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Sir J. Herschel's
is now no longer a dim misty speck, but a sharp | desecrate with their sorceries those hallowed rebrilliant point. I cannot, however, raise a well-gions on which the wizard and the conjuror have defined disc on it.” “ It is like a planetary neb-long ceased to tread.* ula, a little hazy at the edges, 2" or 21", in The elements and perturbations of the sixth diameter.” “I now see a sharp, all but plane- satellite of Saturn having been elaborately investitary disc, diameter fully 1?", quite distinct from gated by Bessel, and very little being known rethe haze about it. It is like one of Jupiter's specting the rest, Sir John Herschel availed himsatellites in a thick fog of hazy light.” “I can self of his advantageous position at the Cape, to hardly doubt,” Sir John adds, “ that the comet make a series of observations on these interesting was fairly evaporated in perihelio by the sun's bodies. Our readers are no doubt aware that after heat, and resolved into transparent vapor, and is the fourth satellite had been discovered by Huynow in process of rapid condensation and re-pre- gens in 1665, Cassini discovered the fifth in 1671, cipitation on the nucleus.” The comet resumed and the first, second, and third, in 1684. Sir W. its former size on the 29th, and afterwards grad- Herschel discovered, in 1780, the sixth and seventh ually disappeared as it receded from the sun. Sir nearer the planet than the rest, the seventh being John notices the following points as especially re- the nearest. As this nomenclature was very unmarkable :
satisfactory, many astronomers named them by 1st. The astonishingly rapid dilatation of its giving numbers corresponding to their distances visible dimensions.
from the planet; and Sir John Herschel has pro2d. The preservation of the same geometrical posed to distinguish them by a series of heathen form of the dilated and dilating envelope.
narnes, as in the following table : 3d. The rapid disappearance of the coma ; and, Order from 4th. The increase in the density and relative
I. 7 W. Herschel, 1780 brightness of the nucleus.
II. 6 W. Herschel, 1780 Enceladus. Our limits will not permit us to discuss the III.
D. Cassini, 1684 Tethys. speculative views which these phenomena have IV. 2
D. Cassini, 1684 Dione. suggested to our author. He rejects the hypothe
3 D. Cassini, 1684 Rhea,
VI. 4 sis of Valz, that the volume of the comet is
C. Huygens, 1655 Titan.
VII. 5 D. Cassini, 1671 Iapetus. directly proportional to its distance from the sun. He maintains that the laws of gravitation are Although it would be difficult to banish from insufficient to account for such a form of equilib- our solar system the names of the heathen gods rium as that of the comet, which was paraboloi- by which the primary planets are distinguished, dal, and that such a form, as one of equilibrium, yet we must enter our protest against the admisis inconceivable without the admission of repulsive sion of a brood of demigods. The nomenclature as well as of attractive forces. “But if we in the first column of the preceding table is doubtadmit,” he adds, “the matter of the tail to be at less the proper one, and the adoption of it can be once repelled from the sun and attracted by the attended with no more inconvenience than we are nucleus, it no longer presents any difficulty.”. In accustomed to in analogous matters. If the houses order to obtain the repulsive power, Sir John of a street are numbered before it is completed, the hazards a theory which supposes the sun to be numbers must be changed whenever a new house permanently charged with electricity. The com- is placed on a vacant area. If it is proper or etic matters vaporized by the sun's heat, in peri- necessary to give names to the secondary planets, helio, the two electricities separated by vaporiza- our mythological knowledge must be more extention, the nucleus becoming negative and the tail sively put in requisition, for we cannot allow the positive, and the electricity of the sun directing the planet Saturn to have a monopoly of the gods tail, in the same manner as a positively electrified We must find names for the four satellites of body would an elongated non-conducting body, Jupiter, and Uranus; and Neptune will make a having one end positively, and the other nega- similar and a heavy demand upon Lemprière. tively excited. The separation of Bielas' comet Sir John Herschel concludes his work with a into two, travelling side by side, like the Siamese Seventh chapter, containing Observations on the twins, presents a new difficulty which it would not Solar Spots, and conjectures respecting their cause. be easy to explain. But here we are beyond our The figures of the spots, of which he has given us depth; and rather than admit electricity as an thirteen in a very interesting plate, were delineated agent residing in every sun and acting upon every system, we remain content with the humbler sup- that M. Leverrier has found that the periodical comets
* Our astronomical readers will be gratified to learn position that the rays of the sun may, in the exer- of 1770 and 1844 are two different bodies ; that two of cise of their chemical and physical influences, find the comets of Faye, Vico, and Lexell, passed close to some ingredients in the tails of comets, upon tached to our system, have come into it and been detained which, by their joint action, they may generate by the action of Jupiter and other bodies. M. Leverrier forces capable of producing the phenomena which proves that the comets of Faye and Lexell have been in we have been considering. If we once admit of times near the earth without being observed. The
our system for at least a century, and have come a dozen magnetism and electricity as agents in our sidereal comet of 1844 he proves to be the same as that of 1678, systems, the mesmerists and phrenologists will / which has travelled into our system from the depths of
infinite space, and been fixed among us centuries ago. form an alliance with the astrologer, and again | It will revisit us in 1849.
