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 http://www.archive.org/details/cu31924012302836 
 
ECCE CCELUM; 
 
 OR, 
 
 Parish Astronomy. 
 
 BY A CONNECTICUT PASTOR. 
 
 THIRTEENTH EDITION. 
 
 BOSTON: 
 
 NOYES, HOLMES, AND COMPANY. 
 
 117 Washington Street. 
 
 1872. 
 
 K 
 
Entered, according to Act of Congress, in the year 1867, by 
 
 NICHOLS & NOYES, 
 
 In the Clerk's Office of the District Court of the District of Massachusetta 
 
 BOSTOS: CORNHILL PRESS. 
 ■TBBKOXrPED XSD FBINTBD BT OBO. C. BAND & ATBBT. 
 
€a 
 
 Rev. W. a. Stearns, D.D., LL.D., 
 
 President of Amherst College, 
 
 OF PARISH LECTURES ON ASTRONOMY IN THE INTEREST 
 . OF RELIGION, 
 
 IS RESPECTFULLY DEDICATED 
 
 r^E AUTHOR. 
 
A REMARKABLE BOOK. 
 
 ECCE CCELUM; 
 
 OB. 
 
 PARISH ASTRONOMY. 
 
 Bt Eev. E. F. burr, D.D. 
 
 1 vol. I81U0, 198 pp. Price, $1.25. Kew Edition. Sen; prepaid by mall 
 on receipt of price. 
 
 ITOTES, HOLMES & CO. 
 
 117 Washington Street, Boston. 
 
 The Publishers request special attention to the following uit 
 solicited testimoniafe, which have been received from source! 
 worthy of regard. 
 
 From Rev. W. A. Steams, D.D., LL.D., President of Aniherst College. 
 " I have read it with great profit and admiration. It is a grand 
 piwJuction, — very clear and satisfactory, scientifically considered, 
 very exalted and exalting in spirit and manner ; and exhibiting a 
 wealth of appropriate emotion and expression which surprises me. 
 May the life and health of the author be spared to show still 
 further that God is and that His works are great, sought out of 
 tliem that have pleasure therein." 
 
 From Rev. Horace Bushnelt, D.D. 
 " I have not been so much fascinated by any book for a loD 
 time — never by a book on that particular subject. It is popi! 
 larised in the form, yet not evaporated in the substance, — : . 
 tingles with life all through, — and the wonder is, that, casting 0. 
 to much of the paraphernalia of science, and descending, for tl, 
 most pan, to common language, it brings out, not so much, but g'j 
 much mare of the meaning. I have gotten a better idea of AstroD 
 
2 
 
 »my, as a whole, from it than 1 ever got before from all athel 
 jourcee, — more than from Enfield's great book, which I once care- 
 fully woikad out, eclipses and all. 
 
 " I trace the progress made, and the methods of the same, and 
 seize on the exact status of things at the point now reached." 
 
 From the BMiotheca Sacra. 
 "This is a remarkable book, — one of the most remaikabl* 
 which has proceeded from the American press for a long time. It 
 hits the reader fairly into the heavens and imveils their glories. 
 The presentation is very full though concentrated, very clear and 
 animating, — with a command of language and a glow of eloquence 
 which is quite extraordinary. The last lecture is hardly less than 
 a Te Deum. The only adverse criticism which, on reading the 
 preparatory lecture, we were inclined to make, was, that the almost 
 impassioned eloquence with which it opened would have bean 
 more impressive further on, and after the imagination had been 
 excited by the facts. But, after finishing the last Lecture, we 
 could not wonder that a mind so full of the great facts, and of the 
 emotion which they necessarily kindle, should, on seeing his own 
 parish charge assembled to listen, break forth in strains whichi-none 
 but a mind fully roused by his theme and his audience would 
 have been able to utter. No person can read through this volume 
 without mental exaltation, and a conviction of the peculiar ability 
 of the author." 
 
 From the New Englander. 
 "It presents an admirable r€sum(fot the sublime teachhigs ot 
 Astronomy, as related to natural religion, — a series of brilliant 
 pen-photographs of the Wonders of the Heavens, as part of God'i 
 glorious handiwork. The first five lectures pass the science in 
 rapid review ; the last treats of the Author of Nature, as related to 
 its leading features. There is not a dry page in the volume, bul 
 jiuch originality and vigor of style, and often the highest elo- 
 quence. It is, withal, evidently by an author at home in his sub- 
 |ect, not " crammed " for the task. It affords a fine example of 
 what an intelligent pastor can do, outside of his pulpit, towardt 
 training an intelligent people, and by imparting to them Nature'i 
 
teachings, leading " through Nature up to Nature's God," — tha 
 God of Revelation as well. To such a book the author need not 
 hesitate to afiljc his name." 
 
 'i'riin Rev. A. P. Peabody, D.D., LL.D., Preacher to Harvard University, 
 and Plummer Professor of Christian Morals, 
 
 " Permit me to thanli you for a worlc in which you have effected 
 a rare union of scientific accuracy, eloquent diction, and rich de- 
 rotional sentiment. It is attractive, instructive, and edifying. It 
 appears at a time when science needs, as never before, to be 
 redeeme i and sanctified by faith in Ilim, in whom are hidden all 
 the treasures of wisdom and knowledge. And, best of all, it does 
 not make Religion cringe to Science, but maintains lier in that 
 queenly status which is the only position she can hold. The book 
 must do great good, and I heartily congratulate you as its author." 
 
 From Rev. S. H. ffatt, D.D. 
 " Ecce Coelum is much more than a book-success. It will be 
 honored as a most timely and admirable treatise to put into the 
 jand of thoughtful young people, to ' turn off their minds &om 
 vanity,' and lead them to God." 
 
 From the New- YorTe Evangelist. 
 " This unpretending, though elegant little volume, gives a most 
 admirable popular summary of the results of Astronomical Sci- 
 ence. The author lias evidently mastered his subject, and he hag 
 presented it in a most striking manner, adapted to the comprehen- 
 eicn of the common reader, and enriched with pertinent illus- 
 trations. The book is perhaps the most fascinating treatise on the 
 Bcence which has been published of late years, ranking indeed 
 In many respects with that of the late lamented and eloquent 
 Mitchell. One of its excellencies is that it does not liide God 
 behind his own creation.' " 
 
 From the Religious Berald. 
 "A New Book, and one that is a book, worth its weight in 
 |old or diamonds, for it is fuU of gold and precious gems, — dia- 
 nonds of law and fact, — truths beaming with celestial light. 1 
 
4 
 
 tpeak of 'Ecce Coelum/ from the pen of Eer. Enoch F. Buss, 
 D.D., of Lyme, Conn., published by iiichols & Noyes, Boston, a 
 duodecimo of 198 pages. Mr. Burr modestly signs himself ' A 
 Connecticut Pastor,' but some college has rent the vail and written 
 out his full name, and added to it a D.D. So much the better for 
 Connecticut and for the world. Such light as the book containi 
 ought not to be under a bushel. 
 
 " These six Parish Lectures are a masterly, vivid, easy, sub 
 lime presentation of the enchanting facts of Astronomy. They 
 are adapted to all classes, — the learned and the unlearned. Th« 
 astounding glories of the skies are tempered to our humble eyes. 
 
 " Let all read the book, old and young. Let it be found in 
 every school, in every library, and .in every home where wisdom 
 is invoked. Bead it, and you will exclaim, what glorious light it 
 sheds from the throne of God upon the lonely pathway of man ! " 
 
 From C. H. BaM>augh^ of Pennsylvania. 
 " It is certainly a wonderful little book. How the world 
 shrinks into an atom as we follow the lofty soarings of the ' Con- 
 necticut Pastor.' I never knew rightly what Dr. Young means 
 by saying, ' an undevout Astronomer is mad ; ' but I now see and 
 feel the power and beauty of the expression. Such a book cannot 
 be read without laying upon us the responsibility of a new charge 
 from heaven. After contemplating such grandeur, we instinctively 
 exclaim, ' What is man that Thou art mindful of him ? ' " 
 
 Fr(mi Hon, S. L. Selden, Late Cliief Justice of New Yoi-h. 
 " A beautiful book. I admire it for the elegance of its style, as 
 well as for the lucid and able manner in which it presents the 
 noblest of the sciences. It will prove, I think, very valuable, not 
 merely for the knowledge it communicates, but as suggestive of a 
 jne of noble and elevated thought. And I am much pleased to see 
 from the numerous notices which have come under my observa- 
 tion that my estimate is confirmed by many persons of the first 
 Sapacity for judging. To have written a work which receives 
 md deserves such very high praise from scholars and men of 
 icleuce cannot but be a, source of great gratification to tha 
 tuthor." 
 
ECCE CGELUM; 
 
 PARISH ASTRONOIMT. 
 
 ELEVEINTH EDITION". 
 
 SUPPLEMENTARY EXTRACTS. 
 
 nvm Oie Theological Echctie, [Edited by Professor Bay, Scliaff, etc.] 
 
 "The style is remarkably graphic and elastic, and the matter ia 
 «o skilfully grouped and lucidly stated as to be level to all classes 
 of readers. The writer has a rare gift at popularizing science, 
 and his book deserves the wide welcome it has received." 
 
 Erom the Kew TorTe Observer, 
 " We have never yet seen a volume on Astronomy that seemed 
 to us to explain more intelligently,to ordinary minds, the visible 
 phenomena of the heavenly bodies." 
 
 From the Congregationalist, 
 " We advise all our readers who have not yet read the book 
 entitled ' Ecce Coelum,' to embrace their earliest opportunity to 
 do so, — a book which certainly has been surpassed by nothing 
 of this general line, for many years, if ever. There is a grandeur 
 of conception — an easy grasp of great facts — a clear apprehen- 
 sion of deep and subtle relations — a power to see, and make 
 others see, the nature and extent of the heavenly movements, 
 such as are altogether wonderful. Many works have been writ- 
 ten from time to time to popularize astronomy — to bring its 
 great leading features within the compass of unscientific miuds. 
 But we do not know of a work in which this has been so finely 
 done as in ' Ecce Coelum.' Six lectures of about an hour each, 
 tell the story, and the reader feels, all the while, as if he were 
 upon a triumphal march. He is upborne and sustained by his 
 
guide, so that he has no sense of labor and weariness on tha 
 journey. The last chapter, on ' The Author of Kature,' is a 
 most worthy and fitting close to the book. We wish it could be 
 read by that great host of so-called scientific men, who are delv- 
 ing away in the mines of nature, with thoughts and purposes 
 materialistic and half atheistic. They need the tonic of such 
 Christian t hinkin g as this." 
 
 From Hours at Home. 
 " This little hook, from thepenofEev. E. F. Burr, D.D., has 
 already been noticed extensively and pronounced a ' remarkable 
 book ' by our best critics. The author first delivered the sub- 
 stance of it to his own people in familiar lectures. It presents a 
 clear and succinct resume of the sublime teachings of astronomy, 
 especially as related to natural religion. The theme is an in- 
 spiring one, and the author is master of his subject, and handles 
 It with rare tact, and succeeds as few men have ever done in 
 giving an intelligent view of the wonders of astronomy, accord- 
 ing to the latest researches and discoveries. It is indeed an 
 eloquent and masterly production." 
 
 From Harper's Monthly. 
 " The title page of ' Ecce Coelum ' is the poorest page in the 
 book. We have seen nothing since the days of Dr. Chalmer's 
 Astronomical Discourses equal in their kind to these six simple 
 lectures. By an imagination which is truly contagious the 
 writer lifts us above the earth and causes us to wander for a 
 time among the stars. The most abstruse truths he succeeds in 
 translating into popular forms. Science is with him less a study 
 than a poem, less a poem than a form of devotion. The writer 
 who can convert the Calculus into a fairy story, as Dr. Burr has 
 done, may fairly hope that no theme can thwart the solving 
 power of his imagination. An enthusiast in science, he is also 
 an earnest Christian at heart. He raakf s no attempt to recon- 
 cile science and religion, but writes as with a charming ignor- 
 ance that any one had ever been so absurdly irrational as to 
 Imagine that they were ever at variance." 
 
 From the Evangelist. 
 
 " We have had many inquiries in regard to the authorship of 
 
 Kcce Coelum,' the volume noticed somewhat at length two 
 
weeks since. To save writing a number of letters, we may say 
 here, that the Country Pastor, who is the author of these six 
 Lectures on ' Parish Astronomy,' is the Kev. E. F. Burr, D.D., 
 of Lyme, Ct. The book is a 16mo of about two hundred 
 pages, but in that small compass it comprises the results of long 
 study, and will be found as instructive as it is eloquent. The 
 grandest truths are made level to the plainest understanding. 
 AVe took it up, expecting little from its humble pretensions, but 
 soon found that it was all compact with scientific knowledge, 
 yet glowing with religious faith, and were not surprised that Dr 
 Bushnell should say he ' had not been so fascinated by any book 
 for a long time — never hy a, book on that subject ' — and that it 
 had given him ' a better idea of astronomy than he ever got be- 
 fore from all other sources.' We don't know if they have many 
 such ministers ' lying around ' in the country parishes of Con- 
 necticut, but if so it must be a remarkable State. 
 
 " While the impression of this fascinating volume is fresh in 
 mind," etc. 
 
 From Bev. G. W. Andrews, D.D., President of Marietta College. 
 
 " The author has succeeded admirably in liis attempt to pre- 
 sent the great facts of Astronomical Science in such form as to 
 be intelligible to those who have not gone tlu'ough with a 
 thorough mathematical training, and to make them intensely in- 
 teresting to aU classes of readers. I cannot express more strong- 
 ly the interest the volume excited than by saying that I read 
 through at once. I can hardly remember when I have done the 
 same with another work." 
 
 From Ben. Edwin Halt, D.D., Professor in Aiibwrn Theological Seminary 
 "I received it last night, and have read it through with intense 
 interest and delight. ■ It is a worthy book on a mighty theme. 
 I wish it might be in every household, and read by everybody. 
 And I am stu-e it will be read with admiration and wonder long 
 after the author shall have been gathei-ed to his fathers." 
 
 From Bev. Prof. E. W. Hooker, D. D. 
 " The book is an admirable argument from the discoveries of 
 modem Astronomers, for the existence of God ; and indirectly 
 for the truth of the Gospel. It is an honor to his kindred, to the 
 
Church and the place of his birth, and, above all, to Him whose gos> 
 pel he preaches." 
 
 From an Obituary of Eev. S. L. Pomroy, D.D., late Secretary of tht 
 A. B. C. F. M. 
 
 " He was a man of extensive information, a ripe scholar, and he 
 retained his scholarly habits and tastes to the last. A few weeks 
 since he read ' Ecce Ccelum' with great pleasure and satisfaction. 
 When he returned it he remarked, ' I have read it all twice, parts of 
 ii three times, and have noted down certain passages.* He was spec- 
 ially delighted with the arrangement of the work — the grouping of 
 the different system so as to give us something like a comprehensive 
 idea of the grand whole." 
 
 From the Congregational Quarterly. 
 
 That a Connecticut Pastor should be able in six lectures to his peo- 
 ble to shed more light on this profound subject — to make it more 
 simple and yet more grand, amazing, and impressive — than many 
 of the great masters who have written before him is a matter of sur- 
 prise. Yet this seems to be the generally conceded opinion of the 
 press. We hear but one testimony concerning Ecce Coelura. Any 
 intelligent reader of it can understand what before has been only a 
 mystery. It is worthy of the widest circulation. 
 
 From the Latorence American. 
 
 There is not a dry page in these six lectures ; but the glories of the 
 skies are presented in a most enchanting manner, vivid, popular, 
 jrand, and glowing. Young and old should read it. 
 
 From The Qiristian Union. 
 We can commend this book in the heartiest manner. It is one of the 
 noblest examples of the moral uses of astronomy that have appeared 
 since Chalmer's astronomical sermons. Besides their intrinsic 
 merit, these lectures show what may be done by a quiet pastor of a 
 village church for the instruction of his people. Every preacher has 
 not the equipment required for a course of scientific lectures : but 
 " where there is » will there is a way," and much more might be 
 done than is done in broadening a pastor's literary education and iK 
 raising the literary tastes of his people. 
 
CONTENTS. 
 
 I. Preparatory. 
 
 USES, 
 
 9 
 
 .. HISTORY i6 
 
 3. INSTRUMENTS OF INVESTIGATION . . . . aa 
 
 II. The Sky. 
 
 .. ASPECT 33 
 
 2. NATURE 39 
 
 3. NATURE OF CONTENTS 43 
 
 4. ARRANGEMENT OF CONTENTS 49 
 
 III. Satellite Systems. 
 
 Example — Earth and Mooh. 
 
 I. DIURNAL REVOLUTIONS 66 
 
 .. MUTUAL DISTANCE 70 
 
 3 SHAPES AND SIZES 71 
 
 4. MUTUAL GRAVITATIONS 77 
 
 5. MASSES AND DENSITIES 81 
 
 6. ORBITS 84 
 
 7. MUTUAL ASPECTS 8j 
 
 5 
 
b CONTENTS. 
 
 IV. Planet Systems. 
 
 Example — Solar System. 
 
 1. ORDER OF BODIES 93 
 
 2. PERIODS . . 103 
 
 3. DISTANCES FROM SUN 103 
 
 «. SHAPES AND INCLINATIONS OF ORBITS . . . iii 
 
 5. SIZES IIS 
 
 6. VELOCITIES 117 
 
 7. MASSES AND DENSITIES 18 
 
 8. PERTURBATIONS 120 
 
 V. Higher Systems. 
 
 SUN SYSTEMS I2S 
 
 GROUP SYSTEMS 137 
 
 3. CLUSTER SYSTEMS 138 
 
 4. NEBULA SYSTEMS 140 
 
 5. ULTERIOR SYSTEMS 146 
 
 6. ULTIMATE SYSTEM 148 
 
 VI. Author of Nature, 
 
 As Related to its Leading Features. 
 
 .. VASTNESS 159 
 
 2 VARIETY IN UNITY 163 
 
 3. FINISH OF MINIMA 168 
 
 4. WISDOM . 171 
 
 5. DYNAMICS 177 
 
 6. RELATION TO LAW 182 
 
 7. REL.ITION TO TIME AND MOTION , , . .188 
 
 8. MYSTERY 93 
 
L 
 
 PREPARATORY. 
 
I. Preparatory. 
 
 I. USES « 
 
 2 HISTORY i6 
 
 } INSTRUMENTS OF INVESTIGATION . . . . ■ 
 
FIEST LECTUEE. 
 
 PEEPARATOKY. 
 
 ASTRONOMY, tlie science of the stars, does 
 - not limit itself to those bright points in the 
 vault of evening which are commonly called 
 stars, but treats of the Sky with its whole star- 
 like belongings — Sun, Moon, Planets, Comets — 
 whatever of this general nature reveals itself in 
 the entire round Heavens. 
 
 What is tlie use of Astronomy ? Had this 
 question been asked a few centuries ago, most 
 intelligent pei-sons would have said that its 
 chief use was to aid astrology. Somehow, men 
 liad conceived the idea that the fortunes of 
 individuals and nations were bound up with the 
 aspects and places of the heavenly bodies, and 
 could be predicted from them. It was univer- 
 sally believed that, could the places of certain 
 bodies in the sky at the birth of any person be 
 well ascertained, it would be possible to infer the 
 general character of his lot in life and its criti- 
 cal periods. Here was grand motive for study. 
 
 9 
 
10 FIRST LECTURE. 
 
 Men have always had great taste for being pro- 
 phets and hearing prophets ; so, witli infinite zeal 
 and pains, they watched the mazy heavens, and, 
 out of such glittering fractions of information 
 as they could gather, built up, as tlieir chief 
 use, a stupendous system of fortnne-telling wliose 
 Twelve Houses, whose Lords of the Ascendant, 
 whose Horoscopes and Nativities, were the busi- 
 ness of sages, and the trust of monarchs and the 
 people for thousands of years. 
 
 It is well that we have some better i-eason 
 than its astrological uses to give for studying the 
 Science of the Sky. 
 
 See where the sun, with face of insufferable 
 splendor, goes swimming thi-ough the day ; see 
 where the soft and silver moon, with fleets of stars, 
 goes swimming through the night ! What an 
 eloquent silence 1 There they shine and move, 
 perhaps wonderfully achieve — hosts upon hosts; 
 but there is no celebrating pomp of sounds, 
 only an all-embracing pomp of silence — not a 
 whisper, not a rustle, through all the vasty dome. 
 Our dhuied ears and. hearts are soothed. Our 
 petty cares and excitements are hushed. Both 
 body and soul are insensibly calmed and refreshed 
 as we gaze into the immeasurable stillness. 
 
 Was ever so noble a sight ! What kindly in- 
 terweavings of tlie great and the lovely — what gor- 
 geous competitions and combinations of tlie majes- 
 tif and the beautiful — and all steeped in the 
 
USE OF ASTRONOMY. H 
 
 grave g] jry of immemorial and supreme antiquity. 
 The skj does not look old. Other books show sad 
 marks of the passing years. Their pure white sul- 
 lies. Their varnished, sharp-cut characters grow 
 dull and vague. Scars and molds and odors of de- 
 cay gather upon them. Not so with this pageant 
 book opened above us, this illuminated missal of 
 the heavens. It shows a page as delicately fair 
 and fresh as if it had just come from the hands 
 of its Author. And yet it is the world's ancient- 
 est heir-loom, the issue of the eldest dawn : and, 
 as we look upon its broad and pictured page, 
 we are reverently aware that the same shining 
 scripture met the gaze of famous empires long 
 since dead and buried ; of those old men of renown 
 whose forms loom gigantically on the outskirts 
 of tradition ; of him, hoarest ancient of all, the 
 Old-Testament Adam. It is a joy and an exalta- 
 tion to peruse such a Natural Bible. 
 
 And then it is so accessible ! Not, like some 
 rare old volume of price, hid away from the 
 people at large in piles of granite architecture ; 
 railed off heavily from the curious handling and 
 close inspection of most of such as are allowed 
 to roam the stately halls ; permitted to unclasp 
 only under the careful liands and cultured eyes 
 of sages and princes — not such is this azure 
 volume above, printed and pictured in silver and 
 gold. It is a book for the people. Its outspread 
 page invites study from all quarters, by day and 
 
12 FIRST LECTURE 
 
 by night. One can feast his eyes on it as freelj 
 as another. If it has any valuable secrets, any 
 precious wisdoms in it, one is just as welcome as 
 another to do what he can toward finding them. 
 G od permits no censorship. His printing is a true 
 publishing. With both hands he has issued his 
 astronomy ; has put it in characters large and 
 shining enougli to be within the range of all eyes ; 
 has opened it as wide as wide can be, and laid 
 it across the sky's fair face for all who clioose to 
 examine, stand they at palace-gates, stand they 
 at cabin-doors, stand they in the silent domes of 
 sIvy-piercing observatories, stand they on the rat- 
 tling mid-road of affairs. All classes welcome 
 — welcome to that divine calm, to tliat refined 
 and exalting pleasure, to that jubilee of sight 
 and poetry and art, to that feast of the gods ! 
 
 And not only to this sensuous and assthetic 
 banquet which lies spread on the golden surface 
 of things for all who liave eyes and souls, but 
 to the more interior and recondite stores of which 
 tliese otliers are mere tokens and crumbs. For 
 tlie sky is not only an accessible book, but, in 
 these last days, an interpreted one. It 1ms been 
 translated out of its aboriginal hieroglyphics, put 
 into the world's vernacular, done into alphabet 
 even, as to its most essential facts. The iiitci'- 
 pretation was hard. Sometimes it seemed as if it 
 would never be made. It actually took great 
 men, and many of them, to make it ; and many a 
 
USE OF ASTRONOMY. 13 
 
 long age crept away while the work was being 
 done. But, lo ! done it is at last ; and the re- 
 sults, though not the methods, are now level with 
 the commonest men. And they are exceedingly 
 serviceable results. Once, men could not see an 
 eclipse or a star with a tail to it without infer- 
 ring pestilence and war ; could not even see a 
 bloody sun or shooting star without fearing na- 
 tional disaster and the fall of thrones. But now 
 humanity no longer falls a-trembling at the signs 
 of heaven. The progress of astronomical science 
 has freed us from our superstitious terrors. We 
 leave such panics to centuries ago and the hea- 
 then. Thanks to the sages who have interpreted 
 to us the Sibyls of the sky ! Thanks to them, too, 
 that commerce no longer rows her scant and 
 Liliput shipping in timid adventure within her 
 native creeks, and along her native shores. To 
 the science of the stars we owe the safety and au- 
 dacity with which unlimited canvas now stretches 
 across the widest seas and darkest nights. By 
 the improvements it has been the means of in- 
 troducing into mathematics and observation, it 
 has raised the whole body of our art and sci- 
 ence ; in fact, created large portions of each. 
 Scarcely a branch of business or knowledge, how- 
 ever humble, or however high, but is debtor, in 
 one way or another, to astronomical investiga- 
 tions. j\.stronomers first taught men the art of 
 questioaing Nature. They were the first inter- 
 
14 FIRST LECTURE. 
 
 preters of her that deserved the name, the first 
 to give dazzling and triumphant examples of the 
 way o'" extorting secrets from her close-fisted 
 keeping. In education, also, astronomy has been 
 of most material service. A large and generous 
 culture of the mind requires familiarity with a 
 wide variety of ideas. We need to be trained to 
 refined distinctions, to subtle analyses, to acute- 
 ness of thought ; and for this purpose other sci- 
 ences will answer better than astronomy. But 
 we also need, still more, culture in breadth and 
 dignity and gravity of ideas, in comprehension 
 and solidity of understanding, in elevation and 
 durable glow of imagination and character ; and, 
 for this purpose, no branch of secular knowledge 
 can compare with the science of the stars. This 
 science is wortli more than all the fictions and 
 poems in the world as a judicious cultivator of 
 the imagination and corrector of insipidity and 
 tameness of character. It is universally admit- 
 ted to be the sublimest of the natural sciences. 
 It is a poem as well as a science — the best ex- 
 ample we have of polished completeness in a 
 science, and the noblest specimen we have of an 
 epic poem. Not Milton, not Homer, ever sang 
 so sweetly and loftily as do the chief theorems of 
 astronomy. And certainly, if one would get just 
 ideas of the grandeur and possibilities of the hu- 
 man mind, in no way could he better accomplish 
 his purpose than by noticing what great astro- 
 
USE OF ASTRONOMY. 15 
 
 nomical problems that mind has grappled with 
 anl conquered. It has been the war of Jupiter 
 with the Giants. When we look at the mighty 
 secrets that men have wrested out of that starry 
 page above us, we say softly and reverentially 
 to ourselves, "In the image of God made he 
 them." We also feel that what man has done 
 man can do. We are encouraged for the future of 
 science, the future of art,tlie future of every thing 
 requiring great endowments in man. But, after 
 all, the most interesting and useful thing about 
 astronomy is the illustration it pours on the attri- 
 butes and glory of the Supreme Being. Let it be 
 repeated, that ancient sentiment, " An undevout 
 astronomer is mad." If one can thoughtfully 
 pace up and down the star-sown fields of astrouo- 
 omy and not conceive a feeling of religious awe, 
 as in the presence of Incomprehensible Almighti- 
 ness, he must be a rare man, a sinner above all the 
 Galileans. The fullest force of this inspired say- 
 ing, " for the invisible things of Him are clearly 
 seen, being understood by the things that are 
 made, even his eternal power and godhead," — I 
 say, the fullest force of these words is only felt 
 by him whose thoughts, leaving the diminutive 
 objects of this world, have gone voyaging througli 
 the inexhaustible wonders of the firmament and 
 gazed intelligently on the files of that infinite ar- 
 mada of luminaries, which, in exquisite harmony 
 and solemn pomp, cruise up and down yonder 
 shoreless ocean of the heavens. 
 
16 FIRST LECTURE. 
 
 Astronomy is universally admitted to be the 
 most ancient of all the natural sciences. How 
 ancient none can tell. Neither history nor tra- 
 dition carries us back to its beginning. We can 
 learn nothing of its founder or founders. Their 
 very names are lost in the darkness of the primal 
 ages. At the time when we get our first clear 
 view of the science, viz. two or three thousand 
 years before Christ, it had already made very con- 
 siderable progress. Some say that Chaldea, with 
 its beautiful atmosphere, was the native country 
 of astronomy ; others stand up stoutly for Egypt, 
 "mother of sciences"; while still others think 
 favorably of the claims of India, with its most 
 ancient of all astronomical tables, the tables of 
 Tirvalore, and its most ancient and studious Brah- 
 mins. Who know ? Not even those persons who 
 have taught that the cradle stood in this country 
 by claiming that here stood the cradle of the hu- 
 man race — that fossils of the human period in the 
 United States go back to a remoter antiquity than 
 those in any other part of the globe ! Astronomy 
 was cultivated in very remote times — hundreds 
 and perhaps thousands of years before the Chris- 
 tian era — by the Chinese as well as by the East- 
 Indians, Egyptians, and Chaldeans. Since the 
 time of reliable history, however, the science 
 has been in a state of decay, if not extinction, 
 among most of these nations. With some it 
 has long been one of the totally lost sciences. 
 
mSTORT OF ASTRONOMY. 17 
 
 We look in vain for a living astronomy through 
 all the countries of the East. We find nothing 
 but a fossil, and a mutilated fossil at that. Civil 
 troubles, with other causes perhaps, killed and 
 buried it before the historic period in ail those 
 remoter Oriental lands. In Egypt, however^ and 
 subordinately in Greece, the science continued 
 to live and occasionally grow till witliin times 
 quite modern. The world will not willingly let 
 die such names as Thales, Pythagoras, Hippar- 
 chus, Ptolemy ; nor the glory of that famous 
 Alexandrian school, which, from three hundred 
 years before Christ, till the sack of Alexandria 
 and the destruction of its famous library, in the 
 seventh century, continued to toil away, and not 
 without success, on the heavens. That terrible 
 vandalism that destroyed the garnered wisdom 
 of so many centuries suppressed astronomical 
 culture in the West for nearly a thousand years. 
 The old Romans were fighters, never astrono- 
 mers. Their disjecta membra, the middle ages, 
 were fighters, never astronomers. Meanwhile 
 the cast-away science found a home among the 
 Arabs. At Bagdad, under the caliphates of the 
 Abassides, arose a new Augustan age for all sorts 
 of learning. Equally enlightened and powerful, 
 those splendid monarchs gathered about them- 
 selves the cultivators of knowledge from every 
 quarter, and spared neither pains nor gold to 
 make their capital the focus of the world. And 
 
18 FIRST LECTURE. 
 
 they succeeded. While it was unrelieved mid> 
 night in Europe, it was midnight lit iip by cal- 
 cium lights iu Arabia. Immense attention, in 
 particular, was given to astronomy ; and the 
 mere names of those Saracenic philosophers who 
 cultivated this and other branches of liberal 
 knowledge would fill a volume. Moreover, it 
 was from the splendid and enlightened king- 
 dom which the Arabs established in Spain that 
 astronomy was again set on her feet in the rest 
 of Europe, at the beginning of the sixteenth 
 century, after well nigh a millennium of exile. 
 After all, the amount of real discovery in the heav- 
 ens made, up to this time, by all these illustri- 
 ous men and schools, of various nations, for thou- 
 sands of years, was comparatively small. Many 
 a single year since has done more for astronomy 
 than was done by all the many thousands of years 
 before. The fact is, the old astronomers were de- 
 stroyed by their theories and visionary philoso- 
 phies. Instead of carefully observing Nature and 
 drawing their systems from it, most of them first 
 arbitrarily formed their systems and then en- 
 deavored to interpret Nature in consistency with 
 them. Like many people now, they scorned to 
 begin at the beginning. They wanted to build 
 their liouse from the roof downward, instead of 
 building it from the foundation upward ; wanted 
 to start with Euclid and Homer and figure their 
 way back to a kno'vledge of the alphabet ; wanted 
 
BISTORT OF ASTRONOMY. 19 
 
 to start with the broadest generalizations of sci- 
 ence and so descend on particulars, like Plato, 
 (heir great master or representative. In conse- 
 quence very little was accomplished, considering 
 the prodigious time and labor expended. It was 
 not till Prussian Copernicus and his immediate 
 successors cast off the old theories and way of 
 studying Nature, that astronomy can be said to 
 have fairly begun her triumphant career. Tlie in- 
 cubus once lifted, she then, under the lead of such 
 men as Tycho Brahe, Kepler, Galileo, Newton, 
 went forward with gigantic strides. Up to the 
 present time, it has been one incessant tramp and 
 thiinder of discoveries. Scarcely would one great 
 truth flash down from the sky before men's at- 
 tention would be called to another. Much of the 
 time, indeed, these truths have come iu sliowers 
 and set the whole sky ablaze. It is not mucli ex- 
 aggeration to say that the heavens, instead of 
 raining stars upon us once eveiy November, are 
 raining them nearly the whole time. Like the 
 tributaries of some Mississippi or Amazon, con- 
 tributions have flowed into the main astronomical 
 current from every quarter and Christian laud. 
 The French (a wonderful nation for every thing 
 save religion and self-government) have particu- 
 .larly distinguished themselves. Since Newton, no 
 names in science so glorious with achievement, 
 to none will a grateful posterity so freely decree 
 triumphs, as to those of Clairaut, La Grange, 
 
20 FIRST LECTURE. 
 
 La Place, and Arago. The English-speaking 
 race liave also found laurels growing in the sky 
 and have liberally plucked them — witness Flam- 
 stead and Halley and Bradley and Maskelyne and 
 the two Herschels. For Germany and Russia, 
 are the great names of Bessel and Argelander and 
 Struve and Msedler — names inseparably con- 
 nected with some of the most recent and dazzling 
 successes of astronomy. They have added, not 
 cities, but provinces, to her empire. Altogether, 
 the astronomers of the last three hundred years 
 have given us the most extensive, sublime, and 
 complete science to be found in the world. 
 
