LIBRARY 
 
 Diversity of California^ 
 JRVINE 
 
 THE LIBRARY 
 
 OF 
 
 THE UNIVERSITY 
 
 OF CALIFORNIA 
 
 IRVINE 
 
 GIFT OF 
 MRS. THOMAS A. ROCKWELL
 
 THE GREAT NEBULA IN ANDROMEDA. 
 (Roberts.)
 
 THE 
 
 STORY OF THE 
 
 STARS 
 
 BY 
 
 GEORGE F] CHAMBERS,- F.R.A.S. 
 s- 
 
 OF THE INNER TEMPLE, BARRISTER-AT-LAW 
 
 AUTHOR OF 
 
 A HAND BOOK OF DESCRIPTIVE AND PRACTICAL ASTRONOMY, 
 PICTORIAL ASTRONOMY, ETC, 
 
 NEW YORK 
 
 McCLURE, PHILLIPS & CO. 
 MCMIV
 
 
 COPYRIGHT, 1895, 
 Bv D. APPLETON AND COMPANY.
 
 THE LIBRARY OF VALUABLE 
 INFORMATION. 
 
 A LIBRARY of useful information is a thing 
 needed alike in the family and in the office. In 
 this age of cheap printing the periodical daily, 
 weekly, monthly, annual brings forward an 
 enormous amount of half-digested reports of do- 
 ings in the world. Each report gives its results 
 in more or less technical language. There is a 
 special technique to each one of the natural 
 sciences and to each one of the departments of 
 history, of philology, jurisprudence, sociology, to 
 say nothing of the fine arts or literature. 
 
 A man or woman or youth who reads the 
 periodical carries away with him as a matter of 
 pure gain what he is able to seize and understand. 
 If ignorant of the technique, he gets very little 
 that is valuable. 
 
 This is the use of general information, to fur- 
 nish one with the technique, an outline of the 
 history of the investigation, and a summary of its 
 results. 
 
 I take as an illustration a volume from this 
 series of useful stories or brief summaries of his-
 
 iv THE LIBRARY OF VALUABLE INFORMATION. 
 
 tory and results. " The Story of Geographical 
 Discovery," by Joseph Jacobs, contains in a com- 
 pact form, in its 200 pages of this i2mo volume, 
 a sketch of ancient and mediaeval geography ; of 
 the development of roads and commerce, the era 
 of search for routes to the Indies eastward, west- 
 ward, and northward, and finally the polar discov- 
 eries. Chapter XI gives an admirable summary 
 in fifteen pages of the exploration and partition 
 of Africa ; Chapter IX, twelve pages, of the par- 
 tition of America ; Chapter XII, seventeen pages, 
 an outline of polar discoveries. 
 
 A book of this kind read by the parents and 
 the older youth of the family furnishes the basis, 
 in many minds of the family, of accurate and 
 satisfactory information upon geographical mat- 
 ters. If the allusion in the newspaper or maga- 
 zine or the book of travels is given in technical 
 language with allusions to matters of history that 
 are not immediately intelligible, the little hand- 
 book is brought into requisition and the subject 
 is explained ; something worth learning has been 
 added to the mind. 
 
 In the twenty-four volumes that have appeared 
 at the present date the following volumes relate 
 to nature in its inorganic aspect. The books relat- 
 ing to the stars and eclipses, the earth, and to the 
 solar system, relate to cosmic nature. The stories 
 of a piece of coal, of the earth's atmosphere, of 
 electricity, of photography, relate to physics and 
 to physical processes. 
 
 In the volumes that relate to organic life
 
 THE LIBRARY OF VALUABLE INFORMATION. V 
 
 that is, to plants and animals there is a story of 
 animal life, of the living machine, of the cotton 
 plant, of life in the seas, of germ life, and of 
 plants. 
 
 Relating to man and the instruments of his 
 civilization are the following: The story of the 
 art of music, of the art of building, of the alpha- 
 bet, of the British race, of King Alfred, of the 
 extinct civilizations of the East, of primitive man, 
 of geographical discovery, of books, and finally 
 the story of the mind. 
 
 To illustrate the usefulness of these books by 
 further example, take that on electricity. Elec- 
 tricity has, so to speak, been taken into the home 
 by the invention of the dynamo and of the various 
 kinds of cells for generation and storage of elec- 
 tricity. The book leads up from the most ele- 
 mentary beginnings to the complex results of the 
 present day, the final chapter relating to wireless 
 telegraphy. Perhaps the distribution of force 
 from great centres of power like Niagara Falls 
 or like the swift river tributaries descending from 
 the Sierra Nevada Mountains, and conducted by 
 wires to industrial centres where the raw mate- 
 rial of force is converted into light, heat, or 
 manufacturing power perhaps this is the most 
 important application of electricity. This is ex- 
 plained with great clearness in Chapter VIII. In 
 the days when the waterfall was the only consid- 
 erable source of power the manufacturing village 
 could choose its place only in the river valley. 
 With the possibility of transmitting power with-
 
 VI THE LIBRARY OF VALUABLE INFORMATION. 
 
 out serious loss the raw material of force may be 
 utilized wherever needed. 
 
 Selecting a book from a number that relate to 
 man and his civilization, " The Story of King 
 Alfred," by Sir Walter Besant, there is presented 
 in a compact form a charming picture of the 
 beginnings of the English nation. It was very fit- 
 ting in 1901 that the English should celebrate the 
 millennial anniversary of the death of that great 
 king. There exists in England to-day a great 
 activity in the way of preparing and publishing 
 new local histories, not only of cities and towns, 
 but of counties, and also new editions of the 
 genealogies of the various families of the nobil- 
 ity of England. An interesting suggestion has 
 been made by President Jordan, of the Leland 
 Stanford Junior University in California, that 
 owing to the law of descent, by which each per- 
 son has two parents, four grand-parents, etc., 
 that in the tenth generation back, counting his 
 parents as the first, there are more than one 
 thousand different ancestors if no allowance is 
 made for intermarriages. Reversing the calcula- 
 tion, the single ancestor should, in the tenth gen- 
 eration of descendants, have a thousand progeny, 
 in the twenty-first generation something over a 
 million, in the thirty-first generation more than a 
 billion, and in the forty-first, which would be 
 approximately the generation from King Alfred 
 in which the English people are living at the 
 present time, he would have a trillion of descend- 
 ants. Intermarriages, especially in former times
 
 THE LIBRARY OF VALUABLE INFORMATION. Vll 
 
 when migration was very limited except among 
 royal families and families of the nobility, were 
 numerous. President Jordan suggests that all of 
 the people in southern England to-day are de- 
 scended not only from King Alfred, but also from 
 the peasant woman who found Alfred an indiffer- 
 ent servant in attending to the kitchen fire placed 
 in his charge during his exile. It is not only 
 possible, therefore, but quite probable, that the 
 majority of the people in the United States from 
 English descent will read in this " Story of King 
 Alfred " the history of an ancestor. " The Story 
 of the British Race " is noteworthy for containing 
 a careful study of the characters of each of the 
 ethnic threads that form the British people. Celtic 
 types of character receive most attention. " The 
 Extinct Civilizations of the East " presents in a 
 readable and instructive form a summary of 
 archaeological discoveries in recent times, with an 
 intelligent discussion of their significance in the 
 light of other sources of information. Still earlier 
 records that do not relate to prehistoric nations 
 so much as to prehistoric races are discussed in 
 "The Story of 'Primitive' Man." 
 
 The present day is a day of revolution not 
 only in machinery and the transfer of energy 
 from the place of its origin to the place where it 
 is needed, and of miracles both in organic and in 
 inorganic chemistry, but it is a day of revolution 
 in medicine and in the diagnosis of disease. The 
 study of bacteria in all parts of the civilized 
 world is making possible the cure and prevention
 
 Vlll THE LIBRARY OF VALUABLE INFORMATION. 
 
 of those great scourges of the human race which 
 have their origin in infusorial life. The condi- 
 tions under which the microbe of some special 
 disease takes its origin and flourishes, as well as 
 those opposite conditions under which microbe 
 life becomes impossible, are one by one deter- 
 mined with accuracy by painstaking experiments 
 and verifications ; especially bacteria found in 
 malignant pustules; in cholera; in croup; in 
 diphtheria; in leprosy; in la grippe; in consump- 
 tion and scrofula ; in typhoid fever. One of the 
 most important books in this valuable series is 
 " The Story of Germ Life," by the Professor of 
 Biology in Wesleyan University. All of the adult 
 members in any family should read this book and 
 get a general acquaintance with the results it 
 describes. Ordinary books on hygiene are of 
 very little value as compared with this small 
 book which gives the history of the discoveries 
 in bacteria. Chapter VI, on the methods of com- 
 batting parasitic bacteria, is full of enlightening 
 information. 
 
 The study of bacteria, too, has proved of 
 great use in scientific agriculture. A very im- 
 portant agent in the growth of plants is nitric 
 acid. It would seem that there is ahead of us 
 great progress possible in the cultivation of 
 sterile soils, supplying to them what is needed to 
 make them rich, and especially supplying them 
 the nitric acid which is needed to convert them 
 into productive soils. " Plants, by building up 
 compounds, form the connecting link between the
 
 THE LIBRARY OF VALUABLE INFORMATION. IX 
 
 soil and animal life; while bacteria, in the other 
 half of the cycle, by reducing these compounds 
 give us a connecting link between animal life and 
 the soil." There are several different kinds of bac- 
 teria that make nitrogen available for the nutrition 
 of plants. Chapter IV, on Bacteria in Natural 
 Processes, gives an account not only of this use,, in 
 the nutrition of plants, but also explains how it 
 is that the leguminous plants rival the best kinds 
 of meat in furnishing nitrogen compounds. Peas, 
 beans, and clover, " in a soil that contains no nitro- 
 gen products and watered by water that contains 
 no nitrogen will, after sprouting and growing for 
 a length of time, be found to have accumulated 
 a considerable quantity of fixed nitrogen in its 
 tissues. Careful investigation discovered that 
 these plants had a way of utilizing the secretions 
 of certain bacteria and thus obtaining nitrogen 
 from the air. Nearly four-fifths of common air 
 is nitrogen. The nests of bacteria found around 
 the roots of leguminous plants have a way of 
 extracting the nitrogen from the atmosphere 
 which permeates the soil, and of infusing it into 
 the juices of these plants. This discovery that 
 certain plants are generators of nitrates is one 
 of the most important discoveries ever made in 
 agriculture. It explains how the practice of the 
 farmer to keep the soil light by stirring it up, 
 hoeing and cultivating it, fills the soil full of 
 common air and thereby furnishes the elements 
 needed by the soil bacteria for the production of 
 nitrogen compounds.
 