from magnified images formed on a screen by action, which lies in a higher region, so that their means of a seven-feet achromatic refractor. One centre (as seen in our water-spouts, which are of these spots, seen on the 29th March, 1837, nothing but small tornadoes) appears to retreat occupied an area of nearly five square minutes, observed during the obliteration of the solar spots,
upwards. Now, this agrees perfectly with what is equal to 3,780,000,000 square miles. “ The black
appear as if filled in by the collapse of their centre of the spot of May 25, 1837, (not the tenth sides, the penumbra closing in upon the spot, and part of the preceding one,) would have allowed disappearing after it.” the globe of our earth to drop through it, leaving
We have been much disappointed at finding that a thousand miles clear of contact on all sides of Sir John Herschel either has not observed or has that tremendous gulf.” For such an amount of not described the extraordinary structure of the fully disturbance on the sun's atmosphere, what reason | luminous disc of the sun, as we and others have can be assigned ? Sir John Herschel justly ob-repeatedly seen it through Sir James Soul's serves, that the heating power of the sun the
great Achromatic ;-a structure which should cause of the great disturbances in our own atmos- have been more distinctly seen at the Cape than phere ; but as there is no such source of heat to in our climate. This structure of which, if we act upon the sun, we must seek for the cause recollect rightly, we have seen a beautiful drawing within the sun itself. Now, the spots are clearly made by Mr. Gwilt, resembles compressed curd, connected with the sun's rotation ; and it has been
or white Almond soap, or a mass of asbestos fibres long known that they do not appear in the sun's lying in a quaquaversus direction, and compressed polar regions, but are confined to two zones, ex. into a solid mass. There can be no illusion in this tending, according to our author, to about 35 phenomenon :—It is seen by every person with degrees of N. and S. latitude, and separated by good vision, and on every part of the sun's lumian equatorial belt, on which spots are very seldom
nous surface or envelope ; and we think affords found. Hence he considers the phenomenon of
an ocular demonstration that that surface or the spots as due to circulatory movements, to and envelope is not a flame, but a soft solid, or thick from the sun's poles, in the fuids which cover its fluid maintained in an incandescent state by subsurface, modified by its rotation about its axis ; jacent heat, and capable of being disturbed by and he tries to find a probable cause for these differences of temperature, and broken up as we movements. Having observed a striking deficiency see it when the sun is covered with spots or openof light in the borders of the sun's visible disc, ings in the luminous matter. extending to some distance within it, he justly
Such is a brief and very imperfect analysis of infers from this deficiency the existence of an
a work which exhibits in a high degree the patience atmosphere ; and he adduces the extraordinary and the genius of its author—a work which had phenomenon of the rose-colored solar clouds wit- he done nothing else would have given immortality nessed during the total eclipse of July 8th, 1842, to his name. Whether we view it as an inde
as definitively settling this question pendent production, or as the completion of the in the affirmative.” Assuming, then, the extent labors of his distinguished parent, it is a work of such an atmosphere “ to be considerable--not truly national, to which, however, the nation has merely in absolute measure—but as an aliquot contributed nothing. To the liberality and devopart of the sun's radius,” its form, in virtue of the tion to science of one individual we owe the laws of fluid equilibrium, must be oblately sphe- valuable results which it records, and to the munifroidal, and consequently its equatorial thickness icence of another its publication in a separate form, greater than its polar thickness. Hence, the and its gratuitous presentation to the universities, escape of heat must be greater from the polar than the societies, and the principal philosophers in from the equatorial zone, and the latter must pos- Europe and America. Wealth may well be coveted sess a higher temperature. In this respect, the when we find it thus judiciously employed when sun resembles our own earth ; and on this sup- in the possession of genius, and thus liberally exposition our author thus reasons respecting the pended when belonging to rank and station. It causes of the spots :
