigners, imprisoned four Italians who had entered the country for the purpose of making investigations into its silk cultivation. The fact having come to the knowledge of the Russian Government, the emperor at once instructed the governor-general of East Siberia to use all means within his power to obtain the release of the travellers.

The British rule in India was, during the year, again threatened with new danger. Another insurrection broke out among the warlike tribes of the mountains of the north-western provinces, and for some time appeared to assume alarming proportions; at the close of the year, however, the Government felt confident that it would soon be suppressed. England now rules in India over a native population of, at least, 137,000,000 inhabitants, of whom only about 4,000,000, including the native Christians, the Parsees, the so-called East Indians (of mixed European and Indian descent), are supposed to be friendly to the preservation of British rule. There is, however, no doubt that India is making more rapid progress in civilization, in education, and material prosperity, than any other part of Asia. (See INDIA.)

France is making extraordinary efforts to extend her territory in Asia. A new insurrection broke out against her rule in Cochin China, but it was soon suppressed. Admiral La Grandière, who is at the head of the French administration in Cochin China, visited the king of Cambodia, the declared enemy of the Emperor Tu-Duc, of Anam, and the result was most satisfactory. The French obtained by treaty the rights of commerce with that vast country; they were authorized to work all the immense forests gratuitously, if for the service of the French Government, and on payment of a small royalty for private commerce. A French resident agent was to be established at Hondon, and that post was confided to a surgeon in the navy well acquainted with the habits of the people, and who will exercise a twofold influence by his diplomatic relations, and by the practice of his surgical skill. The admiral visited in detail the copper mines of Ancorre, which in extent are far beyond anything of the kind to be met with in Europe. A letter to the Paris Moniteur de l'Armée, dated Saigoon, Cochin China, September 6th, 1863, stated that by the treaty concluded between

the king of Cambodia and the French admiral, the whole kingdom had been placed under the French protectorate, and that the main stipulations were: 1. Cambodia recognizes the supremacy of France, entering into the same relation to France in which it formerly stood to the emperor of Anam. It is admitted by the official French paper, that the king of Siam_also claims the rights of a protectorate over Cambodia; but it is said to result from indisputable documents that his claims are not. so old as those of the king of Huc (Cochin China), into whose place France has now stepped. 2. France obtains the right to establish a settlement in Cambodia, on the banks of the river Mei Kong (also called Cambodia), at Nam-Van. This is a point of the greatest strategic importance, and will make the French masters of the largest and most important river in Farther India. The treaty also contains liberal stipulations in favor of the Roman Catholic religion. English papers in India express the opinion, that in less than a quarter of a century the English and French frontiers will meet somewhere between Burmah and Siam.

The war of the Circassians against Russia continued with various vicissitudes throughout the year. (See RUSSIA.) The Russians are constantly extending their territory in Central Asia. It is particularly reported that they have retaken the fortress of Pishpek, on the river Tohu, one of the strongest places in the Sultanate of Khokan, the capture of which seems to augur unfavorably for the independence of the martial Turcomans. The place had been captured by the Russians once before, about three years ago, but subsequently was retaken by the Khokandese.

As to the religious denomination of the Asiatics, the number of Christians may be estimated at about 15,000,000. Of these about 7,000,000 are Roman Catholics, who are quite numerous in the Spanish possessions (5,000,000), India (1,000,000), Farther India (520,000), and China, 337,000. The progress of the French in Farther India, and the influence of the same power in China promise to the Roman Catholic Church a considerable increase of numbers. Protestant Christianity is strongest in India and Farther India, in both of which countries there are many indications of its rapid progress.

ASTRONOMICAL PHENOMENA AND PROGRESS. The year 1863 has been marked by no small degree of activity and success on the part of those engaged in prosecuting this department of science. In the main, the questions that have been most prominent are the same with those named in our record of the preceding year; a larger share of attention, however, having been given to the new form of investigation of the heavenly bodies, by means of observations upon the spectra afforded upon prismatic decomposition of their light, which will be noticed more fully on a future occasion.