 X THE LIBRARY OF VALUABLE INFORMATION. 
 
 The relation of bacteria to the dairy industry, 
 an account of which is given in Chapter III, is 
 invaluable to the farmer. 
 
 In these days of what are called significantly 
 " sky-scrapers " the average citizen wishes to know 
 something in regard to the methods by which 
 these enormous structures can be built with 
 safety and even with greater solidity than the 
 old-style stone building of three and four stories 
 in height. It is cheap steel that has made this 
 possible. Large buildings for thousands of years 
 have been constructed with enormous walls of 
 masonry to hold up the inner framework of floors 
 and partitions, but the present generation has 
 discovered a method by which the framework 
 can be made strong enough with steel to hold up 
 the outside walls of masonry. The tall building 
 is, therefore, said to be not architecture, but en- 
 gineering with a stone veneer. The " sky-scraper " 
 has been called a steel bridge standing on end 
 with passenger cars running up and down within 
 it. The Park Row Building in New York has 
 nearly a thousand rooms and accommodates a 
 population of four thousand people. The enter- 
 prising and ambitious young person will learn 
 from "The Story of the Art of Building" how 
 to recognise the most charming types of church 
 architecture, and will acquire good taste in regard 
 to styles of buildings. 
 
 WILLIAM T. HARRIS. 
 WASHINGTON, D. C., 
 
 October j, iqo2.
 
 PREFACE. 
 
 WHEN invited to write this little book, I was asked so 
 to shape it that it should be a concise but readable out- 
 line of that branch of knowledge which one associates 
 with the expression the " Starry Heavens " liberally inter- 
 preted. I was to cater for those rapidly growing thou- 
 sands of men and women of all ranks who are manifesting 
 in these closing years of the nineteenth century in so 
 many ways and in so many places an interest in the facts 
 and truths of Nature and Physical Science. The task 
 thus imposed upon me was a very congenial one, and I 
 gladly undertook it. How far I have succeeded in pre- 
 senting my facts in a bright and cheery spirit others must 
 determine. But I would ask it to be understood that I 
 have dealt with facts rather than fancies. There are too 
 many of the former available for a writer on astronomy to 
 make it worth while to waste space in dealing with the 
 latter. 
 
 This volume will shortly be followed by another in the 
 same unconventional style entitled, " The Story of the 
 Solar System ; or, The Sun, Planets, and Comets popularly 
 described." I trust, however, that many of my readers 
 will not be content with these mere outlines of a noble 
 science, but will desire to obtain a more complete grasp 
 of the subject in all its bearings by studying first my 
 " Pictorial Astronomy " (Whittaker & Co., 2nd ed.), and 
 then my " Handbook of Astronomy " (Clarendon Press,
 
 6 PREFACE. 
 
 4th ed., 3 vols.), which is a comprehensive treatise, yet 
 written in popular language and form so as to subserve 
 the wants of general readers. From both these works 
 thoughts and ideas have no doubt found their way into 
 the present volume. 
 
 For the chapter on the work of the Spectroscope in 
 connection with the stars I am indebted to my friend Mr. 
 E. W. Maunder, of the Royal Observatory, Greenwich, 
 one of the highest living authorities on this branch of 
 astronomy. G. F. C. 
 
 NORTHFIELD GRANGE, EAST BOURNE, 
 
 December, 1894.
 
 CONTENTS. 
 
 I. INTRODUCTORY THOUGHTS g 
 
 II. FIRST EXPERIENCES OF A STARLIGHT NIGHT . n 
 
 III. THE BRILLIANCY AND DISTANCES OF THE 
 
 STARS 21 
 
 IV. THE GROUPING OF THE STARS INTO CON- 
 
 STELLATIONS 28 
 
 V. THE HISTORY OF THE CONSTELLATIONS . 39 
 
 VI. THE NUMBER OF THE STARS .... 43 
 
 VII. DOUBLE STARS 51 
 
 VIII. FAMILY PARTIES OF STARS .... 59 
 
 IX. COLOURED STARS 62 
 
 X. MOVING STARS 67 
 
 XI. TEMPORARY STARS 75 
 
 XII. VARIABLE STARS 83 
 
 XIII. THE STARS IN POETRY 95 
 
 XIV. GROUPS OF STARS 101 
 
 XV. CLUSTERS OF STARS 106 
 
 XVI. NEBULA 114 
 
 XVII. THE MILKY WAY 129 
 
 XVIII. THE SPECTROSCOPE AND THE STARS AND 
 
 NEBULAE 137 
 
 APPENDIX I. TABLE OF THE CONSTELLATIONS . 150 
 " II. LIST OF CELESTIAL OBJECTS FOR 
 
 SMALL TELESCOPES . . .153 
 
 INDEX 157 
 
 7
 
 LIST OF ILLUSTRATIONS. 
 
 FIG. PAGE 
 
 1. The Great Nebula in Andromeda . Frontispiece 
 
 2. The Points of the Compass 20 
 
 3. Ursa Major and Polaris 31 
 
 4. Orion 43 
 
 5. a Herculis (double star) 51 
 
 6. C Herculis (1865) 54 
 
 7. Herculis (1871) 54 
 
 8. C Herculis (1883) 55 
 
 9. e Lyrae 60 
 
 10. <r Orionis 60 
 
 11. 8 Orionis 61 
 
 12. The Pleiades 104 
 
 13. 13 M. Herculis 107 
 
 14. 5 M. Librae 109 
 
 15. 80 M. Scorpii no 
 
 16. 67 M. Cancri 112 
 
 17. 77 M. Ceti (nebulous star) 113 
 
 18. The Ring Nebula in Lyra (Sir J. Herschel) . . 116 
 
 19. The Ring Nebula in Lyra (Earl of Rosse) . .116 
 
 20. The Nebula 43 1$ I. Virginis 117 
 
 21. The Spiral Nebula 51 M. Canum Venaticorum (Sir 
 
 J. Herschel) 118 
 
 22. The Spiral Nebula 51 M. Canum Venaticorum (Earl 
 
 of Rosse) 119 
 
 23. The "Owl" Nebula in Ursa Major . . . .120 
 
 24. The "Omega" Nebula in Scutum Sobieskii . 126
 
 CHAPTER I. 
 
 INTRODUCTORY THOUGHTS. 
 
 " By the word of the Lord were the heavens made ; and all the 
 host of them by the breath of His mouth." PSALM xxxiii. 6. 
 
 No great while ago a defendant who had to appear at 
 a Court held at Carlisle arrived there true to his time ac- 
 cording to the local time at Carlisle appointed by the Court 
 for the sitting ; but he found that the Court had met by 
 Greenwich time, and in his absence had decided the case 
 against him. This was considered by certain gentlemen 
 " learned in the law " to be both a hardship and an illegal- 
 ity, and the poor man obtained a second chance of being 
 heard. Subsequently to this incident Parliament passed 
 an Act providing that whenever any expression of time 
 occurs in any Act of Parliament, deed, or other legal in- 
 strument, the time referred to shall (unless it is otherwise 
 specifically stated) be held, in the case of Great Britain, to 
 be Greenwich mean time, and in the case of Ireland, to be 
 Dublin mean time. 
 
 Quite recently the following incident occurred at Liver- 
 pool, the outcome of which, by the way, seems hardly 
 consistent with the statute just referred to. A levy was 
 made by the Sheriff's Order on the household goods of 
 some person who urged that, as this was done after sun- 
 set, it was illegal. The Director of the Liverpool Observa- 
 tory being called to testify to the time of sunset on the day 
 of the levy, the defendant's objection was upheld. The 
 conclusion appears unavoidable that, in noting the times 
 of sunrise and sunset, local time, and not Greenwich time, 
 2
 
 10 THE STORY OF THE STARS. 
 
 must be regarded. This, as I have said above, seems not 
 to be consistent with the statute, but I am not concerned 
 here to discuss the question in that aspect. I only want 
 to use the facts referred to as a means of showing that 
 there is something more in the study of the stars than 
 many persons imagine. In other words, that in inviting 
 my readers to give a little thought to astronomical mat- 
 ters, I am asking them to consider things which are not 
 only not necessarily occult, difficult, or fanciful, but which 
 have in one way or another no 'slight bearing on business 
 and pleasures of life. 
 