is then that the fruit of wisdom is better than “ The spots in this view of the subject would gold, and her revenue than choice silver,” and come to be assimilated to those regions on the that they “ who love wisdom shall inherit substance, earth's surface in which, for the moment, hurricanes and have their treasures filled.” and tornadoes prevail-the upper stratum being
Since the work of Sir John Herschel was drawn temporarily carried downwards, displacing by its impetus the two strata of luminous matter beneath, "p,
Astronomy has been making rapid advances (which may be conceived as forming an habitually in Europe ; and as an opportunity may not soon tranquil limit between the opposite upper and under occur of resuming the consideration of the subject, currents,) the upper, of course, to a greater extent we shall now give a brief notice of some of the than the lower—thus wholly or partially denuding most remarkable results which have been obtained, the opaque surface of the sun below. Such pro- and which have very recently been published by cesses cannot be unaccompanied with vorticose M. Struve of Pulcova, in his Etudes d'Astronomie motions, which, left to themselves, die away by degrees, and dissipate ; with this peculiarity, that Stellaire. This interesting work, to which we have their lower portions come to rest more speedily than already had occasion to refer, is, we believe, in the their upper, by reason of the greater resistance possession only of M. Struve's private friends. below, as well as the remoteness from the point of It is drawn up as a report, addressed to his ex
Blars from lot to Oth
Hours of R.
Star from Ist to 9th
cellency M. Le Comte Ouvaroff, minister of pub- an ingenious calculation, that there are 52,199 exlic instruction, and president of the Imperial isting in the equatorial zone. Academy of Sciences at St. Petersburg, and has M. Struve had shown in 1827, that if we divide the subsidiary title of Sur la Voie Lactée, et Sur the celestial vault visible in Europe hy circles parles Distances des Etoiles Fixes.
allel to the equator, the stars are almost uniformly After some historical notices of the speculations j distributed in the zones thus formed, if we include of Galileo, Kepler, Huygens, Kant, Lambert, and at once all the 24 hours of R. Ascension .; but Michel, M. Struve gives a general view of the that a very variable condensation takes place in discoveries of Sir W. Herschel on the construc- each zone in the successive hours of R. Ascention of the heavens, and of his peculiar views sion. This will appear from the following table, respecting the Milky Way. He compares his showing the number of stars existing in the equaopinion on this subject, as maintained in 1785, torial belt from the 1st to the 9th magnitude for with that to which he was subsequently led, and each hour of R. Ascension :arrives at the conclusion, which we have already Hour of R. had occasion to mention, that, according to Sir 1.
XIII. 1533 W. Herschel himself, the visible extent of the II. 1609
XIV. 1766 Milky Way increases with the penetrating power
XV. 1896 IV. 2146
XVI. 1661 of the telescopes employed ; that it is impossible
XVII. 2111 to discover by his instruments the termination of
4422 XVIII. 3229 the Milky Way (as an independent cluster of VII. 3575
XIX. 2751 stars ;) and that even his gigantic telescope of VIII. 2854
XX. 2566 forty feet focal length, does not enable him to IX. 1973
XXI. 1752 extend our knowledge of the Milky Way, which is
1652 incapable of being sounded.