In a communication to the ninth volume (new series) of the "Scientific American," Mr. H. P. Tuttle briefly names some of the most remarkable evidences of the progress of astronomy-a progress, he thinks, behind that of few, if any, of the other sciences-since the beginning of the current century. To the six planets only that were known at the end of the year 1800, we are now able to add 80 others which have been since discovered-79 of them directly by aid of the telescope, and one (Neptune) by its use guided by mathematical deductions from observed phenomena of other planetary bodies. In case of Saturn a new ring and a new satellite have been disclosed. Up to 1812, but one comet (Halley's) was certainly known to return: before the close of 1858, there had been added to the list of periodical comets 9 whose periods vary from 3 to 70 years, and about 20 with periods ranging from 100 to 10,000 years; while nearly 100 are now known whose orbits are of sensibly parabolic form.

Again, while Sir Wm. Herschel was the first to detect the existence of multiple stars-usually binary, or as these are commonly called, "double"-more than 100 instances of such pairs or sets of stars, the members of each of which have a mutual revolution about their common centre of gravity, are now known. In case of some of these double, or generally speaking, "multiple suns," one complete revolution of the sort here referred to, and part of a second, have been already noted. In theoretical astronomy, Dr. Hansen's new tables of the moon, and Leverrier's new tables of the sun, Mercury, and Venus, now enable the astronomer to calculate with an accuracy far exceeding that before attainable the celestial phenomena which were taking place twenty centuries ago. Of course, a chief and indeed indispensable means to all these important results, has been the single device of the telesсоре.

Asteroids. In the preceding volume was given a list of the minor planets from (51) to (76) inclusive-the period of their discovery extending from the year 1857 to Oct. 1862; and also certain particulars of interest connected with the discovery of some of these. Astronomers appear as yet to allow asteroid (75) to retain its place, subject to the result of future observations. The record for 1862 is, then, to be completed by the discovery, Nov. 12th of that year, of asteroid (77) by Dr. C. H. F. Peters, of Hamilton College Observatory. This planet, however, which was at the time near to Feronia, and corresponded in brightness with a star of the 11-12th magnitude, very soon eluded observation, and may even require. discovery de novo. No name appears to have been assigned to it. Asteroid (78) was found by Dr. Luther, of Bilk, March 15th, 1863. It appears as a star of the 10th magnitude, and was named by its discoverer Diana. On the night of Sept. 14th, of the same year, Prof. J. C.

Watson, of the observatory at Ann Arbor, Michigan, discovered asteroid (79). This planet which shows about the 10th magnitude, was independently discovered by M. Tempel, at Marseilles, Oct. 3d and 4th; and later elsewhere. Prof. Watson has chosen for it the name of Eurynome. The supposed asteroid (80) announced by M. Schmidt, of Athens, proves to be an instance of erroneous observation-the before known planet, Hygeia, having in fact been rediscovered.

Thus, the record of these discoveries, from Oct. 1862 to Oct. 1863, is as follows: 1862, (77). 1863, (78) Diana,.

66

(79) Eurynome,.

by Dr. Peters. "Dr. Luther. "Prof. Watson.

Comets. Comet III, 1862, announced in the preceding volume as discovered by Dr. Bruhns, was first detected about three days earlier (Nov. 28th), by Professor Respighi, of Bologna. The discovery of Comet I, 1863, is mentioned in the account of last year. Comet II, 1863, was found, April 12th, by M. Klinkerfues, in right ascension 309, declination 3° south. On the 19th of May, it was 10° distant from the north pole, and appeared as a round nebulosity, 5' to 6' in diameter. Comet III, 1863-by Respighi, April 13th, near B Pegasi. Its nucleus then had the brightness of a star of the 6th magnitude; April 25th, the tail had a length of 2°. Comet IV, 1863, was found, Oct. 9th, by M. Bäcker, of Nauen. Like the other comets of the year thus far named, it was telescopic merely. It attained its greatest brilliancy, Dec. 8th; perihelion Dec. 27th. Comet V, 1863-by M. Tempel, Marseilles, Nov. 4th; this was visible to the naked eye, its nucleus nearly stellar. Comet VI, 1863, was observed by M. Schmidt, at Athens, in the month of December.