 It is not necessary to develope the argument to any 
 great length, but it is just worth a passing thought, in con- 
 sidering the question whether astronomy has any, and if 
 so what, utilitarian value, to remember that those two ob- 
 jects of daily interest and use, the almanack and the diary, 
 entirely depend for their existence on the labours of the 
 astronomer in his observatory. In our case, as English- 
 men, these books are based on the labours of certain very 
 insufficiently paid members of her Majesty's Civil Service 
 at the Royal Observatory, Greenwich, and at the Nauti- 
 cal Almanack office in Gray's Inn Road. Were the staff 
 belonging to either establishment to resort to the fashion- 
 able expedient of a strike for higher pay (and there would 
 be much justification for their doing so), sooner or later 
 all the almanacks and diaries would cease to be published, 
 and the public business of the country would to a large 
 extent come to a standstill. But this is not all. The 
 shipping of England would come to a standstill, or nearly 
 so, and that not figuratively, but literally. Our vessels 
 would have to go back to the principles of navigation 
 practised by the inhabitants of these islands 2000 years 
 ago ; they would have to become coasting vessels, feeling 
 their way from place to place, and chiefly by daylight. 
 Long voyages oversea would be well-nigh impossible, or
 
 FIRST EXPERIENCES OF A STARLIGHT NIGHT. 1 1 
 
 only to be executed in the face of the greatest risks and 
 the wildest chance. Our railway system would become 
 utterly disorganised. A few trains could run, but the in- 
 tervals between them would have to be considerable, and 
 they could only travel by daylight and at very low speeds. 
 These general thoughts will, I trust, serve as a suffi- 
 cient preliminary proof that there is more in the " Story of 
 the Stars " than lies upon the surface of things. 
 
 CHAPTER II. 
 
 FIRST EXPERIENCES OF A STARLIGHT NIGHT. 
 
 LET us suppose a would-be observer of the stars to 
 station himself on some fine evening soon after sunset in 
 an open and if possible elevated position. A varied and 
 striking, not to say picturesque, spectacle would soon un- 
 fold itself to his gaze. Stars invisible during the daytime, 
 because their light was overcome by the superior light of 
 the sun, would soon appear. They would become visible at 
 first only one by one, as it were ; then several would seem 
 to start into being, and finally their number would increase, 
 until it might be supposed that many thousands were visi- 
 ble, though in point of actual fact no more than about ' 
 3000 stars at the outside can ever be seen by the naked 
 eye at any one time or place. 
 
 An attentive scrutiny, prolonged in one case for an 
 hour or two, and in another case for a day or two, will 
 disclose a twofold fact : first, that all the objects assumed 
 to be stars are moving in a body over the face of the sky 
 from hour to hour, whilst two or three brighter ones are 
 to be noticed which not only participate in the constant 
 movement from hour to hour of the whole mass, but have 
 an individual motion of their own in virtue of which either
 
 12 THE STORY OF THE STARS. 
 
 from day to day, or in other cases from week to week, 
 they will be noticed to change their relative positions with 
 respect to the twinkling stars around them. Pausing for 
 a moment to distinguish between these two classes of 
 celestial objects, it may be stated that the bodies which 
 twinkle, and have (seemingly) no relative movement, are 
 the " fixed stars," properly so called ; whilst the others, it 
 may be only two or three in number on any given even- 
 ing, and which do not twinkle, are objects of a totally dis- 
 tinct character, and known as " planets." 
 
 Taking the sky as a whole, with its 2000 or its 3000 
 naked-eye stars, the observer (if in a northern latitude) 
 will notice, if he turns his back to the south, remembering 
 where the sun was at mid-day, that after successive inter- 
 vals, say of a of an hour, new stars are presenting them- 
 selves on the right, rising above the horizon. If he will 
 follow some one group in particular far into the night, he 
 will find that it gradually rises in the heavens in the direc- 
 tion from east to west. After a certain interval it ceases 
 to rise higher ; then descends on his left, and finally dis- 
 appears below the western horizon. This onward march 
 is not an attribute of all the stars quite in the simple form 
 thus mentioned, for of some of them it must be said that 
 they do not rise above the horizon nor sink down below 
 it, because they are always above it. Such are the stars 
 which face our observer, who with his back to the south 
 is looking towards the north. Of the stars thus circum- 
 stanced there are some which seem to describe a pathway 
 which scrapes, as it were, the northern horizon ; whilst 
 others seem to describe circular paths, which become 
 more and more contracted towards a certain star in par- 
 ticular. That star seems almost motionless throughout 
 the entire night, and is known as the "Pole Star." The 
 stars which are, as above stated, always above the hori- 
 zon, would always be visible during the whole 24 hours
 
 FIRST EXPERIENCES OF A STARLIGHT NIGHT. 13 
 
 were it not for the sunlight. As a matter of fact, indeed, 
 the larger of them can on any fine day be traced by means 
 of a large telescope round and round during the whole 24 
 hours day after day throughout the year, weather permitting. 
 The movement of the heavens which has just been re- 
 ferred to is commonly called the "diurnal movement." A 
 better conception of it perhaps may be had if we imagine 
 (as indeed the ancients did) that we are in the centre of a 
 literal sphere ; that the stars are attached to the interior 
 surface of such a sphere ; and that it is endued from with- 
 out with a rotatory motion once in every period of time 
 which we designate a day of 24 hours. Regarding the 
 universe thus, we must, by one more forward stretch of 
 the imagination, consider the heavens to be always revolv- 
 ing around an invisible axis called the axis of the world, 
 which passes through the place of observation and a par- 
 ticular point near to the Pole Star. The direction of mo- 
 tion will be from east to west ; and whilst for us in Eng- 
 land the visible polar point of this imaginary axis will be 
 the North Pole, the other end of the axis will be pointing 
 in the opposite direction to another point called South 
 Pole. For the reader to obtain a full and true realisation 
 of these statements, which in the abstract no doubt have 
 a visionary sound, he must take a voyage to the Southern 
 hemisphere say, to the Cape of Good Hope or Australia. 
 Doing this, he will come face to face with a condition of 
 things which at first sight may be a little puzzling. He 
 will have lost both the North Pole and the Pole Star, and 
 also the constellation of the Great Bear and other constel- 
 lations which we associate with the north, and will find 
 himself called upon to study a very different situation. In 
 order to discover a polar point he will have to face the 
 south instead of the north ; he will find no bright star at, 
 or anywhere near, the South Pole ; and no Great Bear to 
 recall the memories of childhood and the nursery.
 
 14 THE STORY OF THE STARS. 
 
 The remarks in the preceding paragraph will have 
 paved the way for the statement which must now be made, 
 that the study of the stars as regards their location in the 
 heavens is intimately mixed up with terrestrial questions 
 of geography ; in other words, that the observer's oppor- 
 tunity of surveying the fields of view afforded by the 
 heavens ever depends upon the latitude (not the longitude) 
 of his place of observation on the earth. Wherever he 
 may be, provided he be not immediately at the equator or 
 pole, he will have to consider the heavens as comprising 3 
 distinct regions, each with its own particular peculiarities. 
 The first, bounded by an imaginary circle called the " cir- 
 cle of perpetual apparition " ; the second, bounded by 
 another imaginary circle called the " circle of perpetual 
 occultation " ; the third being all the area not embraced 
 by either of the others. All the stars lying between the 
 first circle and the visible pole will be perpetually visible 
 to our observer throughout the year, barring of course 
 accidents of sunshine or weather. All the stars lying be- 
 tween the second circle and the opposite (or invisible) pole 
 will be perpetually invisible to our observer, because none 
 of them rise above his horizon. This is the condition of 
 things as regards an observer in the Northern hemisphere. 
 Looked at on the other hand from a station, say in Aus- 
 tralia, the converse of the foregoing will be the condition 
 of things. The stars perpetually visible in England will 
 be perpetually invisible in Australia, and the stars perpet- 
 ually out of view in England will be perpetually in view in 
 Australia.* 
 
 The reader will by this time quite understand that 
 
 * The statement in the text will only be absolutely and literally 
 true when the stations between which the comparisons are made are 
 in identical latitudes, the one north and the other south. For in- 
 stance, it would be about true of Dunedin, New Zealand, and 
 Geneva in Switzerland.
 
 FIRST EXPERIENCES OF A STARLIGHT NIGHT. 15 
 
 when we talk about the celestial sphere, or the vault of 
 heaven, or the axis of the world, or the poles, we are re- 
 sorting to pure abstractions which are only calculated to 
 convey in a crude fashion ideas of apparent movements 
 which it is difficult to describe in words, or to indicate by 
 pictures, or to reproduce in model with mechanical appli- 
 ances. It may, however, be said that a pair of globes in- 
 telligently studied may be of some service. Perhaps it is 
 worth while to note in passing that ideas and expressions 
 on this subject which we employ simply as figures of 
 speech, were made use of by the astronomers of antiquity 
 in a literal and material sense. Many of them fully be- 
 lieved in the existence of a solid celestial vault with a ma- 
 terial axis provided with pivots turning in fixed sockets, 
 the stars being fastened to the surface of the vault by 
 nails or such-like attachments. Vitruvius may be men- 
 tioned as one of the best-known writers of antiquity who 
 has recorded as facts ideas of this sort. 
 
 It would not be in accordance with the design of this 
 little work to go very deeply into matters of the kind 
 brought under the reader's notice in the pages immedi- 
 ately preceding. Suffice it then to add that whilst the 
 longitude of an observer's position has nothing to do with 
 the question of whether he sees some stars and not others 
 on any given night, it has a good deal to do with the ques- 
 tion of what stars are visible at any given moment of time 
 to an American at New York, to an Englishman in Lon- 
 don, or to a Hindoo at Calcutta. For instance, when a 
 Londoner is going to bed at the hour of n p. m., the 
 New Yorker will be sitting down to his dinner at 6 p. m., 
 whilst the Calcutta Hindoo will be preparing for breakfast. 
 The difference of 1 1 hours of absolute time which exists 
 between New York and Calcutta will result in each of 
 those places having a totally different batch of constella- 
 tions presented to its gaze ; because London occupies an
 
 1 6 THE STORY OF THE STARS. 
 
 intermediate position, the Londoner will see certain stars 
 over his head which to the Calcutta Hindoo will appear 
 setting near the W. horizon, and which to the New 
 Yorker will appear low down in the E. horizon, just 
 rising. 
 
 Whilst it is intended as far as possible to exclude from 
 this volume matters of mathematics and geometry, there 
 are a few such matters which must be stated to and be 
 comprehended by the reader if he would follow up, to any 
 good purpose, the study of astronomy as a pleasant and 
 profitable occupation. 
 