XII. 1604 In his next section, on the “ Progress of Stel
0. 2055 lar Astronomy since the time of Herschel,” he Hence, dividing the whole zone into six regions, gives an account of the labors of M. Argelander, of four hours each, two of these are rich in stars, in establishing beyond a doubt the translation of and four poor, the two rich regions being from V. our sun, with its planets in absolute space, and to VIII. and from XVII. to XX. ; and hence, M. those of his own son, M. O. Struve, in ascertain- Struve concludes, from a closer inspection of the ing the angular velocity of its motion, and in veri- table, that there is a gradual condensation of the fying the direction in which it moves, as deter- stars towards a principal line, which is a diameter mined by Argelander. He gives an account of of the equatorial zone situated between the points the researches of Bessel, on the proper motions of VI 40TM and XVIII 40' of the disc. The line Sirius and Procyon, from which that distinguished of least condensation is situated between the points astronomer inferred the existence of large opaque I5 30' and XIII" 30', making an angle of 78° with bodies round which these motions are performed, the line of greatest condensation. If we divide the and he mentions, without giving it any counte- disc or zone into six circles parallel to the principal nance, the bold speculation of M. Maedler of diameter, the density in successive bands diminDorpat, that the Pleiades forms the central group ishes on both sides with the distance. The line of the system of the Milky Way, and that Alcyone, of greatest condensation does not pass through the brightest star of the Pleiades, may be regarded the sun. The distance of the sun from the prinas the central sun of the Milky Way, round which cipal diameter is about 0 15 a," which is nearly all the stars move with the same mean angular equal to the radius of the sphere which separates velocity, whatever be the inclination of their orbit, the stars of the first from those of the second magand their lineal distance from the central body. nitude. The line of greatest condensation is not
Passing over his notice of the labors of the quite a straight line, but presents extraordinary Russian astronomers, of Sir John Herschel, and lacunæ, as in Serpentarius, and accumulations, as Mr. Dunlop, on the subject of nebulæ and double in Orion. Hence the angle of 78° between the stars, he treats of the structure of the Milky Way, lines of greatest and least density is explained by as deduced from the catalogues of Weisse, Arge- these anomalies, for it would otherwise have been lander, Piazzi, and Bessel. With this view, he 90°. inquires into the arrangement of the stars in the Comparing this description of the state of the equatorial zone or belt, 30° wide, extending to 15° stars in the equatorial zone which encircles the N. and 15° S. of the equator. In the catalogue sun, with the phenomena of the Milky Way, M. of Weisse, there are in that belt 31,085 stars, Struve arrives at the conclusion, “ that the phewhich are divided as follows:
nomenon of the condensation of the stars towards
a principal line of the equatorial zone is closely Bright stars, from 1st to 6th magnitude, 664
connected with the nature of the Milky Way, or Stars of the raw bagnitude,
rather that this condensation and the aspect of the Stars of the 8th magnitude,
8183 Stars of the 9th magnitude,
Milky Way are identical phenomena.
In extending this inquiry to the six million But though only these 31,085 stars were ob
* The letter a denotes the radius of a sphere including served by Bessel, yet M. Struve has shown, by, all the stars seen by the naked eye.
No. of Stars.
Distance of Exterior Limit.
Distance from the principal plane..
Mean distance between
nearly (5,819,100) of stars visible in the twenty-tending this law to stars of other magnitudes, and feet telescope of Sir W. Herschel, M. Struve finds adopting for a new unity the mean distance of stars that the greatest and least densities fall very nearly of the first magnitude, he obtains the following taon the same points of the periphery of the disc, as ble of the relative distances of all classes of stars, in the case of stars of the 9th magnitude ; and he A denoting the magnitudes in Argelander's catagives the following distribution of these stars in logue, B those in Bessel's zones, and H those seen every four hours of R. Ascension :
in the 20-feet telescope :
1.2638 IX “ XIII
1.2638 1.8031 2.1408 XIII “ XVII
387,000 3 A
3.1961 XVII “ XXI
2,365,100 4 A
3.1961 3.9057 4.4374 I 455,600 5 A 4.4374 5.4545
6.2093 6 A
6.2093 7.7258 8.8726 From Oh to XXII" 60% of R. Ascen. 581,900 6 B
7 B We regret that our narrow limits will not per
14.4365 8 B 14.4365
24.8445 mit us to give a full account of M. Struve's latest
37.7364 researches on the Milky Way, in which he deter
227.782 mines the law of the condensation of the stars towards a principal plane. After ascertaining that That is, the number of stars in the whole celestial sphere,