In a supplementary page inserted in the "Amer. Jour. of Science," January, 1864, appeared a note from Prof. Watson, of the observatory at Ann Arbor, in relation to the (supposed) discovery of a new comet by him, on the evening of January 9th, 1864. The comet was then quite large and bright, with a nucleus strongly condensed at the centre, and a tail 1° in length. From observations continued to the 12th, Prof. W. inferred a resemblance, in the elements of the orbit to that of the comet of 1810; and he remarks that subsequent observations must determine whether the comet had returned in the interval. In a later communication ("N. Y. Evening Post," Feb. 1st), he states that the comet would be very near the earth about the date just given, and suggests an attempt to determine by it the solar parallax. It does not yet appear that these anticipations have all been well grounded.

In the "Evening Post" of February 6th, appeared a letter from Messrs. Silliman and Dana, inclosing a communication of Mr. D. M. Covey, of Southville, N. Y., dated December 26th, 1863, and addressed through the "Herald of Progress" to Prof. D. Trowbridge, in which

Mr Covey gives an account of a comet first seen by him, November 21st, preceding, in declination, nearly 15° N., and right ascension 200°. On that date, it had the size of a star of the third magnitude; its course was afterward found to be northeastwardly, from Arcturus toward Vega in the Harp; its brilliancy was diminishing, and it soon became invisible to the naked eye. Messrs. Silliman and Dana say there is hardly a doubt that this was the comet described by Prof. Watson, and detected (it now seems), a few days previously (Dec. 28th, 1863,) by Respighi, of the University of Bologna. The most remarkable circumstance in the case is, that a comet visible to the naked eye should be present in the heavens a full month before its discovery was made at any observatory; but it was visible at about five o'clock A. M., an hour when most astronomers have concluded their labors.

Spectra of Fixed Stars, Etc.--The results thus far arrived at in the way of determining the character of the spectra of different fixed stars, and others of the heavenly bodies, and hence, by inference, their physical and chemical constitution, are as yet to some extent at variance. This, indeed, was to be expected in the outset of observations of so extreme delicacy, conducted by different persons, with different forms of apparatus, and under differing conditions of the terrestrial atmosphere. Prof. Donati finds, in the case of nearly all the stars which have been examined both by M. Frauenhofer and himself, different systems of fixed lines from those originally laid down by the latter; and some differences, again, exist between the systems given by either of these and the spectra of the same stars as noted by M. Secchi in It aly, by Mr. Rutherfurd in New York, and by Dr. W. A. Miller and Mr. Wm. Huggins in England. Frauenhofer had not condensed upon his prism the light of the star to be examined, but placing the prism and a cylindrical lens before the objective of a small (observing) telescope, he directly viewed the spectrum afforded by analysis of the light, of such intensity as it naturally fell upon the apparatus. The cylindrical lens was to supply the place of the fine slit between knife-edges first employed for the solar spectrum by Wollaston; such a lens acting to elongate the image of the star in one direction only, or to a line, and giving to the spectrum the desired breadth without increasing its length.