 We sometimes have to speak of a body being in a 
 " vertical " position. This means " upright," and a heav- 
 enly body is in a vertical position when it is exactly over 
 the observer's head. The vertical of a place, then, is the 
 direction from which a body, set free to fall as it will, 
 seems to come when it strikes the earth at the place. It 
 is indicated by the direction of a string made fast at one 
 extremity, whilst the other extremity supports a weight of 
 some kind. Such a combination constitutes a plumb-line, 
 and is used by masons and bricklayers for the express 
 purpose of ensuring the uprightness or verticality of their 
 work. Further, it may be stated that the vertical of a 
 place is constantly perpendicular to the surface of water 
 there which is at rest. 
 
 The imaginary point in the sky where the vertical pro- 
 longed from the ground upwards meets the celestial vault 
 is the " zenith " of the place of observation. It is of 
 course the point exactly above the observer's head. If 
 one could conceive the vertical prolonged downwards 
 through the earth and coming out on the other side,* and 
 
 * The following " anecdote " illustrates this : An American in- 
 quired of as to the suitability of a certain soil for growing carrots, 
 said that they grew so well in it that the roots reached right through 
 to the other side of the earth, where people stole the carrots by pull-
 
 FIRST EXPERIENCES OF A STARLIGHT NIGHT. 17 
 
 carried forwards till it met the celestial sphere at another 
 point, it would do so at a point which is called the " nadir " 
 of the observer on the upper side, so to speak, of the earth. 
 An observer standing out on an open plain, or better still 
 in a boat on the open sea, will notice that his view of the 
 land in the one case, and of the sea in the other, is cut off 
 from the sky by a circular boundary line, he himself being 
 in the centre of the circle. This circle is called the 
 " horizon." It really is a horizontal plane passing through 
 the place of observation at right angles to the vertical. 
 
 The " plane of the meridian " of a place is an imagi- 
 nary plane passing through what we have spoken of as the 
 axis of the heavens and the vertical of the place. Suitable 
 observation shows that the uppermost and lowermost 
 points in the circles seemingly described by all the stars 
 are situated in this plane. The intersection of this plane 
 of the meridian with the horizon to the north and to the 
 south constitutes what we call the "meridian line," or 
 simply the " meridian " of the place of observation. What 
 it is and what it means will perhaps best be grasped by a 
 consideration of the original meaning of the word. It 
 comes from 2 Latin words, through a single Latin word, 
 the words of origin being medtus middle, and dies, day 
 meaning in effect the point of the horizon immediately be- 
 low the place in the heavens where the sun is when it has 
 run half its daily course from sunrise to sunset. 
 
 With the horizon and the meridian understood, the 
 cardinal points, north, south, east, and west seem to come 
 naturally. An observer placed in the direction mentioned 
 at the beginning of this chapter, that is, facing the Pole 
 Star, will (in England) be facing the North ; immediately 
 behind him will be the South ; whilst on his right will be 
 
 ing them through by the tips, instead of pulling them up (as 
 usually done) by the tops.
 
 1 8 THE STORY OF THE STARS. 
 
 the East and on his left the West. These words in Eng- 
 lish convey very little to us, but in their Latin forms are 
 much more expressive. The Latin, by the way, reappears 
 in the French. For instance, the Latin for " North " is 
 septentrto, which recalls the 7 (septem) stars near the 
 North Pole ; in French it is septentrton. Then the South 
 has already been mentioned and reaches us in French as 
 midi. Then the East is or tens (Fr. I' orient), z. e., the 
 place where the sun rises. And the West is occidens (Fr. 
 I' accident), z. e., the place where the sun falls, *. e., sets. 
 
 It is sometimes necessary to consider the position of a 
 star or the distance of one star from another by making a 
 measurement or an estimate along the plane of the hori- 
 zon, or along some other plane parallel thereto. This is 
 spoken of as a measurement in " azimuth " ; or, to put it 
 in another way, let us imagine a plane passing through 
 the zenith and through any star whatever ; that would be 
 at the moment of observation the azimuthal plane of the 
 star ; and the angle between this plane and the plane of 
 the meridian, or the star's distance from the meridian thus 
 measured, would be the star's " azimuth " at the particular 
 moment when the observation was made. 
 
 A few words respecting angular distances and their 
 measurement seem now needed, but they must be very 
 general because the study of angles is a matter which con- 
 cerns geometry in the first instance and astronomy only in 
 a secondary sense. 
 
 Every circle is considered to be divided into 360 de- 
 grees, every degree () being subdivided into 60 minutes, 
 and every minute (') into 60 seconds. Formerly every 
 second (") was divided into 60 thirds, but this method of 
 counting has become quite obsolete, and when it is neces- 
 sary, as it often is, to deal with fractions of a second, re- 
 sort is had to decimals. Occasions, indeed, sometimes 
 arise when it is convenient to go no further than whole
 
 FIRST EXPERIENCES OF A STARLIGHT NIGHT. 19 
 
 minutes and to express as decimals of a minute the sec- 
 onds which we wish to record. Indeed, on occasions, 
 even the minutes and seconds taken together are set down 
 as simple decimals of a degree. Thus, 45 12' 20" might 
 be expressed as 45 I2'.33 or 45.2O5. 
 
 The whole circle being taken at 360, a half-circle em- 
 braces 1 80 ; a quarter circle, or " quadrant," is 90, whilst 
 the eighth, or " octant," represents 45. An intermediate 
 subdivision, a sixth, or " sextant," furnishes a word which 
 has an astronomical application, but it is to an instrument, 
 and not to the space which the word suggests. The 
 words " octant " and " sextant " as portions of a circle are 
 not in use, notwithstanding that the words themselves 
 exist. 
 
 Applying to the circle thus divided the 4 cardinal 
 points already mentioned we obtain the divisions which 
 constitute the dial of the " mariner's compass," and an at- 
 tentive consideration of the manner in which that is di- 
 vided will pave the way for a due comprehension of the 
 manner in which angles are measured for astronomical 
 purposes. 
 
 It will be seen by the diagram that if a circle is divided 
 into 4 quadrants we are furnished with the 4 principal 
 points, N., E., S., and W. Each quadrant therefore em- 
 braces 90 of the 360 which constitute the entire circle. 
 Dividing each quadrant into two halves gives us the sub- 
 divisions known as N.E., S.E., S.W., and N.W. Each of 
 these represents the half of 90, or 45. Then by subdi- 
 viding each half-quadrant into half again we obtain what 
 are quarter-quadrants, though no such phrase is in use. 
 The quarter-quadrants give us the points known as 
 N.N.E., E.N.E., E.S.E., S.S.E., S.S.W., W.S.W., 
 W.N.W., and N.N.W. 
 
 We have now got our circle divided into 16 portions 
 each of 22^. The sailor, however, carries the matter 2
 
 20 THE STORY OF THE STARS. 
 
 steps further, and by again subdividing into halves the 
 intervals just mentioned he arrives at the 32 " points of 
 
 FIG. 2. The points of the compass. 
 
 the compass," as they are called ; then by another sub- 
 division into halves he obtains 64 subdivision of the circle, 
 though the final appellation is not a " point," but a "half- 
 point." 
 
 Speaking generally, the subdivision of the circle for the 
 purpose of steering a ship does not need (except in special 
 cases, of course) any great refinement ; that is to say, an 
 order to vary a ship's course by half a point, or about 5^, 
 is precise enough on the open seas.* But the astronomer 
 in measuring angular distances in the case of the sun and 
 planets, and still more in the case of the stars, has to deal 
 
 * This remark does not apply to the larger steamers, whether 
 ships of war or belonging to the mercantile marine. These when 
 provided with steam-steering gear are steered to single degrees of 
 the circle.
 
 BRILLIANCY AND DISTANCES OF THE STARS. 21 
 
 with arcs infinitely smaller than those which the " man at 
 the wheel " is concerned with. Not only arcs as small as 
 i", but even fractions of a second have to be taken into 
 account by the use of instruments far larger in size and 
 more finely graduated than the portable instruments, such 
 as sextants and theodolites, used by sailors at sea, and by 
 surveyors on land. 
 
 CHAPTER III. 
 
 THE BRILLIANCY AND DISTANCES OF THE STARS. 
 
 THE stars are not all equally bright, and custom has 
 divided them into certain classes known as " magnitudes." 
 The largest and brightest are said to be stars of the ist 
 magnitude ; next come stars of the 2nd magnitude, 
 and so on by a descending scale. Stars of about the 
 6th magnitude are reputed to be the smallest visible 
 to the naked eye, but by the use of telescopes we can 
 go on observing stars down to about the i5th magni- 
 tude or even smaller. It will be readily understood that 
 this is a very loose and arbitrary phraseology, but it has 
 become so consecrated by time and custom that it will 
 certainly never be set aside. Whilst everybody is agreed 
 as to what is the brightest star in the heavens, namely 
 Sirius, and that about 20 stars are worthy to be ranked as 
 of the ist magnitude, though less bright than Sirius, sharp 
 differences of opinion present themselves when we try to 
 mark off 2nd magnitude stars from ist magnitude stars, 
 and still more when we have to define where the 2nd 
 magnitude stars end and the 3rd magnitude stars begin. 
 Lower down in the scale the difficulties of classification 
 become infinitely greater they may, indeed, be said to be 
 hopeless.
 