 And by what means were tliese grand results 
 reached ? The naked eye has done something — 
 done much. In remote times, men had nothing 
 else with which to explore the heavens : but this, 
 with the help of the pure Chaldean air and leis- 
 urely shepherd life ; this, with the help of the 
 perpetually cloudless Egyptian sky and the free, 
 secluded life of the cultured and inquisitive 
 priesthood, was sufficient to lay the foundations 
 of astronomy. Even to this day, the unaided 
 eye has made, and it need not despair of still 
 making, discoveries in the heavens. Next, as- 
 tronomy is indebted to artificial instruments — to 
 telescopes, and instruments for measuring angles. ■ 
 Contrivances for measuring the angular distances 
 of the heavenly bodies from each other were first 
 used about three hundred years before Christ, at 
 
INSTRUMENTS 01 INVESTIGATION. 21 
 
 A-lexandria. They were Tery rude ; so much so, 
 that Hipparchus aud Ptolemy considered it a great 
 achievement to measure angles of 10' — about one- 
 third of the moon's diameter as it appears to the 
 eye. But even sucli rude approximations to the 
 places of the stai's accomplished several discover- 
 ies, and gave the charts and catalogues which 
 have contributed to still more and greater dis- 
 coveries in modern times. Tycho Brahe made 
 great improvements on the instruments of pre- 
 ceding astronomers. He found himself able to 
 measure angles of 10" — an accuracy sixty times 
 greater than Hipparchus could command. Hence 
 another instalment of discoveries. At the present 
 time we have goniometers of wonderful beauty 
 and exactness — almost an equal feast to the eye 
 of the poet and to that of the mathematician — 
 enabling us, by management, to reach an accuracy 
 ten thousand times greater than was obtained by 
 Tycho with his improved instruments three hun- 
 dred years ago; enabling us to measure celestial 
 arcs no larger than a thousandth part of a second. 
 It is this last style of accui-acy that has, within a 
 few years, enabled us to find the distances from us 
 and from each other of some of the fixed stars, so 
 called, as well as other results scarcely loss won- 
 derful. But those exact instruments and their 
 splendid contributions to astronomy, are largely 
 due to two other meanS of discovery, viz obser- 
 vatories and optical glasses. To secure firm sup- 
 
22 FIRST LECTURE. 
 
 port for instruments, to lift tliem above tlie vapors 
 tliat mori or less always lie along the surface of 
 the groui.d and give to tliem a large and unob 
 structed horizon, massive and lofty towers have 
 been built. On such a tower — Uraniberg, he 
 called it — Tycho placed liis instruments and 
 made his discoveries. On such towers, num- 
 bered by hundreds and fitted up like palaces for 
 every sort of celestial observation, a thoiisand 
 astronomers now watch out the night all over 
 Christendom — at Paris, at Greenwich, at Pul- 
 kova, at Washington. Observatories are the ful- 
 crums of astronomy. They are the war-towers 
 from which we can best attack the skies. If the 
 Tower of Babel had only been designed for such 
 use, as certain incautious persons have suggested, 
 there would have been much good sense in it ! 
 
 At Florence, in the Grand-Ducal palace, there 
 is a room called the Temple. The walls are in- 
 laid with marble and jasper. The ceiling glows 
 with superb frescoes. In niches about the apart- 
 ment are disposed numerous marble busts — por- 
 traits — in the best style of recent art. At the 
 center, the gem and significance of the whole, 
 stands a life-size statue — also a portrait — in 
 whose snowy marble features one recognizes, not 
 only tiie majesty of art, but also the majesty of a 
 well-known sage whose single name is sufficient 
 riches for a country. Here, in 1840, met the 
 Italian men of science to ded"3ate the proudest 
 
INSTRUMENTS OF INVESTIGATION. 23 
 
 cabinet of the Medici to the great memory of 
 Galileo Galilei, whose statue that is, whose dis- 
 ciples' busts tliose are, whose leading life-events 
 that glowing ceiling commemorates — Galileo, the 
 first telescopic explorer of the heavens. Well did 
 he deserve the honor. His single renown more 
 honors his native city than do all her grand dukes, 
 than would permanent rank as capital of Italy. 
 And here, in a press by the wall, is the very tele- 
 scope with which he made his discoveries — two 
 curved glasses rudely fastened in a rude tube, 
 all made with his own hands. With this simple 
 instrument he created a new era in astronomy. 
 With it he poured on the age such a succession 
 of wonders that foolish Rome feared that the im- 
 movable foundations of Holy Scripture would all 
 be swept away by the deluge of innovations,. As 
 if her interpretations of the Bible were the Bible 
 itself ! Since then, the telescope has been bravely 
 plucking laurels from the sky almost incessantly. 
 Made reflecting ; made achromatic ; enlarged from 
 an object-glass of two inches to one of eighteen, 
 and from a speculum of six inches to one of six 
 feet; equatorially mounted, with all the appli- 
 ances for easy motion, exact adjustment, and ex- 
 tremest nicety of measurement ; planted in pa- 
 latial observatories where all the heavens look in 
 at the revolving dome and where scarcely a tre- 
 mor of storms can find its way through the solid 
 masonry ; supported on either hand by Photo- 
 
24 FIEST LECTURE. 
 
 graphy and Telegraphy — in short, the Great Re 
 fractor of Pulkova or the Great Reflector of the 
 Earl of Rosse — the telescope of late years is still 
 pushing incessant conquests in every direction 
 through the sky. Formerly, the telescope was 
 one ; now it is e pluribus unum; and from thou- 
 sands of Uranibergs, public and private, the won- 
 der-working tube is nightly run out against the 
 sky, till the civilized world fairly bristles like 
 a battery in time of active war; and competing 
 observers, under the spur of a generous emula- 
 -tiou, almost nightly bring down upon the earth 
 some mighty truth, or the promise of one, by 
 tlieir voiceless celestial artillery. 
 
 Not long after the invention of the telescope, 
 the means of astronomical investigation received 
 another accession of at least quite as great impor- 
 tance. I refer to that branch of the mathematics 
 called by Newton, one of its inventors. Fluxions, 
 but now universally known among scientific men 
 under tlie name of the Differential and Integral 
 Calculus. It is a species of higher algebra ; and 
 its peculiarity consists in considering all finite 
 quantities as expressible by the ratio of two in- 
 finitely small quantities to each other. It is 
 found that this mode of considering quantities 
 has in it a mysterious and subtle energy for the 
 resolution of problems of the liigher order, be- 
 yond any thing known. It is a natural magic. It 
 is the quintessence of dynamics. The old geom- 
 
INSTRVMEirrS OF INVESTIGATION. 25 
 
 etry, both synthetic and analytic, is a mere infant 
 compared with it. No one is now considered half 
 equipped for astronomical .researcli unless he can 
 wield this splendid instrument. Taking certain 
 facts given by observation, together with the New- 
 tonian law of gravitation that every particle of 
 matter attracts every other particle with a force 
 proportioned directly to its own quantity of mat- 
 ter and inversely to the square of the distance 
 between them — taking these as its fulcrum, the 
 Calculus has proved itself more than the lever of 
 Archimedes ; for that moves only one world, this 
 moves all the heavens. 
 
 To see the feats of this Calculus makes one 
 think of days of enchantment. I have a supreme 
 confidence that none of you have ever heard this 
 Arabian history of what anciently happened to 
 one of the Genii. It seems that this good mon- 
 ster, who was as tall as a mountain and as strong 
 as an earthquake, had, on a certain occasion, 
 amused himself by endeavoring to squeeze his 
 huge figure into a little enchanted black bottle. 
 At last he succeeded. Suddenly the cap flew 
 down and he was caught. Some thousands of 
 years afterwards, a poor man, while at his work 
 one day and thinking how hard it was with his 
 best efforts to make a living, stumbled on this 
 same little bottle. " Let me out — let me out ! " 
 cried the bottle in a half- suffocated whisper. 
 " Can't do it," quoth the man, at once aware of 
 
26 FIRST lEGTURE. 
 
 his good fortune, — "can't do it." "I will do 
 any thing you want if you will," begged the pris- 
 oner. " Will you take away that great mountain 
 between me and the city — will you turn my lit- 
 tle tent into a palace — will you fill it with gold 
 and precious stones —will you promise by all that 
 is sacred to Genii, by the Prophet and Alcoran 
 and Allah ? " " Yes, I promise." After some 
 difiiculty, the man managed to find out the secret 
 of the spring-cap, and lifted it ; when, swift as ah 
 arrow, out rushed a puff of blue vapor, which 
 gradually expanded till, as tall and broad as 
 Mount Shahak, it took the form of a winged 
 man. Without any ado, the monster took up 
 the mountain in his arms and walked off with 
 it a few steps, say a hundred miles or so, and 
 threw it down in a valley behind Bagdad, where 
 he who chooses can see it at this day. Then 
 stepping back, he caught up the little tent 
 and threw it up into the sky out of sight, say- 
 ing, " Come down great, come down precious." 
 In a few minutes, a cloud came settling down 
 on the spot ; and, as it slowly broke away, 
 the man discovered minarets and towers and, at 
 last, a whole gorgeous palace of marble, fit for 
 the Leader of the Faithful himself. Then the 
 Genius plucked a leaf from a majestic palm that 
 waved proudly by the portal and wrote certain 
 strange characters on it with his finger. Tearing 
 it intD small pieces, he puffed them away in every 
 
IN8T1WMENTS OF INVESTIGATION. 27 
 
 direction with his breath. Immediatelj'^, long lines 
 of Ethiopian slaves were seen coming up from all 
 quarters, with immense stuffed sacks on their 
 shoulders (I suppose twelve men in these degen- 
 erate days could scarcely lift one of them) ; and, 
 as each entered the palace and laid his sack on 
 the floor, he laid himself down also by the side 
 of it and became another sack as large and full 
 as that he had brought. In a short time, the 
 palace was full, from foundation to roof. " Come 
 and see," said the Genius. Lo, gold Alraschids, 
 Almansors, and Motassems ! Lo, carbuncles and 
 sapphires and diamonds filled every apartment ! 
 " Have I kept my promise — am I free ? " — "Ay ; " 
 said the enraptured fellow, " and well have you 
 deserved your liberty." — " To tell the truth," 
 quoth the spirit, " I have been so long in that 
 little black bottle that I think I had rather stay 
 there than anywhere else. When you want me 
 you will know where to find me." So, without 
 any more ceremony, he doubled himself up and 
 squeezed into the bottle again. "Was not his 
 name Radib ? Was not that poor man the same 
 Emir Alabdes by whom the Caliph Motassem (for 
 whom Allah be praised), with ten thousand of his 
 attendants, was so sumptuously entertained at 
 his marble palace, in the 180th year of the 
 Hegira ? 
 
 I say, it makes one think of such an Arabian 
 Nights' story, when he looks at some of those lit- 
 
28 FIRST LECTURE. 
 
 tie equations out of which Clairaut and La Place 
 and others have managed to evoke such prodi- 
 gious dynamics as have sufficed to enrich them- 
 selves and their race with uncounted treasures 
 of fame and truth ; as have sufficed to remove 
 mountains from the path of astronomy, and con 
 Pert her humble tent into a spacious palace filled 
 with imprecedented gems of the plundered sky. 
 How much does yonder star weigh ? When will 
 yonder hairy star come back ? Suppose five worlds 
 launched in vacancy from a given position, with 
 given directions and velocities, where will each be 
 twelve thousand years hence ? Such questions as 
 these which men would once have despaired of 
 answering, and even greater questions the terms 
 of which cannot properly be assumed as intelli- 
 gible at this point, the Calculus has conquered 
 and dragged in triumph at its chariot-wheels. 
 And still this prince of good Genii is at the ser- 
 vice of astronomers. , He does not care for his 
 liberty. He still likes to take up headquarters 
 in the little black bottle of a differential equation. 
 When his friends want something great done they 
 know where to find him. And I should not be 
 surprised to see the day when I can tell of new 
 feats of his doing, quite as prodigious as any yet 
 recorded. Do not doubt it — he is as strong as 
 ever. The race of Eulers, Newtons, and La 
 Places, is not yet dead. Gifted men are busily 
 learning the secret of tl\ft spring-cap. And, some 
 
INSTRUMENTS OF INVESTIGATION. 29 
 
 fine morning, men shall read on the bulletin boards 
 of science of new nlountains removed, new palaces 
 built, new whole commissariats of golden and dia- 
 mond truths established for astronomy by the re- 
 doubtable Radib of the Differential and Integral 
 Calculus 
 
IL 
 
 THE SKY, 
 
II. The Sky. 
 
 t. ASPECT 13 
 
 .. NATURE 39 
 
 3. NATURE OF CONTENTS 43 
 
 ♦. ARRANGEMENT OF CONTENTS « 
 
SECOND LECTUEE. 
 
 THE SKY. 
 
 I AM to explain what discoveries have been 
 made in tlie distant sky. To do this *to the 
 best advantage, we must have a picture of the 
 sky, witli its leading aspects and names, fresh in 
 our minds. 
 
 So let us imagine this structure unroofed, and, 
 indeed, well taken down on all sides. And, to- 
 night, let us further imagine that some tall Genius 
 is kind enough to brush away with his besom the 
 envious clouds — those ancient and unutterable 
 enemies of the astronomer. We seem to be at 
 the center of an immense hollow half-globe, on 
 the distant surface of which appear the heavenly 
 bodies. If it were day, we should see on that 
 remote concave the yellow sun : it being night, 
 we see, instead, a multitude of stars and the moon 
 with its silver crescent. Watch the host for a 
 little behind some building, and you may satisfy 
 yourself that they are all in motion towards the 
 west ; that is to say, are all revolving about a 
 
 8 33 
 
34 SECOND LECTURE. 
 
 line drawn through where you are sitting and 
 a point due north, but elevated about 40° above 
 the horizon. Notice that very bright white star 
 low in the west : that is Venus, named after 
 the Greek and Roman goddess of beauty. Yon- 
 der, almost overhead, is another star, of scarcely 
 inferior brightness but of more masculine hue: 
 that is Jupiter, named after the king of the clas- 
 sical divinities. East of the zenith, about one 
 third of the way down, you may perceive a much 
 smaller star of ruddy light — Mars by name — 
 appropriately called from the bloody god of war. 
 Do you see that small star, just visible to the 
 naked eye, almost on the eastern horizon? Well, 
 that is Saturn, named from the father of the prin- 
 cipal gods, and sufficiently dim to represent one 
 who is said to have had the very unfatherly and 
 unhandsome trick of eating his own children. 
 These stars, and many others which are never 
 seen without a glass, are called planets, because 
 they wander about greatly on the sky. Besides 
 these, are certain other bodies, seen only occa- 
 sionally, which are still greater wanderers — 
 comets so-called, hairy stars — a denser part 
 more or less bright, surrounded by a haze which 
 often is found expanded into a pale streamer of 
 prodigious length. 
 
 All others stars bear the name of fixed stars, 
 because, to ordinary observation, there is little 
 or no apparent change in their positions with 
 
ASPECT. 35 
 
 respect to each other. Some of these bodies 
 are veiy conspicuous, real princes for shining, 
 and so, from time immemorial, have been hon- 
 ored with proper names. There, for example, ia 
 one nearly as brilliant as Venus herself — Sirius 
 — with a ray as frosty and keen as ever glanced 
 from an iceberg ; another, Aldebaran ; another, 
 Capella. Nearly half way up the northern heaven 
 is a star by no means bright, but which has been 
 on men's lips and in their eyes oftener than any 
 other star whatever — the star by which ships 
 have steered, and armies marched, and bondmen 
 fled — the North Star. Count some twenty of 
 the brightest of the fixed stars on the whole 
 sphere : these astronomers call stars of the first 
 magnitude. Count some sixty of the next bright- 
 est : these are of the second magnitude. Some 
 two hundred of the next order of brilliancy: 
 these are of the third. Six orders of magnitude 
 are visible to the naked eye : ten orders more 
 include those seen by the telescope. 
 / Notice the unequal distribution of the stars 
 on the sphere. Some are solitary, some in little 
 groups and clusters, some in dense masses that re- 
 semble white clouds; while, among others,- there 
 seem no well-defined natural divisions — they 
 seem sown broadcast and carelessly on the vault. 
 That group of five stars forming the letter V is 
 called the Hyades — rainy Hyades, said the au- 
 cients. That cluster e little further to the west 
 
36 SECOJfD LECTUhE. 
 
 is the Pleiades — Job's Pleiades, with their sweet 
 influences. And here, stretching across the whole 
 hemisphere, like a white fog-bank with torches in 
 it, is the well-known Milky Way which the old 
 poets tell us was inadvertently made by Hercules 
 when an infant. Other objects of the same gen- 
 eral appearance are disclosed by the telescope 
 in various quarters of the heavens — nebulae, so 
 they are called. 
 
 These are natural divisions of the heavenly 
 bodies. There are otliers not so natural, called 
 constellations. The ancients (no one knows how 
 ancient they were), with not a little help from 
 the moderns, pictured the celestial sphere all 
 over with figures of men and brutes and other 
 objects, so as to show almost as extensive a men- 
 agerie as was collected in Noah's ark : indeed, 
 the very ark itself is there ; at least Noah's dove, 
 and we may reasonably suppose the ark to be 
 not far off. There are bears and lions and do- 
 mestic animals and birds and fishes and reptiles, 
 interspersed with warriors and nymphs and cen- 
 taurs and flying horses, all dovetailed into each 
 other so as to include within their outlines nearly 
 all the stars. If the leg or arm of a human figure 
 could not be so disposed as to cover certain stars, 
 a snake, under the sonorous name of Draco or 
 Hydra, was slipped in to wind in and out till the 
 crooked feat was accomplished. Very seldom any 
 resemblance can be traced between the constel- 
 
ASPECT. 37 
 
 lations and the various objects after which they 
 are called. But judge for yourselves. Around 
 the North Star as a center, describe a circle that 
 shall just touch the horizon. Within this circle 
 are the Great and Little Bear, an immense Dra- 
 gon, royal Cepheus with a crown on his head and 
 a scepter in his hand, the helmed head and lifted 
 falchion of Perseus, and on her chair, with a palm 
 branch in her hand, queenly Cassiopeia. Would 
 you think it? Around the point directly over- 
 head, describe another circle that shall just touch 
 the other. Within this new circle we have, tow- 
 ards the north, beauteous Andromeda, with fettei's 
 on her dainty hands and feet ; west, Pegasus, the 
 winged horse ; over our heads, Aries the Ram ; 
 next east, a sort of celestial Spain — for there is 
 shaggy Taurus in full career with horns leveled 
 at giant Orion, who, sworded and belted, with a 
 lion-skin in one hand and a club in the other, is 
 just in the act of dealing the monster a rousing 
 blow between the eyes that will undoubtedly make 
 him see stars. Could you have tliought it-.- such 
 dignified personages, such delightful nymphs, such 
 illustrious heroes, such magical creatures, such 
 stirring tourneys and bull fights, all up and down 
 the arches of the sky ! However, these fanciful 
 figures answer a very good purpose for classify- 
 ing and describing the heavenly bodies. They 
 distribute them into celestial nations and em- 
 pires. 
 
38 SECOND LECTURE. 
 
 Provision is made for still further descrip 
 tion of each celestial district, to any degree of 
 minute accuracy that may be desirable. For 
 many purposes, it is suflScient to tell what con- 
 stellation a star is in. If we have occasion to 
 be a little more precise, we can say in what part 
 of the constellation it may be found, as in the 
 neck of Taurus or head of Andromeda. To pro- 
 ^^ide for still greater precision of statement, as- 
 -^ronomers have named the stars in each constel- 
 lation according to their apparent brightness. 
 The brightest is called after the first letter of the 
 Greek alphabet. Alpha ; the next brightest, after 
 the second letter, Beta ; and so on through all the 
 letters. When the Greek alphabet is exhausted, 
 the Roman is used in the same way. If both al- 
 phabets are not sufficient to take account of all 
 the stars, our common numerals are resoi'ted to. 
 Thus we speak of Alpha Leonis, a Virgiuis, 61 
 Cygni. But it is not always enough, in making 
 a map of a country, to draw its boundaries and 
 set down within them the vai'ious cities and towns 
 of all sizes, in something like their relative posi- 
 tions : some geographical purposes require that 
 you state also their longitudes and latitudes; that 
 is to say, tlieir distances due east or west, and 
 their distances due north or south of a given 
 point on the earih. So, for some astronomical 
 purposes, it is not enough to bound a given con- 
 stellation and set down its stars in nearly their 
 
ASPECT. 39 
 
 relative places, with their names. We requ re to 
 know the longitude and latitude of each star. 
 We must know how far it is from a certain 
 groat circle drawn northerly and southerly on 
 the sphere, and how far also from another great 
 circle drawn at right angles to the other. From 
 very remote periods, astronomers have been en 
 gaged ill getting this latter information. Hip- 
 parchus made out a catalogue of nearly all the 
 stars visible to the naked eye at Alexandria, giv- 
 ing the latitude and longitude of each. Herschel, 
 La Lande, Mayer, and others, have constructed 
 similar catalogues, but giving the places of the 
 stars with much greater accuracy. 
 
 Wo have before us a general picture of the 
 celestial sphere, with the more usual names and 
 classifications of the objects that shine upon it. 
 I am now prepared to state what discoveries have 
 been made. What is this seeming immense hol- 
 low globe of the heavens ? People once thought 
 that the appearance was reality — that they were 
 surrounded at a great distance by an immense 
 shell of crystal, to which all the heavenly bodies 
 were fastened. At a later period, most scholars 
 thought there were several of these spheres: each 
 carrying heavenly bodies, and each having a mo- 
 tion peculiar to itself. But now we know that 
 tliere is nothing of the sort above and around 
 us. The celestial sphere is nothing but indefin- 
 itely extended space, made to appear colored at 
 
40 SECOND LECTURE. 
 
 times by the hue, and to appear rounds i always 
 by the shape, of o\ir atmosphere. There is noth. 
 ing solid yonder to ■which the celestial bodies can 
 be attached. They are absolutely hung on noth- 
 ing — though Milton ventures to take poetic 
 license, and hang one orb, at least, by a golden 
 chain. This idea of unsupported heavenly bodies 
 was quite too hard for the remote ancients : they 
 must have spheres, and, not a few of them, an 
 elephant and a tortoise to hold up the earth and 
 heavens. But, finally, it filtered through the ap- 
 prehension? of people that such supporters must 
 themselves need support quite as much as a star ; 
 also, that no one ever saw them, or otherwise 
 credibly knew of their actual existence. So they 
 were quietly dispensed with. And now nothing 
 remains but the infinite space, which we certainly 
 know to exist, and the stars which we certainly 
 know to exist in it. 
 
 Popularly speaking, this great space which en- 
 virons us on all sides, and contains the heavenly 
 bodies, is empty. It is substantially a vacuum. 
 The ancients said that Nature abhors a vacuum : 
 if so, she has plenty of abhorring to do. There 
 is no atmosphere pervading space : we coidd 
 not breathe in its mid-intervals one single mo- 
 ment ; there is nothing tliere that our senses 
 could perceive. As we ascend from the earth, 
 we find the air gradually become thinner ; and La- 
 Place has shown, that, after a few miles, it must 
 
yATURE OF THE CELESTIAL SOSKERT. 41 
 
 cease entirely. Beyond that point, very large 
 solid bodies, though moving with enormous ve- 
 locity, are found to encounter not the smallest 
 perceptible resistance. Their places, as computed 
 on the supposition that thty move in a vacuum, 
 are such as we actually find them. At the same 
 time, there is reason to believe that the vacuum 
 may not be absolutely perfect. Certain facts 
 which have come to light in late years have con- 
 vinced many astronomers that we must allow 
 the existence of an exceedingly dilute form of 
 matter pervading space. It is nothing that we 
 could detect in the ordinary, sensible way : we 
 could not weigh it, nor see it, nor receive sounds 
 through it ; could not feel it, should we strike 
 our hands through it with our utmost force. 
 Such a mere nothing is it. It is only when some 
 very light body goes rushing through it, at the 
 rate of thousands of miles an hour, that its pres- 
 ence becomes sensible in resisting somewhat the 
 motion. 
 
 If we could visit mid-space, it would seem a 
 perfect void, also dreadfully cold and dark and 
 silent. The higher we go into our atmosphere, 
 the colder it becomes. All mountain summits, 
 above a few thousand feet, are covered with per- 
 petual snow. Persons ascending in balloons at 
 last reach a cold that is intolerable. Tliey evi- 
 dently approach the confines of an eternal winter, 
 that, for silence and motionless fierceness, laughs 
 
42 SECOND LECTURE. 
 
 to scorn all that we have of arctic and an- 
 tarctic. 
 
 According to the calculations of Sir John Her 
 schel, we have only to go fifty miles from the 
 earth's surface to reach — 132° Fahrenheit. Could 
 we suddenly set down any moist thing at this 
 point, it would instantly explode like a pistol, 
 though without sound (for mid-space is sound- 
 less as well as matterless), and turn to stone as 
 if iouched by a magician's wand. And if, at thia 
 short distance from the earth and sun, space is so 
 cold, what must it be in those remote vacancies 
 where the sun shows as a mere star ? In thought, 
 we sail away most comfortably among the con- 
 stellations, without furs or overcoat ; and per- 
 haps our fancies make nothing of stopping whole 
 hours in mid-heaven, leaning against the chair 
 of Cassiopeia, or grasping the horns of Taurus, to 
 admire the glory of the trooping stars ; but one 
 real bodily expedition of the sort would forever 
 cure us of such fancies. Perhaps of some others 
 also; for, when our 'houghts go yachting it 
 through space, they aie very apt to take with 
 them, not only our genial parlor temperature, 
 but also our pleasant earthly light and colors 
 But, in point of fact, the starry spaces are awfully 
 dark. Those who visit the higher regions of 
 our atmosphere, by mountains or balloons, tell us 
 that the pleasant blue gradually passes into an 
 intense black. At last, the stars glitter on a 
 
NATUEE OF TEE HEATENLY BODIES. 43 
 
 background of perfect jet. To an observer out 
 in mid-heaven, the whole sphere would seem muf- 
 fled in a horrible pall, save just at the points 
 where the heavenly bodies are. He would have 
 tlie impression of not being able to see an inch 
 before him. He would see sun, moon, and stars 
 all at the same time ; but they would look as if 
 hissing on a sea of ink. The blackness would 
 seem solid enough to be cut with a knife. An 
 Jjgyj)t in tlie sky would seem to him to have com- 
 pletely overrun its Spain, and indeed its whole 
 atlas of celestial empires. And should he try to 
 express his feelings, and to say, " How awful is 
 this blackness ! " — " How glorious are these lu- 
 minaries ! " — no sound, nor specter of a sound, 
 could issue from his shouting lips. 
 
 Such is the " House I live in " of the heavenly 
 bodies. What are the heavenly bodies them- 
 selves — what this sun, this moon, these planets 
 and comets and fixed stars and nebulae ? 
 
 In remotest times, very likely, men thought 
 them distant heavenly torches, or openings 
 of various sizes through the sky into an ocean of 
 glory beyond. In process of time, they came to 
 be very extensively regarded as intelligent beings 
 — gods and goddesses, also human beings raised 
 to the sicies on account of illustrious merit, or, 
 what was not always the same thing, the favor 
 of the divinities. Tlie sun was Apollo, god of 
 fiery arrows ; the moon was Diana, goddess of 
 
44 SECOND LECTURJ6. 
 
 the silver bow ; and so on, iintil the sky wat, one 
 great ParUament House of deities in everlasting 
 session. Worship was paid to the shining crowd ; 
 to them incense rose, hymns were chanted, and 
 victims bled. In civilized countries of modern 
 times, people are far enough from such views of 
 the nature of the heavenly bodies : multitudes do 
 not even trouble themselves to have any views 
 whatever on the subject. They have never put 
 the question to themselves, " What are tliey — 
 those bright lights above us? " Accustomed to the 
 sight from infancy, busied in their digging and 
 buying and selling, it has never occurred to them 
 to be curious as to the nature of those far-oflF 
 luminaries. They are content to have the use 
 of them — to work by the sunlight, to walk by 
 the moonlight, to steer, and perhaps to steal, by 
 the starlight. In this respect, they are inferior to 
 many in the remotest and rudest ages. And yet 
 the question has long been well answered, and 
 the answer is in possession of tens of thousands 
 on all sides of them. What are the heavenly 
 bodies ! Not lamps, not apertures through which 
 glory shines, not personages ; but immense mass- 
 es of unintelligent matter, some self-luminous, 
 and the rest shining by reflected light. It is 
 found that the light coming direcly from a can- 
 dle, or other sell-luminous object, diifers by a cer- 
 tain property from the same light after it has 
 unda-gone reflection. This fact enables us to 
 
NATURE OF THE HEAVENLY BODIES. 45 
 
 ascertain easily that a part of the objects in the 
 sky shine by reflected light, while the rest are 
 self-luminous. The sun, and fixed stars, and 
 nebulaj are found to be self-luminous ; tho 
 moon, planets, comets, and zodiacal light shine 
 only by the light that comes from these. If a 
 man is confronted by what purports to be a 
 ghost, he pronounces it well-authenticated flesh 
 and blood just as soon as he sees that it casts a 
 shadow ; so, just as soon as we find that the 
 heavenly bodies emit and reflect light, we know 
 that tliey are true matter; and, so far as wa 
 have been able to observe this matter, it has the 
 appearance of that which composes our earth. 
 If the moon is looked at through a telescope, we 
 see a rugged surface of mountains and valleys. 
 In regard to the other bodies in the sky, the glass 
 does not serve us as well ; but the telescopic 
 aspect of most of the planets gives none the less 
 decidedly the impression of an earth-like surface. 
 But the heavenly bodies are not only masses of 
 earthy matter : they are masses of immense size. 
 They look small to us, it is true — the sun and 
 moon occupying no larger space in your eye than 
 does the crown of your hat at the distance of a 
 few feet, -and most of the stars showing as mere 
 needle-points. They do look very small, most 
 certainly ; but so the great earth would if we 
 should go very far away from it. The earth is 
 so large that we can travel upoa.it for months 
 
46 SECOND LECTURE. 
 
 and years without crossing our track ; and yet, 
 should we go off into space from it, this immense 
 bulk would gradually lessen on the eye till at 
 last it would appear no larger than tlie smallest 
 star. Though the dog bays at the moon as if 
 it were within hearing, though the savage thinks 
 that he could almost bring down the sun with his 
 arrow, though so intelligent a person as Virgil 
 tells us of a personage who brushed the stars 
 with his sublime head, yet it is very easily dis- 
 covered that the nearest of the heavenly bodies 
 must be thousands and thousands of miles away. 
 This is proved by the fact that only a few of them 
 appear to change their places on the sky at all in 
 consequence of any change, however great, in our 
 position, and these few only in a very slight de- 
 gree. A few steps will change the place on the 
 heavens of some near objects a whole quadrant : 
 but yonder mountain, twenty miles away on the 
 horizon, would scarcely seem to stir should you 
 walk an hour perpendicular to the line of its 
 direction. Now, as to the heavenly bodies, it is 
 found that one might travel thousands of miles 
 on the earth, without shifting the apparent place 
 of most of them on the vault in the slightest — 
 without shifting the apparent place of any of 
 them, save by a very trifling amount. So it is 
 plain that they must be at a very great distance 
 from us. Why, if a body were displaced oii the 
 sky to the amcunt of the moon's apparent diamo 
 
DISPOSITION OF THE HEaVENLT BODIES. 47 
 
 ter, by our going a thousand miles on tlio eartii, 
 it must be a hundred thousand miles away ; and 
 there is not a body in the whole heaven that would 
 undergo any thing like that displacement were 
 we to remove such a distance. So we must con- 
 clude thai all the heavenly bodies are immensely 
 remote from us, and so of immense magnitude. 
 
 How are these great masses of matter actually 
 disposed in space ? According to some principle of 
 orderly arrangement, we should presume. The Su- 
 preme Cause is no friend to confusion. Still, what 
 the celestial order really is, is not easily discover- 
 able. There is, to first view, no system wliatever 
 iu the distribution of large portions of the heavenly 
 bodies.. It is as if the Genius of disorder had sowu 
 them. In other parts, there are appearances of sys- 
 tematic arrangement ; but then the question arises, 
 Is the apparent arrangement the real one ? Can 
 I say that two stars are actually near each other 
 in space, because they appear near each other ou • 
 the sky ; or that other two stars are remote from 
 each other, because one appears in the east, while 
 the other is seen in the west ? Not as long as I 
 find, that, by putting myself between two trees 
 only ten feet apart, I project them on directly o\y- 
 posite points of the heavens ; not as long as I 
 fine that the tree which is only ten feet from me, 
 falls on the sky at the same point with yonder 
 mountain which is twenty miles away. So there 
 was no small difficulty in ascertaining the real 
 
48 SECOND LECTURE. 
 
 plan among; the celestial bodies; and, in fact, it 
 was not ascertained till after long ages of obser- 
 vation and study. But persuaded, as thinking 
 men were, that there must be system everywhere 
 within the domains of the Supreme Wisdom ; 
 well aware, as most of them were, that apparent 
 confusion, from unfavorable points of view, often 
 covers a system of exactest order — they did not 
 give over to inquire. At last they found the fa- 
 vorable stand-point which laid open the wliole 
 mystery of the celestial arrangements. The lamps 
 of a city, as one approaches it some evening, ap- 
 pear a mere chaos of bright points ; and yet that 
 city is Philadelphia, where streets cut streets des- 
 perately at riglit angles and all the lights gleam 
 on the sides of perfect squares. And they seem 
 so to the same man, when, turned aeronaut, his 
 balloon has shot him up thousands of feet over the 
 jentro of the city. He has now found the true 
 point of view. An army engaged in battle seems 
 an inextricable maze to a looker-on from the same 
 plain — men projected on and crossing men till all 
 individual outlines are lost — and yet here are all 
 the parts of a host, from corps to companies, each 
 under its own leader, in unbroken array and ad- 
 mirable discipline, pressing forward on victory to 
 the rhythm of exulting trumpet and drum as only 
 Napoleon and Austerlitz know how to pour them 
 along. And it seems so to the same man just as 
 wjon as, arrived at yonder lofty hill-top, he mingles 
 
DISPOSITION OF THE HEAYENLT BODIES. 49 
 
 with the Emperor's staff and looks down on the 
 whole scene. He has now the true point of view. 
 So, at last, astronomers have found their true point 
 of view. They look from over the beaming citj. 
 They gaze down on the rushing army. And now 
 the whole celestial economy of arrangement stands 
 unfolded. What is it? The system of arrange- 
 ment is this : — 
 
 1. A body, not self-luminous, has one or more 
 like bodies revolving around it. There are many 
 such systems, which we will call satellite -sys- 
 tems. 
 
 2. Several of these primary systems form a still 
 larger neighborliood, and revolve about a self- 
 luminous body, like the sun. There are many 
 such systems, which we will call planet-systems. 
 
 3. Several of these planet-systems form a still 
 larger neighborliood, and revolve aboiit a com- 
 mon point within it. There are many such sys- 
 tems, which we will call sun-systems. 
 
 4. Several of these sun-systems form a neigh- 
 borliood still larger, and circulate about one point 
 within it. There are many such systems, which 
 we will call group-systems. 
 
 5. Several of these group-systems unite in a 
 still larger neighborhood, and in revolving about 
 a common point within it. There are many such 
 systems, whicli we will call cluster-systems. 
 
 6. Several of these cluster-systems combine into 
 ai., rther system still grander, whose centre of rao- 
 
 4 
 
60 SECOND LECTURE. 
 
 tion ia also common to all its members. There 
 are many such systems, which we will call ne- 
 bula-systems. 
 
 7. Finally, all the systems of space, composing 
 one great neighborhood that embraces all other 
 neighborhoods, revolve around one motion-centre 
 of the creation. This we will call the universe- 
 system. 
 
 You see that it is a wheel within a wheel. Cer- 
 tainly, the ' height of that last, all-embracing wheel 
 is exceeding dreadful.' Each order of system? 
 includes all the orders below it; and each pri- 
 mary system has at least as many revolutions as 
 there are different orders. It is very like the ar- 
 rangement of human society. First, we have the 
 elementary group of the family, revolving about 
 the home ; then several families, making a town, 
 revolving about its central village ; then several 
 towns, making a county, revolving about its county 
 seat; then several counties, making a State, revolv- 
 ing about its State capital ; then several States, 
 making a nation, revolving about the national 
 metropolis ; then several nations, making a world, 
 revolving about the political centre of humanity^ 
 which once was Rome, which now is — shall we 
 say London or Paris or St. Petersburg or Wash- 
 ington ? 
 