1. The last stars visible to the naked eye, acas seen by Sir W. Herschel's twenty-feet tele-cording to Argelander, are at the distance of 8scope, amount to (20,374,034) upwards of twenty .8726 times unity, or nearly nine times the distance millions, he obtains the following values of the of the stars of the first magnitude. density of the stars, and of the mean distance be- 2. The last stars of the ninth magnitude, which iween two neighboring ones, at different distances Bessel has descried in his zones, are at the distance from the principal plane of the Milky Way :- of 37.73 unities, or nearly thirty-eight times the
distance of stars of the first magnitude ; and,
3. The extreme stars descried by Sir W. Her-' 0.00
schel in his sweeps with his 20-feet telescope, are 0.48568
227.8 unities, or two hundred and twenty-eight 0.2
1.611 times the distance of the stars of the first magni0.3
1.779 tude, or 25.672 times more remote than the stars 0.4
of the sixth magnitude, or the furthest seen by 0.5
the naked eye. 0.6
M. Struve next directs our attention to a new 0.7
and very singular speculation, respecting “ the ex0.8660=Sin. 60. 0.00532
tinction of the light of the fixed stars in its passage In order to determine the radii of the spheres through celestial space.” So long ago as 1823,
Dr. Olbers, in a memoir On the transparency of containing the first six classes of stars, or those between the first and the sixth magnitude, M. the celestial spaces, assumed that in the infinity of Struve takes as the basis of his calculation the space there existed an infinity of created worlds
of stars in our northern hemisphere, as given by Ar- its own light; and on this supposition, he demon
suns, each of which, like our own, shone with gelander in his Uranométrie. Thus,
strated that the whole visible heavens should shine Magnitudes, 1 2 3 4 5 6
with a lustre equal to that of our own sun.. But No. of Stars, 9 34 96 214 550 2342
as such a condition of the firmament does not exand from these numbers he obtains the following ist, he infers that there must be such an absorption results, the unity in the second column being the of this sidereal light as to reduce it to what we now radius of a sphere containing all the stars visible see in the heavens. In producing such an effect, to the naked eye :
he proves that an absorption of 1-800th part of the Apparent magnitudes Radius of the Sphere. Progression calculated.
light of each star in its passage through a distance 6 1.000
1.000 equal to that of Sirius from the sun, would be suf5 0.6998
0.7071 ficient. In favor of such an hypothesis, no facts 4 0.5001
0.5003 have been produced, but M. Struve conceives that 3 0.3602
a proof of the actual extinction of light may be 2 0.2413
found in the enumeration of stars of different or1 0.1424
ders of brightness, and that even the rate of exThe agreement between the radii in the second tinction may, within certain limits, be determined. column, and the geometrical progression, with the The penetrating power of Sir W. Herschel's ratio in the third, is very remarkable. Ex- 20-feet telescope, he found to be 61.18, that is, /2'
by the help of this instrument, we can see stars * The radius of the sphere containing all the 20 mil- 61.18 times more distant, than the last stars, lions of stars above mentioned being unity.
(sixth magnitude,) which can be seen by the naked LIVING AGE.
according to Argelander.
eye. This number 61.18, supposes the opening | bold challenge. We confess ourselves unable to of the pupil, to be exactly 0.2 of an English inch, conceive such a mode of arrangement, although but as long-sighted and short-sighted persons have we cannot agree either with Olbers or Struve in different powers of sight, the force of the eye is their conclusion, that the extinction of light, if it not a proper unity, in measuring the force of a tel- does exist, proves that sidereal space is filled with escope. M. Struve therefore substitutes for the some fuid such as ether, which is capable of intereye a small achromatic telescope of 0.211 aperture, cepting a portion of the light which it transmits. and magnifying three times, which will introduce to fill infinite space with matter, in order to erinto the eye exactly the same quantity of light that plain a phenomenon, seems to us the very last passes directly through the pupil when its aperture resource of a sound philosophy. The sun has an is 0.2, while it gives a precise image, independent atmosphere, widely extended in the apprehension of the character of the eye. With this modulus, of every astronomer. The planets have atmosrepresenting the eye as unity, he could almost pheres too : our solar system boasts of about 700 double the number of the stars contained in the recorded comets; and M. Arago is of opinion that maps of Argelander, or to speak more exactly, if the perihelia of comets are distributed throughout he counted 183 when only 100 were in the same the system as between the sun and the orbit of space in the map. In taking, therefore, for unity Mercury, there would be three and a half millions the distance of the last stars of the sixth magni- of comets within the sphere of Uranus. Within tude, (6 A,) which Argelander has seen, the the sphere of Neptune, of course, there must be visual radius or penetrating power of the Herschel- many more ; and Capt. Smith, in mentioning the ian modulus will be 1.83 1.2231, or equal opinion of Arago, adds, that there are many conto 1.2231 + 8.8726 = 10.582 times the mean siderations which, on the same hypothesis, would distance of a star of the first magnitude.