 22 THE STORY OF THE STARS. 
 
 Considering the love of precision and exactness which 
 characterises nineteenth-century science, it is somewhat 
 singular that so little has been done to submit to meas- 
 urement on definite principles the brilliancy of the vari- 
 ous stars, at any rate those visible to the naked eye. 
 Sir John Herschel made an attempt in this direction 
 about 60 years ago. Many years afterwards some Ger- 
 mans, especially an observer named Seidel, nibbled at it, 
 but Professor Pickering in America and the late Professor 
 Pritchard of Oxford, working at Oxford and in Egypt, are 
 the only two observers who have accomplished any results 
 worthy of the subject on a well-organised basis. Picker- 
 ing's labours at Harvard College Observatory, Boston, 
 U. S., have been published in the form of a catalogue of 
 4260 stars, whose magnitudes have been determined in- 
 strumentally on definite and intelligible optical principles. 
 Pritchard's catalogue comprises fewer stars than Picker- 
 ing's, but like its American rival is based upon philosophi- 
 cal principles, an instrument called the Wedge Photometer 
 having been employed. Both catalogues labour under the 
 disadvantage, that having been made in the Northern hemi- 
 sphere they do not include the whole area of the heavens. 
 
 Taking the stars as we find them, a very slight amount 
 of attention will show that not only are they of different 
 degrees of brilliancy, but that they are of different colours. 
 More prolonged and refined study will disclose the further 
 facts that some of them vary both in brilliancy and in 
 colour. These matters are of such extreme interest that 
 it will be best to devote a special chapter to them. The 
 brighter stars are distinguished from one another in vari- 
 ous ways, and many of them received in bygone times 
 quaint and curious names. At a very remote period they 
 were grouped into constellations, most of which survive 
 to the present time and are recognised to be of use to a 
 certain extent.
 
 BRILLIANCY AND DISTANCES OF THE STARS. 23 
 
 Leaving the constellations for treatment in a separate 
 chapter, and confining our attention for the moment to the 
 stars as individual objects, it may be remarked that in 
 order to distinguish one star from another the ancient 
 astronomers often indicated a star by speaking of the posi- 
 tion it occupied in the constellation to which it belonged. 
 Thus Aldebaran was called Oculus Tauri, " the Eye of 
 the Bull." This custom was followed and largely de- 
 veloped by the Arabians, and many of the names invented 
 by them are still in use, corrupted or transformed. A 
 German astronomer named Bayer was the first to attempt 
 (about 1603) on any considerable' scale to simplify, and so 
 improve the old plan, but the Arabian names had, either 
 in their Arabian form, or as translated into Latin, taken 
 such deep root that many of them are even still in constant 
 use. Bayer's plan was to attach to the prominent stars of 
 each constellation the letters of the Greek alphabet, though 
 the popular idea that the opening letters of the alphabet 
 were reserved for the brightest stars and the later letters for 
 the less conspicuous stars, is unfortunately not universally 
 true. However the Greek letters a, /3, and y, do indicate 
 often the 3 brightest stars of a constellation. Bayer's 
 letters are still in vogue, the name of the constellation 
 being put after each in the genitive case. Thus the star 
 which bears the name of Sirius is termed a Canis Majoris, 
 Arcturus is a Bootis, and so on. The Persians are said to 
 have considered 3000 years ago that the whole heavens 
 were divided into 4 great districts, each watched over by 
 a " Royal " star. The 4 stars, each very brilliant and 
 remarkable, which occupied the important positions of 
 "guardians " of these districts were Aldebaran in Taurus, 
 Antares in Scorpio, Regulus in Leo, and Fomalhaut in 
 Piscis Australis, but Arago, who mentions this tradition, can 
 hardly be deemed accurate in his remark that the 4 stars 
 in question divide the heavens into 4 almost equal portions.
 
 24 THE STORY OF THE STARS. 
 
 This chapter may be conveniently brought to a close 
 with a list in the order of brightness of the stars which 
 are commonly ranked as of the ist magnitude : 
 
 1. a Canis Majoris (Sirius). 
 
 2. a Argus (Canopus). Invisible in England and Northern 
 United States. 
 
 3. a Centauri. Invisible in England and United States, ex- 
 cept extreme southern points. 
 
 4. a Bootis (Arcturus). 
 
 5. Orionis (Rigel). 
 
 6. a Aurigse (Capella). 
 
 7. a Lyrse ( Vega). 
 
 8. a Canis Minoris (Procyon). 
 
 9. a Orionis (Betelguese). 
 
 10. a Eridani (Achernar). Invisible in England and 
 United States, except southern part of Gulf States. 
 
 11. a Tauri (Aldebarari). 
 
 12. $ Centauri. Invisible in England and United States, 
 except extreme southern points. 
 
 13. a Crucis. Invisible in England and United States. 
 
 14. a Scorpii (Antares). 
 
 15. a Aquibe (Altair). 
 
 16. a Virginis (Spica). 
 
 17. a Piscis Australis (Fomalhauf). 
 
 18. /3 Crucis. Invisible in England and United States, ex- 
 cept extreme southern points. 
 
 19. Geminorum (Pollux). 
 
 20. a Leonis (Regulus). 
 
 21. a Cygni (Deneb). 
 
 With respect to the first 13 of the above stars it may 
 be said that there is not much difference of opinion as to 
 their relative rank (though some authorities do make Vega 
 and Capella change places), but as to the remaining 7 
 there is not the same accord, some ranking Altair and 
 Spica before Antares, and Regulus before Fomalhaut, 
 Pollux, and /3 Crucis. These stars are pretty evenly dis-
 
 BRILLIANCY AND DISTANCES OF THE STARS. 25 
 
 tributed between the Northern and Southern hemispheres, 
 for 10 are Northern and n Southern. 
 
 The following are the approximate dates on which 
 such of the foregoing stars as are visible in England and 
 the United States come to the meridian at midnight : 
 
 Procyon . . . January 14 
 
 Pollux . . . January 1 5 
 
 Regulus . . . February 21 
 
 Spica . . . April n 
 
 Arcturus . . . April 24 
 
 Antares . . . May 27 
 
 Vega . . . June 29 
 
 Altair . . . July 18 
 
 Deneb . . . July 31 
 
 Fomalhaut . . . September 3 
 
 Aldebaran . . . November 28 
 
 Capella . . . December 8 
 
 Rigel . . . December 8 
 
 Betelgueze . . . December 18 
 
 Sirius . . . December 31 
 
 Not entirely foreign to the question of the brilliancy of 
 the stars is the question of their distance. At the first 
 blush of the thing an uninformed reader might naturally 
 say that to measure the distance of a star from the earth 
 is impossible. But so far as the principle of this task is 
 concerned the problem is an easy one. It is in the prac- 
 tical working out of the principle that the difficulty lies ; 
 and this again rather arises from the extreme delicacy of 
 the measurements and necessary safeguards than from 
 any other cause. The process merely involves the taking 
 of certain angular measurements and applying to them 
 certain familiar theorems of trigonometry. It differs 
 scarcely at all from analogous operations which are car- 
 ried out every day on the earth by those engaged in land 
 surveying. What is involved will perhaps be understood 
 by considering what happens when a person enters a large 
 park at one end, intending to cross to the far side where 
 there are a number of trees in an avenue, passing en route 
 2 or 3 trees in the open. The trees in the far-off avenue 
 seem to be at no great distance apart, and the trunk of 
 one of them is nearly hidden by the trunk of one in the 
 3
 
 26 THE STORY OF THE STARS. 
 
 middle of the park; but soon after the pedestrian has 
 started (perhaps when he has got over 50 yards) he notices 
 that the 2 last-named trees, which a minute or two ago 
 seemed almost in contact, are evidently some distance 
 apart, and after walking for perhaps another minute (say 
 another 50 yards) he sees cause to infer that a space of 
 perhaps 120 yards separates the trees which, before he got 
 in motion, appeared almost to touch. This transforma- 
 tion is the effect of " parallax," and the apparent displace- 
 ment of the trees is due to the real displacement of the 
 observer, owing to his having used his legs. But suppos- 
 ing the 2 trees singled out as above, instead of being 
 within the same park close at hand had been 2 miles off, 
 an advance of 50 yards would have caused so trifling a 
 displacement that, though a telescope provided with a mi- 
 crometer would have detected it, the naked eye might not 
 have done so. Why this ? Because in the first case the 
 distance traversed (50 yards) was a large fraction of the 
 distance (say 400 yards) at which the trees were situated 
 from the starting-point (as 50 : 400 : : i : 8). But in the 
 second supposed case the distance traversed (50 yards) 
 was but a small fraction of the whole distance (say 4000 
 yards) separating the pedestrian from the trees. The 
 proportion is now to be expressed thus : As 50 : 4000 : : 
 i :8o. 
 
 Let us apply these similes to the stars. An observer 
 on January ist is using his telescope when the earth is at 
 a certain known point in its annual orbit round the sun. 
 He determines the position of a certain star. He waits 6 
 months, and then, on July ist, again determines the place 
 of his selected star ; he finds it occupies the same place. 
 He is on July ist removed by twice the radius of the 
 earth's orbit, or 186 millions of miles, from the place he 
 occupied on January ist. If, notwithstanding this enor- 
 mous displacement of himself, the star seems to have un-
 
 BRILLIANCY AND DISTANCES OF THE STARS. 27 
 
 dergone no displacement, our observer argues that the 
 star must be so far off that 186 millions of miles is a frac- 
 tional part of its distance, too small to be appreciable, just 
 as the 50 yards mentioned above is only a small fractional 
 part of 4000 yards. 
 
 The principle of all this has >een applied to several 
 hundred stars, but only about 2 dozen have yielded posi- 
 tive results. These results, so far as they go, seem to tell 
 us that the nearest star of those experimented upon is 
 a Centauri, and that the 4 next nearest are 61 Cygni, 21185 
 Lalande Ursas Majoris, Sirius, and p. Cassiopeia?. 
 
