GOEPPERT, H. R. Ueber die Bernsteinflora. Monatsberichte der k. Akad. der Wissenschaften zu Berlin, 1853, p. 450; also 31ste Jahresbericht d. Schles. Gesellsch., 1853, p. 64; and Edin. New Phil. Journ., 1853, p. 365; Quart. Journ. Geol. Soc., vol. x., part 2: Miscellaneous, p. 1.

Ueber G. C. Berendt's im Bernstein befindlichen organischen Reste der Vorwelt. 32 Jahresbericht d. Schles. Gesell., 1854, p. 57.

See also Berendt.

GUMPRECHT. Ueber einige geoguostiche Verhältnisse des Grossherzogthums Posen. Karsten's Archiv, vol. xix., 1845, p. 627.

HAGEN, H. Beschreibung der Früchte und des fossiles Holzes, welche sich in den Bernstein-grabereien in Preussen finden. Gilbert's Annalen, vol. xix., 1805, p. 181. See also Berendt.

Cracow, 1580; Riga, 1600. Trans. Entom. Soc., vol. i.,

HERMANN, D. De Rana et Lacerta Succino insistis. HOPE, F. W. Observations on succinic Insects. part 3, 1836, p. 133; vol. ii., part 1, 1837, p. 46. JOHN. Naturgeschichte des Succins. Cologne, 1816. KAWALL. Der Bernsteinsee in Kurland. Rigaer Correspondenz-blatt, vol. vi. p. 69.

LOEW, H. Ueber den Bernstein und die Bernstein-fauna. Berlin, 1850.

MACCULLOCH, J. On Animals preserved in Amber, with observations on the nature and origin of that substance. Quart. Journ. Science, Literature, and Art, vol. xvi., 1824, p. 41.

MERCKLIN, von. Ueber fossiles Holz und Bernstein in Braunkohle aus Gischiginsk in Kamschatka. Bull. Acad. Petersburg, vol. xi., p. 81. MIQUEL, F. M. W. See Venema.

OUCHAKOFF. Notice sur un Termes fossile. Bull. Soc. Imp. Nat. Moscow, 1838, vol. i., p. 37; also Annales des Sciences Nat., 2me Série, vol. xiii., p. 204; Neues Jahrbuch, 1839, p. 122; Archiv für Mineralogie, vol. ii., p. 289.

PICTET, F. J. General Considerations on the Organic Remains, and in particular on the Insects which have been found in Amber. Edin. New. Phil. Journ., vol. xli., 1846, p. 391; also Nouv. Mém. de la Soc. Helvétique des Sciences Nat., vol. vi., 1847, p. 5. See also Berendt.

ROSE. In 'Reise nach dem Ural,' vol. i., p. 486.

Roy, Van. Ansichten, &c., Danzig, 1840.

RUNGE. Ueber das Vorkommen und die Gewinnung des Bernsteins im Samlande. Journ, f. prakt. Chemie, vol. cii., p. 120.

SCHWEIGGER. Beobachtungen auf Naturhistorischen Reisen. Berlin, 1819. Anhang, p. 105.

SENDEL, N. Historia Succinorum corpora aliena involventium, et naturæ opore pictorum et cælatorum ex regiis Augustorum cimeliis Dresda conditis aeri insculptorum conscripta, etc. Leipsig, 1742.

STEINBECK, A. Ueber die Bernstein Gewinnung bei Brandenburg an der Havel. Brandenburg, 1841; also N. Notiz. de Froriep., vol. xiv., 1840, p. 257; also Neues Jahrbuch, 1844, p. 121.

THEBESIUS, D. G. In Baltische Studien,' vol. iii., 1835, p. 28.

THOMAS, K. On the Amber-beds of East Prussia. Ann. Mag. Nat. Hist., 2nd Series, vol. ii., 1848, p. 369, translated from 'Die Bernsteinformation d. Samlandes.' Ostpreuss. Prov. Blätt., April, 1847.

VENEMA, G. A. and F. A. W. MIQUEL. De Barnstein in de provincie Groningen. Verhandelungen uitgegeven door de Commissie belast met het vervaardigen erner geologische beschrijving en Kaart van Nederland. Tweede Deel, 1854. WALCH and KNORR. Lapides diluvii Testes.

WINKLER'S Waarenlexicon, Article Bernstein.'

ZADDACH, G. Ueber die Bernstein und Braunkohlenlager des Samlandes. Schriften d. physik.-ökonom. Gesellsch. Königsberg, 1860, vol. i., p. 1.