Mr. Rutherford (" American Journal of Science," Jan. and May, 1863) states that throughout the course of his observations he received the light through a slit on its way to the prism; but that, finding that the necessity of throwing the star slightly out of focus occasioned a considerable loss of light upon the jaws of the slit, he was later led to add to the arrangement the use of the cylindrical lens-introduced between the objective of the condensing telescope and the prism-and with the effect of largely increasing the light, and, of course, the

distinctness of view of the parts of the spectrum obtained. The lens is useful only in the analysis of merely luminous points, as the stars may be assumed to be, and not in case of the planets, sun or moon. Excepting the addition now named, the spectroscope was simply that of Bunsen and Kirchhoff, "consisting of a condensing telescope with adjustable slit, a scale telescope with photographed scale of equal parts showing bright lines upon a dark ground, a flint-glass prism of 60°, and an observing telescope with Huyghenian eye-piece, magnifying about five times." If the telescopes be not perfectly achromatic, some change of focus will be required in order favorably to observe the different regions or colored spaces-the ultra-red rays requiring a slight, and the violet and indigo a considerable, change of focus from that answering for the intervening portion of the spectrum. For exact comparison of different observations, the place of the sodiumline D was, in each instance, brought to coincide with the division of the scale marked 30.

With the apparatus so adjusted, the locations of the seven principal lines of the spectrum of sunlight, as determined by Mr. Rutherfurd, are as follows (the letters reading of course, from red to violet): B 33.1, C 32.3, D 30, E 27, 26.5, F 24.4, G 19.3, H 14.5. 13.9. By means of a plate (highly valuable for reference) he gives a comparative view of the spectra of the sun, moon, Jupiter, Mars, and 17 of the brighter among the fixed stars. In the lunar spectrum he finds the principal solar lines, B, C, D, E, and F, and he supposes that G may yet be detected. The lunar lines just named are very strong and well defined; and other marked features are beyond F, a broad faint band at 21.05, a broad line at 19.9, and a broad dark line at 18.09.

Most noticeable in the spectrum of Jupiter are the distinct line D, and two broad bands respectively at 32.1 and 31.12; in that of Mars D is wanting, though there is a well-defined line near its place, at 30.25, other strong lines at 27.1 and 26.55, and a broad band at 24.4.

Without attempting to fix upon any final principle of classification for the stars he has examined, Mr. Rutherfurd for the present divides their spectra into three groups: "first, those having many lines and bands, and most nearly resembling the sun-viz., Capella,

Geminorum, a Orionis, Aldebaran, y Leonis, Arcturus, and 8 Pegasi. These are all reddish or golden stars. The second group, of which Sirius is the type, present spectra wholly unlike that of the sun, and are white stars. The third group, comprising a Virginis, Rigel, etc., are also white stars, but show no lines; perhaps they contain no mineral [query-metallic?} substance, or are incandescent without flame.' Taking Capella and Sirius as good examples of the first two classes of stars just named, their spectra are thus described: Capella-a line respectively at 30.22, 27.73, 27.38, 26.75. and 24.78; Sirius-a broad black line, or band,

respectively at 32.4, 24.8, 19.9, 16.8; the limit at 14.5. In the spectrum of this last star no fine lines have been found; the lines observed are all broad and black, with margins well defined, being in fact so many complete interruptions of the colored field. The spectrum of a Orionis is marked by three broad bands, that of Aldebaran by four, and that of ẞ Pegasi by eight, these in all cases lying mainly within the less refrangible half-length of the entire field; and all these, as well as the bands in the light of Jupiter, are supposed by Mr. Rutherfurd to be absorption bands due to the atmosphere of the respective bodies, but which may yet possibly be resolved into lines.

In conclusion he alludes to the evidence now possessed to the effect that the stars differ in their constituent materials, and asks "What then becomes of that homogeneity of original diffuse matter which is almost a logical necessity of the nebular hypothesis ?"

In his second article he mentions having added a prism by means of which the spectrum from a spirit lamp is constantly present in the field of view. He finds this a most useful check, and by means of the comparison so afforded he has proved the presence in the spectrum of Arcturus of the lines D, E, b, and G, and has become almost certain that each line furnished by its light has its counterpart in the solar spectrum.