 Such standards as miles, or even millions of miles, are 
 quite unmanageable in dealing with distances such as 
 those which separate the nearest stars from the earth, so 
 it is customary to employ as the unit of stellar distances 
 the distance traversed by light in one year. Now light 
 travels at the rate of about 185,000 miles in one second, or 
 about 63,000 times the earth's distance from the sun in 
 one year. Applying these figures to the circumstances of 
 a Centauri, we find that as the parallax of that star is only 
 about f of a second of arc, a ray of light from it would not 
 reach the earth in less than 4^ years. This distance ex- 
 pressed in miles amounts to 24,750,000,000,000 ; and a Cen- 
 tauri is, so far as is known, the nearest star ! The reader 
 will hardly require any further explanation of the state- 
 ment made above that a mile is a hopelessly ineffective 
 and inadequate unit in which to express stellar distances. 
 It only remains to add that it is doubtful whether any of 
 the stellar parallaxes hitherto arrived at are accurate to 
 within -yV of a second of arc. Now -^ of a second is 
 the angle subtended by -fa of an inch at a distance of 10 
 miles ! Observations of stellar parallax, therefore, need 
 very first-class instruments and men, and it is on this ac- 
 count that the results up to the present time are neither 
 very numerous nor particularly consistent.
 
 28 THE STORY OF THE STARS. 
 
 CHAPTER IV. 
 
 THE GROUPING OF THE STARS INTO CONSTEL- 
 LATIONS. 
 
 THE visible stars are. commonly treated as arranged in 
 groups which are called " constellations." The circum- 
 stances under which this grouping was brought about in- 
 volve so many interesting historical points that the history 
 of the constellations may well form a separate chapter. 
 Let me then limit the present chapter to a few general hints 
 and remarks on the finding of the constellations. 
 
 A reader who wishes to be able to do this with facility 
 must enter upon the study of the stars methodically, and 
 in accordance with a definite plan, and must be prepared 
 to persevere with his work at regular and not very long 
 intervals of time through an entire period of 1 2 months. 
 In making this suggestion I lay a good deal of stress on 
 the work being done systematically, and without any con- 
 siderable gaps of time in the doing of it. The importance 
 of this will be understood when it is borne in mind that a 
 given star comes to the meridian every night 4 minutes 
 sooner than it did on the preceding night. This has the 
 effect in the course of a fortnight of displacing a star by 
 1 5 of arc, the time of observation remaining the same. In 
 other words, if an observer wishes to see a given star on 
 the meridian a fortnight after his first observation of it, 
 he must take post at his telescope (supposing he is using 
 one which only works up and down in the meridian) one 
 hour earlier in the evening than the hour at which the first 
 observation was made. It would soon be seen in practice 
 why there was not only no advantage in thus altering 
 one's times but a positive disadvantage. The ordinary 
 object of a professed student would be, not to have a con- 
 stant change in the hours of his occupation, but to have
 
 GROUPING OF STARS INTO CONSTELLATIONS. 29 
 
 a constant change in the occupation itself ; that is, in the 
 stars he is wishing to learn the names of, the hours of 
 work remaining (for his personal convenience) probably 
 much the same, say 9 p. m. to midnight. 
 
 There is another and also cogent reason for keeping at 
 this work regularly and avoiding long breaks. Though 
 the stars maintain, so far as they themselves are con- 
 cerned, speaking generally, the same relative positions 
 throughout the year, yet it makes a good deal of differ- 
 ence to the unpractised eye in the identification of par- 
 ticular stars whether they are looked at whilst they are in 
 the neutral position (as it may be called) of the meridian, 
 or when they are oblique to the meridian, eastwards of it 
 and rising, or westwards of it and setting. These differ- 
 ences can only be properly appreciated by being consid- 
 ered experimentally on a starlight night in the open air, 
 for no verbal account of them can be adequate. 
 
 A tourist who is travelling through a hilly country, un- 
 less he is a professional land surveyor employed on profes- 
 sional work, does not go through the formality of marking 
 off his meridian line and of setting out by an instrument 
 the bearings of particular peaks and towers for the pur- 
 pose of getting a record of them on paper. As a mere 
 traveller for pleasure he will probably have with him noth- 
 ing more than a map and a pocket compass ; and his aim 
 will be only to identify particular mountain-tops, church 
 towers, villages, or other objects of special interest. 
 There is only one way in which he will attempt to pro- 
 ceed. Assuring himself by means of his guide-book or 
 map, or by the aid of local information, of some one, two 
 or three prominent objects, the identity of which evidently 
 admits of no doubt, he will then feel his way by eye first 
 from one point and then from another point, constantly 
 consulting his map and compass. By some such process 
 as this, after starting with two or three objects recognised
 
 THE STORY OF THE STARS. 
 
 to a certainty, he will be able to learn the names of all the 
 places within sight which he wishes to identify, to the 
 number it may be of several dozen. 
 
 This mode of procedure may be commended to the 
 would-be student of the Starry Heavens. Such an one 
 should obtain practice for his work by making sure at 
 starting of the names of two or three prominent stars. 
 He should then feel his way in between them by fixing in 
 his mind, one after another, minor triangles of stars, com- 
 paring every one with his map as he goes along, taking 
 particular care not to proceed with the identification of a 
 second triangle until he has quite satisfied himself that he 
 has accurately identified the stars forming the first. 
 
 It has already been mentioned that the practice has 
 long prevailed of designating the more conspicuous stars 
 in every constellation by the letters of the Greek alphabet. 
 An adequate knowledge of the small letters of this alpha- 
 bet is therefore an indispensable accomplishment for every 
 student of the starry heavens. These letters are : 
 
 a Alpha. 
 
 Beta. 
 
 7 Gamma. 
 
 8 Delta. 
 
 e Epsilon. 
 
 C Zeta. 
 
 T] Eta. 
 
 Theta. 
 
 Iota. 
 
 K Kappa. 
 
 \ Lambda. 
 
 /j. Mu. 
 
 v Nu. 
 
 { Xi. 
 
 o O-mlcron. 
 
 IT Pi. 
 
 p Rho. 
 
 <r Sigma. 
 
 T Tau. 
 
 v Upsllon. 
 
 <f> Phi. 
 
 X Chi. 
 
 $ Psi. 
 
 a Omega. 
 
 I will now endeavour to apply the foregoing ideas to the 
 study of the stars, starting with the Great Bear as being 
 the most conspicuous of those constellations which never
 
 GROUPING OF STARS INTO CONSTELLATIONS. 31 
 
 set In the latitude of London. The tail and hind-quarters 
 consist of 7 brilliant stars. Four of these (a, ft, y, 8) have 
 long been likened to a wain or waggon, the other 3 (e, , TJ) 
 being fancifully called the horses ; the 7 taken together 
 making " Charles's Wain " or the "Plough " to mention 
 some old English designations.* The hind wheels or the 
 2 stars (ft, a) farthest from the horses are called the 
 " Pointers," because they point towards the Pole Star (a 
 Ursae Minoris) at the tip of the Little Bear's tail. A line 
 carried from the Pointers beyond the Pole Star leads to 
 Cepheus and Cassiopeia constellations abutting on the 
 Milky, Way where it comes nearest to the Pole. Cassio- 
 
 t FIG. 3. Ursa Major and Polaris. 
 
 peia comprises several prominent stars which form a group 
 resembling the letter W or the letter M, according to the 
 
 * The popular name in the United States is the " Dipper." All 
 of the seven stars are not visible at their lower culmination south 
 of about the latitude of Philadelphia, but the two " Pointers" never 
 set at any place north of Charleston, S. C.
 
 32 THE STORY OF THE STARS. 
 
 time of year at which they are viewed. The 2 northern- 
 most wheels of the waggon (8, a, Ursae Majoris) point to 
 the bright star Capella in Auriga, which is also circum- 
 polar in British latitudes, but not in the United States. 
 The stars of the Great Bear may be advantageously em- 
 ployed by the student as an approximate scale of angular 
 distances in making estimates of the distances between 
 star and star. Thus : The Pointer (a) nearest to the 
 Pole is 28f from it ; from ft to y is 8 , from f to rj is 7 ; 
 from 8 to e is 5^ ; from a to is 5 ; from y to 8 and from 
 e to is in both cases 4^. 
 
 Descending diagonally along the Milky Way from Cas- 
 siopeia towards Capella (a Aurigae) we come to a Persei, 
 and a little farther from the Pole we find Algol (J3 Persei), 
 a celebrated variable star in Medusa's head. If we carry 
 our eyes across the Milky Way in the opposite direction 
 we arrive at Deneb, the brightest star (a) of Cygnus (the 
 Swan) ; and beyond Cygnus, a little out of the Milky 
 Way, is Vega, the brightest star (a) in Lyra (the Lyre). 
 Draco (the Dragon) consists of a long winding chain of 
 stars running partly round Ursa Minor (the Little Bear). 
 In the space bounded by Cass^peia, Cygnus, and Draco, 
 lies'the constellation Cepheus. 
 
 Near Algenib (y Pegasi) and pointing directly towards 
 it are 2 conspicuous stars of Andromeda (a, )3), whilst a 
 3rd (y) lies a little beyond them. Andromeda will always 
 be readily known by reason of the connection of the bright 
 star (a) in her head with the large trapezium of Pegasus 
 (a, /3, y), the 4 stars forming the well-known " Square of 
 Pegasus." 
 
 An imaginary line projected through the Great Bear 
 and Capella passes to the " Pleiades," the celebrated group 
 in Taurus (the Bull), of which we shall have more to say 
 hereafter (in Chap. XIV. post), and then turning at a right 
 angle reaches Aldebaran (a Tauri, alias the "Bull's-eye")
 
 GROUPING OF STARS INTO CONSTELLATIONS. 33 
 
 and the shoulders (a, y) of Orion. Orion is to the naked 
 eye by far the most magnificent of all the constellations, 
 whilst it is peculiarly rich in telescopic objects. Orion 
 may always be identified by the 3 bright stars in its 
 " Belt," which occupies the middle of a large quadrangle 
 of still brighter stars. Aldebaran is a reddish star, the 
 most prominent of the " Hyades," a cluster resembling the 
 letter V, and not far from the Pleiades. Aldebaran, the 
 Pleiades, and Algol (/3 Persei) make the upper, while Men- 
 kab (a Ceti), in the Whale's jaw, with Aries, make the 
 lower points of a large W. The head of Aries (the Ram) 
 is indicated by two principal stars (a, /3), the latter of 
 which has a small attendant. 
 