See also numerous Articles in Gilbert's Annalen,' e. g., vol. xix., p. 181, A. 354; vol. xlv., p. 435; vol. xviii., pp. 234, 237, 311; vol. lxiii., p. 387; vol. lxx., pp. 297, 303, 305; vol. lxxiv., p. 107, A. 110; lxxiii., p. 336; lxv., p. 20.

V. SIR JOHN HERSCHEL AND MODERN

ASTRONOMY.

ASTRONOMY is remarkable, as the solitary example of a science, for which exactness has been secured by the elucidation of the laws regulating a power which is associated with every form of matter. The laws ruling the influences of that power or principle, as exerted through space, have been developed with a clearness which removes every shadow of doubt.

When Newton determined by the most careful examination of facts, and by the penetrating power of his mental analysis, that every body circulating in space, was compelled to move in obedience to the force of Gravitation, acting according to the law of the inverse square, he furnished the key by which all astronomical problems connected with "the stars in their courses" could be solved. The stone flung into the air by the playing child-the ball projected at high velocity from a piece of artillery—the planet rolling with majestic regularity across the celestial vault-the twin and triple stars circulating mysteriously about each other in the remoteness of the heavens-the yet inscrutable nebula-and the space-exploring comets,-are, each and all, equally bound to move in obedience to a force, of which we know only the law of action. But the knowledge of this law has placed a wand in the grasp of the astronomer, by which he feels out worlds, ere yet they are visible to human sense.

Every reflecting mind will naturally inquire, What is this allpervading power which we call GRAVITATION, binding the Moon to the Earth, the Planets to the Sun, and the Solar System itself, to some immeasurably-distant star; which, though it be the centre of motion to our small group of planets, may be itself but the satellite of some yet grander luminary-distributing its energies from depths of space to which no telescope has ever penetrated? And such a mind-while impressed with the immensity of power displayedwill ever feel its littleness when compelled to own, that of the cause of that power it is deeply ignorant.

"the

"The law of Gravitation," says Sir John Herschel, most universal truth at which human reason has yet arrived— expresses not merely the general fact of the mutual attraction of all matter; not merely the vague statement that its influence decreases as the distance increases, but the exact numerical rate at which that decrease takes place; so that when its amount is known at any one distance, it may be calculated exactly for any other."

* A Preliminary Discourse on the Study of Natural Philosophy.'

P

Yet, the author of that paragraph was heard by the writer of this article to declare, on this point, the weakness of his knowledge -and, at the same time, with something like prophetic inspiration, to express a feeling, amounting to conviction, that Gravitation was the effect of vastly superior causes, ascending in grandeur of action, one above the other, until we reach the Great First Cause of All.

May it not be, that while we are groping our way amongst the interstices of matter, and learning a little of "molecular forces," to which we have given many names-we are slowly obtaining dim glimpses of modified forms of this force, at once so powerful and universal in heavenly space, and so subtle when confined in the labyrinths of earthly matter? However this may be, all "celestial weighings and measurings" (as Sir John Herschel phrased it, in one of those popular articles which he can write so well) are carried out entirely by our knowledge of the law of Gravitation, and thus is Astronomy made an exact science.

As we improve our instruments we shall see yet deeper into the heavens, and by long-continued and well-directed observations, we shall make new discoveries among the stars, and learn yet more of the arcana of space. But these discoveries, though they will enlarge our knowledge, will not disturb that which we know; and of no other science than Astronomy can this be said.

If we intended a review of modern Astronomy, it would be necessary to notice the labours of many men who have, in this country, in Europe, and in America, by their powers of observation, their unwearying industry, and their skilful analysis, largely increased the sum of human knowledge. Between the time when William Herschel discovered Uranus, and Adams pointed to the spot where a planet must exist, and where Neptune was found, many eminent men have yoked their names with astronomical researches of the highest value. Of none of these is it our purpose to speak; our only intention is to set forth, in brief, the labours of one man who has proved that he combines in his own person the assiduous astronomical observer, the acute mathematician, the deep-thinking philosopher, and the graceful poet,—that man being Sir John Herschel. It is not to many men that intellectual powers of so high an order have been given-it is not in many men that we find such perfect balancing of those varied powers-it is in few men that we discover such profound humility, and such a deep sense of reverence for the Creator of those works, the study of which has been a life-labour of love. When we have examples before us of superior intellects wandering away into error, deluded by the meteor-gleam of their own great, but irregularly-trained, and therefore, now uncontrolled, powers, it is of the utmost importance that the example of the brighter star, moving in brilliancy around the Centre of all good, should be con

VOL. V.