M. Secchi, of Rome, has used a Janssen's spectrometer of direct vision, and he is astonished at the magnificence of the results-probably favored by an unusually pure atmosphere -which he thus obtains. He has published the determinations only of five stars. He finds in a Orionis a line at F, and four between F and G, where one only is given in the Greenwich observations. The spectrum of Aldebaran is of greater extent, and 16 bands of various breadths were noticed in it. He finds a spectrum of Rigel, as well as of Sirius, both white stars; these are longer than the spectra of red stars, and in the former also the prominent lines appear chiefly in the blue and violet spaces at one extreme, and the red at the other. The band F, which so far would appear to be as prominent in the light of all the stars as it is in that of the sun, Secchi thinks, may be due to absorption by our atmosphere.

Mr. Huggins and Dr. Miller have examined a series of from 30 to 40 stars, and obtained microscopic photographs of Sirius and Capella. The former takes the solar line D as the starting point for his measures, having the solar and a stellar spectrum in the field at the same time. And since he finds that, generally, length of spectrum corresponds with heat of flame, he hopes that by means of these observations we shall yet determine not only the chemical constitution, but also the comparative heat of the sun of our system, and certain of those other suns which we name the fixed stars.

The Sun and Stars Photometrically compared. -Mr. Alvan Clark, of Cambridgeport, Mass.,

gives "Amer. Journal of Science," July, 1863) an account of certain experiments intended to determine on a new principle the relative intensity of the light of the sun and fixed stars; and approximately, therefore, the relative distances of those bodies.

Suppose a lens of known focal distance, say one foot, is placed between the eye and a star of the first magnitude, and that the lens is then made to recede from the eye in the line of the star until the effect is to diminish the latter to a point of light barely visible-in other words, to reduce it to a star of the sixth magnitudeat that moment when the lens (if convex) is 11 feet from the eye at this distance of the lens the star has undergone a reduction of ten diameters; and accordingly, on the supposition that there is no absorbing or extinguishing medium in space, it follows that such star would itself. be visible, though then barely so, if it were removed to ten times its distance in space from the observer. Hence, the distance to which different ones of the self-luminous celestial bodies must be removed to bring them respectively to the point of bare visibility-to a minimum visibile becomes a direct means of comparing the intensity of their light; and, so far as we can assume their actual sizes and brilliancies identical, a means of determining indirectly their distances.

In the use for this purpose of a convex lens, the measure is commenced at the focal point: and the number of times the diameter is reduced is equal to the number of focal distances the lens is removed less one (e. g., 11 focal distances, less 1, give a reduction of ten times in diameter, and in brightness); but with a concave lens, the measure is the actual distance from the lens itself. For these observations Mr. Clark has an underground, dark chamber, 230 feet long, accessible at one end from his workshop, and communicating with the surface at the other end by a vertical opening, one foot square. A common plane silvered-glass mirror, set at a suitable inclination over the orifice, reflects the rays of the sun or star down the vertical opening in the ground upon a prism so placed as to throw the light, by total reflection, in the line of the axis of the horizontal chamber; and no light can enter the latter save through this lens. To the side of the prism facing the chamber is cemented with Canada balsam (so perfectly as to render the two optically one medium) the flat side of a planoconvex lens, say of 1-20th of an inch focus. Then an observer in the cellar 230 feet distant sees through this lens the sun reduced 55,200 times; and its light varies little from that of Sirius. To multiply the reducing effect, a second lens of known focal distance, say 6 inches, is mounted on a little car, which, by cords and a pulley, can be sent to any required distance on a track toward, and in the line of, the fixed lens.

At noon, March 19th, with a perfectly clear sky, Mr. Clark found the sun barely visible

=

through the two lenses when the movable one was 12 feet from the eye, and when being 218 feet from the fixed lens, the reduction given by the latter alone was 52,320 diameters, and the multiplying effect of the second lens 12 x 2 - 123 times, the total reduction being thus 1,203,360 times. By observations expressly devised for such purpose, he concludes that the proportion of the light of the sun or a star that will be lost in these experiments by the extinguishing action of the mirror, prism, and lenses, will be in effect almost exactly compensated by the additional light also reflected by the mirror from a small region of sky just about the sun or star. Proceeding upon this admission, the following are the results at which, in his earlier observations, Mr. Clark arrived; The sun is visible when reduced....1,200,000 times. The full moon..... Sirius............ Procyon........................