But greatly increase that number. If we consider, Herschel has determined photometrically that this also, the enormous extent of the tails of these radius is equal to twelve times the distance of stars bodies, some of them millions of miles long, and of the first magnitude, a remarkable coincidence the increase in the dimensions of comets as they which could scarcely be expected. Hence the recede from the sun, we shall have no difficulty in range of the telescope of twenty-feet is 61.18, concluding that, within the limits of our own sysV1.83=74.89 times the distance of the stars 6 A, tem, there is an immense mass of atmosphere or or 74.83 + 8.876 = 663.96 times the mean dis- nebulosity capable of extinguishing a portion of the tance of stars of the first magnitude. But instead light which falls upon it. Let us, then, fill the of 74.83, the gauges of Herschel give us 25.672 infinite universe with similar systems with similar for the radius of the stars 6 A. It follows there-obstructions to light, and we shall not require an fore that the range of Herschel's telescope, as de- ethereal medium to account for the want of lumitermined by astronomical observations, exceeds by nosity in the starry firmament. The reviewer scarcely one third the range which corresponds to
whom we have quoted, not satisfied with an instanits optical force. How are we to explain this fact, taneous demolition of the speculation of Olbers and asks M. Struve ? I can see no other explanation, Struve, again slays the slain. ‘Light, it is true," he adds, than that of admitting “ that the intensity
says, “ is easily disposed of. Once absorbed, of light decreases in a greater proportion than the it is extinct forever, and will trouble us no more. inverse ratio of the squares of the distances, or, But with radiant heat the case is otherwise. This, what is the same thing, that there exists a loss of though absorbed, remains still effective in heating light, an extinction, in the passage of light through the absorbing medium, which must either increase celestial space.” In computing the amount of the in temperature, the process continuing, ad infiniextinction, M. Struve finds that it is one per cent. tum, or, in its turn, becoming radiant, gire out for stars of the first magnitude, (1 A,) eight per from every point, at every instant, as much heat as cent. for stars of the sixth magnitude, (6 A,) thirty
it receives. We do not think that we are in a per cent. for those of the ninth magnitude, (9 B,) condition to draw this conclusion. The law of the and eighty-eight per cent. for the Herschelian transmission of heat through the celestial spaces is
a problem unsolved ; and till we can explain how These views, which appear to us well founded, the luminous and chemical rays of the sun reflected have been challenged by an eminent writer in the from the moon, are transmitted to the earth, while Edinburgh Review,* who, while he admits the ab- those of heat cannot be exhibited, even when consolute infinity in the number of the stars, maintains centrated by the most powerful burning instruments, that the foundation of the reasoning of Olbers and we are not entitled to urge the objection of the reStruve may be "struck away,” by certain “modes viewer. of systematic arrangement of the stars in space,'
M. Struve concludes bis interesting report by which, it is easy to imagine,” these modes being giving us an abstract of the unpublished but highly “ entirely in consonance with what we see around interesting researches of M. C. A. F. Peters, of us of subordinate grouping actually followed out.” the central observatory of Pulkova, on the paralIt would have been desirable that the reviewer had laxes and distances of the fixed stars.
After a stated one of these modes in justification of this historical notice of the labors of preceding astrona
mers on the subject, M. Peters determines the * Edinburgh Review, January, 1848. No. 175. actual parallaxes of the stars from observations