 An imaginary line drawn from the Pole Star and car- 
 ried midway between the Great Bear and Capella (a 
 Aurigas) passes to Castor and Pollux (a, /3 Geminorum), 
 two well-known stars in the heads of Gemini the Twins ; 
 whilst forwards to the S. of Gemini it will meet Procyon 
 (a Canis Minoris) the brightest star of the Lesser Dog. 
 From thence by bending the line across the Milky Way 
 and carrying it as far again it will reach Sinus (a Canis 
 Majoris) in the Greater Dog's mouth, and will then pass 
 to a somewhat conspicuous star, which in England is quite 
 in the southern horizon, a Columbae, 33 S. of the middle 
 star in Orion's belt. 
 
 Algol (/3 Persei) and Castor point to Regulus (a Leonis, 
 alias Cor Leonis, the " Lion's heart ") which is situated at 
 one end of an arc with Denebola 03 Leonis), the tuft of 
 the Lion's tail at the other end. S. of Regulus and pre- 
 ceding it, /'. e., coming to the meridian before it by about 
 hour, is Cor Hydras (a), the space between them being 
 occupied by the modern and insignificant constellation of 
 the Sextant. 
 
 The Pole Star and the middle horse of the waggon (f) 
 direct us to Spica, the brightest star (a) of Virgo, consid-
 
 34 THE STORY OF THE STARS. 
 
 erably distant, whilst forwards, towards the horizon, we 
 shall reach Centaurus. The Pole Star and the first horse 
 (17 Ursas Majoris) conduct us nearly upon Arcturus in 
 Bootes (a), by which fine star, with Spica (a Virginis) and 
 Regulus (a Leonis), a splendid triangle is formed. Fol- 
 lowing at a distance to the southward is Antares (a 
 Scorpii), " the Rival of Mars," which with Arcturus and 
 Spica constitute another large triangle, having within it 
 the two bright stars, a and /3 Librae. 
 
 Corona Borealis, the Northern Crown, is nearly in a 
 line between Vega (a Lyrae) and Arcturus (a Bootis) ; and 
 the heads of Hercules and Ophiuchus lie between Lyra 
 and Scorpio. In the Milky Way, below the part nearest 
 to Lyra and on a line drawn from Arcturus through the 
 head of Hercules, is the bright star Altair in the Eagle (a 
 Aquilse), which makes with Vega and Deneb (a Cygni) a 
 conspicuous triangle. Closely following Aquila is a re- 
 markable group of stars forming the constellation Del- 
 phinus, the Dolphin. 
 
 The last and brightest (a) of the 3 principal stars in 
 Andromeda makes with 3 stars of Pegasus (a, /3, y) the 
 large " Square " or trapezium already mentioned, of which 
 the side formed by )3 and a points to Fomalhaut (a Piscis 
 Australis), situated in the mouth of the Southern Fish, 
 between the tails of Cetus and Capricornus. 
 
 The line of the ecliptic may without difficulty be traced 
 by the observer when his eye becomes familiar with the 
 stars now about to be enumerated. Not far from the 
 Pleiades are the Hyades with Aldebaran (a Tauri), a little 
 S. of the ecliptic. To the N. W. of Aldebaran at some 
 distance is the chief star of Aries (a) ; while to the N. E. 
 of that star are Castor and Pollux (a and /3 Geminorum). 
 Regulus (a Leonis) is on the line of the ecliptic; and 
 Spica (a Virginis) is but a very little to the S. of it. A 
 start being thus made with the ecliptic, the zodiacal con-
 
 GROUPING OF STARS INTO CONSTELLATIONS. 35 
 
 stellations will be easily distinguished in their order from 
 W. to E. as follows : Aries lies immediately between 
 Andromeda on the N. and Cetus on the S., the three 
 asterisms reaching nearly from the horizon to the zenith ; 
 Taurus will be recognised by the Pleiades, Aldebaran (a) 
 and the Hyades ; Gemini, the highest of the signs as seen 
 in the Northern hemisphere, by Castor and Pollux (a and 
 |8) ; Cancer, by the historic group Prassepe, in the midst 
 of a waste rather void of stars ; Leo by the stars Regulus 
 (a) and Denebola (/3) ; Virgo, by Spica (a) to the S. of 
 Coma Berenices; Libra in mid-distance between Virgo 
 and the next constellation Scorpio ; Scorpio, by the red 
 star Antares (a) and its 3 other very conspicuous stars (/3, 
 8, jr,) ; Sagittarius as being the lowest (/'. e., most south- 
 erly) of all the signs ; Capricornus S. of the Dolphin ; 
 Aquarius under the neck of Pegasus ; and the Pisces be- 
 tween Pegasus, Andromeda, and Cetus. The following 
 familiar lines, though they do not rise to a high standard 
 of " poetry," are nevertheless very convenient as an aid to 
 the memory : 
 
 The Ram, the Bull, the heavenly Twins, 
 And next the Crab, the Lion, shines. 
 
 The Virgin, and the Scales ; 
 The Scorpion, Archer, and Sea-goaf, 
 The Man that holds the water-pot, 
 
 And Fish with glitt'ring tails. 
 
 The account just completed of what may be called a 
 " personally conducted " tour of the heavens, is at the best 
 a hasty and superficial performance, and I hope that the 
 bulk of my readers who have accompanied me thus far 
 will aspire to something higher and more exact, even 
 though there may be involved some details, the mastery 
 of which will require a certain amount of effort and appli- 
 cation.
 
 36 THE STORY OF THE STARS. 
 
 A full list of the several constellations arranged in the 
 order in which they come to the meridian, that is to say 
 in the order of their Right Ascensions, will be found in 
 the Appendix ; but it is necessary to explain here what 
 the term " Right Ascension " means, and also what an- 
 other and allied term " Declination " means. Perhaps this 
 will be easiest done by means of a terrestrial analogy. 
 
 Everybody, I suppose, knows that Khartoum, the 
 scene of a grievous tragedy, is in Africa. But how many 
 of my readers could open an atlas, turn to the map of 
 Africa, and go straight with his finger-tip to the city of 
 Khartoum ? But if he knew beforehand that Khartoum 
 was situated in latitude 15 35' N. and longitude 32 30' 
 E. of Greenwich, the finding of it would be an easy mat- 
 ter, promptly accomplished by the aid of a network of 
 lines running up and down and across the face of the 
 map. Now what latitude and longitude are for terrestrial 
 geography, declination and right ascension are for celestial 
 geography (so to speak), only just a little different. 
 
 It is not difficult to make clear what declination is, but 
 an explanation of right ascension will not be taken in so 
 readily. We have already seen that the whole visible sky 
 is to be regarded as in some sense a sphere, with us, on 
 the earth, apparently as its centre ; and that the aforesaid 
 sphere turns on an imaginary axis directed to 2 poles. 
 Midway between the 2 poles lies the equator, and as it is 
 a semi-circle (or 180) from pole to pole the polar distance 
 of the celestial equator (which is the earth's equator pro- 
 longed to the heavens) will be 90. For some purposes 
 it is occasionally the practice of astronomers to count 
 angular distances from the N. pole towards the equator, 
 but the regular and ordinary practice is to count from the 
 equator to the poles, N. or S., as the case may be. Hence 
 we obtain the expressions " north declination " and " south 
 declination," as applied to the places of the stars, and
 
 GROUPING OF STARS INTO CONSTELLATIONS. 37 
 
 these expressions are, in a certain sense, the counterpart 
 of the expressions " north latitude " and " south latitude " 
 used with reference to places on the earth. 
 
 The term " right ascension " is not to be brought home 
 to the mind quite so easily. In the case of terrestrial 
 longitudes there is no difficulty in finding a definite and 
 immovable terminus to start from. Many European na- 
 tions are using the meridian of Greenwich for this pur- 
 pose, though Frenchmen count from Paris, Germans from 
 Berlin, and so on. But in the case of the stars a fixed 
 zero is not so easy to find and still less easy to keep. How- 
 ever, astronomers have long been agreed to make what is 
 called the " First point of Aries," alias the " Vernal 
 Equinox," their starting-point for right ascensions. This 
 is the point where the sun, in the course of its annual 
 journey through the signs of the zodiac, crosses the equa- 
 tor, going from south to north, in the month of March on 
 the 2oth day of that month. The phrase " vernal equi- 
 nox " means the moment of equal day and equal night in 
 the spring.* It is also at this moment that the clocks 
 used by astronomers in their observatories read oh. om. 
 os. Owing to the operation of disturbing causes, the na- 
 ture and description of which do not belong to this chap- 
 ter, or indeed to this volume, this point is incessantly 
 shifting in the heavens. By virtue of a change called 
 "the precession of the equinoxes," the actual place of the 
 equinox goes backwards about 50" every year, and this is 
 what I meant by saying above that the zero for celestial 
 longitudes is not only not easy to find but when found 
 cannot readily be kept. It must suffice, then, for my 
 present purpose to remark that if we wish to fix the right 
 ascension of a star we must imagine a meridian to pass 
 through it ; then imagine a meridian to pass through the 
 
 * Lat. ver, spring ; ceguus, equal ; nox, night.
 
 38 THE STORY OF THE STARS. 
 
 vernal equinox and note the angle which the former 
 meridian makes with the latter measured in degrees of 
 arc along the equator from W. to E. That angle will be 
 the star's R. A. It may be expressed either in degrees, 
 minutes, and seconds of arc ( ' "), or in hours, minutes, 
 and seconds of time (h. m. s.). The latter method is now 
 universally employed, the former having been discarded. 
 