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trasted with their meteor-flights--" a moment bright, then gone for ever."

Sir John Frederick William Herschel, Bart., was born in 1790 at Slough, near Windsor. He is the only son of Sir Frederick William Herschel, whose name is for ever associated with astronomical discovery. From the father the son derived his passion for the study of the stars,-and it may be incidentally noted here that in this family we have the rare example of the father, the son, and the grandson (Alexander Herschel) pursuing with great success the study of the exactest of the sciences. There is a pleasure and a purpose in tracing the progress of an individual mind, especially when that mind has made itself a place in the history of science. We have not the information necessary for treating inductively our examination of the development of the mental powers of the young John Herschel. We have heard numerous anecdotes of an absent, a retiring, a star-gazing boy, but, although there may be traces of truth in some of these, we believe they generally resolve themselves into the every-day expression of those who do not understand the condition of a meditative youth, loving solitude, because in solitude alone could he hold communion with nature's works and view her charms unrolled. John Herschel was a student of St. John's College, Cambridge, where he achieved the honourable position of Senior Wrangler, and became Smith's Prizeman in 1813. He appears from this time to have devoted himself seriously to those pursuits with which his father's name was already associated.

In 1816 we find him giving a large amount of time to observations on the multiple stars; these observations were continued, sometimes alone, and sometimes in conjunction with Sir James South, until, as the result of ten thousand observations, we find in the Philosophical Transactions for 1825' "a series of micrometric measures of 380 double stars, executed in conjunction with Sir J. South in 1821-2-3."

、

Previously to this we have the subject of this notice producing, with Dr. Peacock, the well-known Dean of Ely, a reconstruction of Lacroix's treatise 'On the Differential Calculus,' and he was at the same time a zealous student of chemistry and of the physical sciences. The Philosophical Transactions for 1826' contain an important paper, entitled "An account of a Series of Observations made in the Summer of 1825, for the purpose of determining the difference of the Meridians of the Royal Observatories of Greenwich and Paris." For several years, especially in 1825, 6, and 7, Mr. Herschel was occupied at Slough with the 20-feet reflector making observations on the multiple stars. The labour of these investigations may be judged of by the titles of the several series which were published in the 'Memoirs of the Astronomical Society,' and which we copy so far as to show the work performed :

384 more new double stars.

1,236 double stars, the greater part not previously described.

These observations were continued with the most untiring industry, and in 1832, Mr. Herschel published, as a fifth series, a catalogue of 2,007 double stars, of which 1,304 were new, and a sixth series was produced in the following year. In the 'Philosophical Transactions for 1833' there is a valuable communication, "Observations of Nebula and Clusters of Stars," with a 20-foot reflector. In this memoir we have a most careful examination of all the conditions observed in star-clusters and nebulous masses. Some two thousand of these mysterious classes of bodies were examined, and their physical construction, as far as possible, is described. The result of all this labour may be examined with much advantage in the Outlines of Astronomy.' In the paragraphs of that work which are devoted to this subject, the speculations of Sir William Herschel are cautiously reviewed. The "nebular hypothesis," as it has been termed, supposes the existence of an elementary form of luminous siderial matter, and its gradual subsidence and condensation by the effect of its own gravity, into more or less regular spherical or spheroidal forms. "Assuming that in the progress of this subsidence local centres of condensation, subordinate to the general tendency would not be wanting, he (Sir W. Herschel) conceived that in this way solid nuclei might arise, whose local gravitation still further condensing, and so absorbing the nebulous matter, each in its immediate neighbourhood, might ultimately become stars, and the whole nebulæ finally take on the state of a cluster of stars." Sir John Herschel's leaning towards this view will be evident from the following remarks:-" Among the multitude of nebulæ revealed by Sir W. Herschel's telescopes, every stage of this process might be considered as displayed to our eyes, and in every modification of form to which the general principle might be conceived to apply. The more or less advanced state of a nebula, towards its segregation into discrete stars, and of those stars themselves towards a denser state of segregation round a central nucleus, would thus be, in some sort, an indication of age. Neither is there any variety of aspect which nebula offer which stands at all in contradiction to this view."*

Another contribution to astronomical science was his 'Observations on the Satellites of Uranus,' published by the Astronomical Society; and this was followed by two series of micrometrical measurements of double stars, made at Slough with a seven-foot Equatorial.

* 'Outlines of Astronomy,' pp. 598, 599.