 Take another illustration ; for it is important 
 to have this matter familiar. In these warlike 
 times, i^. is hard to resist dealing in warlike ill us 
 
DISPOSITION OF THE HEAVENLY BODIES. 51 
 
 (.rations : oesides, it may fairly be presumed thai 
 tliey will be understood witli special facility. Ima- 
 gine the encampment of a great army. On enter- 
 ing it, the order in which the tents are disposed 
 docs not readily appear. But, on examination, 
 we find that there is a very rigid system of ar- 
 rangement, and that this is it, First, the camp of 
 the company about its captain, separated by a 
 plain interval from all other company -camps. 
 Next, expanding around this, is the camp of a 
 regiment about its colonel, separated by a still 
 more marked interval from all other regiment- 
 camps. Then, expanding around the regiment, 
 is the camp of the brigade about its brigadier, 
 separated by an interval still more decided from 
 all other brigade-camps. Further, expanding 
 around the brigade, is the camp of the division or 
 corps about its major-general, separated by an 
 interval still broader from all other corps-camps. 
 Lastly, expanding around the corps, is the whole 
 encampment of tlie grand army about its general 
 or marshal or monarch. See here a picture of 
 the great encampment of the sky! I say " en- 
 campment ; " for, to one watching the sky for a 
 short time, every thing seems stationary. But, 
 really, the sky is not a camp. It is rather a glo- 
 rious parade ground, full of motion, full of or- 
 derly, systematized motion — a flaming bannered 
 field on which the various celestial powers are 
 going through their various related evolutions 
 
52 SECOND LECTURE. 
 
 under their respective leaders — companies of 
 stars manoenvering under star-captains ; regi- 
 ments, brigades, divisions, whole hosts of stars, 
 mauoeuvering under star- chiefs of as many as- 
 cending grades of rank and splendor. Hail, liost 
 of lieaven ! Hail, glittering rank and file ! Hail, 
 gorgeous commanders in golden mail, and sliin- 
 ing far o'er the field ! Veterans all, though un- 
 scarred, as far as we can now see, — all liail ! for, 
 as we shall soon find, sucli brilliant equipment, 
 sucli skillful commanding, such perfect obeying, 
 such complicate wheeling on exactest time and 
 admirable step, was never seen in any terrestrial 
 army. 
 
 But you would like the evidence tliat sucli is 
 the arrangement of the heavenly bodies. It is 
 observed that every thing on the earth is heavy. 
 We never take up any thing about the earth, 
 whether great or small, whether this sort of mat- 
 ter or that, without finding it to have more or less 
 weight. That is to say, the earth attracts it, or it 
 attracts the eairth, or, perliaps, botli mutually at- 
 tract. Newton, on thinking the matter over (we 
 know how it happened, under the famous apple 
 tree, and how, as the apple came down,tlie thought 
 of the philosopher went up), concluded to adopt 
 the last view, and to suppose that an attractive 
 force, developing itself equally in all directions, 
 and extending to all distances, belongs to every 
 atom of matter, terrestrial and celestial. On the 
 
DISPOSITION OF THE BEAYENLY BODIES. 53 
 
 basis of this assumption, lie was able to prove, 
 mathematically, that every body must attract 
 every other body with a force proportioned di- 
 rectly to its own quantity of matter, and inverse- 
 ly to the square of the distance between tlie bodies. 
 If you double the amount of matter in a body, 
 you double its attractive force ; if you double its 
 distance from another body, you quarter its at- 
 tractive force on that body. With this law, he 
 proceeded to demonstrate, by the most rigorous 
 of mathematics, that, if two or more free bodies 
 in space form a neighborhood, they must instant- 
 ly rush together, or they must all revolve about 
 their common centre of gravity ; meaning, by 
 this common centre, that point among them 
 where their several attractions just balance each 
 other, so that a particle at that point would have 
 no tendency to move. The fact that such bodies 
 are found apart, after an existence of thousands 
 of years, will then be proof that they are all re- 
 volving about their common centre of gravity. 
 Hence, if several celestial bodies are found con- 
 tiguous, as compared with others, we must infer 
 that they form a system of revolution by them- 
 selves ; if several of these minor systems are 
 found contiguous, as compared with others, we 
 must infer that they compose a still larger revolv- 
 ing system ; and so on. Or, if we find certain 
 heavenly bodies forming together a system of 
 revolution, we must infer their relative contiguity 
 
64 SECOND LECTURE. 
 
 to eajli other in space. We need only to estab 
 lisli, by observation, the actual existence of either 
 such celestial neighborhoods as bare beeit de- 
 scribed, or such related motions as have been 
 described, in order to establish the existence of 
 both. Now we can always do the one or the 
 other. 
 
 But one suggests, " There is an assumption at 
 the bottom of this argument. Newton assumed 
 that attractive power, flowing out equally in all 
 directions and at all distances, belongs to every 
 particle of matter, celestial as well as terrestrial. 
 Where is the proof that this assumption is cor- 
 rect?" I answer, that we have no other proof 
 than is involved in the fact, that, after very long 
 trial, the results flowing from the assumption have 
 not been contradicted by any known fact, while 
 they wonderfully harmonize with and explain 
 all the leading astronomical phenomena. A man 
 computes, by the law of gravity, just where in the 
 sky a planet or comet ought to be found at a given 
 time ; and, when the moment comes, we look at 
 the spot, and lo ! the body is there. Feats of this 
 kind have been so numerous ; the law of gravity 
 has been tried for the explanation of sucli hosts 
 of astronomical facts, and with such invariable 
 and brilliant success — that astronomers have at 
 last come to rely on its truth with unbounded 
 confidence. And they are philosophically obliged 
 to do so. The original assumption stands proved 
 
DISPOSITION OF TSE HMA7ENLY BODIES. 55 
 
 by an overwhelming experience. It lus been 
 gradually established by an immense induction of 
 particulars. And now men can not refuse confi- 
 dence to it without rejecting that Baconian phil- 
 osophy which lies at the foundation of all our 
 modern science. 
 
 That you may still better realize the weight of 
 this proof, let us suppose a case. Imagine an im- 
 mense castle, with every gate and door about' it 
 locked. You are informed, on authority that you 
 can not question, that there once existed a single 
 key which could open every room and closet and 
 drawer of the edifice ; but, alas ! it has long been 
 lost. One day, in walking about the premises, 
 you stumble on something that looks very much 
 like a key, an ancient key, a key that on pressure 
 of a spring can be made to take almost any shape. 
 Well, you can not help your thoughts : they do at 
 once suggest to you that, perliaps, you have been 
 fortunate enough to fall in with the long-lost won- 
 derful bit of iron that can let you into every part 
 of the sealed castle. Still you could be surer — 
 a great deal surer ; in fact, you have very serious 
 fears lest, on trial, your key shall prove a mere 
 pretender. Tremblingly you try it on the court- 
 yard gate : after some trouble, the gate flies open. 
 Your courage rises. Eagerly you approach the 
 main entrance, and try that : after a while, that 
 too gives way, and you enter the castle pi'oper. 
 You are now still more sanguine tha* your key is 
 
56 SECOND LECTURE. 
 
 the true one. Still, it may fail at the very next 
 trial. So you proceed to question another door, 
 and another, and still another ; with continually 
 augmenting confidence as success follows success. 
 You find very great difficulty at times, both in 
 adapting and turning the key ; you have to de 
 lay before some doors a long time; but, in nearly 
 every case, success comes at last. And now, on 
 counting up, you find that your key has opened 
 for you all the main rooms in the castle ; in fact, 
 all that you have seriously and patiently tried — 
 doors of oak, doors of iron, doors with locks of 
 the strangest and most intricate pattern — it has 
 conquered them all. At length you are perfectly 
 satisfied. You would not give the snap of your 
 finger for any additional evidence that your key 
 is the genuine. Should some one come to you 
 and say, " My dear sir, are you not a little too 
 credulous — do you not give your faith in this case 
 a little too easily — as for me, I am not quite 
 sure that there is no mistake, am afraid you 
 have not the true key yet I " — you would be 
 tempted to reply, " My very wise sir, when did 
 you escape from the asylum?" Such a man is 
 beyond argument. 
 
 Now, this is just' the case that has been pre- 
 sented to astronomers. Here is the immense sky- 
 castle, that, from the beginning, has been fast 
 locked up from men — a huge, inaccessible, inhos- 
 pitable warrior-monastery. Men knew there must 
 
DISPOSITION' OF THE HEAVENLY BODIES. 57 
 
 be some clew to those mysterious cloisters — soma 
 key or keys that could match the wards of those 
 innumerable locks. Where was it? None knew. 
 It had never been seen from the beginning. Did 
 the architect, as soon as ihe magnificent struc- 
 ture was finished and carefully locked up, like 
 the God of the "Night Thoughts," fling the key 
 from the 'starred battlements far into the pitchy 
 and bottomless abyss of space ? But no, this 
 could not be ; and so men went to roaming about 
 the purlieus of the heavens, looking for that lost 
 Pleiad of a key ; and oh, how often, mean- 
 while, did they throw longing, not to say despair- 
 ing, glances at that stern, unrelaxing sky where 
 such treasures of science were keeping eternal 
 quarantine ! At last Newton, one of these seek- 
 ers, stumbled on the law of gravity. Is this the 
 key ? It has the look of one ; for it is seen at 
 once to harmonize and explain many terrestrial 
 facts. It looks like a multiple key ; for it is won- 
 derful what a variety of great theorems may be 
 drawn out of this same law of gravity. As it 
 were, you have but to press a spring to make it 
 assume"^ n almost endless variety of forms. So 
 Newton's heart fluttered with hope — mere hope. 
 Tremblingly he put his key to the test. "What 
 was his joy to hear that first ponderous bolt fall 
 back? Success followed success; courage swelled 
 on courage. Newton himself lived long enough 
 to unlock several of the main gates of the heavens 
 
58 SECOND LECTURE. 
 
 with his own bands. Encouraged by his success, 
 many other strong and skillful hands grasped the 
 victorious law of gravity and essayed other en- 
 trances, — sometimes succeeding easily, and some- 
 times with no small difficulty and delay, but nearly 
 always succeeding. So it has gone on up to the 
 present time — door after door opening — doors 
 of oak, doors of iron, doors of brass, doors of gold, 
 doors of the strongest look and lock-pattern, doors 
 by scores and hundreds — they have gone on yield- 
 ing, one after another, to the wondrous key, till 
 now we may speak of the Open Heavens. " What, 
 Earth and Moon open ! Have you unlocked their 
 hundred-gated theory?" Yes: not a consider- 
 able gate of that Thebes but has described a com- 
 plete semi-circle. "What, Sun and Planets open ! 
 Has your key of gravity set their thousand gates 
 a swinging ? " Yes, swinging to their full capa- 
 city — thanks to the dexterous and patient hand- 
 ling of wedded observation and geometry. '■ What, 
 Star Groups open ! They have a myriad of strange 
 and ponderous gates ; and have even these yield- 
 ed? " Ask the Herschels and Souths and Bessels. 
 Yes : even those wards are not too intricate to be 
 traversed by the victorious tenons and tongues of 
 the law of gravity ; and now, if you choose, you 
 can step over the golden threshold of many a 
 planetary sun, and see for yourselves the marvels 
 within. " What, Clusters open ! What Nebulas 
 open I And now I say, Hail to the law of grav- 
 
DISPOSITION OF THE HEAVENLY BODIES. 59 
 
 it/, if' it can fling open to tlie gazing science of 
 men tliose million-gated and doubly-locked re- 
 gions ! Can it, indeed, do that topmost feat ? " 
 Ask the Struves and Peters and Argelanders 
 and Maedlers ; and have not we ourselves heard, 
 with our own ears, the recoil -thunder of some 
 bolts under the strong hands of these giants? 
 Yes : I have myself seen some of those burnished 
 gates shot back to the very wall, and the philoso- 
 phers who accomplished the feat yet standing, 
 key in hand, with flushed faces, gazing into the 
 atidience chamber and royal pavilions of that 
 highest heaven of matter. God bless the key ! 
 
 It is GENUINE. 
 
Ill 
 
 SATELLITE SYSTEMS. 
 
in. Satellite Systems. 
 
 Example — Earth and Moon. 
 
 1. DHJRNAL REVOLUTIONS 68 
 
 -.. MUTUAL DISTANCE . 7" 
 
 3. SHAPES AND SIZES 7> 
 
 4 MUTUAL GRAVITATIONS 77 
 
 5 MASSES AND DENSITIES 8i 
 
 6. ORBITS &4 
 
 7 MUTUAL ASPECTS «» 
 
THIRD LECTURE. 
 
 SATELLITE SYSTEMS. 
 
 IN the last lecture I stated how the Heavenly 
 Bodies are arranged in space. They are dis- 
 tributed into neighborhood systems of at least 
 seven orders. These are tlie Satellite Systems, 
 the Planet Systems, the Sun Systems, the 
 Group Systems, the Cluster Systems, the Nebula 
 Systems, the Universe System. Each order of 
 systems includes all the orders below it ; and the 
 members of each system revolve about its center 
 of gravity. I will now proceed to prove and in- 
 terpret these systems in the order named. 
 
 A Satellite System consists of two or more con- 
 tiguous heavenly bodies which are not self-lumi- 
 nous, and wliich revolve about their common cen- 
 ter of gravity. There are many such systems ; but 
 the most accessible and useful example, which I 
 am able to present is that of the earth and moon. 
 
 It was long before men were prepared to reckon 
 the earth among the heavenly bodies. It seemed 
 at first view so d'fferent from them — so unshin- 
 
 63 
 
64 THIRD LECTURE. 
 
 ing, SO like an indefinitely extended plain with 
 solid foundations of endless depth. But fuitlier 
 thought corrected this mistake. Whence come 
 the sun and stars as they rise in the east, and 
 whither go they as they set in the west I It is 
 clear that they pass, on the average, twelve houis 
 out of the twenty-four under the eartli. So tlie 
 earth is really a body of finite though great ex- 
 tent, lying loose in space — space under it, space 
 over it, space all around it. Of course it must 
 be so. As to the notion that the earth does not 
 shine like the distant heavenly bodies, it is quite 
 without foundation. Our world does not appear 
 as brilliant, simply because we do not see it from 
 out of the midst of the night as we do the moon 
 and stars. They do not appear bright by day 
 ^ for the most part do not appear at all — it is 
 only when they are in the light while we are in 
 the dark, that they seem to us to shine. If, some 
 evening, when your room is brilliantly liglited, 
 you take your stand in the middle of it and try 
 to look out into the street, you can see nothing ; 
 but persons passing can see you and all your 
 movements. To them you shine. And could 
 we take ourselves away into that pitchy space 
 that expands around us, till the earth should ap- 
 pear no larger than the moon, it would appear as 
 bright as that luminary. 
 
 The earth shines like a star. It shines, i.ow- 
 ever, only b; reflction. Just as soon as the 
 
SATELLITE SYSTEMS. 65 
 
 light of the other heavenly bodies is shut off from 
 any part of its surface that part becomes dark. 
 Ill this respect the moon is like it. We notice 
 that it is only that side of the moon that is toward 
 the sun that is bright ; and so it happens that for 
 the greater part of the time the great light that 
 rules the night appears to us under a broken 
 circle. Also, the fact already referred to, viz., 
 that reflected light has a different property from 
 that which comes to us directly, enables us to 
 pronounce the moon a mere reflector. So neither 
 the earth nor moon is self-luminous. They fulfill 
 the first condition of a satellite system. 
 
 Do they fulfill the second condition ? Are they 
 contiguous to each other as compared with other 
 heavenly bodies ? If so, the law of gravity proves 
 that they both revolve about their common center 
 of gravity. Now this matter of neighborhood is 
 easily settled. Ask whether any other heavenly 
 body shifts its place on the sky any thing like as 
 much as the moon, in consequence of a given 
 change in our place. By going four thousand 
 miles on the earth we change the moon's place 
 by about twice its apparent diameter. No other 
 body in the heavens experiences the hundredth 
 part of this change. The earth and moon, there- 
 fore, form a neighborhood. Hence they must re- 
 volve about their center of gravity. And being 
 both heavenly bodies, shining by reflected light, 
 they mak« a satellite system. 
 
66 THIIiD LECTURE. 
 
 Now let us notice the chief facts which have 
 been ascertained concerning this primary system. 
 And, first, each member is found to turn around 
 0)1 itself. Wiiat makes the stars rise in the cast, 
 move uniformly across tlie sky in parallel lines 
 without disturbance of their mutual positions, set 
 in the west, and, at the end of twenty-four hours, 
 appear in the east again ? Tlie most simple ex- 
 planation is that the earth turns around on one 
 of its diameters from west to east, with a uniform 
 motion, once in twenty-four hours, while wc are 
 held to its surface by tlie attraction of gravitation. 
 Indeed no other explanation is admissible. Tlie 
 idea that we are the center of creation, and that 
 all the host of heaven, at as many different and 
 immense distances, have their motions so adjusted 
 to each other as to make the circuit of the earth 
 in exactly the same time, is altogetlier too cum- 
 brous to suit either philosophers or practical men. 
 Besides, such a system is irreconcilable with the 
 law of gravity. If it is in the nature of things 
 possible that the earth is the center of the uni- 
 verse, it is not possible that all the heavenly bodies 
 should so fly in the face of gravity as to revolve 
 about this center — or rather au axis passing 
 tlirougli it — in parallel circles, in precisely the 
 same time or in any times. So we are bound to 
 conclude that tiie earth moves about an axis 
 within itself, and thus gives us the beneficent al- 
 ternation of day and night. 
 
DIURNAL nEVOLUTIONS. 67 
 
 But why are we not sensible of this motion ? 
 How iij it possible that we can be whirled around 
 so fast as the rotation of so large a body implies, 
 and be a good part of the time, as people say, 
 standing on our lieads, and yet remain entirely 
 uninformed by our senses of what is going on ? 
 Why, every thing about us shares our motion ; 
 even the atmosphere goes aroxind as fast as wo 
 do; there is no jolt nor jar — how should we 
 know, except by seeing objects moving by us, 
 that we are in motion, any more than does the 
 man engaged in tlie fairest summer sailing ? 
 Were he to shut liis eyes, there is nothing in his 
 sensations to sliow him that he is gliding along : 
 were he to open them only on the yacht and its 
 furnishings he would seem at rest : he must look 
 away to the sliore, and see the trees and houses 
 slipping by. So we are rolled around the world 
 so smoothly and equably that we have to look 
 away to the stars to know that we are rolling at 
 all. Noiselessly, without hitches, without tremors 
 — it is the perfection of lubricated and luxurious 
 progress ! The softest, downiest, springiest char- 
 iot that ever went rolling over its McAdam, with 
 a prince inside, is an earthquake compared with 
 this natural omnibus in which we have taken 
 passage. As to the prejudice which some persons 
 feel against having their heads point in diametri- 
 cally opposite directions at different hours of the 
 day, I do not know what can be done for theiv 
 
68 THIRD LECTURE. 
 
 relict", unless it be to assure them that they shall 
 have th3 privilege, during their daily somer- 
 saults, of always pressing their feet against the 
 ground and holding their heads aloft in the 
 
 air. 
 
 A single evening's watching of the stars is 
 enough to show us that the axis of the earth 
 points nearly at the North Star ; that the motion 
 around it is easterly ; that it is a perfectly uni- 
 form motion, just the same distance being made 
 in the same time. So much a single evening can 
 show us. But it would take a great many even- 
 ings to show us another striking fact, none the 
 less sure, viz., that the axial revolution is always 
 accomplished in exactly the same time. It is on 
 evidence that our day has not varied the hun- 
 dredth part of a second for two thousand years. 
 Tiiere lias not been the slightest change within the 
 long sweep of history and tradition. We must, 
 however, allow one or two exceptions. " Sun 
 stand thou still on Gibeon, and thou Moon in the 
 valley of Ajalon ! So the sun stood still in the 
 midst of heaven, and hasted not to go down about 
 a whole day." Tiie Chinese have a tradition that 
 there was once a day of double the usual length. 
 And the Greeks have a fable that may refer to 
 the same tiling — that the son of the Sun once 
 persuaded his father to allow him to drive his 
 fiery chariot for a day. The result was that such 
 another Phaetonizing never took place. The met- 
 
DIURNAL REVOLUTIONS. 69 
 
 tlesome steeds ran away with the youth ; wan- 
 dered up and down the sky, settuig every thing 
 in a blaze ; and did not reach the gates of the 
 west — how could they — till a long time after 
 they were due. So there has been a day of ex- 
 traordinary length. The Bible-miracle, however, 
 may have consisted, not in suspending the mo- 
 tion of the earth on its axis, but in simply bend- 
 ing the rays of liglit from the sun and moon so 
 as to continue the illumination, apparently from 
 the same points of the sky, long after the bodies 
 themselves had passed at their usnal pace below 
 the horizon. Certainly, one or two miraclef 
 aside, the length of our day has never changed 
 by the breadth of a hair: the earth wheels about 
 on its axis now in just the same period as at the 
 creation. So we have a beautiful unit of time to 
 carry along with us in our terrestrial journeys, 
 though altogether too small for journeys astro- 
 nomical. 
 
 On looking at the moon, to find whether it also 
 turns around on itself, first appearances are 
 against it. Bring a telescope to bear on its face. 
 We can see many striking objects, but no consid- 
 erable movement among them. In case of a ro- 
 tation we ought to see all such objects moving 
 across the disc in parallel lines. But, instead of 
 tills, we find them substantially stationary. 
 Strange to say, this very fact, which at first view 
 seems conclusive against a rotation, is the very 
 
70 THIRD LECTURE. 
 
 fact which establishes it. For, on second thought, 
 you perceive that in case tlie moon docs not turn 
 on itself, whether we move around it or it moves 
 around us, we ought in the course of a revolution 
 to see it on different sides. The fact that we see 
 but one side can only be accounted for by suppo- 
 sing that tlie body turns around on one of its own 
 diameters, just as fast as the other revolution is 
 made, in tlie same direction and nearly in the 
 same plane. We shall soon see that this revolu- 
 tion consumes about twenty-seven days. This, 
 then, is the time in which the moon turns com- 
 pletely around on its axis. This is the moon's 
 day. Its day and month are of tlie same length. 
 I have said that the moon is greatly more 
 displaced on the sky by a change in our place on 
 the earth than is any other heavenly body. 
 Hence I inferred that it must be greatly nearer 
 to us. But that is not saying that it is very near ; 
 indeed, it is not saying bat that it is a matter 
 of some millions of miles away. The fact is, that, 
 though a neighbor, the moon is a very remote 
 neighbor ; at least, according to such standards of 
 distance as we use in our every-day affairs. But 
 we must hasten to enlarge our common units 
 both of space and time. Astronomical systems, 
 we sliall find, are laid out on a different scale 
 from the neighborhoods of this world ; and miles 
 and days make but a sorry figure in attempting 
 to deal with Uie smallest of the mighty parishes 
 
DISTANCE BETWEEN THE TWO BODIES. 71 
 
 of the sky. The moon is 240,000 miles away. 
 And this is a very close astronomical neighbor- 
 hood ; though hardly close enough to enable us 
 to act the part of the good Samaritan to our 
 neighbor, in case it should fall among thieves ; 
 though hardly putting it within visiting distance, 
 except for our thoughts, which have both the 
 tasle and the faculty for riding on beams of light 
 and the Pegasus of poets. 1 say 240,000 miles, 
 on the average, and in round numbers. One 
 French astronomer. La Lande, goes to Berlin, in 
 Prussia ; another, La Caille, goes to the Cape of 
 Good Hope. One marks where he pi'ojocts the 
 inoon on the sky at a given moment; the other 
 where he projects it at the same. Tiiey compare 
 notes. Difference between the two projections 
 found to be so many minutes and seconds. How 
 far apart are the two stations ? So many degrees 
 of latitude, and so many miles in a straight line. 
 Nothing more necessary than to sit down, and by 
 a simple calculation in triangles which any child 
 well advanced in his arithmetic can perform, find 
 the distance of the moon from, the earth's center. 
 The exact mean distance is found to be 238,545 
 miles. 
 
 Now let us turn our attention to the shapes 
 and sizes of the members of this satellite system. 
 And, first, each member has been found to be a 
 round body, slightly flattened on two opposite 
 sides. A rubber ball slightly compressed between 
 
72 THIRD LECTURE. 
 
 your two palms will represent the figui-e. How 
 round the sky looks ! Whoever has been at sea 
 has noticed that the topmasts of ship? are seen 
 first, from whatever quarter they may come. 
 Look at the drops of rain ; the beads of dew with 
 which the spider-tliread is strung, or which start 
 from the brows of labor and terror ; the round 
 shot, which, when a moment ago they left the top 
 of the sliot-tower, were one irregular mass of 
 molten metal. Newton has proved mathemati- 
 cally, that the particles of a body, if free to move 
 under the influence of gravity, must always ar- 
 range themselves in a globular shape. Now ge- 
 ologists tell us that the particles which compose 
 the earth were once in this free state ; that far 
 back, before man's day, the entire solid, rocky 
 world was in a state of fusion. We should there- 
 fore expect to find it of a rounded figure. More 
 than this. The eartli revolves on an axis. Tlie 
 necessary effect of this rotation on a fluid mass 
 would be to draw it in at the extremities of the 
 axis — the poles so called ; and puff it out midway 
 between these points — that is to say, at the equa- 
 tor. But we are not left to this reasoning. 
 Have not men sailed around the world by sailing 
 always in one general direction, and without 
 being sensible of any abrupt change of level ? It 
 has been proved that the attraction of a round 
 body on objects external to it is as if all its atoms 
 were cj ncentrated into one at its center. This 
 
SMAPES AND SIZES OF TEE TWO BODIES. 73 
 
 being so, if one ■would be nearer the center of the 
 earth when at its pole than when at its equator, 
 bodies ought to fa;ll more rapidly as we pass from 
 the one toward the other. They are found to 
 do so. A pendulum descends with increasing 
 speed as we increase our latitude ; and it has 
 been found that the rate of increase in the motion 
 is such that the pole must be nearer the center of 
 the earth than the equator is, by a six-hundredth 
 of an equatorial diameter. 
 
 Now the moon is just another such body — 
 rounded, but not a perfect globe. At the full, its 
 disc appears as a complete circle ; and its apparent 
 shape at other times — ^_as crescent, half-moon, gib- 
 bous — can only be accounted for on the supposi- 
 tion that it exposes a globular surface to the rays 
 of the sun. And, as it revolves about one of its 
 own diameters, we conclude from analogy as well 
 as from the demonstrated tendency of the atoms 
 of all rotating bodies, that it is slightly flattened 
 at the poles. 
 
 Almost every one has himself moved about on 
 the earth enough to satisfy him that it is a very 
 large body. The man who has sailed around it, 
 and at the end of his two or three years of voy- 
 age finds himself where he started, does not need 
 to consult his log-book to know that its circumfer- 
 ence must be some thousands of miles. But 
 this knowledge is far too vague. So we will 
 make a still further approximation. Find a level 
 
74 THIRD LECTURE. 
 
 region, and then measure due north or south on 
 it till you have changed your latitude one degree. 
 This measure multiplied by three hundred and 
 sixty gives you the true circumference of the 
 earth, supposing that circumference to be strictly 
 circular. The result is about twenty-five thou- 
 sand miles. This is a close approximation ; for, 
 after all, the earth differs but very little from 
 a perfect sphere. Still astronomers are not con- 
 tent. They know the body is not an exact 
 sphere. They have a sort of constitutional weak- 
 ness for the last degree of accuracy — tliey must 
 hunt down, if possible, tlie ten-thousandth part 
 of a mile in favor of both equatorial and po- 
 lar diameter. And, indeed, it was a matter of 
 such great practical consequence to know these 
 elements with minute precision that Governments 
 stepped in with their vast resources to help mea- 
 sure them. Coalitions in behalf of the balance 
 of power became, for the time, coalitions in behalf 
 of astronomy. For the time, jealous and hostile 
 powers resolved themselves into a Committee of 
 the Whole on the diameter of the earth. Nations 
 took stock in degrees of latitude as people lately 
 did in petroleum. " Select your men and instru- 
 ments," said some six or eight Governments to 
 men of science, " and we will pay expenses." So 
 the work was put into choicest hands ; the choicest 
 instruments were gathered ; and the illustrious 
 laborers bent themselves to their task with the 
 
SHAPES AND SIZES OF THE TWO BODIES. 76 
 
 determination to spare neither time, nor pains, 
 nor expense, to secure the most reliable results. 
 Their object was the same as in the case just sup- 
 posed. It was to measure lines running due 
 north or south on the earth — only they would 
 measure very long lines, very many of them, and 
 in as widely differing latitudes as possible. Thus 
 they would get a choice average length of a de- 
 gree of latitude, and also settle with great preci- 
 sion its rate of increase as we go from the equator 
 toward the poles. But it is hard to find level dis- 
 tricts of great length on due north and south 
 lines. So they determined to follow the level re- 
 gions in whatever direction they ran, and indeed, 
 on occasion, forsake them altogether ; and after- 
 ward reduce their zigzag measurements to the 
 meridian and sea-level, by means of triangles and 
 levels. And so they did. They wove a network 
 of triangles across large tracts of country in vari- 
 ous parts of the world. They went stooping 
 along the dead plains, chain in hand, for their 
 base lines ; they went spying from hill-top to hill- 
 top, and from beacon to beacon, with their theod- 
 olites and circles — as our own Coast Survey 
 Commission were seen dohig in this neighborhood 
 some years ago, and as they have been doing on 
 other parts of our mighty coast as fast as the 
 mighty war would suffer them. International 
 triangles united countries as international rail- 
 roads do now. Let France hold up this angle, 
 
76 THIRD LECTURE. 
 
 Spain that, Italy the other ! No climate was too 
 hot, none too cold, for these zealous workers. Trig- 
 onometries could stand any climate — why should 
 not Clairaut and Godin ? So forward, ye pil- 
 grim geometers ! Spread out your triangles 
 along the plains ! Hang them from the tops of 
 mountains ! Float them along the seas ! Stretch 
 them across the sands of the desert! Shadow 
 tlieul with jungles and palms, and blister them 
 with vertical suns ! Anchor them to icebergs, and 
 bury them in eternal snows ! And so they hardi- 
 ly and audaciously did. A line of 16° of latitude 
 was measured in India, of 12° in France, of 4° in 
 England, of 8° in Russia, of 3° in Peru, of 2° in 
 Italy, of 1° each in Sweden, Lapland, Africa, Unit- 
 ed States — indeed, twenty independent measure- 
 ments in all. The results obtained from a com- 
 bination of these were 7,925.648 miles for the 
 equatorial diameter, and 7,899.170 for the polar. 
 The old magicians drew circles ; these new ma- 
 gicians drew triangles. The former were sup- 
 posed to get wondrous results out of their figures, 
 drawn with many a muttered hard word and 
 strange gesture — what will these philosophers 
 get with their words as liard, and pointings as 
 mysterious, and figures as imcouth ? Nothing, 
 my friend, nothing but the diameter of the earth 
 in good British statute miles and thousandths of 
 a mile — which, however, happens to be worth 
 more than all the work done by all the magicians, 
 
MUTUAL QRAYITATIONS. 77 
 
 astrologers, and soothsayers, from the days of Be- 
 rosus downward. 
 
 The moon can not boast snch great dimensions 
 as the earth. Still it is wonderfully larger than 
 it looks. It looks, say, a foot in diameter ; it 
 really is eleven million times that. It is plain that 
 can not be a small body which, on being carried 
 away from us 240,000 miles, appears as large as 
 the moon. But this is altogether too vague in- 
 formation to content astronomers — astronomers 
 who want to split a second into one thousand 
 parts, and an inch into 200,000. " What is the 
 exact length of the diameter in miles and small- 
 est possible fractions of a mile ? " demand they. 
 And they answer themselves in this way. Sup- 
 pose two lines drawn from the earth's center to 
 opposite sides of the moon ; then the real diame- 
 ter of the moon makes with these a triangle. 
 Now measui'e the moon's apparent diameter, 
 which is the angle included between the supposed 
 lines. The lines are about 240,000 miles eacli ; 
 the angle is about 31'. Then the simplest sort 
 of mathematics gives you two thousand one 
 lumdred and sixty miles for the required diam- 
 eter. 
 
 Though the moon is so small a body compared 
 with the earth, and withal so remote from us, it ia 
 able to produce on us some very remarkable effects. 
 Most certainly I do not here refer to its supposed 
 bearing on the weather, on the complexion, on 
 
78 THIRD LEJTURE. 
 
 the health, on the mind in producing or modify- 
 ing insanity, on the proper times for planting, 
 reaping, felling timber, killing of domestic ani- 
 mals. Though the impression was once almost 
 universal, and is still exceedingly prevalent, that 
 the moon is a powerful and controlling agent in 
 these and such particulars, still we must admit 
 that it is an altogether erroneous impression. 
 This has 1ieen very satisfactorily established by 
 the extended observations and expcrimexits of 
 several European philosophers, and especially of 
 the illustrious Arago. No : I refer to quite a dif- 
 ferent class of phenomena. And, first, the moon 
 takes hold of that protuberant equator of ours, 
 as if it were a mere convenience for wrestlhig, 
 and pulls and twists it about after itself, making 
 tlio pole describe a wavy, nodding circle of some 
 46° diameter through the sky — a little more than 
 the hight of the North Star above our horizon. 
 This effect is due partly to the sun ; but the moon 
 is the chief agent. For long periods, however, 
 this motion of the pole would not be noticed by 
 common observers ; it is so exceedingly slow, 
 requiring about twenty-six thousand years to 
 make an entire revolution. In consequence of 
 it, the axis of the earth which now points nearly 
 at the North Star, will, after pointing a little 
 nearer to it, gradually recede, and twelve thou- 
 sand years hence point 40° away from it ; and 
 then the bright star Lyra will be the pole-star. 
 
MUTUAL GRAVITATIONS. 79 
 
 Let the men of the year 13,860 look in the north- 
 west for their north. 
 
 Another more noticeable effect of the moon's 
 attraction are the tides. Twice a day tlie earth, 
 like every good man, attempts communion with 
 the sky. Twice a day the bosom of the seas swells 
 heavenward. The explanation is this. As the 
 earth, in revolving on its axis, presents all parts 
 of its surface in succession to the moon, that 
 body, by the attraction of gravitation, draws up 
 the water in a ridge toward itself, at the same 
 time making a similar ridge by drawing the earth 
 away from the water on the opposite side : so that 
 we have two great tidal swells, convex toward the 
 west, about twelve hours apart, apparently follow- 
 ing the moon in its daily movement around the 
 earth ; checked somewhat in their movement by 
 their own inertia and friction among the barriers 
 of shores and irregularities of sea-beds ; re- 
 flected in this direction and that, according to the 
 lay and shape of coasts ; about two and a half 
 feet high on the average, but heaped up as high as 
 fifty or even one hundred and twenty feet in 
 some confined places of peculiar conformation, 
 aud then almost or quite dissipated by shoals and 
 other dispersive agencies. Thus it would seem 
 to a bird's-eye view. But really there is no pro- 
 gressive movement of the water in tlie open sea 
 in the case of the tides. No European water is 
 rolled over to America at the rate of a thou- 
 
80 THIRD LECTURE. 
 
 sand miles an hour. It is merely a successive 
 rising and sinking of the sea all round the world. 
 The effect is owing in part to the attraction of the 
 sun ; but the moon is the chief agent. When the 
 sun and moon act in the same line, or nearly so, 
 — at the times of new and full moon — the tide- 
 swell is considerably increased, making what 
 are called spring tides. When they act at right 
 angles to each other, they impair each other's in- 
 fluence and the tide-swell is decreased, making 
 what are called neap tides. 
 