Pollux... Castor....

3,000

66

20

66

12

66

66

11 10.8"

The following comparisons will show the relation in which these results stand to the measures of the sun's light previously given by Dr. Wollaston, and by Mr. Bond, of Harvard College Observatory. To reduce our sun to the brightness of the star a Lyræ, the distance of the former must be increased, according to Wollaston, nearly.. Bond, Clark...

46

.425,000 times. 155,000 ..102,000

66

of entire extinction of the light which would otherwise reach us from the larger proportion of the stars of those regions. But Mr. Clark suggests, what is obviously true, that if different stars actually differ in original or inherent splendor, then it will be the least luminous which at any given distance will first elude the eye, and as the distance is increased, a continually larger proportion of all the stars will thus -as a simple effect of reduction by increasing distance-disappear; so that the sparseness of stars in the outermost yet penetrated regions of the universe does not necessarily prove the presence of an absorbing medium, or ether, between their place and the earth, but may merely illustrate the known and simple relation of the apparent magnitude or brilliancy of a visible object to its distance.

The Question of the Sun's Distance from the Earth.-Professor Joseph Lovering, of Harvard College, has communicated to the "American Journal of Science" (Sept., 1863), a highly important paper upon the subject of the sun's distance from the earth, as computed from the several sorts of data relied on, and especially upon the remarkable variance of the result very recently obtained by M. Foucault from previous calculations, and the general effect of this variance, if confirmed, upon the distances and magnitudes of the various astronomical bodies. First, as to the usual methods for determin

Mr. Clark's method, it will be seen, does not depend upon comparisons with artificial lights, but makes a simple reduction of the luminary observed to a minimum visibile, under the most favorable conditions of observation, the standard in all cases.

In his later experiments, he prepared a close covering for the opening to the dark chamber, with a circular perforation, subtending at the prism an angle of 32", and substituted a lens of one-eighth-inch focal distance. Then, by use of two additional lenses, adjustable by sliding, and placed in a telescope tube properly darkened within, he found that it required on some occasions a reducing power of nearly 1,600,000 to send the sun completely out of sight.

Mr. Clark shows that these observations have an important bearing on the question of the existence of an extinguishing medium in space. The more powerful telescopes reveal, in proportion to their power, a far less number of stars than are visible to the unassisted eye; in other words, the appearance is as if the remoter fields of space were more and more thinly tenanted with stars, in comparison with the number within the sphere of direct vision. This fact has been made an argument for an extinguishing medium in space; the greater sparseness of the more distant or telescopic stars being supposed due to the circumstance

any body is an act of binocular vision. In case of near bodies, the interval between the two eyes is the base-line of a triangle of which straight lines from the object to the eyes respectively form the other two sides; and the sensation of effort in converging the eyes upon the object, guided by experience, gives us approximately the distance. As the object is farther removed, the base-line must be taken greater, until, in attempts to determine the distance of the sun, it is made the distance between two telescopes directed toward that body from points at the opposite extremities of the earth's diameter; and certain parts of the triangle, giving the distance of the object, are now found by calculation. The angle between the directions of the two telescopes is the "solar parallax ;" and the distance of the sun will vary-the base-line being supposed known-as the magnitude of this angle. Since a small error in the solar parallax would involve a large error in the sun's distance, astronomers select a planet coming nearer the earth than the sun-either Venus, at inferior conjunction, or Mars at opposition. The former observation can only be made in case of a transit across the sun's disc, the quantity determined being the difference of parallax between Venus and the sun: viz., from about 21" to 25". From the combined observations of the two transits of Venus last occurring-1761 and 1769-Encke deduced the solar parallax as 8".57116. This corresponds to a solar distance of 95,360,000 miles. Transits of Venus will occur in 1874 and 1882; but