 This constant heaving of the water tends to 
 keep it pure. It also agitates to some extent the 
 atmosphere, and so keeps that in a livelier and 
 purer state. It enables all the coasts of the world 
 to become vast beds of a peculiar animal and ve- 
 getable life, and twice a day throws open the re- 
 positories to the plundering hands of men. The 
 farmer wants his sea-weed and salt grass. All 
 persons, almost, want their shell-fish. Millions 
 of people find their chief support in those vast 
 tribes of animals that can only live where tides 
 are felt. Shoals are laid bare and quickened by 
 the sun. The tide-wave brings up the water 
 again with its flotilla of semi-marine animals and 
 influences to impregnate and refresh the conge- 
 nial sand or slime. So the beach swarms. Races 
 of creatures belonging to both land and sea, and 
 partaking of the qualities of both, present them- 
 Bclves for our tables in countless numbers — not 
 
MASSES AND DENSITIES. 81 
 
 by spontaneous generation, that figment of athe- 
 ists, but by the good providence and almighty 
 power of God. 
 
 How much matter is contained in the earth ? 
 What is its average degree of compactness ? In 
 the year 1774 — the same year we Americans 
 were weighing the maternity of England in the 
 balance and finding it wanting — England at- 
 tempted to weigh the world. For that purpose, 
 the astronomer royal, Dr. Maskelyne, betook him- 
 self to Schehallien, in Scotland. He suspended 
 a plumb-line near the mountain, and noticed how 
 much it was drawn out of the perpendicular. 
 This showed what proportion the quantity of 
 matter in the mountain bore to that in the earth. 
 Theu cuts into the mountain in every direction 
 were made to show tlie average density of tlie 
 materials of which it was composed. With this, 
 the size of the earth being known, it was very 
 easy to arrive at its average density — which was 
 found to be about five and a half times that of 
 water. This greatly exceeds the density of the 
 surface. So there must be a great increase of 
 condensation toward the center. It does not fol- 
 low, however, that the earth is perfectly solid, 
 — the contrary is known — only the parts that are 
 solid must be exceedingly so ; fit walls against 
 those tremendous internal fires that help the sun 
 defend us from the tremendous cold of space ; 
 fit walls against the noxious gases and vapor 
 
 8 
 
82 THIED LECTVEE. 
 
 wliicli those fires can not fail to generate in pro- 
 digious amount ! For the earth is like some men 
 — with a cold exterior, but a heart of fire. It is 
 a traveling furnace. Wherever we dig into it, 
 we find a steady increase of heat — one degree for 
 cacli fifty-four feet as we descend. And you know 
 liow unlike are the climates of different countries 
 having the same latitude and level — for exam- 
 ple. Southern Europe and New England and tlie 
 States due west of us. When the ancients saw 
 JSiiuVi in eruption, they supposed tlie mountain to 
 be the chimney to the great blazing and resound- 
 ing forges below, where Vnlcan the god-black- 
 smitli, with his journeymen-Cyclops, were ham- 
 mering out the thunderbolts of Jupiter. When 
 vsre see -^tna and its three hundred sister volca- 
 noes, in all parts of the world, in action, we make 
 no question but that the immense roaring fires 
 are beneath them, if not the forger and the 
 smiths and the thunderbolts. That the great 
 amount of vapor and gases which must be de- 
 veloped by these fire-beds does not all escape 
 through fissures and volcanoes as fast as formed, 
 is plain ; for the many violent and far-spreading 
 earthquakes that occur, come fi'om the struggles 
 of imprisoned elements to escape. They are 
 densely accumulated in great caverns. And it is 
 well that the walls of these caverns are denser 
 than the densest metals known to us, so that 
 but comparatively little of the deadly air within 
 
MASSES AND DENSITIES. 83 
 
 succeeds in escaping to the s irface. Indeed, so 
 little lieat escapes that the earth has not dimin- 
 ished its mean temperature by the tliree-liun- 
 dfcdtli part of a degree for two thousand years. 
 
 Can we also weigh the moon in our astronomi- 
 cal balance ? We can ; by means of tlie tides. 
 Add togetlier tlie average spring and neap tides 
 — the one expressing the sum, and tlie other the 
 difference, of tlie solar and lunar attractions. This 
 gives us tliat part of tlie tide-wave which is due 
 to the moon alone. Now how does this show the 
 quantity of matter in the moon ? You see it is 
 a case of contest between the earth and moon as 
 to -which shall have the water. ■ The earth pulls 
 with all its might — that is to say, with all its quan- 
 tity of matter ;■ and the moon pulls with all its 
 might — that is, with all its quantity of matter. 
 The moon acts at disadvantage from its greater 
 distance, tlie earth acts at disadvantage from 
 the tendency to fly off which the water lias in con- 
 sequence of rotation ; but, when allowance is 
 made for these things, the position which the 
 water talces between the two pulling bodies shows 
 their relative strength. It is tlie case of Greece 
 and Troy dragging at the body of Patroclus. 
 The one tugs at the head, and the other at the 
 feet ; the direction in which the body actually 
 goes shows which party is the stronger, and the 
 rate at which it goes shows how great the superi- 
 ority is. At last the dead hero moves swiftly 
 
84 THIRD LECTURE. 
 
 toward the ships. Not eighty wrestli..g Troys 
 could prevent it. In this duel for the seas, we 
 are Telamonian Ajax, and the will of Jupiter 
 besides ; and it would require more than eighty 
 moons to turn the fortunes of the day, and tear 
 its prize from the stalwart earth. Just as soon 
 as we know the relative quantity of matter in the 
 moon, its known size shows what is its relative 
 density. It is about three-fifths of the density of 
 the earth. 
 
 It has been shown that the earth and moon, 
 making as they do a neigliborhood by themselves, 
 must revolve about their center of gravity. Now, 
 since the earth contains eighty times as much 
 matter as the moon, this center must lie eighty 
 times nearer to the center of the earth than to 
 that of the moon. But the eightieth part of two 
 hundred and forty thousand miles is three thou- 
 sand. So you see tliat tlie point around which 
 tlie two bodies revolve falls one thousand miles 
 witliin the earth's surface — our semi-diameter 
 being near four thousand. Hence it is compara- 
 tively but a very small orbit that the earth de- 
 scribes — only six thousand miles across ; while 
 the moon describes one wliich is four hundred and 
 eighty thonsand miles across. One is as nothing 
 to the other. So, for popular purposes, it isccm- 
 uion to consider the earth as stationary, so far as 
 the moon is concerned, with the moon revolving 
 around it. Turning, then, to this greater orbit, 
 
ORBITS. 85 
 
 I will state some of the more interesthig facts 
 about it. Plainly, it can not differ much from a 
 circular curve ; for the moon always looks just 
 about so large during its revolution around us. 
 If its distance from us varies considerably, of 
 course its apparent size ought also to vary consid- 
 erably. Very nice measurements, however, of its 
 apparent diameter at different times, show that 
 its distance does alter somewhat — more than it 
 ought on account of our being a little out of its 
 center of motion ; shows in fact that the orbit 
 must be what is called an ellipse — such a figure 
 as a flexible hoop would make if compressed at 
 opposite sides — having the common center of 
 gravity about twelve thousand miles one side of 
 its center, on the longer axis. It takes a little 
 more than twenty-seven days for the moon to 
 make the complete circuit of this orbit. This is 
 traveling at the rate of fifty-four thousand miles 
 a day. In passing around this orbit, our satellite 
 often passes, either wholly or partially, through 
 the earth's shadow; giving rise to lunar eclipses. 
 As to tlie position of the orbit, we notice that the 
 moon does not move around our axis at right 
 angles to it, but obliquely ; so that the plane of 
 the orbit makes an angle of about sixty degrees, 
 with the axis. This inclination is of great ser- 
 vice to us ; for it is owing to this that we have so 
 much more liglit from the moon in winter than 
 in summer ; it causing the full moon to ride 
 
86 THIRD LEQTURE. 
 
 highest when we need the most light. Here, 
 then, we have the orhit — four hundred and 
 eighty thousand miles the longest way across, 
 lying obliquelj across the axis of tlie earth, and 
 traversed at a pace of fifty-four thousand miles 
 a day. This is how the matter stands now. But 
 you are not to suppose that it has always been so, 
 or that it will always be so. The orbit is contin- 
 ually becoming smaller; the moon with every revo- 
 lution is getting nearer and going faster ; and 
 some persons have been afraid that, at last, our 
 neighbor would become too ueigliborly — in fact, 
 come rushing in upon us, and with one tremen- 
 dous concussion dash every thing to pieces. Tlie 
 fact of the gradual approach of the moon to us 
 is certain ; observations establish it beyond ques- 
 tion. But it is an exceedingly slow approach, 
 only ten seconds on the time of revolution being 
 now gained in a century. Still, however safe wo 
 and many generations after us may be, the idea of 
 such an ending of an astronomical system is not 
 pleasant. We pity that distant generation to 
 come. We pity the graves of our fathers and 
 our own. However, we need not be alarmed. 
 La Place, with his splendid geometry, has shown 
 from the doctrine of gravity that this graduol 
 contraction of the orbit is not to continue indefi- 
 nitely ; but that, after millions of years, it will 
 again slowly expand and finally become as large 
 as. ever ; then contract again — and so sweep back" 
 
MUTUAL ASPEOTE. 87 
 
 ward and forward through a period th3 vastncss 
 of which bewilders the imagination. T.Ms change 
 in tlie lunar orbit is by no means the only one. 
 There are some sixty such changes ; and about 
 half that number are so considerable that they 
 must be taken account of, whenever we wish to 
 compute the place of the moon with tolerable ex- 
 actness. Indeed, the moon's orbit is a very wavy, 
 changeable, battered affair. It is continually be- 
 ing pushed out and in, twisted in this direction 
 and in that, drawn sidewise and edgewise, re- 
 volved in its own plane and in almost every other 
 by attractions from many quarters. Could you 
 see the path which our satellite actually de- 
 scribes in space — could it leave a visible wake 
 as a rocket does — ^you would wonder greatly at 
 its intricacy, and how men could ever get able to 
 predict the moon's place on it to within five sec- 
 onds of the truth. Yet this they can do. And 
 astronomers have found out, by means of the law 
 of gravity and that wonderful differential and 
 integral calculus which is the good Genius of 
 astronomy, that, notwithstanding the sad usage 
 which the lunar orbit gets from all quarters, 
 it has, like much assailed christian goodness, 
 within and around it all the elements of eternal 
 stability. 
 
 I will close my account of our satellite system 
 by a few words as to the appearance which ita 
 members present to each other. 
 
88 TBIBD LECTURE. 
 
 The appearance of the moon under the teles- 
 cope is very beautiful. And yet it looks very 
 much as if it had had the small-pox iu the natu- 
 ral way, and had it sadly. We see a desperately 
 pitted and scarred face — valleys and mountains 
 — valleys four miles deep ; mountains five miles 
 high ; volcanoes, conical, ring-shaped, with long 
 streams of lava spreading down tlieir sides in 
 every direction; peaks gleaming with the first kiss 
 of the morning sun ; shadov?s advancing across 
 the plains. As to atmospliere and water on the 
 moon, appearances are indecisive. Some things 
 seem to prove tlieir presence, and other things 
 seem as strongly to prove their absence. Cer- 
 tainly the moon has never any clouds. However, 
 if it could be demonstrated that it has neither air 
 nor water, it would not follow that it has no in- 
 habitants. It would only follow that, if there are 
 living beings there, they must be differently con- 
 stituted from ourselves. And who will undertake 
 to show that beings widely diverse from us are 
 impossible or improbable in the universe of so 
 versatile and magnificent a Creator as He who 
 spake into being these wonderful worlds of as- 
 tronomy ? 
 
 This is how the moon looks from the earth. 
 And how does the earth look from the moon, if 
 there are people there to see ? Half of the moon 
 never sees us at all. To the other half we seem 
 a brilliant orb about thirteen times larger than the 
 
MUTUAL ASPECTS. 89 
 
 moon seems to us — always occupying nearly the 
 same place in tlic sky — successively crescent, gib- 
 bous, and full — in fact, another moon. Under a 
 telescope, what with our clouds and seas and val- 
 lej's and mountains, the earth would present even 
 a more pocked aspect than the moon does to us. 
 Never did veteran come home from the war with 
 half so scarred and battered a countenance! But 
 never mind, ancient earth ! Thou hast a better 
 look on closer acquaintance. And, besides, " hand- 
 some is that handsome does," and thou gener- 
 ously givest us flowers and fruits and harvests 
 and coal and silver and gold and gems ; green 
 fields, stately forests, musical streams ; sweet 
 vales of Tempe, hoary Alps sublime, august 
 oceans with their eternal anthems ; above all, a 
 standing place on which Holy Christ and sinful 
 we may work out for ourselves the wonders of 
 eternal life. 
 
IV. 
 
 PLANET SYSTEMS. 
 
IV. Planet Systems. 
 
 Example — Solar System. 
 
 .- ORDER OF BODIES 93 
 
 I. PERIODS 103 
 
 3. DISTANCES FROM SUN 103 
 
 4. SHAPES AND INCLINATIONS OF ORBITS . . .111 
 
 5. SIZES , 115 
 
 6. VELOCITIES 117 
 
 7. MASSES AND DENSITIES 118 
 
 8 PERTURBATIONS tia 
 
FOURTH LECTURE. 
 
 PLANET SYSTEMS. 
 
 IN my last lecture I gave an example of the 
 First Order of Systems among the heavenly 
 bodies — the Satellite Systems. This evening I 
 propose to give an example of the Second Order 
 — the Planet Systems, or systems each of which 
 is composed wholly or in part of Satellite Systems 
 revolving about a self-luminous body or sun. 
 
 Tlie rotation of the earth makes all the heav- 
 enly bodies seem to move across the sky in parallel 
 lines, without any disturbance of their mutual po- 
 sitions. But some of these bodies have very much 
 motion of another kind — a motion among them- 
 selves. They go this way, and they go that ; they 
 go forward, and they go backward — describing 
 quite rapidly very irregular paths on the sky. I 
 have already called your attention to these very 
 roving bodies, under the names of planets and com- 
 ets. About ninety planets, and some one hundred 
 and eighty comets, have been carefully noticed. 
 
94 FOURTH LECTURE. 
 
 Some of these change their places among the Dther 
 stars, on the average, as much as eight times the ap- 
 parent diameter of the sun in a single day — indeed 
 some comets have been known to traverse, iu the 
 same time, eighty times this diameter. Besides 
 these, the sun itself is found to be a great traveler, 
 though never a retrograde one — making tlie 
 whole circuit of the heavens in a year. Now, tlie 
 thing to be particularly noted, is the great difler- 
 ence in amount between the apparent motions of 
 these bodies and the apparent motions of all others. 
 Wliy, all otliers liave no motions at all, that ordi- 
 nary observers can detect, and lience are called 
 fixed stars. And when astronomers mount their 
 instruments, and do succeed iu detecting small an- 
 nual changes of place among them, they find tliat 
 the greatest of these changes is a thousand times 
 less than that of tlie slowest planet. Now what 
 makes this great chasm ? Why do these three hun- 
 dred bodies seem to move so much, while all the 
 rest seem to move so little ? There is but one an- 
 swer. Those greatly moving bodies are greatly 
 nearer to us than are the others. There is a great 
 interval between the two classes of bodies in space, 
 corresponding to the interval between them in mo- 
 tion. If there were no space-chasm between them, 
 the law of gravity would require them all to belong 
 to the same system of revolution ; of course, the 
 real motions, and so the apparent, of all would be 
 of the same general order of magnitude. Suppose 
 
ORDER OF BODIES. 95 
 
 yourselves at sea in afleet. Here are three hundred 
 ships witliin two miles of you. Some are standing 
 this way and some that, some advancing and some 
 retrograding ; but all noticeably changing their 
 positions with respect to you and each other every 
 minute. Now let another fleet appear on the hori- 
 zon. You count a thousand tiny masts. Their 
 progress seems as petty as their size, hours scarcely 
 showing any change of position. What say you''' 
 That those Liliput ships with their Liliput mo- 
 tions are mingled with your own squadron, be- 
 cause, forsooth, you happen to see them between 
 the neighboring hulls and masts ? Not so. If 
 they belonged to you, they would take signals 
 from your flag-ship, and all the exuberant ship- 
 ping in sight would have a family likeness as to 
 the character and degree of their sailing. But here 
 is quite another order of motions. They plainly 
 belong to another fleet, under another admiral, 
 far away in the offing ; and distance has dwarfed 
 both figure and motion. A great breadth of sea 
 lies between the two navies. We reason in the 
 same way in regard to the heavenly bodies. 
 These three hundred bodies, more or less, that 
 show so much motion, we conclude to belong to 
 our fleet of stars ; the others that scarcely stir on 
 the sight belong to other fleets or fleet, separated 
 from ours by a wide interval. The three hundred 
 and the earth are astronomical neighbors. The 
 three hundred and the earth are a system by 
 
96 f JURTH LECTURE. 
 
 themselves — if you please, an astroi oraical Leoa- 
 Idas and his Spartans, keeping ward at the Ther- 
 mopylse of the sky, and endeavoring to beat off 
 the crowd of Chaldean astronomers that seek to 
 reach the very heart of the heavens. They can 
 not be beaten off. By dint of numbers and pa- 
 tience, if not of boldness and genius, they shall 
 break through. The very heart of that Greece 
 shall be laid open. 
 
 According to the law of gravity, all the mem- 
 bers of this system must be in a course of revo- 
 lution about their common center of gravity. 
 Where is this common center ? It may be an in- 
 visible point out in the void of space, far away 
 from any member of the system ; and again, as in 
 the case of the earth and moon, it may lie near 
 the center of some body. The ancients always 
 assumed the last supposition to be the true one ; 
 and further assumed that the earth is that central 
 body about which, not only the sun and planets 
 and comets, but all the huge varieties of naiure 
 revolve. Themselves were the center of creation. 
 It is something in their favor that they did not 
 know how large creation was. But the children 
 are wiser than the sires. Since the time of Co- 
 pernicus — tliat astronomical Columbus — men have 
 seen reason to change their opinions on a great 
 many subjects ; on this among the rest. Now 
 we know that the sun occupies nearly the center 
 of motion of that system of planets and comets 
 
ORDER OF BODIES. 97 
 
 to which we belong. This should have been sus- 
 pected from the beginning — especially in view of 
 the desirableness of having the only self-luminous 
 body in the system placed somewhere near its 
 center. And the suspicion should have been 
 easily turned into a conviction. Suppose the 
 earth to be practically at the center of motion. 
 Then all" the planets and comets would seem to 
 describe, in a course of perpetual progress, regular 
 circles about us; whereas they all, without ex- 
 ception, advance and retreat ou most irregular 
 curves. So the earth can not be the center. 
 Next, suppose one of the other members of the 
 system to be it. Then that central body, being 
 the center of our motion, would appear to describe 
 in unbroken progress a regular circle among the 
 fixed stars. Now the sun is the only body in the 
 system which fulfills this condition. Its apparent 
 patli is a regular circle ; described in one year, 
 without any retrogradations whatever ; while, as 
 I have said, every other member of the system 
 apparently moves ou a very irregular line — now 
 forward, now backward, now sidewise, now stop- 
 ping altogether — in short the picture of irresolu- 
 tion. More eccentric vagrants than those planets 
 and comets seem to be, it would be hard to find. 
 But the sun marches steadily along. He seems 
 to know what he wants and the way to it. Right 
 forward on the periphery of a great circle, with- 
 out a step to the right hand oi to the left, he 
 
98 FOURTH LECTUBE. 
 
 presses, till he comes around to the same fixed 
 star again. So the sun is practically the center 
 of the system It is the sun, and not the earth, 
 wliois tlie patriarcli of yonder seemingly wayward 
 and disorderly family, and wlio — shall we say it 
 — is responsible for this misbehavior. But things 
 are not what they seem. There is nothing dis- 
 orderly in the universe save intelligent beings. 
 Could we stand at the sun, the motion-center of 
 all these graceless nomads of the slcy, they would 
 no longer seem so indictable for vagrancy and in- 
 subordination. All their zigzags would be straight- 
 ened out, all iheir stops and retreats would be 
 turned into one constant advance. See how much 
 depends on having the right stand-point for view- 
 ing things ! And the wisdom of the Great Architect 
 of astronomical systems is saved from aspersion 
 as we see tlie chief source of light and heat in our 
 stellar community so placed as to be of the great- 
 est service to the greatest number — so placed as 
 to oppose, as much as possible, extreme variations 
 of illumination and temperature on any world. 
 
 But now what are these bodies thus revolving 
 about the sun ? First, we have tlie earth and 
 moon — one satellite system. Next, talie a tele- 
 scope — a common spy-glass will answer — and 
 bring it to bear on tlie planet Jupiter. You see 
 a well-defined disc, and four brigiit points in its 
 immediate neighborhood. Watcli, and you shall 
 notice these bright pcints approaching the planet, 
 
ORDER OF BODIES. 99 
 
 crossing its face, going a little beyond it, then 
 coming back to it, disappearing behind it, after a 
 while appearing on tlie opposite sido, and then re- 
 ceding from it as far as before ; watch them, and 
 you shall find them keeping with the planet in all 
 its wanderings among the stars, advancing when 
 it advances, reireating as it retreats, becoming 
 stationary relatively to other stars when it becomes 
 stationary. Plainly, another satellite system — 
 a reflecting primary, with four moons waiting upon 
 and revolving around it. There is the planet 
 Saturn ! Look at it with a more powerful glass, 
 and see — what you shall see. If your eyes are 
 good and your telescope is of the first class, you 
 will by patient watching be able to detect eight 
 l)right atoms in the neighborhood of a curiously 
 beringed disc, behaving toward it just as the 
 satellites of Jupiter do toward their primary. 
 Plainly Janissaries ; plainly, another satellite sys- 
 tem — a reflecting primary, with eight moons re- 
 volving around it. — Hunt up the plane't Uranus, 
 never visible to the naked eye, out seen well 
 enough with an instrument; and, if you manage 
 your instrument as well as Sir W. Herschel and 
 his sister did theirs, eighty-four years ago, you will 
 see that reflecting disc moving about with what is 
 evidently its body-guard of six moons. Another 
 satellite system ! — So of Neptune — a newly-dis- 
 covered planet. Hunt patiently in its close iieigh- 
 borhood;, as it shines in the field of a powerful 
 
100 FOURTH LECTURE. 
 
 telescope, and, if you do as well as Struve did at 
 Pulkova, and Bond at Cambridge, you will find at 
 least one minute point of light playing the hench- 
 man to his chief. Another satellite system! 
 Thus it appears that we have a great system of 
 heavenly bodies, composed largely at least of 
 satellite systems revolving about the sun. No 
 satellites have as yet been discovered in connection 
 with other planets. This discovery, however, may 
 yet be made. One has been suspected waiting 
 on beautiful Venus. In short, we have an ex- 
 ample of a stellar system of the second order. 
 We have a Planet System. We have a number 
 of heavenly sires with their comely families of 
 various sizes about them, still bound in invisible 
 bonds to, and in course of circulation around, the 
 ancient and majestic grandsire — whose eye, how- 
 ever, is not yet dim, nor natural force abated. 
 
 Having thus found our Planet System, let us 
 proceed to consider its chief points of interest. 
 And, first, tlie order of the bodies composing it. 
 Suppose one to start from the sun and travel to the 
 frontiers. What body would he reach first, what 
 secondly, and so on ; supposing them all ranged 
 on the same side of the sun, at their average dis- 
 tances ? At first glance it looks a hard matter to 
 answer these questions. The members of the 
 system seem quite too insubordinate to adhere to 
 any order of position and revolution that may 
 have been assigned to them. Here, is one refrac- 
 
OSDER OF BODIES. 101 
 
 tory planet with its strange path ; there, a still 
 more refractory comet with its stranger ; one is 
 going this way, another that ; one is creeping 
 northward, another striding westward — in short, 
 it is a perfect maze of positions, directions, and 
 motions that we see. But there is a clew to the 
 labyrintli. There is a key to this sky-cipher and 
 hieroglyphic. . And it is something that does not 
 look particularly like a key at first sight, though 
 it can be made, in connection with the law of 
 gravity, to interpret, not only the order, but also 
 the periods and distances from the sun of all the 
 members of our system. This Rosetta stone is . 
 the average apparent daily motions, which any one, 
 almost without instrument but with a plenty of pa- 
 tience, could approximately determine for him- 
 self; and which, with such instruments as every 
 observatory is now furnished with, can be deter- 
 mined with admirable exactness. A word as to 
 the general method. The law of gravity proves 
 that the more remote a revolving body is from 
 its center of revolution, the more slowly it must 
 move ; and, of course, the more slowly it must 
 seem to move, as seen from that center. Hence, 
 if we can only find how the motions of the planets 
 and comets, as seen from the sun, compare wiih 
 each other, we shall know their relative distances 
 from that body. Now this is easily done. We 
 have merely to find what their average motions 
 are as seen from the earth. As we are nearer 
 
102 FOURTB LECTURE. 
 
 to each by a whole diameter of the earth's or Ail 
 at one time than at another, taking tlie average 
 i-educes the motion to what it would appear mid- 
 way between opposite sides of the orbit. Well, 
 being thus reduced, how do the motions compare 
 with each other ? For the planets, they decrease 
 in the following order : Mercury, Venus, Earth, 
 Mars, some eighty small bodies called asteroids 
 or planetoids as you may prefer, Jupiter, Saturn, 
 Uranus, Neptune. This then is the order in whicii 
 tliese several planets would be reached by one 
 going outward from the sun, could they all be ar- 
 ranged on the same side of that luminary at tlieir 
 average distances. Comets would be encountered 
 in great numbers all along the glittering journey 
 — the best known of them in the following order ; 
 Encke's, Biela's, Halley's, comet of 1811, comet 
 of 1680. 
 
 Such are the various places which his glittering 
 nobles hold in that great court which the solar 
 monarch maintains in the sky. Mercury holds 
 the place of honor ; he waits perpetually in pres- 
 ence. Neptune is a mere hanger-on at court — 
 getting comparatively few rays of favor, and 
 obliged to content himself with exceedingly dis- 
 tant and dim views of his sovereign. The eartli 
 has a golden mean of position — not a Steenie, in 
 the dangerous post of a favorite putting up at the 
 palace — not a governor-general of Van Dieman's 
 Land and all British Antipodes — but Duke 
 
PERIODS OF PLANETS. 103 
 
 Percy, living in an independent way o.a his estates 
 in Nortluimberland, in a very genial temperature 
 of court favor, neither loved too much nor too 
 little, always welcome and never wanted, far 
 enough from St. James's and not too far. 
 
 How long are the members of our system in 
 ti-aveling around the sun ? The average daily 
 motion, as seenJi-om the sun, answers this ques- 
 tion also. For if you find this motion to be — say 
 1° — you know that it will take three hundred and 
 sixty days for the planet to accomplish the whole 
 circumference of the heavens. If Mercury moves 
 around the sun at a mean daily rate of 4° 5', as 
 it does, it will take it eighty-eight days to go 360°, 
 or an entire circuit. And so on. In this way we 
 find the period of Mercury to be three months, 
 of Venus seven months, of the Earth one 
 year, of Mars two years, of Jupiter twelve, of 
 Saturn twenty-nine, of Uranus eighty-four, of 
 Neptune one hundred and sixty-four. Ask that 
 man of silver hairs how old he is. Eiglity-four 
 years, does he say ? Tiien he was born when 
 Uranus was last at its present point in its orbit 
 — the point where Sir William Herschel was 
 tljcn finding it. The child, whose fresh, dewy orbs 
 to-day look up wonderingly at the spangled vault 
 where Neptune hides itself, will have grown up, 
 fought life's battle, grown old, died, and lain in 
 his grave a hundred years, by the time that fron- 
 tier planet is able to get around again to its pres- 
 
104 FOURTH LECTURE. 
 
 ent place jn the sky ! According to the Neptunian 
 calendar, it is only thirty-six years since the cre- 
 ation of Adam ! But even sucli years are trifling 
 when compared with those of some comets. What 
 think you of a voyage about the sun requiring 
 four thousand of our years for its completion ? 
 The comet of 1811, when it last saw the earth, 
 saw it yet dripping with the waters of the flood ; 
 tlie comet of 1680, when it last saw the earth, 
 saw it without form and void, and prophesying 
 but faintly of an Eden and an Adam still three 
 thousand years distant. When it sees the earth 
 again, where shall we be — ourselves, our homes, 
 our cities, our race ? May Heaven grant that the 
 next nine thousand years shall suffice to prepare for 
 exhibition to the gaze of that mighty voyager, tlie 
 predicted new heavens and new earth in which 
 shall dwell righteousness ! 
 
 Having the periods of the members of our sys- 
 tem, and the actual distance of one of them from 
 the sun, we can find the distances of all the rest. 
 For the mathematics of Newton have proved, that, 
 in case the central body of a system is greatly 
 superior in mass to the sum of all the others, it 
 follows from the law of gravity that the squares 
 of the periods of any two of them are as the 
 cubes of their mean distances from the center. 
 Tliat this condition is fulfilled in the case of our 
 own system is clear ; for all observation shows 
 that the sun, relatively to the planets and comets, 
 
DISTANCES FROM THE SUN. 105 
 
 is substantially at rest. Hence the law which 
 Newton proved is applicable to our system — the 
 squares of tlie periodic times are as the cubes of 
 Iho mean distances from the sun. By the help of 
 this law and the periods, if we can hud the mean 
 distance of one planet from the sun, we can find 
 tlie mean distances of all the planets. Let us then 
 find the distance of the earth from the sun, as a 
 means to that of every other member of the 
 system whose period is known. 
 
 One very easy way of approximating to our 
 distance from the sun was employed by the an- 
 cients. Sometimes a half-moon is visible during 
 tlie day. A.t such a time let a line be drawn from 
 the center of tlie sun to that of the moon, thence 
 another line to tlie center of the earth, thence 
 another back to the center of the sun — making 
 a right-angled triangle. Now let us measure the 
 angular distance of the moon from the sun. 
 This, with the known distance of the moon from 
 tlie eartli, enables us to find with the greatest ease 
 that other side of the triangle which is the dis- 
 tance between the centers of the sui? and earth. 
 But this is only a rough approximation. In those 
 times astronomers would curl the lif at such 
 coaiT.e measurements as. these. Why, tl>eu, not 
 find our distance from the sun in the san»e way 
 we did our distance from the moon — that is, by 
 noticing how much the sun is apparently dis- 
 placed on the sky by a giv?n change in our place 
 
106 SOURTB LECTURE. 
 
 on the earth — that is to say, by its parallax ? 
 This will do : only, on account of the exceeding 
 smalhiess of the solar parallax, we can lot employ 
 the same method for determining it as was used 
 in the case of the moon. A very accurate method, 
 however, was discovered, by Dr. IT alley, the 
 friend of Newton, and bequeathed by him to the 
 next generation of astronomers, to be used when 
 fitting occasion should arrive. This was the 
 method. Occasionally the planet Venus crosses 
 the sun's disc. Now, if we can only find -liow 
 mucli Venus is displaced on the disc at that 
 time by our going a given distance on the earth, 
 we can know liow much the sun is displaced on 
 the sky by the same change of place ; for the one 
 displacement is to tlie other as the distance of 
 Venus from the sun is to her distance from the 
 earth. But this latter ratio is easily obtained 
 from the average apparent daily motions of the 
 two bodies, by means of that law connecting the 
 periods and distances which has just been referred 
 to. It is as 21- to 1. So, in 1769, the English, 
 Frencli, Russian, and other European Governments 
 fitted out expeditions to observe, from as widely 
 separated parts of the world as possible, the transit 
 of Venus which occurred that year. One corps of 
 observers went to Wardhus — a small island on the 
 Coast of Lapland ; another corps was carried by the 
 celebrated Captaii Cook to Otaheite, now Tahiti, 
 in the South Sea All possible means were used 
 
DISTANGES FROM THE SUlf. 107 
 
 to wecure extreme accuracy of result. It was un- 
 derstood by all parties, that they were measuring 
 a base line that would be used iu determiuing all 
 the other distances in our planetary system, and 
 perhaps distances stretching across the void of 
 space to where other isles of light, and archipela- 
 goes of such isles, go swimming about other glow- 
 ing continents in endless circumnavigations. So 
 the science and art of the day did their very best. 
 The extremest refinements, both of observation 
 and .theory, were brought to bear. Spider lines 
 were split by the observer, and differentials by the 
 mathematicians. The result was 8" 57 — about 
 2^1^ of the sun's apparent diameter, — for the mean 
 change made in the sun's place by our passing 
 from the surface to the center of the earth. From 
 this, by simplest triangle-proportion, was found our 
 mean distance from the sun — 95,298,260 miles. 
 Taking this distance and the law expressing 
 the relation between the distances and the periods, 
 we come, by a simple proportion, to a knowledge 
 of the average distances of all tlie principal bodies 
 in our system. We find Mercury to be thirty- 
 seven millions of miles from the sun, Venus 
 sixty-eight millions. Mars one hundred and forty- 
 five millions, Jupiter four hundred and ninety- 
 five millions, Saturn nine hundred millions, 
 Uranus eighteen hundred millions, Xeptuno two 
 thousand eight hundred millions. Some of the 
 comets have still greater mean distances. That 
 
108 FOURTH LECTURE. 
 
 of the comet of 1811 is not far from tweuty-two 
 hundred millions of miles ; while that of the 
 comet of 1680 astonishes us with the mighty 
 stretch of forty-foui* thousand millions — sixteen 
 times the solar distance of Neptune ! 
 
 You see that we have come to a new order of 
 distances in our astronomy. The distances wo 
 have to deal with in our every-day life are such 
 as we pass over in going to our fields, neighbors, 
 schools, ch arches, markets, occasionally a neigh- 
 boring city ; and hours and miles answer very 
 well to express such movements. Next, wo learn 
 that the earth we live on is nearly eight thousand 
 miles through — this lifts us to quite another 
 plane of distances. Our common walks and rides 
 are lost by the side of such mammoth lines. 
 Then we learn that the moon is two hundred and 
 forty thousand miles away. See another plane 
 and order of distances still 1 The word " miles" 
 begins to empty itself of its meaning in such com- 
 binations. But we go on to learn that the moon 
 is at our very door as compared with other mem 
 hers of our planet system — that the sun is. four 
 hundred times as remote ; Neptune eleven thou- 
 sand times ; while the comet of 1680, that Minis 
 ter of Foreign Affairs to his Solar Majesty, buries 
 itself in that tremendous Ultima Thule whose dis 
 tance is one hundred and eighty thousand times 
 that of the moon. Do you take the meaning of 
 such enormoc'i intervals ? Have miles any meau' 
 
DISTANCES FROM THE SUN. 109 
 
 ing left to them ? Does not tlie hight of this 
 last plane of our astronomical arithmetic seem 
 almost too dizzy and cloud-mixed to stand upon 1 
 ^ud, when you are told that a car, running ex- 
 press from the sun to that frontier of this planetary 
 system of ours, would not need to put on brakes 
 for five hundred thousand years, do your concep- 
 tions seem any the less dizzy and astounded ? In 
 that great calculus which has done so much for 
 astronomy we encounter infinitely small quanti- 
 ties of different orders. The zeros of the first 
 order are of no account as compared with finite 
 quantities — zeros of the second order of no ac- 
 count as compared with those of the first — zeros 
 of the third of no account as compared with the 
 second — and so on. In practical astronomy we 
 liave the other end of tlie scale — infinites instead 
 of infinitesimals — successive orders of largeness 
 and grandeur g.radually ascending into the dizziest 
 higlits of sublimity, to each of which that below 
 it is as nothing. 
 
 On comparing among themselves the various 
 distances of the tnembers of our planetary system 
 from the sun, certain interesting facts become aj)- 
 parent. At our distance that lumhiary appears — 
 you know how large — and so bright that you can 
 not look at it a single moment with unwounded 
 eyes. The brightest flame disappears when held 
 up between it and us. At our equator men get 
 from its disc an average temperature of 70° or 
 
110 FOURTH LECTURE. 
 
 80° Fahrenheit. Now, suppose our thoughts tc 
 I e chariots, and let us travel off in them toward 
 the sun. At the distance of Mercury, the sun 
 would appear six times larger and brighter than 
 it did on the earth, and must be that number of 
 times hotter — other things being equal. What 
 a summer-two o'clock in the afternoon the Mer- 
 curians must have ! If the supposed planet 
 Vulcan were real, the sun from it would appear 
 fifty times as large and bright as it does at the 
 earth ; and the mean heat at the most exposed 
 parts of the planet would be more than 3000°. 
 What a long thermometer, not to say incombus- 
 tible, must the Vulcanians require ! Going on 
 still, as we near the surface of the sun, it expands 
 so as to fill a half-heaven with its disc, and the 
 heat is now three hundred thousand times what 
 we have been accustomed to on the earth. Had 
 we not had the^ prudence to provide ourselves with 
 a jerkin of the very best asbestos, were not our 
 thought-chariot itself a salamander safe of the 
 very best quality, our traveling would now be 
 for ever ended. But, as it is, we are able to pass 
 around the sun ; and then, speeding outward as 
 only thought-chariots, fancy-driven, can — past 
 belted Jupiter, past Saturn with its tlu'ee won- 
 drous rings — we stop not till we reach Neptune. 
 Looking back, we see the sun dwindled to the size 
 of Venus — nine hundred times less than we saw 
 it from the earth, and nine hundred times as dim 
 
DISTANCES FROM THE SUN. Ill 
 
 and cold ; and yet giving as mucli liglit as six 
 hundred of our moons. And, if our courage 
 does not fail us on these dim frontiers and with 
 the thermometer already standing some 50,000° 
 below zero — if it is not too much of a transition 
 even for us, thought-pavilioned as we are, to pass, 
 all in a single minute, from the immeasurable 
 furnace of the sun to the immeasurable refriger- 
 ator of the very pole of our planetary system — 
 let us keep on one stage further to where the sun 
 appears a star of inappreciable diameter, and 
 where, in the heart of eternal night and of infinite 
 congelation multiplied by two liundred and fifty- 
 six, cruises the last known picket of our planetary 
 system, the comet of 1680. We can not deny 
 that, if worlds thus situated are peopled, it must 
 be with beings very differently constituted from 
 ourselves. And what of that ? We will not be 
 guilty of the unphilosopliy of assuming that the 
 Infinite Creator has made but one pattern of liv- 
 ing creatures, or that the patterns are not as 
 various as the circumstances of the spheres which 
 liis almighty liand has shaped and sent whirling 
 through the void. 
 
 You notice that I have spoken of average dis- 
 tances from the sun. I did this, because I did 
 not wish to assume what is contrary to fact ; viz., 
 that the orbits of the planets and comets are cir- 
 cular. Instead of being circles, tliey are all ellip- 
 ses. This does not follow from the law of gravity, 
 
112 FOURTH LECTURE. 
 
 as some treatises on astronomy seem to intimate. 
 No body revolves about another through force of 
 gravity alone. Mere gravity would cause them 
 to rush together on tlie same straiglit lino. It 
 takes both gravity and a projectile force across the 
 direction of gravity to make a system of revolv- 
 ing bodies. The nature of the curve described — 
 whether a circle or one of those other sections of 
 a cone which mathematicians call ellipses, parab- 
 olas, and hyperbolas — depends on the relation 
 which the attracting force bears iu amount and 
 direction to the projectile. Now, as we do not 
 know what the force and direction were with 
 which Deity launched the various members of our 
 system into space, we are forced to rely on obser- 
 vation to settle the nature of tlie curves tliey 
 describe. Let us then observe. If the orbits 
 were exact circles, tlie law of gravity would 
 cause them to be traversed at a constant pace. 
 The apparent daily motion of the same body, as 
 seen from the sun, would be always the same. Is 
 it so in the case of any member of the system ? 
 In no single case, whether of comets or planets. 
 In that of the earth, its apparent daily motion 
 as seen from the sun — which is the same as that 
 of the sun as seen from the earth — is observed to 
 be quite unequal. It is also noticed that there is 
 a variation in the apparent diameter of the sua 
 iu the course of the year ; showing that we arc 
 at greater d' itances from it at some times than at 
 
SHAPES AND INCLINATIONS OF ORBITS 113 
 
 others. So we both satisfy ourselves that our 
 orbit is an ellipse, and can tell just how elliptical 
 it is. To find the exact form of the other orbits, 
 and their inclinations if any, to our own, we can 
 manage thus. You know that, if Cuvier found a 
 single bona of an animal, he could build up the 
 whole creature and picture it to you in just 
 the size and shape with which it walked the 
 earth twenty thousand years ago. In a similar 
 manner, astronomers can, from a small piece of 
 an orbit, build up the entire thing for usi just as 
 it stands in nature ; give us its exact shape and 
 size and bearing in space, in fact, a perfect fac- 
 simile. Any piece that you can cut out of a 
 given circle will not fit any other circle, or any 
 other curve line whatever. Each kind of curve, 
 and each specimen of a given curve, has its own 
 law of curvature. The problem, then, is to get a 
 true piece of each orbit — to find the single bone 
 from which to reconstruct the mastodon. If you 
 could only place yourself at the sun, and draw 
 innumerable lines of know;n length to points oc- 
 cupied successively by a planet, you could by con- 
 necting the extremities of these lines get its real 
 path. Now this you can do, in efiect, by finding 
 its apparent daily motion, as seen from the earth, 
 at two times sufficiently apart to give you a sen- 
 sible difference between the motions ; also care- 
 fully noting the amount and direction of the 
 motion during tlie interval. These elements, re* 
 
114 FOURTH LECTURE. 
 
 duced to what they would seem at the sua, have 
 certain definite mathematical relations to the lines 
 desired, by means of which they may be drawn to 
 any extent, and so the astronomer maps down a 
 section of the orbit just as it stands in nature. 
 Tims standing, that bit of a curve has wrapped 
 up in it all tlae characteristics of the entire orbit, 
 and they may be pressed out of it by the hydraul- 
 ic press of rigorous mathematics. You may press 
 out of it the eccentricity, the inclination to our 
 orbit, the place of intersection, tlie place of near- 
 est approach to tlie sun. In this way we can find 
 that all tlie planetary orbits are ellipses, differing 
 but little from circles, and all — those of the aste- 
 roids excepted — lying in nearly the same plane , 
 while the comets revolve on ellipses of great ec- 
 centricity, wliicli lie across the orbits of the planets 
 and incline to them at all angles. In some few 
 instances the broken pieces of cometary orbits 
 have seemed to belong to parabolas instead of 
 ellipses ; but the observations were too rough to 
 be reliable. If parabolas, the bodies traversing 
 them, on going away from the sun, would never 
 return. 
 
 Observation shows that all the planets, aud all 
 their satellites, excepting tliose of Uranus, revolve 
 in the same direction, from vrest to east. The 
 comets are not at all particular about following 
 this example. Having set up in business on a 
 principle of eccentricity, each goes off about the 
 Bun in the direction thai pleases him. 
 
SIZES OF SUN AND PLANETS. 115 
 
 How large are these astronomical neighbors 
 and companions of ours — this sun, these planets, 
 these comets, most of whom look so small ? Have 
 we been spending our time in considering the 
 order a:id periods and distancas and orbits of 
 what, after all, are scarcely more than rounded 
 pebbles ? Having already found the size of the 
 earth to be something considerable, we have a 
 curiosity to see how it compares with that of our 
 fellow-travelers about the sun, as well as with 
 that of the monarch himself. Are we so much 
 larger than them all that we can plume ourselves ; 
 so much larger as to give color to the ancient 
 notion tliat tlie axis of the earth is tlie axle of 
 the universe ? The fact that the earth is not tlie 
 center of the system discourages the idea, Also 
 these tremendous distances from us at which our 
 Admiral Sun is anchored and his subalterns sail, 
 taken in connection with the appreciable discs 
 whicli most of them show in the field of the tele- 
 scope, give us still furtlier inkling that they must 
 be bodies of extreme magnitude. But let us 
 reduce the matter to figures. How large does 
 the diameter of the sun appear to the eye ? So 
 many minutes and seconds. What is its distance 
 from us ? So many miles. With these data, a 
 single "jproportion and a single triangle give 
 885,680 miles for the real diameter — making a 
 Bpace within vvliich might nearly be described two 
 whole orbits of the moon. This makes our astron- 
 
116 FOVITH LECTURE. 
 
 omical chief one and a half million times larger 
 than ourselves. A very Caesar and Charlemagne I 
 The process for those of the planets which 
 have appreciable discs, as well as for all the 
 comets, is the same ; only we have to reduce tlie 
 apparent diameters at the earth to what they 
 would be at the sun, in order to \ise the mean 
 distances, which are always given from the center 
 of the system. Thus we get the following real 
 diameters, in round numbers : of Mercury, three 
 thousand miles ; of Venus, eight thousand ; of 
 Mars, four thousand; of Jupiter, eighty-nine thou- 
 sand ; of Saturn, seventy-nine thousand ; of Ura- 
 nus, thirty-five thousand ; of Ncptuue, thirty-one 
 thousand. As the asteroids have no apparent 
 discs, we do not know precisely their size ; but, 
 knowing their distances, we can make certain that 
 none of them exceed one Imndred and sixty miles 
 in diameter. Tlicy are the infants of the plane- 
 tary family — the fledglings of the planetary flock 
 — the pinnaces and nautiluses of the planetary 
 fleet. As to the comets ; they are of all sizes, 
 from mere specks of a score of miles across, to 
 such a mighty cloud as the great comet of 1811 
 with its head of 947,000 miles in diameter, and 
 train of one hundred and thirty-two millions in 
 length. However, the same comet varies exceed- 
 ingly in size, expanding as it approaches the sun 
 and contracting as it retires into the frosty sub- 
 urbs of the system. 
 
VELOCITIES OF PLANETS. 117 
 
 So we see that, while many of our astronomical 
 neighbors are smaller than tlie earth, some of 
 them are vastly larger — so much larger that 
 the earth is a mere babe by the side of them. 
 But we must not fall out of conceit with our 
 little planetary home. The bulkiest bodies are 
 not always the best. The largest homes are not 
 always tlie happiest. The largest empires are 
 not always tlie most prosperous, or powerful even. 
 Would you see a famous land ? Look to little 
 Greece, and not to mammoth China. Would 
 you see a theater of great actions and sublime 
 events ? Look to little Thermopylae, and little 
 Austerlitz, and little Calvary — not to New York 
 nor London. Still, it does undoubtedly tend to 
 modesty in us to compare the narrow limits of 
 our present abode with the magnificent propor- 
 tions of such planets as Saturn and Jupiter, and 
 especially of the tremendous suu ! We are 
 obliged to confess ourselves and our home mere 
 atoms. And if we are so happy and so philo- 
 sophic as to have a religious turn of mind, per- 
 haps we shall bow our heads and say, " What is 
 man that Thou art mindful of him ! " 
 
 See now the wonderful velocities that must 
 prevail among some of these great bodies ! Know- 
 ing their mean distances from the sun and their 
 periods, we readily calculate their average hourly 
 pace on their orbits. Msrcury moves one hun- 
 dred and nine thousand miles an hour, Venus 
 
118 FOUSTB LECTURE. 
 
 eighty thousand, Earth sixty-eight thousand, Nep- 
 tune eleven thousand, the comet cf 1680, at 
 its fastest, eight hundred and eighty-four thou- 
 sand miles an hour. We have wondered at the 
 great pace of the eagle, of the winds, of the can- 
 non-ball, of the moon with her fifty-four thou- 
 sand miles a day ; and yet the moon, on her 
 monthly journey about us, is but an indifTcrcnt 
 traveler compared with the most leisurely of the 
 planets. They all seem as if on some urgent 
 errand — some errand of life and death. When 
 one is resting his weary body from a third to a 
 half of his whole time, and happens to think of 
 the tremendous and remorseless activity of those 
 great revolving spheres, he is discontented with 
 himself. What miraculous fleetness ! What if 
 those flying orbs should, through some want of 
 balance in the system, encounter each other in 
 mid-heaven ! 
 
 We weighed off the earth against a Scottish 
 mountain. We weighed off the moon against the 
 earth, by means of the tides. Can we not also 
 weigh the other planets, and even the sun itself, 
 in some great astronomical balance ? Yes : one 
 of the easiest things in the world — at least so far 
 as the sun is concerned. And, first, we may 
 R'eigh the sun, as we did the moon, by means of 
 the tides. Another method is by comparing the 
 curvatures of the terrestrial and lunar orbits. 
 In this way, we really compare the attractions of 
 
MASSES AND DENSn:^S. 119 
 
 the sun and earth at different distances ; for, of 
 course, the degree of curvature depends on the 
 force of gravity at the center. A simple propor- 
 tion will then compare their attractions — that is 
 to say, their quantities of matter — at the same 
 distance ; since they vary inversely as the squares 
 of the distances. In this way we may find that 
 the sun has three hundred and fifty-two thousand 
 times the earth's quantity of matter. It would 
 weigh down three hundred and fifty thousand 
 earths ! The philosopher sits with scales in his 
 hands — as Homer says Jupiter did on Ida, to 
 weigh the contending fates of Greece and Troy. 
 He puts the earth into one scale, and rolls the 
 sun into the other. Instantly the earth flies aloft 
 with tremendous precipitation. He throws in 
 two worlds like ours — ten — one hundred — one 
 thousand — with scarcely better success. In a fit 
 of impatience, he trundles all the earths he has 
 into the capacious scallop. At last an equipoise 
 seems establishing : the scales hang see-sawing ; 
 and, at last, settle into motionlessness at the same 
 level. With mingled curiosity and astonishment 
 he counts up those terrestrial globes, and finds 
 Ihem three hundred and fifty-two thousand in 
 number. Knowing the quantity of matter in the 
 sun and its size, we can find its density, or rela- 
 tive compactness of matter, to be only one-quarter 
 that of the earth. In a similar way, we may find 
 the masses and densities of all the planets that 
 
120 FOURTH LECTURE. 
 
 have satellites with orbits of known dimensions. 
 As to those planets which have no such satelHtes, 
 their masses are known from their effect in dis- 
 turbing the motions of tlieir nearest planetary 
 neighbors. For example, compare tlie curve 
 whicli the earth when nearest Venus actually de- 
 scribes with that we should describe in case 
 Venus exerted no attraction on us, and we have 
 a measure of her attracting power or quantity of 
 matter. So of the rest. In tliese ways we can 
 reach the following results. Jupiter and Uranus 
 have about the density of water ; Mercury, Venus, 
 Earth, Mars, a density from five to six times 
 greater ; while Saturn and Neptune have scarcely 
 more than one-tenth of the solidity of our own 
 globe. Though comets are so numerous — mil- 
 lions, in fact — and some of them occupy sii.ii 
 immense spaces, the quantity of matter in iho 
 total of them is exceedingly small ; estimated by 
 careful men at only -^-^ of that contained in 
 the earth. You can see stars tlirough their 
 trains, and sometimes through the very nuclei. 
 They liave sometimes passed very near to planets 
 without sensibly disturbing their motions. They 
 are mere planetary fogs. And, summing up, it 
 appears that the sun contains more than eight 
 hundred times as much matter as all the ether 
 members of the system put together. 
 
 All the orbits of our system are continually 
 undergoing small changes, through the mutual 
 
PERTURBATIONS. 121 
 
 attractions of its various members. Tliey ex- 
 pand, they contract, they rock, they turn com- 
 pletely round in the same plane, their points of 
 intersection with our orbit travel round through 
 the whole circumference of the lieavens. This 
 fact gave rise, years ago, to much perplexity, 
 many hard problems, many grave fears. It was 
 feared that these gradual changes might so com^ 
 bine and accumulate in process of time as to 
 throw the whole system into disorder and wreck, 
 dashing planets against planets in hideous con- 
 cussion and disaster. At last the great geometers 
 Euler, La Place, and La Grange, undertook to 
 settle mathematically whether the changes in the 
 orbits were of such a nature as to conduct to 
 such a deplorable issue. At last the mighty 
 problem stood resolved. It was found that, in 
 the particular case where the central body of a 
 system is vastly heavier than all the rest, and all 
 the planetary orbits nearly circular, and nearly 
 in the same plane, and traversed in the same 
 direction — all of which features, as we have 
 seen, belong to our system — there are two 
 things about every orbit that can never change ; 
 viz., the greater axis and the period. For exam- 
 ple, our mean distance from the sun, as found 
 for a single revolution, can never vary ; nor can 
 the length of our true year. Next, it was proved 
 that in such a system all the changes that do 
 occur must be periodical, flowing and ibbing like 
 
122 FOURTH LECTVBE. 
 
 the tides of the sea — enlarging for perhaps mil- 
 lions of years, and then returning to the old 
 point. So the stability of tlie system stands de- 
 monstrated. It has in itself no seeds of deatli. 
 The invisible bonds of the law of gravity hold the 
 amazing leviathans of the sky so strongly and 
 surely that they can not escape from tlieir splieres. 
 The system was built capable of standing for ever. 
 And yet how easily it could have been otherwise ! 
 Suppose tlie sun had not been made vastly heavier 
 than all the other bodies ; suppose Deity had 
 not so tempered the projectile force, in amount 
 and direction, to the force of gravity of each 
 planet as to make it describe nearly a circle ; 
 suppose he had shot off tlie planets at all sorts 
 of angles with reference to each other — and he 
 might have done each of these things ; indeed it 
 required care not to do them — then tlie system 
 would have been unstable, and, sooner or later, 
 our whole Congress of worlds would have gone 
 plunging together in frightful and unutterable 
 catastrophe. 
 
V. 
 
 HIGHER SYSTEMS. 
 
V. Higher Systems. 
 
 1. SUN SYSTEMS 115 
 
 I. GROUP SYSTEMS 137 
 
 3. CLUSTER SYSTEMS 138 
 
 4. NEBULA SYSTEMS 140 
 
 5. ULTERIOR SYSTEMS ........ 141: 
 
 6. ULTIMATE SYSTEM 14S 
 
FIFTH LECTURE. 
 
 HIGHER SYSTEMS. 
 
 AS an example of the Satellite Systems, I have 
 described the earth and the moon. As an 
 example of the Planet Systems, I have described 
 our sun with its revolving planets and comets. 
 We come now to systems of the Third Order — 
 Sun Systems — each of which consists of two or 
 more planet systems revolving about their com- 
 mon center of gravity. 
 
 More than six thousand fixed stars, so called, 
 that appear single to the naked eye or to some 
 powers of the telescope, are found to consist, each 
 of several stars, when proper glasses are brought 
 to bear upon them. Some are double, some triple ; 
 and in one case six stars are found to make up 
 what appears a single star to the unassisted eye. 
 The list of these compound stars enlarges every 
 year. Recently, a very important addition has 
 been made to the list by the discovery that great 
 Sirius, the glory of our winter nights, is double. 
 
 126 
 
126 FIFTH \ECTURE. 
 
 An American has the honor of this discovery, and 
 of receiving for it the La Lande prize from the 
 French National Institute. 
 
 It is to certain of the double stars that I would 
 first ask your attention. Look at the bright star 
 Castor. Had you a good telescope bearing on it, 
 you vsrould find it to consist of two nearly equal 
 members. And, could you follow from year to 
 year the bearings of these two members with re- 
 spect to each other, you would, in time, find one 
 of them in course of revolution about the other — 
 just as the moon is about the earth, and the earth 
 about the sun. What does this mean ? Why, it 
 means one sun with its attendance of planets re- 
 volving around anothersun with its attending plan- 
 ets. That these stars in Castor are self-luminous 
 bodies we know from the character of their light, 
 as well as from the impossibility that bodies shin- 
 ing by mere reflection of light from our remote 
 sun or from any neighboring star equally remote, 
 should be visible at such vast distances from is 
 as all the fixed stars must be. That each of 
 these suns is the center of a planetary cohort 
 that brilliantly escorts him on his way, we infer 
 from the analogy of our own system and from the 
 wisdom of the Creator. When we see a lamp in 
 a house, we infer the neighborhood of some per- 
 sons who need the light ; when we see the pier- 
 cing Fresnel blaze of the light-house pouring far 
 and wide across the darkling seas, we believe in 
 
SUM SYSTEMS. 12; 
 
 roving ships to be guided and benefited by it ; 
 and when we lift our eyes to wliere a sun blazes 
 as a celestial Eddystone through pitchy space, we 
 conclude that there are bodies needing to be 
 lighted and cheered by its beams, just as the bodies 
 of our planet system need to be lighted and 
 cheered by our solar orb. Thus we have a new 
 and higher order of systems for our astronomy. 
 Behold a sun revolving about a sun, a planet sys- 
 tem about a planet system ; necessarily, two planet 
 systems about their common center of gravity. 
 
 Now more than a hundred such pairs of stars 
 have been caught in the act of revolution. The 
 Pole Star is one of them. A famous star in the 
 Constellation of the Swan, known as 61 Cygni, 
 is another. In the case of some of these stars, a 
 complete revolution has been accomplished since 
 attention was directed to them ; in one case, two 
 full revolutions have been completed. But these 
 revolving suns are not confined to sets of two. 
 There are sets of three, of four, of more stars — 
 in each of which the members have about the same 
 brightness and distance from each other, and are 
 in the course of years observed describing curved 
 lines among themselves. Evidently, more systems 
 of the third order — suns with tlieir escorts of 
 planets revolving, without any intermediate mo- 
 tions, about their common center of gravity. In 
 addition to these systems whose revolutions we 
 Bee, there are multitudes of others whose revolu- 
 
128 FIFTH LECTURE. 
 
 tions we do not see, on account of their distance 
 or slowness ; but of which we are just as certain 
 as if we saw them. Since the beginning of tlie 
 century, has ripened one of the most important of 
 the sciences, under the name of the Calculus of 
 Probabilities — a branch of that subtle and power- 
 ful Differential and Integral Calculus which has 
 served the Prosperos of astronomy, not only to put 
 a girdle around the earth, but also around the 
 whole visible heavens. According to this science, 
 there is no chance worth considering, that any stars, 
 optically so close together as to appear single to 
 the naked eye, are not actual neighbors in 
 space, and so in course of mutual revolution. 
 This principle gives us more than a thousand ad- 
 ditional sun-systems. But these are not all. 
 Many stars that do not appear single to the naked 
 eye are proved to constitute similar systems, by 
 the identity of what are called their proper mo- 
 tions. Tliousands of stars are found creeping 
 along the sky, not on curves, but on straight lines. 
 The progress is exceedingly slow — scarcely aver- 
 aging more than yj,^^^ of the moon's apparent 
 diameter per annum. Now, whether this is due 
 to our own motion, or to that of the stars them- 
 selves, or to both, it could not be the same both 
 in amount and direction, in the case of two or 
 more optically near stars, without their being 
 actually near each other in space, and so forming 
 a mutually revolving system. This principle en- 
 
8UN-STSTEMS. 129 
 
 ables us to make another large addition to the 
 number of our sun-systems. Yonder are Mizar and 
 Alcor, two stars in the tail of the Great Bear, 
 more than a third of the moon's diameter apart, 
 which are thus proved to compose a sun-system. 
 They are creeping across the sky in company ; 
 going in just the same direction, and at just the 
 same pace. Prom satellite neighborhoods we 
 have risen to planet neighborhoods ; and now, 
 from these, we have evidently risen to grand solar 
 neighborhoods, where orbed sun* go grandly 
 wheeling about suns, carrying with them in insep- 
 arable union their glittering retiimes. 
 
 How far from us are these sun-systems ? At 
 one time astronomers almost despaired of being 
 able to answer this question. They found that 
 the method used for finding the distances of the 
 moon and sun from us would not apply to the 
 fixed stars. No change in onr place on the earth, 
 though it has a diameter of eight thotisand miles, 
 caused the slightest change in the apparent place 
 of any of those twinkling points. If we could 
 only travel off two or ten times eight thousand 
 miles on a straight line ! Well, can you not — 
 do you not ? Do you not, every year of your life, 
 make a vastly greater travel than that ? Is not 
 the earth sailing away with you about the sun at 
 the rate of sixty-eight thousand miles an hour, 
 and so at the ends of every six months putting 
 you at the opposite extremities of a straight line 
 
130 FIFTH LEOTUBE. 
 
 one hundred and ninety millions of miles long ? 
 So observers set themselves to see whether such a 
 monster base line as the diameter of the earth's 
 orbit would make any impression on the places 
 of the fixed stars. Their triangles informed them 
 that iu case a star should be displaced on the sky 
 less than the eighteen-hundredth part of the 
 moon's apparent breadth, by their going that im- 
 mense distance, it must be more than one hun- 
 dred thousand times that distance from them. 
 And they could not find any star that showed a 
 clear annual displacement of even that small 
 amount. So they put up their bulletin, and in- 
 formed the world that no fixed star could be 
 nearer to us than one hundred thousand times one 
 hundred and ninety millions of miles. A most 
 bewildering distance ! It would take light itself, 
 that fleetest of known travelers, that Mercury of 
 science, whose pace is one hundred and ninety- 
 two thousand miles a second, more than three 
 years to sweep across it. Here it was feared our 
 knowledge must end. We could tell the point 
 from us within wliich the fixed stars could not be ; 
 but their actual distances, who could ever know ? 
 But Providence was kiud. It gave the world, at 
 length, a Bessel to bridge over that tremendous 
 chasm between us and the sun-systems of remote 
 space, and set up mile-stones along it — ^ a man 
 who found himself able to measure a smaller bit 
 of tiie sky than one second, who found that by 
 
SUA^-STSTEMS. 131 
 
 management he could make sensible in liis as- 
 tronomy even so trifling a fraction as the thou- 
 sandth part of a second — a man who could not, 
 indeed, like one of his countrymen, write him- 
 self, " By the grace of God, King of Prussia," but, 
 what was far better, who could write himself, 
 " By the grace of God, King of Prussian astron- 
 omers." He found that, by going over the whole 
 diameter of the earth's orbit, one would alter the 
 apparent place of the double star 61 Cygni about 
 one-third of a second. This makes its distance 
 from us three hundred thousand times one hun- 
 dred and ninety millions of miles — an interval 
 which it takes light nine years to traverse. 
 
 This was in 1838. Since then, about forty stars 
 have yielded up their distances from us to our 
 curiosity. The nearest sun-system yet found be- 
 longs to the southern hemisphere — Alpha Cen- 
 tauri, the brightest star in the Centaur, and in- 
 deed in the whole southern vault. This is only 
 one-third as remote as 61 Cygni. The Pole Star 
 system, on the other hand, is five times as remote 
 — one million five hundred thousand times one 
 hundred and ninety millions of miles. The mar- 
 iner and the fugitive have used light to guide 
 them on their way which has been forty-six years 
 in coming to them for that purpose. 
 
 One would like to know how large these i-c- 
 volving suns are ; how they compare in this re- 
 spect with our sun. If they showed real diame- 
 
132 FIFTH LECTURE. 
 
 ters under the telescope, we conld at once make 
 the comparison. But they do not. So we are 
 driven to another method of a less satisfactory 
 kind, but still one that will help us to some just 
 idea of how the different suns of space comi)are 
 with each other in magnitude. Delicate instru- 
 ments have been invented for measuring the rel- 
 ative amounts of light from the heavenly bodies. 
 With what is perhaps the best of these instruments, 
 it is concluded that we receive twenty-two thousand 
 million times the light from our sun that we do 
 from the sun-system Alpha Centauri. But that sys- 
 tem is two hundred thousand times further away. 
 Hence it follows, that, if it were brought as near to 
 us, it would give a little more than twice as much 
 light as our sun ; that is, each of the two nearly 
 equal suns that compose the star is about equiva- 
 lent, in the matter oflight, to our luminary. In the 
 same way we find that the 61 Cygni system gives 
 about half as much light as our sun ; making 
 each of its two nearly equal members equivalent 
 to a quarter of our sun. The Sirius system is 
 equal in light to sixty-three of our suns ; the Pole- 
 Star system to eiglity-six. In each of these, the two 
 stars composing the system differ exceedingly 
 from each other in brightness, and the larger star 
 must be credited with most of the brilliancy. 
 Think of an eighty-fold sun ! However, some 
 stars are still more astonishing ; Vega, for ex- 
 ample, which blazes with the light of three hun- 
 
SUN-STSTEMS. 13;! 
 
 dred a/id forty-four suns ; Capella, -for example, 
 whic!i blazes with the light of four hundred and 
 thirty ; Arcturus, for example, which blazes with 
 the light of five hundred and sixteen ; Alcyone, 
 for example, which blazes with the light of twelve 
 thousand ! As we have seen, our sun is no trifle. 
 Its astonishing orb would nearly fill the whole lu- 
 nar orbit; and would weigh down, eight hundred 
 times over, its whole ponderous cortege of satel- 
 lites, planets, and comets. And yet it is only one 
 of the lesser liglits of space. Not the smallest, in- 
 deed — forbid it, little 61 Cygni — but still a 
 mere rush-light and glow-worm as compared with 
 many of the huge luminaries which pour their 
 glories adowu the immensity of nature. It could 
 not remain visible a moment in the presence of 
 such golden-haired and majestic day-kings as even 
 Sirlus and Polaris to say nothing of those huger 
 mouarchs whose effulgence floods the celestial 
 spaces. 
 
 Knowing the distance of one of the systems 
 from us, we can find how far apart its members 
 are at any time, by observing the apparent dis- 
 tance between them. The two suns of Alplia 
 Centauri are apart by only seven diameters of the 
 earth's orbit — something less than the distance 
 of Uranus from our sun — so that planets belong- 
 ing to the system will sometimes have two suns 
 above the horizon at once, while at another time 
 one sun will rise while the other sets. The two 
 
134 FIFTB LECTURE. 
 
 Buns of 61 Sygni are apart by twenty-one diame- 
 ters of our orbit ; those of the Pole Star by one 
 iiundred and five diameters ; Mizar and Alcor by 
 at least five tliousand diameters — five thousand 
 times one hundred and ninety millions of miles — 
 a line on which could be ranged three hundred 
 and sixty planet-systems like ours. 
 
 Several of these systems having made entire rev- 
 olutions since tliey began to be scrutinized, we may 
 be said to liave seen their periods. Others have 
 advanced so far on their orbits that we can readily 
 estimate the times required to accomplish the re- 
 mainders. And others still have been under ob- 
 servation sufficiently long to furnish us with very 
 considerable pieces of the curves they describe; 
 from which, like the naturalists, we can build up 
 the entire orbits, and press out of them by our 
 powerful geometry all their characteristics — 
 among other things, the periods and ellipticities. 
 The periods differ among themselves wonderfully. 
 One is forty years ; that of Alpha Centauri is 
 seventy-seven years ; that of 61 Cygni four hun- 
 dred and fifty-two ; another three thousand ; and 
 that of Mizar and Alcor must be something like 
 two hundred thousand years ! Wonderful year 
 of two hundred millenniums ! Wonderful orbits 
 also, as far as observed — wonderful for their el- 
 lipticity ! In one case, that of Alpha Centauri, 
 the orbit is five times as long as it is broad. 
 What extremes this means may be seen from the 
 
SUJf-STSTEMS. 135 
 
 case of Halley's comet. This body has an orbit 
 four times as long as it is broad ; and the con- 
 sequence is, that, while at, one point it ap- 
 l)roaches the sun as near as Mercury, at another 
 it"recedes from it six hundred millions of miles 
 beyond Neptune — the least distance from the sun 
 being to the greatest as one to eighty-five. Such 
 variations would be fatal to an inhabited earth ; 
 but to a sun, that movable furnace that carries 
 its own light and heat with it wherever it goes, 
 what matters it how far it strays off from its cen- 
 tral orb into the cold of space — to a sun that is 
 never at less than white heat, what matters it if it 
 sometimes gets a good deal whiter ! We may be 
 sure, however, that those sun-systems which con- 
 sist of three or more suns do not contain such 
 eccentric orbits. It would be inconsistent with 
 their stability. As our planet system would fall 
 to ruin were not its orbits nearly circular, nearly 
 in the same plane, and controlled by a force at 
 the common center of gravity greatly superior to 
 any individual force in the system, so would 
 every higher system made up of more than two 
 members. 
 
 Before dismissing these sun-systems, I rnust say 
 a word as to their color. All the colors of the 
 rainbow are represented in them. Some sys- 
 tems are white, some blue, some red, some yellow, 
 some green ; and this, you will observe, means 
 differently colored days for tlie planets of those 
 
136 FIFTH LECTURE. 
 
 systems. Castor gives his planets green days. 
 The Pole Star gives his yellow. There are more 
 than sixty blue systems, one of these consisting 
 of a great number of members. In the southern 
 hemisphere are stars, yet to be found double, 
 which in the telescope look like drops of blood — 
 all about tlie constellations of the Cross and 
 Altar, as if to gloriousl}' symbolize the sprinkled 
 blood of our redemption. Also the suns of the 
 same system often have different colors ; one 
 shining like an emerald, another like a ruby, and 
 perhaps a third like a sapphire. And, as if t@ 
 make that Southern Cross the fairest object in all 
 the heavens, we find in it a group of more than 
 a hundred variously-colored I'ed, green, blue, and 
 bluish-green suns, so closiely thronged together as 
 to appear in a powerful telescope like a superb 
 bouquet, or piece of fancy jewelry. Let no one 
 say that the Creator, who makes gems and flow- 
 ers for the earth, and sets gems and flowers in 
 the sky, cares not for natural beauty : though 
 it be most true that the ' beauties of holiness, es- 
 pecially from the womb of the morning, when 
 thou liast the dew of thy youth,' are still more 
 precious in his sight. 
 
 Group-systems 1 Near the bright blue star 
 Vega is a star which the telescope finds to be 
 quadruple. The four stars are arranged in pairs 
 — the pairs being many times further apart than 
 
GEOUF-STSTEMS. 137 
 
 are the individuals of each pair. The whole 
 form a system by themselves; as is shown by the 
 sameness in amount and direction of their proper 
 motions. But, grouped as they are, the law of 
 gravity requires each pair to i-evolve around its 
 center of gravity, and then both pairs about their 
 common center of gravity. The revolution is 
 not seen, as in the case of many double stars ; but 
 we are just as sure of its reality as if we saw it. 
 
 In Orion is a star which the telescope finds to 
 be sextuple. The six stars have all the same 
 proper motion, and so are neighbors in spacei 
 Pour of them are at about the same distance from 
 each other ; but two of these have each a small 
 companion much nearer to it than are the others. 
 The law of gravity requires each pair to form a 
 revolving group by itself, and then all the spheres 
 to wheel about the common center of gravity of 
 the whole. That superb wheeling is not seen, on 
 account of distance; but we are just as sure of 
 it as if we saw it. Another Group-system ! 
 
 Look at the famous and beautiful Pleiades ! 
 Gathered about the brightest star of the group 
 Alcyone, the telescope sees fourteen conspicuous 
 stars. These are all creeping along the sky, 
 equally fast and in the same direction. The cal- 
 culus of probabilities assures us that the chances 
 are hundreds of millions to one against their 
 being merely optically connected. They form 
 
138 FIFTH LECTURE. 
 
 one grand astronomical neighborhood in space, 
 aromd whoso center of gravity they all revolve ; 
 one grand company of celestial navigators, ex- 
 ploring their way by unerring instinct, witliout 
 chart or compass, through trackless space. But, 
 if you should see a map of these fourteen stars, 
 you would find them distributed into several 
 groups, each of which must contain its own cen- 
 ter of revolution, while all these centers must be 
 borne in majestic sweep about the gravity-center 
 of the whole sparkling family. Invisible or- 
 bits within orbits ; but as certain as if we saw 
 their fiery ellipses burnt into the dark concave 
 of evening ! The distance of this group-system 
 from us has been determined by the determina- 
 tion of the distance of Alcyone ; and is twenty-five 
 million diameters of the earth's orbit. Were tlie 
 Pleiades this moment blotted out of existence, 
 they would still blaze away in the neck of Taurus 
 for more than seven hundred years ; for that is 
 the time spent by light in passing from that sys- 
 tem to us. 
 
 These specimens of the gr.oup-systems must 
 suffice. We pass to the next higher order — 
 Cluster Systems. 
 
 There are thousands of small roundish spots 
 on the sky which, when examined by telescopes, 
 prove to consist of crowded stars ; sometimes 
 uniformly distributed ; in other cases, gradually 
 
CLUSTER-STSTMMS. 135 
 
 Oecoming denser till all individuality is lost in a 
 general blaze of liglit at the center ; and in other 
 cases still, arranged into several nuclei wliich lie 
 quite evenly over the mottled face of the cluster. 
 On examining tlie nuclei carefully, thrsy are some- 
 times found to consist, each, not of a single group, 
 but of a cluster of groups. Behold systems of 
 the Fifth Order ! The artificial form of each gen- 
 eral cluster, and the chasm of black space all 
 around it, show that it is a system by itself in 
 space, with its one center of revolution for all the 
 nuclei. Then each nucleus has its own subordi- 
 nate center for all the groups composing it ; and 
 next, each group has its still more subordinate 
 center for all the suns composing it. Many of 
 these great systems must contain from ten to 
 twenty tliousand stars each. Think of a system 
 made up of twenty thousand revolving suns ; each 
 sun with its planets occupying at the same time 
 a three-fold orbit, and spinning at once around 
 three widely separated centers — first, around the 
 center of the group ; next, around the center of 
 its cluster of groups ; and then, around the center 
 of the whole great cluster ! 
 
 As an example of these cluster-systems, I in- 
 stance a cluster found in the constellation 
 Hercules. It is famous among astronomers as 
 being the grandest object of its class in the 
 whole heavens. When Sir William Herschel saw 
 it fur the first time through liis great reflector, it 
 
140 FIFTH ZECTURE. 
 
 almost made liim leap, with mingled astonishmeul 
 and delight. An eminent astronomer doubts 
 whether any person ever saw it for the first time, 
 through a large telescope, without a shout of won- 
 der. Certainly it is an object of wonderful glory, 
 — that golden shield of packed suns ! Sliall we 
 cdll it the segis of immortal Jove ? Call it, 
 rather, the flaming buckler of the Christian 
 Creator, hung out for sign ou heaven's blue bat- 
 tlements, and on whose thick bosses those men 
 insanely rush who, in the face of the stars, pre- 
 sume to doubt Almighty God ! The first Herschel, 
 sounding the heavens with his telescopes, con- 
 cluded this cluster-system to be deep in the 
 abyss several hundred times the distance of the 
 nearest fixed star — say some two thousand years, 
 as light travels. Its locomotive suns, with their 
 long trains of planets, do not, at bucli a distance, 
 render to our eyes those miglity three-fold curves 
 on which they are rushing; but we are just as 
 sure of their reality as though we saw them — 
 saw them as we see the orbits of binary stars — ■ 
 saw them as we see the track of the rocket when 
 it describes its flaming parabola through the air. 
 
 We advance another step, to systems of the 
 Sixth Order, — Nebula Systems ! 
 
 Scattered, or rather arranged, over the sky by 
 thousands are those bright-misty spots, called 
 nebulae, which no power of the telescope has yet 
 
NEBULA-SYSTEMS. 141 
 
 been able to resolve into stars. It las been 
 claimed that they do not consist of stars, but only 
 of a sort of fire-mist, out of which siuis and 
 planets and satellites are in process of being made 
 by natural law. There are many objections to 
 this view. But it is enough that there is not*a 
 single proved case of such fire-mist in space ; that 
 the hypothesis is altogether unnecessary to ac- 
 count for the facts observed ; and that nebulae, 
 apparently as irresolvable as any, have, by improve- 
 ments of telescopes, been turned into clusters of 
 stars. In my view, they all consist of stars, so 
 packed together by local neighborhood and un- 
 speakable distance that all individuality of im- 
 pression on the eye is lost. They are found in 
 great variety of singular and beautiful forms — 
 sometimes perfectly round, sometimes oval, some- 
 times lens-shaped, sometimes ring-shaped and 
 even consisting of a series of concentric rings. 
 One beautiful nebula resembles a crab ; another, 
 a fan ; another, an hour-glass ; another, a whirl- 
 pool, whose eddies are made evident to the eye 
 by, as it were, floculi torn from the famous 
 ^■olden fleece of Colchis. Some of tliem are 
 perfectly continuous, and uniform in appearance. 
 Others are " spotted as a pard," with numerous 
 centers of condensation : while others still are 
 broken up into more or less distinctly separated 
 nebulous patches ; like a defeated army whose 
 great corps are just in the act of separating to< 
 
142 FIFTH LECTURE. 
 
 ward all points of the compass. The groat frag- 
 ments of these routed nebulse appear in the best 
 telescopes very much as the cluster-systems do in 
 the smaller — that is to say, dappled with nuclei 
 pretty evenly distributed. They are evidently 
 cluster-systems. And, taken together, they form 
 a revolving neigliborhood in space, of another 
 order still higher — a Nebula System iii which 
 nebulaB of clusters of groups of suns sweep their, 
 at least, quintuple orbits in harmonious combi- 
 nation around the gravity-center of the whole 
 nebula. 
 
 What is the Milky Way, so called, which we 
 see belting our heavens ? Nothing but the nebula 
 to which we belong, expanded all round the sky 
 and easily resolved into stars by the fact that we 
 are in the midst of it. A little observation and re- 
 flection suffice to show that its shape is that of a 
 thick mill-stone, with its rim split in the middle for 
 about a third of its length and somewhat opened. 
 Our place is near the plane of this cleavage, but 
 considerably one side of the center. When we, 
 from our place in this cleft wheel of stars, look 
 off in the direction of the circumference, the stars 
 appear very numerous ; when we look toward the 
 sides, we see comparatively few. All the scat- 
 tered stars, all the groups, small and large, that we 
 see in any direction, belong to our Milky Way — 
 to our nebula. They are nearer to us than any 
 other stars in space. All the stars whose dis- 
 
NEBULA-SYSTEMS. 143 
 
 tances have been determined, all the multiple 
 stars whose orbits have been observed, all the 
 stars whose proper motions have been noticed, are 
 as much part of our Millcy Way as the millciest 
 part of it. All the examples of astronomical sjs- 
 tems which I have hitherto given, at least up to 
 the cluster-systems, were from this same uobula 
 of ours. And cluster-systems themselves can be, 
 easily supplied from it. If you will scan on some 
 favorable night the remoter parts of tliis white 
 Wonder, you will find that it is by no means a 
 continuous nebulous zone, but rather a succession 
 of star-clouds, many of which are mottled after the 
 manner of the cluster-systems. And such they 
 are. The whole, from satellites to sun-clusters, 
 are in process of revolution about the great force- 
 iul heart of the nebula. We know it must be so, 
 in advance of all observation. But in this case it 
 is thought that observation has made assurance 
 doubly sure. First, our sun is in motion — like 
 Castor and Polaris ; like the thousands of stars 
 that show proper motions, and, in part, because 
 they show them. A wonderful thing has been 
 noticed in that part of the heavens that is now 
 passing over our meridian southward from the 
 zenith ; the region occupied by Orion, the river 
 Po, Sirius, and especially the Dove. It has been 
 noticed that the stars in this region are gradually 
 diawing together, just as the ships of a fleet would 
 seem to do to one sailing away from them ; while 
 
144 FIFTH LECTURE. 
 
 at the opposite quarter of the sky the ^cars are 
 gradually separating, just as the ships of another 
 fleet would seem to do to one sailing toward 
 them. Great Hercules is yearly becoming huger 
 and brawnier ; his club, and especially his bow, 
 growing every year more formidable. This has 
 been going on now for a great number of years. 
 Of course, there is but one explanation. Our 
 sun, with its retainer-worlds about it, is sailing 
 away tlirough space toward Hercules, on an orbit 
 so Tast that the part of it which has been described 
 from the date of the earliest accurate observations 
 does not differ sensibly from a straight line. At 
 last, however, we shall double the wondrous cape 
 of our great ellipse ; and then the Dove will begin 
 to expand and plume her heavenly wings, while 
 champion Hercules will dwarf behind us. Bit 
 this does not determine where tlie center of mo- 
 tion is. Where is it ? Astronomers have sought 
 to answer this question, and apparently not in 
 vain. By methods which can not now be ex- 
 plained, it is found that Alcyone — most beautiful 
 star of the beautiful Pleiades — is the center of our 
 motion ; and that we are moving about it at Ihe 
 rate of more than a hundred millions of miles a 
 year, on an orbit whose diameter is" fifty million 
 times larger than that on which we move about 
 the sun. As the distance of Alcyone is approxi- 
 mately known, we can find our period. It is only 
 about twenty millions of years. 
 
NEBULA-SYSTEMS. 145 
 
 Such is our sun's center of motion. And the 
 celebrated Maedler has shown that it is also the 
 center of a great number of other suns — in fact, 
 that the proper motions of the stars in all quar- 
 ters of the heavens conform to the idea that they 
 are spurring in glorious curriculum around the 
 same point. He concludes that Alcyone is tlie 
 center of the whole nebula. And though the 
 English Astronomer Royal has recently dissented 
 from this conclusion, and though we certainly are 
 not authorized to claim for it the most absolute 
 proof, yet it is probably as much like the truth as 
 most photographs are like the persons who sit for 
 their pictures to the sun. 
 
 Mysterious continental islands of the remoter 
 heavens ! (ireatest empires of suns that have 
 yet sent greeting light to us ! There ye lie to- 
 night, seemingly steeped in breathless quietude 
 and uttermost sleep, where the earliest observer 
 saw you : and yet what mighty race-courses are 
 those on which your orbs go panting their eternal 
 rounds about the great nebular heart ! Why, let 
 us measure two of these celestial Astrodromes. 
 According to the best estimates of our own neb- 
 ula it contains some eighteen million suns ; and 
 the thickness of its golden wheel is about eight 
 million diameters of the earth's orbit, while its 
 diameter is one hundred and seventy million such 
 diameters. One of its Border States would re- 
 quire not far from one hundred millions of y=ars 
 
 10 
 
146 FIFTH LECTURE. 
 
 to put orbit about metropolis Alcyone ; and, 
 though so remote, has never been in danger of 
 parting company 'with us. There is the oval ne- 
 bula of Andromeda, just visible to the naked 
 eye and yet giving no sign of resolvability in the 
 six-foot speculum of the Earl of Rosse. A nebula 
 of which such things are true, is easily shown to 
 be so far away that the light by which we see it 
 must show it as it was at least a million of years 
 ago, instead of as it is to-night. The rays have 
 been all that time charging across the void at the 
 rate of 192,000 miles a second. At such a dis- 
 tance, its apparent diameter, half that of the 
 moon, means for the nebula a breadth of thirty 
 thousand years — the fifty-three foot reflector 
 being surveyor-general, and a light-sprite carry- 
 ing the chain. 
 
 We have found all the suns, and groups of 
 suns, and clusters of groups of suns, in each neb- 
 ula, engaged in revolution about its center of 
 gravity. Is this center itself in motion on another 
 orbit still larger ? Is each nebular fleet, instead 
 of riding at anchor in the sky, sailing away on a 
 circumnavigation more stupendous than any we 
 have yet noticed ? It is even so. There are 
 Ulterior Systems. We find nebulae disposed in 
 groups of two or more ; of about the same bright- 
 ness, coming into view with about the same power 
 of the telescope ; evidently belonging to the same 
 order of distances from us. Just as there are 
 
ULTERIOR-SYSTEMS. It7 
 
 double and multiple stars, so there are double, 
 triple, quadruple, quintuple, sextuple nebulae ; 
 and recently D'Arrest, a Dani&li astronomer, lias 
 announced that he has actually caught a nebula 
 in the act of revolving about a nebula. Very 
 likely he is mistaken ; it seems as if he must 
 be ; in any event, we need no such ocular dem- 
 onstration. We have long been as sure of re- 
 volving nebulae as if wo had seen them — sure 
 of some Alcyone, 12,000 suns strong, revolving 
 about another Alcyone, perhaps 100,000 suns 
 strong. More than this. The Magellanic Clouds, 
 so called, of the southern hemisphere, are nothing 
 but two great beds of clusters and nebulae ; three 
 hundred nebulae in one, and tliirty-seven in the 
 other : and in the constellation Virgo, especially 
 in one of its wings, the nebulae are scattered al- 
 most as the grain will be sown in your fields this 
 spring — swarms of them, in groups and clusters 
 of groups ; and it is just as certain that each of 
 these great beds is in course of revolution about 
 its center of gravity as it is that over that amaz- 
 ing congeries of firmaments is stretched the scep- 
 ter of law. 
 
 Mightiest of astronomical neighborhoods jet 
 seen ! What wondrous outskirting orbits have 
 we here — what abysses of periods — what year 
 Great and Wonderful in which some picket sun 
 of one of those picket nebulae spins out its ellipse 
 about the whole nebulous stratum to which it 
 
148 FIFTH LECTURE. 
 
 belongs ! What abysmal grandeur.? of motion 
 are piled and compacted within that circle of 20° 
 diameter about tlie wing of Virgo ! The ancients 
 did not liuow what wonders were swarming in 
 tliis region ; and, had they known, they could 
 hardly liave covered its flying hosts with a more 
 appropriate symbol than they have done — a 
 broad celestial wing. You easily understand tlie 
 utter inadequacy of figures, whether expressing 
 miles or diameters of the earth's orbit or the largest 
 measured distances of fixed stars or years of light- 
 motion even, to express the dimensions of this 
 Titanic nebular system. 
 
 Such are the various orders of systems which 
 we can prove to be within the range of our tele- 
 scopes. But no astronomer doubts that within 
 this range may lie hundreds of different orders, 
 wheel within wheel, in astounding climax and 
 bewildering complexity : even that within this 
 range our own earth may be describing a thou- 
 sand-fold orbit about a thousand different centers. 
 
 But there must be, at last, a Universe System 
 — a system composed of all the bodies that people 
 space, and in which each body revolves about the 
 gravity-center of the whole material universe. 
 Let us devote a few thoughts to it. 
 
 Eighteen million suns belong to our firmament. 
 More than four thousand such firmaments are 
 visible ; and every increase of telescopic power 
 adds to the number. Where are the frontiers — 
 
UNIVESSE-SYi'TEM. 140 
 
 the last astronomical system — that remote spot 
 beyond which no nebula, no world, glitters on the 
 black bosom of eternal nothingness ? Probably, 
 some one of those many nebulae just brought 
 into faint view by the great reflector at Rosse Cas- 
 tle, is but another nebula of Andromeda ; which, 
 though visible to the naked eye, gives no sign of 
 being resolved into stars by an instrument of fou/ 
 hundred times the eye's space-penetrating power. 
 Think of the distance expressed by four hundred 
 times the distance of the milky way of Androme- 
 da — five millions of years, as flies the light ! 
 Alas, how feeble are our powers I How they la- 
 bor and bow under the weight of such mighty 
 numbers — such gates of Gaza I What wondrous 
 chronometers those must be which could take fit- 
 ting account of the ongoings of such far-off firma- 
 ments ! Could you stand, with a wand in your 
 hand reaching to that remotest galaxy, and sweep 
 it around you in every direction, what an empire 
 fit for a Jehovah would fall within the embrace 
 of those glorious circles I And yet who shall say 
 that even this is the whole astronomical universe ? 
 What right have we to stop just where the power 
 of our instruments happens for the moment to 
 havo stopped, and say, " This is the end — these 
 are the Pillars of Hercules ? Turn back, ad- 
 venturous explorer — nothing but night and void 
 in this direction — thou hast reached the last 
 outpost of the kingdom of the Eternal ! Ne plus 
 
150 FIFTH LECTURE. 
 
 ultra ! " No : thrice no. On still through peo- 
 pled infinitude, through raining galaxies and 
 tornado-nebulae; and, while thou goest outward 
 still through the charging, storming hosts of suns 
 as long as thought can fly, or angels live, say ever 
 to thyself, " Lo, these are parts of his ways ; but 
 liow little a portion is heard of him ! The thunder 
 of His power, who can understand ? " Is not space 
 infinite ? Is not He infinite ? And who dare 
 say that his works are not wellnigh infinite too 
 — at least that the limit to which our gasping and 
 bewildered astronomy has hitherto conducted us 
 is not, as it were, but the first mile-stone of peo- 
 pled space ; and that great swarming sphere which 
 our mightiest telescopes have gauged, but the 
 merest rain-drop compared with another swarming 
 sphere which embraces it ? But let us suppose 
 an end ; suppose an orbit so large as to include 
 in its unspeakable round the entire magnificence 
 of the sidereal heavens. At last the Ultima Thnle 
 is readied. We have the total universe of matter 
 which God has made — one all-comprehending as- 
 tronomical neighborhood — and around it stretches 
 in all directions the black wastes of an altogether 
 endless vacancy. All members of this great ulti- 
 mate system must be in motion about its common 
 center of gravity. Whether this sublime center 
 is, or is not, a mathematical point, where not an 
 atom of matter nestles, our present science has no 
 means of determining. But is there not some- 
 
UNIVERSE-SYSTEM. 151 
 
 thing at the bottom of our hearts better than sci- 
 ence, which invites us to believe that what would 
 be so fitting and beautiful is also triumphantly 
 actual ; namely, that at the center of this august 
 totality of revolving orbs and firmaments — at 
 once the center of gravity, the center of motion, 
 and the center of government to all — is that better 
 country, even the heavenly, where reigns in glory 
 everlasting the Supreme Father and Emperor of 
 Nature ; the capital of creation ; the one spot 
 that has no motion, but basks in majestic and per- 
 fect repose while beholding the whole ponder- 
 ous materialism which it ballasts in course of cir- 
 culation about it. All hail, Central Heaven ! All 
 hail, innermost Sun Palace and celestial Alham- 
 bra ! All hail, believer's Last Home — from 
 which an adult astronomy, fitted with the pictured 
 and dynamical wings of angels, shall immortally 
 radiate to all the girdling worlds and immortally 
 bi'ing home fresh proofs of the glory of Him who 
 has so long been defrauded of His rights among 
 men of science by the empty names of law and 
 nature ! 
 
AUTHOR OF NATURE, 
 
 AS RELATED TO ITS LEADING FEATURES. 
 
 163 
 
VI. Author of Nature, 
 
 As Related to its Leading Features. 
 
 VASTNESS ;S9 
 
 VARIETY IN UNITY. t63 
 
 FINISH OF MINIMA ; . . i6S 
 
 WISDOM 171 
 
 5. DYNAMICS 177 
 
 6. RELATION TO LAW 182 
 
 RELATION TO TLME AND MOTION .... 188 
 
 MYSTERY 93 
 
 154 
 
SIXTH LECTURE. 
 
 AUTHOR OF NATURE. 
 
 IS there an Author of Nature ? Hitherto, the 
 affirmative has been steadily assumed ; and 
 I hope that at tliis point such a question seems 
 almost an insult to your understandings — freshly 
 returned as they are from sweeping through the 
 unutterable glories of the astronomical universe. 
 
 Still, let the preposterous question bo enter- 
 tained. We are not likely to realize too vividly 
 the existence of an invisible Divinity. Though 
 we are not atheists ; though we would be shocked 
 to receive that dreary and awful name ; though 
 perhaps it has never once occurred to us, with 
 our Christian training and surroundings, to doubt 
 that this glorious nature about us has the God of 
 the Scriptures for its Father and King, we still 
 belong to that fallen race whose strong and uni- 
 versal tendency is to be without God in the world. 
 
 Theists and atheists agree as to the advantage 
 of approaching the question of a Divine Being 
 
 155 
 
156 SIXTH LECTURE. 
 
 with a mind freshly steeped in the leading facta 
 and courses of nature. The atheist claims that 
 nature malies on minds thoroughly imbued with 
 her spirit an impression adverse to faith ; and 
 points in evidence to some eminent cultivators 
 of the physical sciences wlio have been as skep- 
 tical as they have been scientific. So he is in 
 favor of the study of nature. On tlie other hand, 
 the theist is in favor of it for the very oppo- 
 site reason. He denies tiie atheism of science. 
 He refuses to infer it from the unbelief of some 
 French and German pliilosophers — with here and 
 there a second-rate English disciple — wliose 
 minds from childhood have been poisoned witli 
 the writings of Voltaire and his school, who have 
 seen around them only a grotesquely corrupted 
 form of religion, and whose private lives for the 
 most part were such as to make it greatly for 
 their interest to have no God. To him the case 
 of sucli exceptional men only shows the exceed- 
 ing force of native depravity, evil training, evil 
 surroundings, and evil habits, at withstanding 
 tlie natural tendency of their pursuits. Tiiis 
 tendency he regards as strongly theistic. He 
 thinks he sees premonitions, prophecies, presumj> 
 tions, and even proofs of Divinity in the great 
 universe that expands around him ; and believes 
 that, other things being equal, the more fully 
 one comes under the influence of the astronomy, 
 the geology, and tlie other branches of natural 
 
AUTHOR OF NATURE. 157 
 
 Bcieuce whose findings have amazed mankind, 
 tlie more easily he will admit and the more 
 strongly he will hold, the doctrine of a Divhie 
 Being. 
 
 What all classes think it well to do, let us at- 
 tempt. Wo will attempt to place our hearts still 
 more fully en rapport with nature. We will, if 
 possible, get them into yet closer communication 
 and syrapathy with its great leading fiicts and 
 courses. These are chiefly astronomical. Yet I 
 shall not restrict myself to astronomical facts, 
 technically so called, but shall allow myself to 
 gather from the whole of that broad field of 
 science of whicli astronomy is the undisputed 
 and all-comprehending Chief. And I can not but 
 think that the effect will be to preclude objec- 
 tions, to furnish presumptions, and generally to 
 dispose the mind to a miglity faith in God. I 
 am persuaded tliat any man. who can be fairly 
 set down in the midst of nature, and thrown 
 honestly open to all its subtle inductions, mag- 
 netisms, inspirations, will silently drink in theism, 
 as a fleece spread out under the stars drinks in 
 the dew. 
 
 Suppose it claimed that a certain veiled paint- 
 ing is the work of Titian. If, on gradually lifting 
 the veil, we find exclusively trait after trait such 
 as might have been expected in a woik by that 
 great master, our disposition to think favorably of 
 the claim increases with every step : and if, wheu 
 
158 SIXTH LECTURE. 
 
 the canvas is entirely exposed, every leading fea- 
 ture seems Titianic and the whole worthy of 
 such an author, our minds are far advanced 
 toward faith — they are in a state of high prep- 
 aration for any ulterior evidence, and only com- 
 paratively little of it will be required to secure 
 full conviction. And this is reasonable. Pre- 
 vious to examination, how could we be sui-e that 
 there were not lurking under that veil incompat- 
 ibilities, or at least disagreements ? Now our 
 uncertainty is removed. We have found positive 
 harmonies. The facts match the claim. The 
 picture is such as might have been expected from 
 Titian - -sucli indeed as he would surely have 
 painted. His great cliaracteristics are striliingly 
 here. And tliese are so many verisimilitudes, so 
 many presumptions in favor of the claim : and, iu 
 the absence of all evidence to the contrary, at 
 least authorize the critic to stand at the very 
 verge of assent, facing it kindly and with foot 
 uplifted, ready to cross the border at the first 
 competent invitation. Let such an invitation 
 come in the shape of an assurance tliat the paint- 
 ing is almost universally accepted as the work of 
 Titian, especially among the most intelligent and 
 fair-minded judges ; further, tliat the hypotliesis 
 whicli ascribes the work to him is, as compared 
 with otlier liypotheses, altogether the simplest, 
 the least embarrassed, the most useful, as well as 
 the most historical — this would and should plant 
 liis feet in the very center of faith. 
 
FASTNESS OF NAl'JRE. 159 
 
 Now it is claimed that nature is the worii ol 
 God. Let us, step by step, unveil its leading 
 features and see if they do not strikingly harmo- 
 nize with tlie claim : and, as they may be found 
 to do so, let unbelief approach its frontier ; and, 
 wlien at last the general scheme of nature appears 
 cliaracteristic and worthy of God, let the traveler 
 at least stand on the last boundary of his chill 
 and somber territory, all ready to cross with de- 
 cisive and I'inging step into a brighter land at 
 the first summons of the positive evidence. 
 
 What I propose, then, in the present lecture, is 
 to illustrate the general harmony between nature 
 and the doctrine of a God. Of course, a few 
 specimen illustrations are all that can be offered. 
 One will do well to feel the pulse of nature still 
 more fully in the worlcs of Ray and Good and 
 Paley, in the Bridgewater Treatises, and in later 
 works of tlie same character. 
 
 One of the most striking features of what we 
 call Nature is its vastness. 
 
 I do not forget that I am speaking to those who 
 have become familiar with tlie wonders of physical 
 science. But neither do I forget that even the 
 scholar must refresh his impressions of things in 
 veiy much the same way with other men. So I ask 
 you to think of plains stretching to the horizon ; 
 of mountains piercing the clouds ; of roomy con- 
 tinents anchored in roomier oceans ; of this whole 
 earth-sphere, with its huge baldric of twenty-flva 
 
160 SIXTH LECTURE. 
 
 thousand miles, covered with innumerable ve- 
 getable products, peopled with men to the poten- 
 tial figure of a thousand millions, swarming still 
 more potentially witli the lower animals, and so 
 flooded witli microscopic life that almost every 
 cubic inch of air and water and soil is panting 
 with an incalculable population, — some of whose 
 smaller individuals multiply themselves into 
 one hundred and seventy billions in four days ; 
 gather their five hundred millions in a single 
 drop of water ; and yet make up, with the stony 
 cerements of the merest fraction of their fossil 
 ancestry, whole mountains and geologic beds. 
 Such is our world. Out in yonder vault, find 
 that millioufold world which we call tlie sun, 
 with its invisible retinue of a hundred earths • 
 out in yonder vault, when night falis, find a 
 thousand suns similarly attended ; with tube 
 Galilean, thousands more; with tube Herschel- 
 ian, millions more; with tube Rossiau, billions 
 more. Is this the end ? What asti'onomer for 
 one moment imagines that another enlargement 
 of the great speculum at Parsonstown would 
 show our vision to be already hard up against 
 the frontiers of nature ? Not even Darwin doubts 
 that successive improvements in the space-pene- 
 trating power of our instruments would go on 
 indefinitely opening up firmaments at eveiy step. 
 Where is the verge of the universe ? Who would 
 undertake the roll-call of its orbs ? Who dares 
 
VASTNESS OF NATURE. 161 
 
 to say that he could count through She grand 
 total of its firmameuts, even though he should 
 count a thousand years ? Figures go but a small 
 way toward expressing the dimensions of such a 
 universe — whether one considers the number of 
 its worlds, or the expanse of space tlirougli which 
 they are distributed. Our world spins round its 
 ellipse, of well-nigh two hundred million axis, 
 without ever having a neighbor nearer than 
 thirty millions of miles, save its own moon. 
 Tlie interval between our sun and the nearest 
 star of the same galactic nebula is six hun- 
 dred thousand times this distance. And then 
 the distance from nebula to nebula — it is abso- 
 lutely awful. Our telescopes sweep a sphere of 
 stars whose diameter is seven millions of years, as 
 light travels. Calculation covers its abashed face 
 with its great wings in the presence of these over- 
 whelming amplitudes. And such is nature ! 
 
 Certainly such a universe as tliis does not cry 
 out against the existence of a God whose essen- 
 tial' attribute is immensity. On the contrary, it 
 is just such a universe as one would have ex- 
 pected to come from such a being. Nay, given a 
 Deity who is practically at home in every point 
 of space, whose attributes are laid out on a scale 
 of imbounded vastness, to whom it is just as easy 
 to make and govern a trillion of worlds as it is a 
 grain of sand, and the imperial fitness of things 
 would demand that he people vacancy with very 
 
1G2 SIXTH LECTURE. 
 
 much that profusion and breadth »f being that 
 we actually see. The work ought to express and 
 honor the workman. And when I am lold of an 
 author of nature who is immense with a three- 
 ■ fold boundlessness of intelligence, might, and 
 years ; so that to him our great and small, our 
 far and near, our center and circumference — 
 though that circumference sweep around all the 
 expanses of modern astronomy — are practically 
 the same ; so that he can properly challenge, "Do 
 not I fill heaven and earth ? " — when I am told 
 of this, and I then place myself out under the 
 open dome of nature, amid its exuberant objects 
 and marvelous stretches, I feel myself silently 
 drinking in predispositions to faitli as the fleece 
 spread out luider the open heaven drinks in the 
 dew. I feel that the doctrine matches facts ; that 
 the theory has in its favor a comprehensive veri- 
 similitude and presumption ; that Nature, instead 
 of saying, " There is no immense God," signifi- 
 cantly asks, in a tone of encouragement and with 
 a look of incipient expectation, "Is there not such 
 a Being ? " In fine, I feel that our slight lifting 
 of the veil fi-om the painting lias disclosed a fea- 
 ture strikingly characteristic of the great master 
 to whom the work is attributed — a feature which, 
 in the absence of all counter-evidence, naturally 
 sets our faces faithward — one, of several har- 
 monics which, as successively presented, will war- 
 rant us in looking faithward with overgrowing 
 kindliness of aspect. 
 
VARIETY IN UNITY. 163 
 
 Notice with me tlie variety in unilj that char- 
 acterizes Nature. 
 
 Some luiiidreds of millions of creatures on our 
 earth are so much alike that we put them into a 
 class by themselves and call them men. They are 
 all alike in certain fundamental features ; and yet 
 each man differs materially, both in body and soul, 
 from every other man. So of every other class 
 of things — animal, vegetable, inorganic; while 
 there is a sub-stratum of unity among the mem- 
 bers of each, on account of which they are 
 classed togetlier, there is not one which is not 
 veiy unlike, in many respects, all its fellows. Ail 
 animals have great points in common : but how 
 many, many sorts of animals ; and how great the 
 difference between the eagle and the microscopic 
 mote, between the cetus and the polyp, between 
 the most perfect man (body and soul) and the 
 rudest of the polypi ! All vegetables are similar- 
 ly constituted : but whose memory can master all 
 the distinct kinds of vegetables in the wide intep- 
 val between the spire of grass and the huge tree 
 that wrestles victoriously with stormy centuries ; 
 and reckon np the great differences that exist, as 
 to shape and size and color and flavor and odor, 
 among fruits and flowers and leaves and grasses 
 and shrubs and trees. Great threads of unity 
 obviously connect all the forms of terrestrial 
 being, organic and inorganic ; but this we know, 
 that, if only single specimens of all the plainly 
 
164 SIXTH LEGTUHE. 
 
 separated species were atteaipted to be brought 
 together 'into one Crystal Palace of a miiseuin, we 
 should have to roof in empires, instead of acres, 
 in order to accommodate their mighty array: and as 
 our eye would run over the wliole superb collec- 
 tion, and at last bring together tlie two termini — 
 viz., the material man and the material stone 
 just crumbling into dust — our sense would be 
 that of a miraculous diversity efflorescing out of 
 the unity of our world. So with those other 
 worlds that shine or hide in the vault above. 
 They are all spheres, all have orbitual and prob- 
 ably axial motions, all are governed by the same 
 principle and law of gravitation, all are ligiited 
 and colored and warmed by the same mysterious 
 element or impulse ; but on sucli basal unity is 
 superimposed an almost infinite variety. Observe 
 our solar system. One member of it is self-lu- 
 minous, and, relatively to the other members, a 
 nearly stationary body ; the others are dark, and 
 far-wandering planets. One is one hundred miles 
 in diameter, another nearly one hundred thou- 
 sand, while still another contains more than 
 eight hundred times as much matter as all the 
 remainder of the system can boast. Some have 
 atmospheres and seas, otliers have neither. Some 
 have moons, others have none. Saturn rides 
 forth in the poi ip of three great equatorial rings, 
 as well as of eight moons ; no other planet is simi- 
 larly furnished. These orbs of our system differ 
 
VARIETY IN UNITY. 165 
 
 greatly in density — one is as lead, another as 
 cork, another still is mere vapor. One receives 
 seven times as much liglit from the sun as 
 we, another only a three hundred and sixtieth 
 part of as much. Neptune's year is equal to 
 one hundred and sixty-live of our years. Saturn's 
 day is only one-half of our day. Of course 
 the products and scenery of these worlds, as 
 well as the constitution of their hihabitauts, 
 must differ exceedingly. But pass we on to 
 tlie region of the fixed stars. Have we es- 
 caped into immeasurable uniformity out of im- 
 measurable variety ? Lo ! we skirt systems, clus- 
 ters, hraiamjiits, and never two alike, while some 
 stand apart by whole universes of difference ! 
 Lo, systjms with several suns each, from one to a 
 hundred ! Lo, systems lighted, some witli white 
 suns, some with ruby, some with emerald, and 
 some with suns of many different colors ! Lo, 
 suns dilfering exceedingly in size and amount of 
 light they shod : for tlie great Sirius that flashes 
 first magnitudes on all our charts as well as on 
 the dazzled retina of the savage, is not as near 
 to us as the little 61 Cygni, and its light must 
 be equal to that of nearly a hundred suns 
 like our own ! Alcyone shines with a forco 
 of twelve thousand suns. And then we have 
 suns themselves combined into systems of all 
 sizes and shapes — systems of two, of three, 
 of many, of millions, — firmaments which, uu 
 
166 SIXTH LECTURE. 
 
 der the name of nebulae, are .he last gen- 
 eralization and most stupendous variety of mod- 
 ern discovery : sometimes rolled up into spheres : 
 sometimes gatliered into circular or elliptic rings; 
 now fan-shaped ; now like an hour-glass ; now 
 broad wheels of compacted suns, large, glitter- 
 ing, and sublime enough to under-roU the chariot 
 of immeasurable God. There are not two leaves 
 or grass-blades perfectly alike in all this verdant 
 world ; not two worlds, nor systems of worlds, 
 accurately alike in all the prodigious realms of 
 astronomy. 
 
 Now no one, to say the least, can claim that this 
 vast variety imbosomed in unity makes positively 
 against the idea of one Creator of boundless in- 
 vention and executive faculty. On the contrary, 
 it is just wlrat we s'.ianld have expected from such 
 a being. Given just such a many-sided, versatile, 
 complete Deity as is affirmed — we should say 
 that, in case he should set himself to produce a 
 vast universe, he would be likelij to produce one 
 in which great outlines of unity would be steeped 
 in immeasurable variation ; one in wiiich resem- 
 blance and diversity, both robed and featured like 
 goddesses, would hold each other by the hand 
 and go treading with wedded and festival step up 
 and down the whole quickened area. Nay, this 
 sort of universe one would make sure of finding; 
 would be greatly disappo'nted if he sliould not 
 5nd. The eternal laws ol his own nature would 
 
VARIETY IN UNITY. 167 
 
 demand it of the 'Great Builder. The invin- 
 cible beauty and fitness of things would de- 
 mand it. Perfect uniformity, however piled up 
 in magnificent magnitudes —even a uniformity 
 only varied after so cramped and frugal a fashion 
 as would be perpetually suggesting poverty of re- 
 sources — would belie the inexhaustible Divinity. 
 If he build at all, he must not misrepresent and 
 disparage himself in his worii ; his fruitful na- 
 ture, teeming witli all imaginable fertilities and 
 seeds, must surely blossom into very much that 
 marvelous fruitfulness of product and pattern 
 which we observe. And when I am told of an 
 author of nature whose being swarms in resistless 
 force toward every point of the compass, nay of the 
 sphere ; who is both a unit and a polygon, facing 
 every desideratum and possibility witli a flashing 
 side, both of thonglit and action, that out-dazzles 
 ilie sun — when I am told that such a being is 
 the author of nature, and I then put myself 
 forth under the open dome amid the glorious di- 
 versities that root themselves in the glorious 
 unity of nature, and open myself freely to all 
 their subtle suggestions and magnetisms, I feel 
 myself drinking in predispositions to faith, as the 
 exposed fleece drinlis in the dew. I. feel that 
 again the doctrine matches facts, that again the 
 theory has a comprehensive verisimilitude and pre- 
 sumption, that Nature instead of saying that 
 there is m God whoie unity is arborescent 
 
1 68 SIXTH LECTURE. 
 
 with endless varieties of beauty and power, sig- 
 nificantly asks, " Is there not such a Being ? In 
 fine, I feel that our continued lifting of the veil 
 from the painting has disclosed a second trail 
 strikingly characteristic of the Great Master to 
 wliom the work is attributed ; a trait which, added 
 to the first, warrants our faith ward look in taking 
 on new kindliness of aspect. 
 
 Another characteristic of nature deserving of 
 notice is the perfection of its details. 
 
 The exquisite finish of nature in its minutest, 
 parts is about as wonderful as its vastness and va- 
 riety. Scan that leaf. Examine the wing of tliat 
 butterfly. Let the tinted and polished antennae 
 of that moth glitter in the focus of your instru- 
 ment. Subject to the skilfullest notice of science 
 and art the smallest veins of any animal or ve^ > 
 table. Push the analysis just as far as possible, 
 and submit that last visible minimum of organi- 
 zation in the crystalline lens of the cod, with its five 
 millions of muscles and sixty thousand millions 
 of teeth, to ihe most searching criticism of the su- 
 perbest microscope. What exquisite details ; 
 What elaborate refinement of workmansliip ! It 
 Is not as with some master-piece of human paint- 
 ing — the main points only cared for, while all 
 the subordinate are too rude to bear close inspec- 
 tion. Titian painted this landscape. Well, it is 
 worthy of him — the general effect is beautiful. 
 Yet, if you approach, and closely examine the fo- 
 
FINISH OF MINIMA. 169 
 
 liage of the trees, the grass with which tlie ciin- 
 vas is green, or even the limbs and features of 
 the animals, they will be found very coarsely and 
 incorrectly executed. The microscope turns the 
 most finished work of man into coarseness and 
 clumsiness — indeed, almost immediately carries 
 the sight where traces of skill have totally disap- 
 peared. Not so with the works of nature. A 
 real landscape you may analyze to your heart's 
 content, and inspect its details as critically as 
 eye armored with lens can do, without finding 
 the workmanship growing less exquisite the fur- 
 ther you push inquiry. A real man — you may 
 descend to the minutest particulars of his organi- 
 zation, and get as near its primary elements as 
 an Ehrenberg with his superb instruments and 
 practiced vision can carry you, without finding 
 the least falling off from that delicacy of execu- 
 tion which appears on the larger masses and out- 
 lines of the body. So everywhere among natural 
 objects — the great and the small, the outlines 
 and the minute filling-up, as far as utmost optical 
 resources can carry our observation, are wrought 
 with apparently the same overflowing outlay of 
 attention and skill. It is not so in a few instances 
 merely, nor in a thousand — it is so universally. 
 
 That there are any so preposterous as to think 
 that this feature of nature makes positively 
 against the idea of a sparrow-watching, hair-num- 
 bering, and thought-weighing God is, of course, 
 
170 SIXTB LECTURE. 
 
 not to be imagined. Of course, it is a feature 
 that fully harmonizes with such an idea. A na- 
 ture finished exquisitely down to the most infinites- 
 imal of its details is just what one would have 
 predicted from a God of this description. An- 
 nounced the fact that He was about to create, 
 and expectation would have stood on tiptoe to look 
 for just such a nature as we see. A God for whose 
 vision nothing is too small, who necessarily gives 
 as complete attention to the affairs of an atom as 
 to those of an empire, who can concentrate his 
 almightiness with as much freedom and accuracy 
 on a mathematical point as on a world, who is 
 embarrassed no more by unlimited multiplicity 
 than by unlimited minuteness of details, who can 
 with equal ease paint a landscape on the point of 
 a needle — say, if you please, forty thousand of 
 such landscapes at once, with all their innumera- 
 ble and minima particulars, back of the reticu- 
 lated eyes of a single butterfly — can with equal 
 ease do this, and roll a solar system on its tri- 
 umphant path about the Pleiades ; do I not know 
 that a being with such a striking attribute as this 
 would surely give it expression in his works ? Do 
 I not know that he who is equally at home in 
 maxima and minima, and to wliom beauties and 
 glories in the world of infinitesimals would be just 
 as apparent and practicable as they are in the 
 world of infinites, would lay himself out on the 
 one very much as on the other — would effulge 
 
WISDOM OF NATURE. 171 
 
 himself into the microcosmos very much as into 
 the cosmos ? When, then, I am iohl tliat such a 
 behig is the author of nature, and I proceed to 
 place myself out under the open dome amid the 
 exquisite elaborations that swarm on every hand 
 down through the veriest miracles of littleness 
 and detail, and to uncover myself candidly to all 
 their subtle whisperings and magnetisms, I feel 
 myself softly drinking in predispositions to faith, 
 as the exposed fleece drinks in the dew, I so feel 
 the force of a doctrine matching facts, and but- 
 tressing itself again and again with comprehen- 
 sive verisimilitudes and presumptions, that to 
 me nature becomes articulate, and, instead of 
 swearing with uplifted hand that there is no 
 wondrous God, significantly points upward, and, 
 witii bated breath and expectant look, asks, " Is 
 there not such a Being ? " — in fine, I feel that 
 our continued lifting of the veil from the paint- 
 ing has disclosed another characteristic of the 
 Great Master to whom the work is attributed, the 
 third of those several harmonies which, as suc- 
 cessively presented, warrant us in looking faith- 
 ward with ever-growing kindliness of aspect. 
 
 Another feature of Nature is what I shall call 
 its wisdom. 
 
 The world is full of what, if accepted as the 
 work of an intelligent being, would be called con- 
 trivances — adaptations of means to ends — often 
 of the most complex and elaborate description. 
 
172 SIXTH LECTURE. 
 
 For example, the birds — how admirably adapted 
 to flying ; in shape, feathers, bones, wings ! The 
 fishes — how adapted to swimming and life in the 
 water ; witness their shape, their smooth and 
 unctuous scales, their pairs of fins, their tails and 
 gills ! The land-animals — how adapted to walk- 
 ing and running and feeding on the earth's sur- 
 face ; to eat the grass or catch their special prey ! 
 The trees — how adapted to stand firmly ; by their 
 roots, their perpendicularity, their balanced 
 branches, their moderate flexibility — how adapt- 
 ed for shade, for abating the violence of winds, 
 for fuel 1 Or, if you will consider particular or- 
 gans of the organic tribes, look at the bark of 
 trees as related to their nourishment, at the web- 
 foot in its double relation to land and water, at 
 the teeth and other preparers of food for the 
 stomacli, at the stomach as a preparer of food for 
 the blood, at the lungs as purifiers of the blood, 
 at the heart as the engine for forcing the blood to 
 all parts of the system, at the hand as the general 
 servant of the whole body ; in short, at almost any 
 organ of either animal or vegetable structures. 
 The adaptations are wonderful. They are physi- 
 cal miracles — the means are shaped and applied 
 to the ends so exactly, beautifully, triumphantly. 
 For example, no work of human ingenuity tliat 
 ever you saw is equ.al to that natural marvel, the 
 human eye— an organ having reference to an 
 element quite external to itself, whose chief source 
 
WISDOM OF NATURE. 173 
 
 is millions of leagues distant ; and also to millions 
 of external objects which compose our scenery of 
 earth and sky — au organ placed in the most ele- 
 vated part of the body so as to command tlie most 
 extensive prospect ; placed in the front so as most 
 readily to preside over the direction in which we 
 habitually move ; placed in a strong bony socket 
 which defends it from the heavier external in- 
 juries; imbedded in a soft cushion, so that its del- 
 icate texture can not be hurt by the bony walls 
 around it, as it rests on them, and turns swiftly 
 hither and thither at the bidding of the will ; 
 furnished with lids, like curtains, to close over it 
 in sleep, to wipe it, to cut off the outer rays of 
 light that would confuse vision, to protect it by 
 their involuntary and instantaneous shutting 
 •against the lighter kind of injuries; furnislied 
 with an apparatus of muscles by which it can be 
 rapidly turned at choice in any direction, so as to 
 vary the field of vision as the needs of life may 
 suggest ; furnished with a self-acting system of 
 appliances by which the ball is kept lubricated for 
 easy movement; furnished with a conduit to 
 carry off the superfluous moisture ; furnislied 
 with just that shape, out often thousand possible 
 shapes, which mathematicians have demonstrated 
 to be the only one which can refract all the rays 
 of light to a single surface, and thus afford dis- 
 f' ict vision, viz., that of an ellipsoid of revolu- 
 tion ; furnished with a retina or natural canvas 
 
174 SIXTH LECTURE. 
 
 on which its pictures of external objects can be 
 formed, of just the right size, and at just the right 
 distance beliind tlie lenses of the eye ; furnished 
 witli lenses of different substances having differ- 
 ent refractive powers, thereby preventing the light 
 from being resolved into the prismatic colors, anil 
 thus misrepresenting and unifoi-ming objects ; fur- 
 nished in front with a perforated membrane tliat 
 by self-adjustment adapts it to different degrees 
 of light, also with a system of pulleys and liga- 
 ments that at a moment's warning alter its con- 
 vexity and the relative position of parts so as 
 to adapt it to objects at different distances and, 
 what is more wonderful than all, provided in 
 some inscrutable manner with the means of ex- 
 pressing the mind itself, so that one may look into 
 its crystal depths and see intellectuality and scorn 
 and wrath and love, and almost every spiritual 
 state and action. Now, if this is not an amazing 
 congeries of adaptations, there is and can be noth- 
 ing amazing. If found to be the work of a human 
 artist, it would be called a perfect marvel of in- 
 genuity and wisdom. And yet some insects have 
 twenty thousand such eyes combined into one. 
 But the eye is only one among an infinity of 
 natural contrivances. Animate and inanimate 
 nature is mountainous and glittering witli them. 
 Down into the regions of the infinitely small, 
 whither only the most searching microscopes car- 
 ry the sight ; up into the regions of the infinitely 
 
WISDOM OF NATURE. 173 
 
 large and far, whither only mightiest telescopes 
 lift our struggling knowledge ; among the mech- 
 anisms of the atomic nations that people a sin- 
 gle leaf, and among the mechanisms of those 
 swarming celestial empires whose starry banners 
 sweep our nightly skies — it is everywhere the 
 same ; exquisite adaptations crowding exquisite 
 adaptations, profound contrivances (so inven- 
 tors and mechanicians would be tempted to call 
 them) heaped on profound contrivances, in such 
 endless amounts and varieties of wise structure, 
 as exhausts all human understanding and dwarfs 
 into nothingness all the products of human in- 
 genuity. 
 
 Does such a nature as this swear against a 
 Divine Contriver. Does it protest against him, or 
 testify against him, or breathe even a suspicion 
 against him? Many absurd things are done in the 
 world : but it will be hard to find the man who will 
 care to deny the positive and emphatic harmony 
 between the doctrine of an omniscient and omnip- 
 otent God and a univer.se crowded with such 
 splendors of natural mechanics. A God of end- 
 less invention, and whose powerful and skilled 
 hands can magnificently realize all that he has 
 magnificently planned — we should expect that 
 such a being, in case he should create a nature, 
 would set it all ablaze with the monuments of 
 his supreme intelligence and power — should be 
 disappointed to find no such monuments, but, in 
 
176 SIXTH LECTURE. 
 
 their stead, mere stupidity or tameness of work. 
 We sliould call the work unworthy of the work- 
 man. Nay, we should hasten to say to ourselves 
 that we must have mistaken him — He could 
 really be nothing more than such a petty divinity 
 as the poor heathen have fabled to themselves. 
 For we should be sure that one having unlimited 
 command of ways and means, both as a knower 
 and worker, would display it in his works. It 
 being just as easy for him to have exquisite 
 adaptations, and a gloriously endless variety of 
 them, as to have no adaptations at all — it is 
 plain what sort of nature he. ought to make and 
 would make. Now let me be told of a framer of 
 nature in whom are hid all the treasures of wis- 
 dom and knowledge, whose light has in it no dark- 
 ness at all, whose smallest deeds have from the 
 hoary everlasting been pavilioned and charioted 
 toward being amid the glories of xUmiglity Om- 
 niscience ; and I then place myself out under 
 the open dome mid the wilderness of wonderful 
 constructions and chemistries, and candidly un- 
 cover myself to all their subtle sympathies and 
 magnetisms — I feel myself, all sileiitly, drinking 
 in predispositions to faith, as the exposed fleece 
 drinks in the dew. I feel that the God who is af- 
 firmed is just the God to match the nature which 
 I see — here the ball and there the socket, here 
 tlie foot Titanic and there its footprint, here the 
 shapely hand and there its glove, here the sover- 
 
POWER OF NATURE. Ill 
 
 eign sword and there the golden scabbard that just 
 fits it — that these noble adaptations and mechan- 
 isms, spangling and blazoning all the fields of 
 matter, are in rejoicing Sympathy with tlie idea 
 of a Creator who is wonderful in counsel and ex- 
 cellent in working ; tliat the alabaster-box of 
 precious wisdom that has been emptied, not only 
 on the queenly head and shining tresses of Na- 
 ture but on her very feet, scents bravely of One 
 who is himself a " mountain of such spikenard ; " 
 that, in fact, the theory is again smiled upon 
 by a comprehensive verisimilitude and presump- 
 tion ; that Nature, instead of swearing with 
 uplifted hand that there is no AU-wiso Creator, 
 with flushed clieek and upward-glancing eye of 
 expectation, significantly asks, " Is there not such 
 a Being ? " In fine, I feel that our continued 
 lifting of the veil from the painting has disclosed 
 still another characteristic of the Great Master 
 to whom the work is attributed ; has cleared up 
 another stretch of that vista at the end of which 
 is Titian at his easel — ^^the fourth of those several 
 harmonies, which, as successively presented, war- 
 rant us in looking faith ward with ever-growing 
 kindliness of aspect. 
 
 Another striking feature of Nature is its power. 
 
 No contemptible degree of force resides in the 
 muscles of some men — the Samsons and Milos 
 of their time. Huge rocks are lifted, tough oaks 
 are riven, great sti'uctures are shaken down by 
 
178 SIXTH LEO TUBE. 
 
 their hands. Many brute animals display still 
 greater muscular strength ; witness the elephant, 
 and tliose gigantic mammals which towered 
 and ruled over the post-tertiary savannas. A 
 combination of animal forces with wliat are called 
 the mechanical powers often generates measures 
 of force more striking still ; and when men stand 
 by such piles as the Egyptian pyramids, they are 
 deeply impressed with tlie prodigious uplift that 
 must have put those mighty blocks in their high 
 places. But it is to inanimate nature that we 
 must go for our most brilliant examples of phys- 
 ical force. What power in the wind, when, as a 
 tornado, it sweeps along at more than one hun- 
 dred miles an hour ; demolishing mansions, up- 
 rooting forests, and lifting ponderous ships far in- 
 land on their eddies ! What power in the ocean- 
 swell as it tosses an entire navy to the skies with 
 apparently as much ease as if it were a single 
 cockle-shell ! — What is tliis that comes rushing 
 through the landscape with smoky breath and 
 thunderous step, dragging thousands of tons at 
 the pace of winds ? Witliin that flying iron cra- 
 ter is imprisoned one of nature's brawniest forces, 
 steam — throwing off feats of toil with its vaporous 
 arms, which arms of flesh and blood have never 
 even been fabled to do. — What have we here ? A 
 few l)arrels filled with very simple black grains. 
 One has but to drop a spark among them to wit- 
 ness a sudden development of power that shall 
 
POWER OF NATURE. 179 
 
 deafen earth and heaven with its voice, and lift, a 
 city into mid-air. — Would you see a mightier 
 energy still ? It is the year 17o5. Au unwonted 
 tj'embling stirs tlie air and ground of Lisbon. In 
 a lew moments the broad city is in lieaps. The 
 plain around runs in waves, like the sea when 
 lashed by a tempest. See — the distant moun- 
 tain-ranges themselves impetuously shake and 
 rend and topple ; Europe, to the Higlilands of 
 Scotland, heaves ; heaves Africi ; heaves the 
 whole broad Atlantic, with all its huge gravi- 
 ties, from the Pillars of Hercules to the New 
 World ! When oceans and continents are so 
 tossed and shot aloft, what stalwart slioulders of 
 gas and steam and fire are heaving at the mighty 
 burden ! Other forces among us are not small ; but 
 this of the earthquake is easy king over all these 
 terrestrial children of pride. Terrestrial, I say : 
 but there are forces not terrestrial wliicli are of a 
 still huger and loftier pattern — celestial forces, 
 to which those of our earth are what the bubble- 
 globules of the children are to the globed worlds 
 of space. When such a planet as Jupiter is 
 juoving at the rate of some thirty thousand miles 
 an hour ; when such a sun as ours is moving at 
 the rate of some three thousand miles a minute ; 
 when such a nebula as our Milky Way, with its 
 eighteen millions of suns, goes wheeling at the 
 same average speed about its center of gravity 
 • — there is a momentum for you, a magazine 
 
1 80 SIXTB LECTURE. 
 
 of force by the side of which earthquakes are 
 puny, and all the stormy winds that ever blus- 
 tered and fought in their fabled caves mere zeros ! 
 Some say that there is but one force in all nature 
 — none perhaps more apt to say it tlian the 
 rejecters of the supernatural — that the forces 
 which pump and assimilate and reject in every 
 blade of grass and leaf and animal fiber ; the 
 forces that throb in every ray of light and heat 
 and electricity and magnetism, the forces that 
 swell and toil in every atom of matter, the me- 
 chanical forces, the chemical forces, the spiritual 
 forces, the forces liere and the forces yonder to 
 the universe's last suburb — tliat all these forces, 
 with tlieir incomprehensible sum-total of simul- 
 taneous impulses, are, after all, but branches of 
 one great central force pushing outward in an in- 
 finite variety of directions and forms. If this is 
 so — and who is competent to positively deny it — 
 what a single force that is which can diffuse itself 
 over so immense an area, and divide itself so in- 
 finitely, and yet tliunder away at special points 
 with such marvelous and terrible energy ! If 
 this is not so, still wliat a wondrous hive of 
 swarming and independent dynamics in this wide 
 nature of ours ! 
 
 Of course, no one coulil have tlie hardihood to 
 say that a nature stocked with sucli energies as 
 these makes positively againd tlie doctrine of a 
 Creator who is himself an Almighty Force. On 
 
POWER OF NATURE. 181 
 
 the contrary, there is a friendly harmony between 
 the doctrine and the fact. Were we to find in 
 actual existence a Personal Power to whom noth- 
 ing is impossible, and learn that he is about to 
 produce a universe, we should expect to see pro- 
 duced just such a wonderfully strong nature as we 
 actually have — a nature peopled with strengths, 
 momenta, brawny agencies of most imposing forms 
 and magnitudes. A weak system, a system that 
 is puny in its operations and trifling in its effects, 
 would misrepresent him — shall I not say, would 
 be unworthy of him ? Most persons would cei-- 
 tainly call it unsuitable ; would say that his 
 very nature as an Infinite Power would demand 
 of him that he should produce a system that 
 would be continually turning out the greatest re- 
 sults, and so must include forces of the greatest 
 efliciency. When, then, I am told that a Sublime 
 Force, who has Almighty for his name, is the au- 
 thor of nature ; and 1 then proceed to place my- 
 self out under the open dome amid the pulsings 
 and tossings of innumerable and sometimes im- 
 measurable momenta, and so lay myself honestly 
 open to all their subtle hints and magnetisms; I 
 feel myself silently drinking in predispositions to 
 faith as the exposed fleece drinks in the dew — ] 
 feel that the doctrine matches facts ; that the as- 
 serted creator and creation fit each other as do 
 the die and the face of the coin which it lias 
 etamped ; that the theory has at least the bene- 
 
182 si:s:th lecturs. 
 
 diction of yet another verisimilitude and presump 
 tiou ; tliat Nature, instead of making oath with se- 
 rene brow and uplifted hand, that there is no won- 
 drous God, significantly asks, with abashed voice, 
 "Is there not such a Being?" — in fine, I feel 
 that, as the veil continues to rise from the face of 
 the painting, it reveals still another characteristic 
 of the Great Master, clears up another stretch of 
 tliat vista which conducts the sight toward Titian 
 bending over his canvas — the fifth of those sever- 
 al harmonies which, as successively presented, 
 warrant us in looking faithward with ever-grow- 
 ing kindliness of aspect. 
 
 Another feature of Nature is its remarkable re- 
 lation to law. 
 
 Notice law and Us exceptions — the general 
 steadfastness of modes of being and action in na- 
 ture, and tlie occasional breaches in that stead- 
 fastness. 
 
 On tlie earth's surface, in its dark interior, in 
 the air and vault above, iu the instant present and 
 the ancient past — everywhere, law waves its 
 mighty scepter. Atoms and masses, the jwuder- 
 ables and inponderables, the organic and inor- 
 ganic, tlic living and dead — all are evidently 
 subjected in their modes of being and action to 
 certain fixed i-ules, sometimes particular, but 
 more often covei'ing whole classes of objects. 
 Not a particle floats at random or as a unit : not 
 a leaf grows or falls save according to rigid gene- 
 
RELATION TO LAW. 183 
 
 ral principles of science. All chemical elements 
 have their modes and measures of combination to 
 wliich they steadfastly adhere. All heat, electri- 
 city, magnetism, gravity, act according to abiding 
 methods which philosophers have gradually dis- 
 covered and arranged into the sciences of natural 
 philosophy. The great processes of vegetable aud 
 animal life proceed after the same forms and steps, 
 from age to age. The stone beds of the world are 
 formed aud modified in certain set ways which 
 are the same now as in the periods anterior to 
 man. Even the weather, so often called fickle, 
 has its stable methods; almost every year bring- 
 ing to light some new general fact in meteorology, 
 or extending the application of an old one. Day 
 aud night succeed each other, every twenty-four 
 liours, witliout variation. The seasons do not 
 change their order or general character. All of 
 Kepler's and Newton's laws are as operative to- 
 day as they ever have been since their discovery. 
 The planets shoot round the sun aud are circled 
 by their own moons, on substantially tlie same 
 elliptical orbits, in the same times, aud with the 
 same principles of alternate retardation aud accel- 
 eration as of old. All known changes in the plan- 
 etary orbits have been found to be bound in a 
 kiw of periodicity which is apparently invariable, 
 oo beyond the solar system. Law still ; nothing 
 but law ; law everywhere on ten thousand bla- 
 zing- thrones ; largely the same laws that prevail 
 
184 SIXTH LECTURE. 
 
 ill our own system! As far as we can observe — 
 and it is no little that has been observed — those 
 distant orbs reverence the various principles of 
 gravitation and mechanics, and keep as rigidly to 
 tlieir behests, as when the earliest astronomy gazed 
 at them from its rude Uraniberg of a hill-top. 
 And every man of science is well persuaded that, 
 could his observation alight on particular orbs of 
 those remote and twinkling hosts, he would find 
 their minutest details bound up in the chains of 
 the same adamantine regularity that rules our 
 own globe. 
 
 So in general we speak. But we must not be 
 understood to speak with absolute precision of 
 language. In this wide scene of steadfast ar- 
 rangements, there are outbreaks of anomaly — 
 ruptures and rents and dislocations in the habits 
 and ongoings of nature, like those in the strata 
 of tlie earth. It is a settled law of nature that 
 like sliall produce like ; yet from perfect animals 
 and vegetables occur occasional monstrosities of 
 organization. It is a settled course of nature 
 that certain substances, called poisons, if freely 
 introduced into animal systems, destroy life ; yet 
 now and then a man is found who is even nour- 
 ished by these agents of destruction. It is a fixed 
 mode of nature that frost withers flat foliage ; yet 
 the flat leaves of the wild laurel flourish out our 
 hardest winters. It is a fixed way of nature that 
 the heavenly bodies move in ellipses ; yet there 
 
RELATION TO LAW. 185 
 
 is reason to believe that some comets have been 
 found moving on the curve called a parabola. 
 The steadfast habit of nature is against a general 
 planetary deluge, or conflagration, or glacier- 
 period, or destructive convulsion ; yet such disas- 
 ters, if geology may be trusted, have several times 
 occurred, at immense intervals, in the history of 
 our own planet. Great exceptional events ; 
 phenomena without fellows through an astonish- 
 ing stretch of ages ; what have the appearance 
 of broad fractures and dislocations of nature, 
 though in reality they may be the rare resultants 
 and accumulations of innumerable natural forces 
 and laws crossing each other in all directions ; 
 the entire destruction and rehabilitation of animal 
 and vegetable species — such events have taken 
 place on this globe again and again. Repeatedly 
 has the earth been drowned and torn in pieces. 
 It has been piled with snow and ice from pole to 
 pole. It has been all ablaze and fused. And is 
 it not on the idea of such a conflagration that we 
 can best account for the new stars that have some- 
 times flashed suddenly on the sight with all the 
 splendor of Venus at its brightest, and, after a 
 few mouths of changing color and gradual decay, 
 finally disappeared ? Thus in the bosom of a 
 general steadfastness are found occasional out- 
 breaks of anomaly. It is as among the geologic 
 strata — where are found faults, dislocations, fis- 
 Bures, and even reversions of those great rock- 
 
186 SIXTH LEOTURE. 
 
 beds which in general are laid down on a plan of 
 utmost regularity. The course of nature is like 
 some great tlioroughfare, which advances through 
 great distances witliout the slightest solution of 
 its continuity, but at last finds a great river thrust 
 squarely across its track. On this side the thor- 
 oughfare, on that side the thoroughfare, and here 
 the broad, deep flow of the bridgeless river — 
 a river worth to the public, it may be, many 
 times what the perfect continuity of the road 
 would be. 
 
 Now this much is certain. No one can say that 
 this characteristic of nature makes positively 
 against such a steadfast and yet miracle-working 
 God as is affirmed in the Christian Scriptures. 
 Instead of opposition, there is positive harmony 
 between the fact and the doctrine. Indeed, such 
 a nature as is obsei'ved is just what one would 
 have expected to come from such a Creator as is 
 taught. Nay, as general laws are necessary to 
 make science possible, to enable men to forecast 
 and profit by experience, to serve as a basis for all 
 comprehensive business and for all civil govern- 
 ment — as the broader and profounder the intel- 
 ligence, the more it is pleased witli and tends to 
 work by general principles, wo may say that the 
 very nature and circumstances of Deity would de- 
 mand of him, in case he should create, to create a 
 generally steadfast, law-abiding universe. At the 
 same time, a miracle-worker — one who sees acer- 
 
RELATION TO LAW. 187 
 
 tail! essential imperfection and intractability in 
 soco id causes, preventing their matching on all 
 occasions the perfection of his ideas ; who, more- 
 over, sees it undesirable to allow mere nature to 
 hide its Maker altogether behind its swarming 
 s(;reen, and give to the ideas of necessity and fatal- 
 ity full sweep in liuman minds — I say, such a 
 being would be under a loud call to provide in tlie 
 constitution and course of nature such sugges- 
 tions and prophecies of miracles as would gradu- 
 ally, though perhaps unconsciously to them, pre- 
 pare the mhids of men for those crowning 
 abnormals of the system. He must have tlie 
 glory of his personal agency glimmer through 
 occasional rents in the uniformity of nature. 
 An anomaly-sprinkled, miracle-suggesting, as well 
 as stable, universe must proceed from his won- 
 drous hand. He would be in conflict with 
 himself were he to produce any other. And 
 when I am told of one who is actually just 
 this sort of divinity — both law and miracle : 
 botli giver and keeper to an almost infinite 
 extent of moral laws which shall not pass away ; 
 while his iron will, throned as supremely in 
 the realm of matter as of morals, yet launches 
 forth into special providences and miracles on 
 extraordinary occasions — when I am told of 
 him, and I tlien place myself out under the 
 open dome amid tlie massive but occasionally 
 rifted uniformities, and open myself freely to all 
 
188 SIXTH LECTURE. 
 
 their subtle hints and magnetisms, I feel myself 
 softly drinking in predispositions to faith, as the 
 exposed fleece drinks in tlie dew. I feel that the 
 doctrine and the facts are at one ; that the asserted 
 Ci-eator and the observed creation fit each other 
 as do the signet and tlie seal just stamped ; tliat 
 another verisimilitude spreads blessing, if. trem- 
 ulous, hand over the theory ; that Nature in- 
 stead of sonorously swearing tlmt there is no 
 Divine Being whose double name is Law and Mira- 
 cle, significantly asks, v^^ith abashed and startled 
 tones, " Is there not such a Being ? " In fine, I 
 feel that, as tlie veil continues to rise from the face 
 of the painting, it reveals still another cliaracter- 
 istic of the Great Master, clears up another stretch 
 of that vista which conducts the sight toward 
 Titian bending over his canvas — the sixth of 
 those several liarmonies which, as successively pre- 
 sented, warrant us in looking faithward with ever- 
 growing kindliness of aspect. 
 
 Another feature of Nature is its wonderful re- 
 lation to time and motion. 
 
 How long has our race existed ? .The infidel 
 may choose to say a hundred thousand years ; 
 none will say less than six thousand. How long 
 has the earth itself existed ? The atheist may 
 choose to say, Forever. The geologist, thinking 
 of his coal beds and deltas and rocky strata sown 
 with the bones of extinct species, and of the time 
 requisite for their formation, is sure of several 
 
RELATION TO TIME AND MOTION. 189 
 
 hundred thousand years. How long are the 
 earth and its confederates in the solar system 
 calculated to endure ? Geometry declares tliat 
 no element of decay within endangers tlio sta- 
 bility of the system of the world. That year 
 wliich circumscribes onr seasons is only throe 
 hundred and sixty-five days ; but the earth lias 
 another year to which tliis is a mere point — its 
 pole goes nodding throtigh space in a circle which 
 it talces twenty-five thousand years to traverse. 
 What think you of a planet whose winter is more 
 than forty of our years, of a comet whose year is 
 more than tliirty of our centuries, of a sun whose 
 year is more than eigliteen thousand of onr mil- 
 lenniums? All the planetary orbits pass through 
 cycles of changes varj^ing in length from a few 
 centuries to nine tliousand, to seventy thousand, 
 to even many million years ; but the greatest of 
 these planetary cycles are as nothing compared 
 with those enormous periods which bound the 
 perturbations and express the secular equations 
 of the sun and fixed stars — periods including 
 more years than imagination has ever succeeded 
 in realizing to itself. What amazing longevities! 
 What portentous numerals ! They are hiero- 
 fzlyphics of the everlasting. They lift us among 
 the dizziest peaks of the sublime. 
 
 These immense periods, interspersed witli others 
 exceedingly small, sometimes express an- exceed- 
 ingly slow movement among the powers of nature. 
 
100 SIXTB LECTURE. 
 
 In other cases, the movement with which they 
 are connected is exceedingly rapid. The timea 
 consumed in the formation of the coal-beds and 
 rock-strata, and in the long perturbations of the 
 planetary and stellar orbits, are examples of the 
 first class of periods ; the years of the planets and 
 stars in their orbits are examples of the second. 
 In the first class, natural forces creep along to 
 their objects with miraculous slowness ; in the 
 other, they flash along with swiftness equally 
 astounding. Some orbits gradually lengtlien 
 themselves, say an inch in a thousand years. 
 Some of the stars dart along their year of one 
 hundred and eighty thousand centuries at the in- 
 comprehensible rate of one hundred and eighty 
 thousand miles an hour. Covild we plant our- 
 selves immovably at a certain point in the celes- 
 tial spaces, and sec our sun go sailing by with all 
 its glorious squadrons of planets and moons — 
 sailing down the abyss as if driven by ten thou- 
 sand hurricanes — would not the sight of such 
 celerity almost irrecoverably daze both senses and 
 spirit ? 
 
 If, now, one should start up to say that these 
 great cycles, imbosoming unutterable extremes 
 of movement, makes positively against an Eter- 
 nal God who is able to move to his purpose like 
 the light or at a rate so trifling as to be quite im- 
 perceptible by human senses, we should laugh his 
 logic to scorn. We know better. These are facts 
 
RELATION TO TIME AND MOTION. 191 
 
 that palpably agree with such a theism. Instead 
 of contradicting it, they express a state of things 
 that might have been expected from a being who 
 has both unlimited time and unlimited speed at 
 his disposal — who, if ho chooses to wait, has 
 never occasion to haste ; or, if he chooses to haste, 
 has never occasion to wait — who is alike able to 
 dart on his purpose as if infinite whirlwinds were in 
 his wings, or to approach it at a rate so minute that 
 no human sense can discern the movement in the 
 lapse of generations. Suppose such a God to be 
 about to create a nature, could you not confidently 
 predict after this manner — " This Being of mighty 
 periods will establish mighty periods : this Being 
 who can readily proceed on his endlessly varied de- 
 signs, at all imaginable and unimaginable rates of 
 ijjeed, will diversify his works with all the veloci- 
 ties." A God who himself has no duration to speak 
 of — if there may be sucli a God — would never 
 have stored his nature with such mighty cycles; a 
 God who himself never did a swift thing would 
 never have set his laws to spurring on planets and 
 suns so astoundingly ; a God who himself never 
 did a slow thing would never have yoked such 
 slow-footed forces to events, as we observe actually 
 dragging at some of them. It is only a God who 
 has substantial forevers on his hands, and who on 
 occasion can lighten and on occasion can linger 
 ineffably along the highway of his purposes, who 
 is properly represented by such a nature. In case 
 
192 SIXTH LECTURE. 
 
 he gives any nature at all, his character demands 
 of him to give just this — one expressing his own 
 attributes. So when I am told of one wliose lon- 
 gevity is eternity, wliose orbit of existence has an 
 infinite axis, who reaches an Atonement after 
 slowly beating toward it for forty centuries, wlio 
 is ages and dispensations in establishing his king- 
 dom in the world, who commonly approaclies the 
 punishment of sinners with steps lingering tlirough 
 numberless delays and forbearances, and who yet 
 sometimes yokes steeds of wind ajid fire and foam 
 to his car — as when some Korali and his com- 
 pany go down quick into the pit; or some Uzziah^ 
 profanely grasping an ark, falls dead ; or some 
 Ananias and Sapphira, lying to the Holy Ghost, are 
 ruslied to judgment in an instant's brief space — 
 when I am told of such a God creating natuvr; ; 
 and I then betake myself abroad under the open 
 dome amid those swarming and wondrous orbits 
 of time, now scarred and smoking witli the hot 
 hoofs of electric forces, and now pressed by tlie 
 velvety and trackless feet of forces born of the 
 snail ; and frankly lay myself open to all their 
 subtle hints and magnetisms — I feel myself silent- 
 ly drinking in faith, as the exposed fleece drinks 
 in the dew — I feel that there is a significant 
 matching of what we are taught with what we 
 observe ; that such theism is on most excellent and 
 embracing terms with Nature, which, so far from 
 saying with uplifted, oath-making hand, ' that 
 
MTSTESIOUSNUSS OF MATURE. 193 
 
 there is no Eternal God who, as an agent, is equally 
 at home in an instant and an age,' at least stands 
 tremulously querying, " Is there not such 4 Be- 
 ing ? " — in fine, I feel that, as the veil continues to 
 rise from the face of the painting, it reveals still 
 another characteristic of the Great Master, clears 
 up another stretch of that vista which conducts 
 the sight on Titian painting away suhlimely at his 
 glowing and glorified landscape — the seventh of 
 those several harmonies which, as successively 
 presented, warrant vis in looking faithward with 
 ever-growing kindliness of aspect. 
 
 Another feature — the mysleriousness of Na- 
 ture. 
 
 Who does not know it ? — terrestrial nature 
 is one huge spliinx. She vomits enigmas on us 
 in seas. Riddles too profound for the highest 
 science yet in our possession lurk in every ray 
 of light, in every blade of grass, in every rudest 
 stone. Only some of the coarser facts in rela- 
 , tian to a few things here and there, have been 
 picked up and systematized ; and these are what 
 compose our boasted sciences. From surface to 
 center, the earth is choked with mysteries whose 
 stony rind has never yet received a blow, much 
 less a fracture, from the mallet of investigation. 
 Come now, ye great Computers, compute for us 
 how long it will be before the science, which loses 
 itself at the very threshold of the complexities 
 of this world, will be able to swoop down with 
 
194 SIXTB LEGTURE. 
 
 triumphant wing upon the surfaces and to the 
 fiery centers of those fellow planets that myste- 
 riously weave and interweave paths across the 
 concave, and thoroughly solve the problem of all 
 their swarming contents ! A disorderly maze 
 are the apparent patlis of the members of our 
 solar system ! But you say that the real paths 
 are not as intricate as the apparent. Take your 
 stand, then, at the sun, and observe planets and 
 comets going and coming at all distances and 
 rates of velocity and directions ; while around 
 most of the larger planets are similarly moving, 
 other systems of satellites — is it not an intricate 
 as well as a brave sight? Can you see through 
 the mazy plan ? But you say that it has been 
 seen through, and planetariums have been made 
 that clearly represent the whole thing to us with- 
 in a few feet of space. How many centuries 
 and philosophers, Copernicus — Copernicus, I 
 say, away yonder in the depths of four hundred 
 years ago — did it take to make that orrery and ■ 
 solve that riddle of the system of the world ? 
 Indeed, it is yet very far from solution. Astron- 
 omers can only completely account for the move- 
 ments of a system of two bodies. A system of 
 three is quite beyond them; one of a hundred 
 and more bodies, like our solar system, immeasur- 
 ably beyond them. There is not even a hope 
 tliat science, with all its dynamical calculuses, 
 (vill ever overtake this higher problem. But 
 
SfTSTESIOUSNESS OF NATURE. 195 
 
 there is a higher problem still. Solar system 
 revolves around solar system ; a group of such 
 systems around a similar group; a cluster of 
 such groups around a similar cluster ; a firma- 
 ment of such clusters around a similar firmament. 
 Indeed, as we have seen, the whole universe of 
 stars, with all the countless fleets of planets and 
 moons which they represent, must, according to 
 the law of gravity, revolve aboiit a last center of 
 centers. Let us go to it. Standing at this 
 Heaven — for is not this the dazzling metropolis 
 where dwells the sublime Cesar of the creation — 
 standing at this wondrous point, and looking 
 forth on the countless nebulae coming and going 
 at all imaginable distances, speeds, and direc- 
 tions — lo, what a glorious scene of bewilder- 
 ment and unsearchable complexity ! It fairly 
 takes away our breath to look. There is no 
 more spirit left in us. If a system of three 
 bodies is too much for the most subtle and com- 
 prehensive science yet known, what can ever be 
 done by all coming generations and geniuses, 
 however imperial, toward mastering such laby- 
 rinthian immensity of involved orbs ? 
 
 Now hearken to the Christian Scriptures — 
 afGrming a Maker of nature who is himself the 
 mightiest of all enigmas. "Verily, thou art a 
 God that hidest thyself— Canst thou by searching 
 find out God ; canst thou find out the Almighty 
 to perfection — It is high as heaven ; what canst 
 
196 SIXTH LECTURE. 
 
 thou do : deep as hell ; what canst thou know ? ' 
 Does the aspect of nature contradict this doc- 
 trine? Who will presume to deny that the in- 
 comprehensible materialism about us, to say 
 uotliing of the more incompreliensible spiritual- 
 ism witliin us, is just what one would expect to 
 find issuing from the hands of an incomprehensi- 
 ble Creator — a being mysteriously without a 
 beginning, mysteriously self-existent, mysteriously 
 able to make tlie greatest and noblest things out 
 of nothing by simple volition, mysteriously all- 
 knowing, mysteriously unfettered in the appli- 
 cation of his power and knowledge by all con- 
 ditions of space and duration and personal 
 presence, mysteriously Three in One — in short, 
 a being enveloped in a terrible pomp and majesty 
 of sunset-clouds, wliose broken lines never per- 
 mit the orb that glorifies them to appear, even 
 for a moment, in clear and golden contour on 
 our rapt sight. Such a being, setting out to 
 create, would be likely to give us the present 
 enigmatic universe, nay — for why state the mat 
 ter so feebly — would be sure to give it. Like 
 every other copious author, he would reproduce 
 his own traits. -An unutterable spliinx himself, 
 his creatures would be sphinxes. A nature from 
 the hands of God that I can comprehend, or 
 make any approach to comprehending — prepos- 
 terous ! A creation that to me, with my low 
 place and filmy vision and narrow orbit, is not 
 
MYSTERIOUSNESS OF XATURE. 19'^ 
 
 steeped in seas of mystery — preposterous ! If .'» 
 Jehovah build the temple of nature at all, he will 
 fouud it on mysteries, frame it with mysteries, 
 cover and dome it with mysteries, pillar and 
 ballast it with mysteries, pave and ceil it with 
 a mosaic of mysteries — surely he will. And 
 when I am told of a being whose own nature is 
 an overwhelming problem ; whose attributes l\avo 
 no horizon, no zenith, and no nadir; whose ends 
 respect all possible objects and interests, and 
 spread tliemselves out in plans of boundless \ast- 
 ness whose merest corners and differentials only 
 are visible to men of the widest scope : when T 
 am told of him, and I then place myself out un- 
 der nature's open dome, amid its Protean inscru- 
 tableness of leaf and star, of whole crowded earth 
 and circumventing heavens — tlie peopled heavens 
 where sweep in inextricable maze the hurricane 
 hosts of advancing and retreating orbs ; and open 
 my soul candidly to all their silent suggestions 
 and magnetisms — I feel myself drinking in faith, 
 as the fleece spread out under the stars drinks in 
 the dew — I feel that the facts give embracing 
 arms to the doctrine ; that the actual universe, 
 instead of swearing with decisive voice and liand 
 uplift to heaven that there is no inscrutable God, 
 significantly asks with panting whisper and color 
 that comes and goes, " Is there not such a Being ? " 
 In fine, I feel that our continued lifting of the 
 veil from the painting has disclosed another char- 
 
198 SIXTH LECTURE. 
 
 acteristic of the great master to whom the work 
 is attributed ; has cleared up another stretch of 
 that vista which conducts tlie sight to Titian in 
 the act of glorifying his canvas into the Milanese 
 Coronation-Christ — anotlier of those many har- 
 monies which, as successively presented, warrant 
 us in looking faithward with ever-growing kindli- 
 ness of aspect 
 
PATER MUNDI, 
 
 OR, 
 
 MODERN SCIENCE TESTIFYING 
 
 TO THB 
 
 HEAVENLY FATHER. 
 
 nY THE AUTHOR OF "ECCE CCELUM." 
 
 The First Series is now ready. Tinted paper. 300 pp. 12rao. 
 I'rice, $1.50. Sent post-paid on receipt of the price, by 
 
 NO YES, HOLMES, & COMPANY, 
 117 "WaslLington Street, Boston. 
 
 The publishers of Ecce Caelum now solicit the attention of 
 scholars and of the public at large, to a still more important 
 work by the same author. Pater Mundi is believed to meet a 
 great need of the times. Men are busy, as never before, at taking 
 away the ancient Jehovah in the name of Science. In books, in 
 popular lectures, in journals having wide circulation and relig- 
 ious pretensions, and even in colleges whose founders hoped and 
 demanded better things from them, the public is being industri- 
 ously persuaded that it is scientific as well as natural to be witb- 
 out God in the world. Let all who would see for themselves 
 liow little ground exists for such claims, read Pater Mundi ; and 
 let all who wish well to the popular faith, to our holy religion, 
 ind to the safety of society, promote its circulation to the ut- 
 most. It is a book for the times. Though in the form of col- 
 lege lectures, and claiming scientific thoroughness, it is believed 
 10 be easy and luminous reading for all classes. 
 
EXTRACTS FROM NOTICES. 
 
 From the liev. W. A, Steams, D.D., L.L.D., President of Amherst College 
 I havp heard them with the deopest interest. They are so clear, so log 
 leal, so rich in illustration, so unexcepiionable and boautirul in style, aul 
 60 conclusive in the argum ut attempted, that I have profoundly ad- 
 mired them. Those gentlemen who heard them when delivered here, 
 would, 1 am sure, from the comments which they made upon them, agree 
 with me entirely in the judgment I have expressed. May the Great Being 
 who<o existence these lectures bo nobly defend from the attacks of the 
 looiish, though calling themselves scientists and philosophers, spare the 
 life of the author and enable him to complete the full course of thinking 
 on which he has so triumphantly entered and advanced. 
 
 From liev. Prof. C. S. Lyman, of Yale College. 
 All whom I have heard speak of these lectures have expressed for them 
 the highest admiration. In thought and diction they are worthy of 
 Chalmers. 
 
 From Prqf^ JtUiua JT. Seelye, Professor of Mental and Moral Philoso- 
 phy in Amherst College. 
 
 It 13 with great delight that I have received the new book. I like, es- 
 pecially, its whole attitude respecting the question discussed; that it is so 
 full of faith and so uncompromising. Atheism is as unworthy the intel- 
 lect, as it is repugnant to the heart; and I am tired of tame apologies 
 ft-om timid believers in a God. I like to see a book that has sometiung 
 of a clarion ring about it, and is not afraid to defy denial, when it speaks 
 of the being and the glory of the Heavenly Father. 
 
 I believe that Pater Blundi will do great good, and I thank the Lord 
 for permitting the author to prepare and publish it. 
 
 From Reo. A. P. Peahody, D.D. L.L.D., Preacher to Harvard Uni 
 
 versify, and Plummer Professor of Christian Morals. 
 I Ihank the author with all my heart for Pater Mundi, It is the most 
 efficient work of its class which the present generation has produced; 
 and as the now existing scepticism is deeper, more [pseudo] scientific, 
 more pretentious, than that of any preceding age; the book which, like 
 Pater Mundi,l3 adapted to our times, must need be both broader and 
 more profound than previous needs have elicited. Its treatment of the 
 great theme is at once thoroughly philosophical and popular, both in 
 style and in adaptation to the capacity of all readers of average intelli- 
 gence. It wa'^ an unspeakable privilege to the students of Amherst Col- 
 lege, to have heard the lectures; I trust that the same privilege will be 
 extended through the press to thousands of our young men. While I 
 dod no fault nor deficiency in the treatment ot any branch of theargu- 
 
ment. I am specially impressed by the Seventh Lecture, as the eleaiost, 
 Btrongest, and most eloquent statement of the need of God, and of tha 
 demonstration thence resultinrr of His existence, in the plenitude of Hii 
 attributes, that has come within the range of my reading. 
 
 From Rev. Albert Barnes, 
 
 T was so profoundly impressed, or, if I may say so, oppressed and uver- 
 wnelmed with the sublimity and grandeur of the truths presented in Ecce 
 Ccelum, and with the manner in which the author presented these great 
 truths, that I am glad he has followed with another volume on the same 
 general subject. I anticipate in the perusal of it great plca'^ure and 
 proflt. T think the author is doing great service to the cause of truth 
 and I hope that Cod will spare him to complete his work. 
 
 So far as I am able to judge, the greatest enemy which Christianity baa 
 to encounter now, is found in the oppositions of science, so-called. In 
 fact, so far as X undcrstaad lliem, the aim and tend 'ncy of much of this 
 science, are to blank Atheism ; and 1 think a man can do no better service 
 In this age, than to meet and counteract this tendency. I rejoice that 
 God raises up mem who are qualified to do it. I believe that the author of 
 EccG Coelum is such a man. He has a noble work before him, and I hope 
 he will be enabled to do it. ^ 
 
 From the Independent, 
 
 "We had not read. Ecce Ccelum^ and imagined that the enconiums which 
 we had seen pronounced upon it must be too high wrought for sober 
 truth. Cut now that we have read Pater Mundi, by the same author, we 
 are ready to believe every word of praise to have been within bounds* 
 The present volume is no dry, didactic treatise. It is warm, alive, elo- 
 quent The author proves himself, in his freshness of thought and in the 
 eloquence of liis argument, inferior to no writer of the day. We find no 
 slips in science, nor in his multiplied illustrations from ancient and mod 
 em literature. And we do find a grandeur of conception and a striking 
 originality of conception, so audacious that scarcely any other writer we 
 know of would have ventured upon it. We see no reason why our au- 
 thor's writings should not become classics in the language. Nothing can 
 be more invigorating to the thoughtful reader. 
 
 From the Congregationaltsi, 
 
 Wo have read it with keen enjoyment, and are disposed to regard it as 
 he rao.it substantial and serviceable contribution to tho natural theology 
 of this generation, as it is the freshest and most popular. No better book 
 none more entertaining, can bo placed in the hands of inquisitive readers, 
 especially bright minded young men and women* The author lays out his 
 work with a singularly clear perception of the crepuscular skepticism 
 tvhich needs to be dissipated; and entprs upon it with manly and gener- 
 
ous fairresa of statement. Tlgor of argument, and amplitude of apposite 
 and convincing illustration. His style is in the main so admirable, that 
 It may seom ungenerous to talie exceptions. Probably the excess oi 
 ornamentation, the overfulness of illustration, the easy affluence of the 
 most highly poetic diction, and iho general gorgeousness of rhetoric will 
 Becure a hearing for the truth by pprsons whom it Is desirable to influ- 
 ence, who might not be attracted by an ordinary book. 
 
 From the //nurs at Home. 
 
 The decidedly oratorical style will serve to make the essays. Incisive — 
 eloquent, and eminently pliilosophical as we acknowledge them to be— all 
 the more widely popular and useful. 
 
 From the Religious Herald. 
 Cogent argument is so lighted up with brilliant Illustration, as to make 
 Interesting the profoundest thoughts. 
 
 From the Christian Uninn. Pev. IT. W. Beecher. 
 
 The author, who, in Ecce Ccelum, established a reputation for that rare 
 combination of excellencies— f'rvid rhetoric, scientific accuracy, and com- 
 mon sense^has produced auuther book designed to defend and ill .strate 
 the doctrine of Theism. It is like breathing mountain air to feol this 
 man's earnestness; it is a true mental tonic. One sees instantly that he 
 ij able-souled, that he can push aud climb without getting short of 
 breath ; and it is almost a foregone conclusion, after reading the first 
 chapter, that one must either stride with him to his high conclusion, or 
 part company before starting. This unequivocal earnestness and power 
 display themselves at the outset; great heart is warmed up to begin with; 
 so that ono is almost inclined to distrust a leader who has so much the air 
 of a parti-^an. The face set like a flini does not wait to be struck to emit 
 its sparks, but glows with a fiery zeal which inflames everything it looks 
 upon. Yet, no candid reader will say that Be.. Bubb is dogmatic; he 
 only pliCs error with weapons for which Infidelity has claimed a patent 
 Hght. No one who reads this first volume, will wish that the author had 
 written lesB or otherwise than he has. 
 
 From the Advance. 
 
 The previous work entitled Fcce Cmlum, received the highest commend, 
 ntion from the most competent judges. The present volume will still fur- 
 ther augment the reputation of the author as a thinker and writer He 
 puts the Atheistic hypothesis to severe and annihilating tests; fully meet- 
 lug its objections and cavils. Tlie arguments of this work are not only 
 cogent, but are expressed in a lucid, glowing, and eloquent style; and the 
 book entitles the writer to a position among our best religious authors. 
 
fW wew. Edwin Hall, D.D., Professor in Auburn llteologicai Seminary. 
 
 I h^ve read the work with constantly increasing satisfaction and delight 
 It is entirely worthy of the author of Hcce C(Blum and of its subject. So 
 far as my reading extends— and T have long endeavored to read in that de- 
 partment wliatever 1 could lay my bauds on that promised to give me 
 light — I regard it ad the most original and valuable contribution to the 
 subject, which the age has produced. I shall waic with longing for the. 
 second volume. lathe meantime, 1 hope the work may have a circula- 
 tion as extensive as its worth deserves. If i* were left for me to fix that 
 desert, there should not he a library or a family in the laud without it. 
 From the Watchman and Reflector. 
 
 The thousands of readers of "Ecce Coelum" have not got fairly over the 
 feeling of astonishment and admiratioh which the perusal of that remark- 
 able book brought to them, before another of equal merit from the same 
 author is announced. "Pater Mundi," we are confident, will lessen noth- 
 ing of the high character which Dr. Burr has won as an acute and accu- 
 rate thinker, an accomplished scholar, a brilliant rhetorician, and a 
 humble, childlike believer in God and Uis revelation. The purpose of the 
 author is to defend and illustrate Theism and Christianity from the side of 
 Modern Science. There is a wonderful candor in the entire process of ar- 
 gumentation. Nothing is assumed beyond what the eyes of man behold 
 and his reason assents to. The conclusion, without being asserted, is irre- 
 sistibly forced into one's own view, and wins acceptance from the thought- 
 ful, reasonable soul. The eloquence of some of these passages respecting 
 the fatherhood of God is overwhelming in effect. "We earnestly com- 
 mend the book to the carelul study of our so-called scientific men who are 
 trying hard to rule a personal God out of the universe. AVe wish, too, 
 that every young man in the nation would read these pcges. We are sure 
 that nothing more fascinating in interest and really healthful and elevat- 
 ing in influence can be found among all the books of the day. The book 
 Is handsomely printed by Nichols & Noyes of this city. 
 From the Sunday School Times. 
 
 This volume is an eloquent and unanswerable protest against modern 
 atheism in all its forms. "Modern science testifying to the Heavenly 
 Father," is the author's secondary title, and it describes accurately the 
 course and object of his argument. His methods of presenting the sub- 
 ject, however, are entirely original, and are wonderfully effective. The 
 ivork is particularly opportune. There are in all our congregations 
 thoughtful, cultivated, quiet men, whose faith has been shaken by the bold 
 assamptions of infidel scientists. Dr. Burr's book is just suited to restore 
 0uch persom to their equilibrium. It ia written in a most attractive stylo 
 
and Bhows a masculine vigor of thought that cannot fail to command re< 
 epect. 
 
 From the Theological Eclectic. Professors Day, Schaff, etc. 
 
 We have already spoken of the able work entitled Ecce CcElum, in terma 
 of high commeudation. The present work by the same author pxhibita 
 the same jjower of comprehensive grouping and vivid presentation, and 
 abounds in great thoughts freshly pat. 
 From Eev. Mark Hopkins, D.D.. L.L.D., President of Williams College, 
 
 I am greatly indebted to the author of Tater Mundi. It is a freah and 
 powerful work. If any commendation from me will aid its circulation, 
 it is freely given. 
 
 Fr<mi C. II. Balshaugh, Pa. 
 
 Ccrtahily this is a book to stop the mouth of skeptics. It seems to me 
 tliat never was atheism in its protean lorms more squarely met on its own 
 ground, and never more clearly discomfited with its own weapons. No 
 two links of its argument are left together. The author has triumphantly 
 vindicated the title of his book. Its matter and style appeal to both our 
 Innate susceptibility to truth, and our sense of the beautiful. In my view, 
 never did logic and poetry more heartily embrace each other; never did 
 beauty smile more divinely on the face of the sternest facts. 
 From the X<iW York Evening Post. 
 
 The clear and beautiful logic, and the crystal style of Ecce Coslum, fas- 
 cinated religious minds everywhere in this country. This book is written 
 by the same perspicuous pen. That it is in the form of lectures, rather 
 Improves it than otherwise. The special aim of the author is to wrest 
 from the wild materials of this day the powerful sceptre of science, which 
 they have seemed to wield. All the teachings of science and nature 
 point to the "Father of the AVorld." This book is one calculated to 
 strengthen the faith of professors of religion, and to lead captive young 
 minds straying into error. We ought to mention in closing, the beautiful 
 typography of the book. Published by Nichols & Noyes. 
 From the Evening Wisconsin, Milwaukee. 
 
 The style is clear, and always strong and forcible in an unusual degree 
 while many passages rise to great beauty and eloquence. Seldom have we 
 read anything upon the subject of Christian evidence that was so enter- 
 taining, so instructive, and so satisfactory as this book. It is the offspring, 
 of a vigorous intellect, and it is a most valuable addition to religious cul- 
 ture. 
 
 From the Christian Recorder^ Philadelphia, 
 
 So charmed are we with this magnificent production of Dr. Burr's, thai 
 really we scarce know where to begin its p'Tiise. Its excellence ia uaiform- 
 
Lecture first and lecture eigKth equally dcniand admiration. So every pari 
 of each lecture. The chain of gold is not only complete, but every link is 
 complete. The Colonnade is not only symraelrical, but its minute carv- 
 ings are perfect. To quote ftom it to our own satisfaction, would be to 
 quote the whole book, but we remember that Messrs. Nichols & Noyes, the 
 publishers, havp a copyright. 
 
 How majestically does the author of Ecce Coelum send forth his 
 thoughts into the worldl lu majesty do they stride torth either to con- 
 quer, to convince, or to woo. Now as a mailed warrior are they peeu, fully 
 pauopled from bead to foot, and crushing by the strength ot his argu- 
 mnnts every foe — crushing every atheistic shield, and helmet, and breast- 
 plate. On almost everypage of Pater JIundi. these all-crushing arguments 
 are to be met— on almost every page we see victims lying mangled and 
 bleeding. 
 
 We do not know that the author of Pater Mundi lays claim to the po- 
 etic gift ; and yet has he given us a sublime Didactic Poem. Not in verse, 
 is it given; it is neither Dactylic, Anapiestic, Iambic, nor Trochaic. 
 But poetic imagination shines on every page. Untrammeled by rule, 
 and enjoying a freedom that the utmost poetic license could not allow, 
 the author has given us a poem infinitely sublimer than could pos&ibly 
 have been done in any other form. Would that we could give our read- 
 ers the concluding pages of Lecture VII. Such poetic thought! Such 
 beauty of expression! Such smoothness! Such harmony! Words an- 
 swer to words, and sentence to sentence, with such sweetness that one 
 glides along to the conclusion, as smoothly as a New England sleigh, and 
 as merrily as its ringing bells. 
 
 From the Norwich Bulletin, 
 
 It will be a great advantage to the reader of this work to have made the 
 acquaintance of Dr. Burr's previous volume, "Ecce Coslum," as thus many 
 of the references in "Pater Mundi" will be the more intelligible and vivid. 
 The quality of the new work is in all respects admirable. Dr. Burr hag 
 a wonderful enthusiasm, always fTsh and intense. He is full of bis sub- 
 ject. He has the faculty of so treating profound and sublime themes, as 
 to bring them easily to the comprehension of all. He has a fervid style, 
 whose richness seems inexhaustible. He has great fertility in argument, 
 and presents his suggestions with rare simplicity and force. The volume 
 will go far to combat the sophistries of Atheism, both in uncultured minds 
 and in those of strong logical power". We cannot too highly commend 
 It, and we predict that it will find a place in every well stocked religious 
 library. 
 
 From the Standard, Chicago, 111. 
 
 If any one should infer from the title of this book that it is a heavy and 
 prosy mssertation, he would be «Btonished on looking over its pagea 
 
rTothing could be fUrther ftom the truth. The author Is an enthusiast, one 
 of those who have not "discovered that one must be indifferent in order to 
 be fair." The book is fresh, earnest, and eloquent, and we felt its strong 
 spell before reading a dozen pages. The statement of arguments is admira- 
 bly clear, the development of them is natural and impressive, and there ia 
 displayed a wonderful power in massing fact^ so as to give their full and 
 combined effect. 
 
 Frorr^ the Chicago Tribune. 
 
 This work in some rosp(>cts is Tery remarkable^ Tt is not only compact 
 In argument, and forcible and clear in statement, but it is also absolutely 
 brilliant and sparkling in manner, and rich and copious in illustration. 
 Judging only from the one volume before us, we .should pronounce it as 
 one of ihe most remarkable and fascinating books of the day. 
 From the Orfeans Uvpubtican, Albion, N. Y. 
 
 Tlie author's premises are bold, and his line of argument cl?ar, forcible 
 and persuasive; shirking nothing, anticipating, and answering objec- 
 tions with equal fairness. The work is calm, liberal, and large thoughted; 
 full of admirable logic, and profound reasoning; and the last three lec- 
 tures, especially, are grand with beautiful and terrible imagery, exquisite 
 poetry, and striking allusions to those mysterious facts and forces of na^ 
 ture which startle and awe believer and unbeliever alike; and his conclu- 
 sion is singularly suggestive and poweriU. 
 
 From Rev. Austin Phelps, D.D., Professor in Andover TlieologictU 
 
 Seminary. 
 
 I wish to thank the author for " Pater Mundi." Not that it needs any 
 commendation from me : hut I cannot but be grateful to any man who helps 
 me to a new depth or vividness of conception of God; and this you have 
 done by your book. 1 am specially impressed by the power with which it 
 draws the great alternative, — a God benevolent, or a God malignant. The 
 reductio ad absurdum is fearfully overwhelming ; and the recoil with which 
 one springs back from it gives one a lodgment and u resting-place in the 
 Infinite Love which no gentler discipline could secure so well. This vigor 
 of religious sensibility in your works charms me. We need it greatly in our 
 Christian literature, to supplement alike the wiry intellect of which we have 
 enough, and the emotive softness of which, perhaps, we have a little more. 
 From the American Baptist, 
 
 The author has a strong and vigorous style, and a power of grasping 
 and grouping great truths, which make all that he utters luminous and 
 convincing. Though prepared specially for educated men, they are adapt* 
 ed to all readers, have no abstruseness of diction, no intricate, far-tetched 
 or dubious arguments. The author will impart no small measure of the 
 indignation he feels towards atheism, concealing itself under the name oi 
 science, to those who read his book, and we trust it may have a very wid« 
 ^i^culation. 
 
From The New England<ir» 
 
 Theaathor of EcooGoBlum could not well be expected to write a dull 
 book on any subject, much less one in which God and nature were the 
 chief topic. But whether he would be able to clothe a skeleton of 
 a two-volume argument for Theism — often so dry and grim in otner 
 hands — with the flec-h and muscle, the life and beauty, that charm ua in 
 Parish Astronomy, could only be shown conclusively by the production of 
 a work like that before us. Pater Muudi, will, by the glow and magnet- 
 ism of its rhetoric, and the enthusiastic earnestness of its tone, as well as 
 the strength of its argumpnt, bo sure to command everywhere, appri^cia- 
 Cite and admiring readers, and prove, we trust, ofspecial value to those who 
 are inclined to regard science as hostile to religion. Its logic is vitalized 
 and made effective by the force and richness of the illustrations drawn 
 from thj various fields of science. It is these all glowing often with poetic 
 fervor, that rivet the attention at once, and carry the reader on insensibly 
 from topic to topic. In some of the lectures, indeed, the argument as- 
 sumes the elevation and almost the form of a grand poem. The sixth, for 
 example, like a sublime ode, returns, strophe by strophe, with each point 
 made in the argument, to the same exultant chorus, which becomes at 
 once a quod crat di- inonstrandum to the un lerstanding, and an inspi- 
 ration of faitu to the heart. 
 
 The second volume promises to be even more attractive than the first ; for it 
 la to be still more replete with the marvels and sublimities of the sciences 
 as illustrative of the argument. It is too much forgotten by many that God 
 may be studied In flower and forest, in storm and star, and in the soul of 
 man," as well as in Moses and the prophets. The glowing pages of " Pater 
 Mundi, " teach impressively that the God ofKevelation is the God of 
 Katureaswell. 
 
 From tJie Methodist, 
 
 Th^ many gratified readers of" Ecce Ccelum." will welcome this new 
 and important work of Dr. Burr. It is a book for the times. Natural 
 Theology can no longer retain iti old form ; the progress, not only of Sci- 
 ence but of speculative thought, demands a thorough revision, ''Pater 
 Mundi" meets this demand with masterly ability. 
 
 Frotn the Amerivati FvethyU'riitti Itevietv, 
 
 A new work by the author of" Ecce Cesium" is sure to attract unusual 
 attention; nor will expectation be disappointed. Dr. Burr is an original 
 and independent thinker, and he writes in a style of singular freshness 
 and rhetorical beauty. His book is timely. Though popular in its ad- 
 dress, it sacrifices nothing to effect, and is wholly free from that euperfi- 
 cialty which is usually found in the attempt to reduce the conclusions of 
 science to the level of a popular audiance. It discusses with masterly abil- 
 ity the testimonies of Modern Science to the being of a God, and defends 
 Theism from the attacks of sk^jticul scivT^ce is. a. bold and critical spirit 
 
worthy of all praiso. Tt is as profoundly religious as it is thoroughly sci- 
 entific. While it freely accepts the results of the freest inves tigatiom, it ably 
 argues that there is notliing in one of these to shake the christian's faith, 
 but much to confirm it. The work cannot fail to haTP an important influ- 
 ence on Natural Theology— bringing it into harmony with tlie progress of 
 Science and speculative philosophy, and arming it with a new power of 
 demonstration. 
 
 From the Princeton Jtevieiv. 
 
 Dr. Jiurr, known to us in his youth as a modest and studious lad, and 
 BincL', as the faithful and unpretending pa-;tor of a rural congregation, has 
 eudden'y burst on our vision as an author of the first mark in the highest 
 ro-lms of thought, aad as a leading d^'fyader of precious truth against the 
 ivssauUs of scientific pretender-' and pretentious sciolists. He calls to raind 
 the days when the great New Euglaad divines, the Edwardses, Rellamy, 
 Backus, ftmalley, Einniois, wore pastors of agricultural congregatio:is 
 
 The universal approbation of Pater Jlund! and the previous volume, by 
 the press and by christian thinkers of the highest reputation, we fiud 
 borne out by actual inspection. Real science is proved to be the hand- 
 maid of true religion, in a series of di-^cussions which evince a masterly 
 compreheujioa of the issues inv )lv'jd— a th )rough acquaintance with 
 modi^rn scienci- and its relations to religion — the whole in a style clear 
 and simple, vivid and graphic. We think t!ie quiet of a country charge 
 more propitious to thorojgli study and d 'op thinking, than the din and 
 whirl of metropolitan excitements. 
 
 Front Prof. 2>. C. Gllntan, Yale College, 
 
 I feel moved to express my hearty appreciation of the service the author 
 of " Pater Alundi " is rendering to the world by the publication of these 
 earnest, brilliant and impressive discourses. 
 
 From Uoti, Heart/ L. I}iw's, M. C. 
 
 The pleasure with which I read aloud to my family " Mcce Ccelum" has 
 prepared me for an increased delight and profit in reading" Pater Ulundi." 
 I am very proad of the author, and rejoice in his growing fame. 
 From Our JMonthly, Cineinnati, Ohio* 
 
 We are veiv glad to welcome and commend this book The author does, 
 with singular ability, what he proposes to do. His trumpet utters no un- 
 crtain sound. There is no danger of any one mistaking his meauing. 
 A7e think it high time the arrogant assumptions and speculations of some 
 scientific men in the interest of infidelity and atheism were exposed, and 
 the harmony of all true science and revelation vindicated, made more ap- 
 parent, and presented in some popular form. This Dr. Burr is doirg, and 
 the first installment of his work we have in this aeries of lectures. Tliat 
 tbey mil be found interesting and convincing we need not say to thosa 
 who have read * Ecce Ccelum."