 The relation of arc to time in connection with the 
 measurement of angles of right ascension will be readily 
 remembered by noting that a minute or second of time 
 represents a space of 15 times the corresponding denomi- 
 nation in arc, while the hour is 1 5 times one degree, that 
 is 15. The minute and second of time are denoted by 
 the initial letter of their names, whilst the minute and 
 second of arc are denoted by special symbols. Thus we 
 arrive at the following little table which the reader should 
 get clearly fixed on his mind : 
 
 i h = 15 
 i m = 15' 
 i* = 15" 
 
 i = 4 m 
 i' = 4 s 
 i" = o.o66 
 
 Perhaps this is as good a place as any at which to 
 warn the reader against a trap which he is very apt to fall 
 into. The " signs of the zodiac " are not the same as the 
 " constellations of the zodiac " (more often spoken of as 
 the zodiacal constellations). Twenty centuries or so ago 
 the astronomers of antiquity, with the 12 zodiacal constel- 
 lations within their knowledge, got into the natural and 
 not inconvenient habit of talking of the sun in its apparent 
 annual journey through the heavens along the ecliptic as 
 passing successively into and out of the several signs of 
 the zodiac. Each of these signs was regarded as occu- 
 pied by a constellation from which it took its particular 
 name. Commencing at the vernal equinox the first 30 
 through which the sun passed, or the region of stars in
 
 THE HISTORY OF THE CONSTELLATIONS. 39 
 
 which the sun was located during the month following, 
 was called the sign Aries. The second 30 was called 
 the sign Taurus, and so on through the 12 signs, which 
 are identical in name and follow in the same order as the 
 existing 12 zodiacal constellations. Although there are 
 still 12 signs and 12 constellations, sign and constellation 
 no longer correspond. Though the sun when it crosses 
 the equator in the month of March enters the sign Aries, 
 it does not reach the constellation Aries till nearly a month 
 later. This discrepancy is due to the yearly accumulations 
 of 50* each which have been going on during the 20 cen- 
 turies mentioned and which are connected with the phe- 
 nomenon of the precession of the equinoxes already briefly 
 alluded to. 
 
 These preliminary explanations will suffice to enable 
 the reader now to settle down seriously to a study of the 
 constellations. This task must be carried out on starlight 
 nights with the aid of a good star-atlas * and a bull's-eye 
 lantern, assisted or not, as may be convenient, by an 
 opera-glass. In the Appendix will be found a Table of 
 the constellations, omitting a few insignificant modern 
 ones not generally recognised by astronomers. 
 
 CHAPTER V. 
 
 THE HISTORY OF THE CONSTELLATIONS. 
 
 To the grouping of the stars into constellations may 
 well be applied the legal phrase that the custom is so an- 
 cient that the memory of man runneth not to the contrary. 
 
 * I have found no English one as good as Keith Johnston's, edited 
 by Hind : and this because the stars show as white on a deep blue 
 background. Klein's, published by S. P. C. K., is also cheap and 
 very good.
 
 40 THE STORY OF THE STARS. 
 
 The germs of it are evidently to be found in Holy Scrip- 
 ture. The three following passages, which I cite from the 
 Revised Version, whatever else may be said of them, 
 clearly imply that the allusions are to some well-established 
 usage : 
 
 " Which maketh the Bear, Orion, and the Pleiades, and the 
 chambers of the south.'' (Job ix. 9.) 
 
 " Canst thou bind the cluster of the Pleiades, 
 or loose the bands of Orion ? Canst thou lead 
 forth the Mazzaroth in their season ? Or 
 canst thou guide the Bear with her train ? " 
 
 (Job xxxviii. 31-2.) 
 
 " Seek Him that maketh the Pleiades * and Orion." 
 
 (Amos v. 8.) 
 
 The constellations now in use are about 80 or 90 in 
 number, counting a few minor ones devised during the last 
 century, chiefly for the Southern hemisphere, but by no 
 means counting all that have been proposed. It has been 
 well remarked : " Half a century ago no astronomer 
 seemed comfortable in his position till he had ornamented 
 some little cluster of stars of his own picking with a name 
 of his own making." Of the constellations now recog- 
 nised, no fewer than 48, and those including with scarcely 
 any exception the largest and best known, are recorded 
 by Ptolemy, and therefore have an unchallenged antiquity 
 of 2000 years, yet the date of the actual invention of even 
 one of them is quite unknown. Seneca attributed the 
 subdivision of the heavens into constellations to the Greeks 
 1400 years before Christ, but there is no proof of this, and 
 if it is permissible to draw inferences without having many 
 facts to go upon (a common practice nowadays), I should 
 be rather inclined to give some of the credit of inventing 
 
 * The Authorized Version has here "The Seven Stars."
 
 THE HISTORY OF THE CONSTELLATIONS. 41 
 
 the constellations to the Chaldasans or Egyptians, or to 
 both of them in shares, the Egyptians having developed 
 that which they derived from the Chaldaeans, as the Chal- 
 daeans may have developed something they derived from 
 peoples which preceded them. Some writers, indeed, 
 have thought that a much greater antiquity should be as- 
 signed to the constellations, and there are not wanting 
 traces of proof to support this idea. Neglecting for the 
 moment the ancient constellations as a whole, it certainly 
 seems clear that a special degree of antiquity attaches to 
 the signs of the zodiac, and no wonder, seeing that they 
 remind us, amongst other things, of the apparent annual 
 path of the sun amongst the stars. 
 
 It seems more than probable almost certain that 
 the word " Mazzaroth " quoted above from Job xxxviii. 32, 
 and left untranslated in the text by the authors of the Re- 
 vised Version, means what they have suggested in the 
 margin, namely, the circle of the zodiac. And it is quite 
 consistent with this to find, as a modern writer has pointed 
 out, that : " These signs were known among all nations 
 and in all ages. From the almost antediluvian chronol- 
 ogies of China, India, and Egypt, to the traditions of the 
 recently discovered islands of the South Sea, traces of 
 them are discovered most clearly among the most ancient 
 and earliest civilised nations. In the remains of Assyria 
 they are recognised ; in those of Egypt they are perfectly 
 preserved ; in those of Etruria and Mexico they are trace- 
 able. This wide diffusion indicates a common origin, 
 both of the race of man and of the symbols of astronomy. 
 The love of symbols has been considered as natural to 
 man ; the creation amid which he is placed is symbolical. 
 Of this universal tendency the inventors of astronony seem 
 to have availed themselves, rendering it subservient to 
 man's spiritual education by familiarising to his mind the 
 lofty truths of Divine revelation." 
 4
 
 42 THE STORY OF THE STARS. 
 
 " The earliest positive evidence of the primeval exist- 
 ence of the signs is in the Chinese Annals, where it is said 
 that the Emperor Yao, 2357 years before the Christian 
 era, divided the 12 signs of the zodiac by the 28 mansions 
 of the moon ; but it is not said that he invented them. 
 The Chinese national emblem of the dragon appears to be 
 the dragon of the sphere, which was at that time the polar 
 constellation, the brightest star in the dragon's head hav- 
 ing been the Pole Star in the antediluvian ages. The 
 Egyptians, on whose early monuments the signs are 
 found, acknowledged that they derived their astronomy 
 from the Chaldasans. The Chaldasans attributed their 
 science to Cannes, supposed to be Noah. The Arabs 
 and Brahmins, among whom astronomy was early culti- 
 vated, seem to have derived it from Abraham, through 
 Ishmael, and the children of Keturah. The Greeks sup- 
 posed their imperfect knowledge of the subject came 
 through the Egyptians and Chaldasans. The Romans are 
 thought to have received through the Etrurians the names 
 of the signs still in use among European nations. The 
 Etrurians are considered to have de'rived them, with their 
 other arts and sciences, from Assyria. The early Greek 
 poet Hesiod is said to have made use of Assyrian records. 
 He mentions some of the constellations by the names 
 they now bear. Cleostratus [circa 500 B. c.] was ac- 
 quainted with the signs, and wrote on Aries and Sagit- 
 tarius. A later Greek poet, Aratus, described the constel- 
 lations such as we now have them, and by equivalent 
 names. He gave neither history nor conjecture as to 
 their date, their meaning, or their origin. They were to 
 him, as to us, of immemorial antiquity." 
 
 The thoughts unfolded in the foregoing extract are of 
 great interest, but it is obvious that a thorough investiga- 
 tion of this subject would lead us far beyond the limits of 
 this little volume.
 
 THE NUMBER OF THE STARS. 
 
 43 
 
 CHAPTER VI. 
 
 THE NUMBER OF THE STARS. 
 
 To say much that is definite about the number of the 
 stars is in one sense a very difficult thing to do if the idea 
 is to furnish any trust- 
 worthy or adequate 
 information on the 
 subject. The words 
 of Holy Scripture, 
 " Look now towards 
 heaven, and tell the 
 stars, if thou be able 
 to number them," * 
 cover much more than 
 appears at first sight. 
 To say that the stars 
 are innumerable is far 
 from being a mere po- 
 etic phrase ; it is in- 
 deed no more than a 
 prosaic matter of 
 fact. Nevertheless it 
 may probably surprise 
 some persons to be 
 told that according to 
 the estimate of the FIG. 4. Orion, 
 
 distinguished German 
 
 astronomer Argelander the number of stars visible to the 
 naked eye in the latitude of Berlin is only 3256, and must 
 be put no higher than about 5000 in all for the whole 
 heavens. Trie number to be seen becomes greater as we 
 
 * Genesis xv. 5.
 
 44 THE STORY OF THE STARS. 
 
 approach the equator from the middle latitudes of either 
 hemisphere, owing to the wider expanse opened up to an 
 observer stationed at the equator. An observer located in 
 a place the latitude of which is o will see in the course 
 of the year all the naked-eye stars in the heavens. 
 
 Argelander's totals arranged in magnitudes are as fol- 
 lows : 
 
 Stars. 
 
 1st magnitude = 20 
 
 2nd " = 65 
 
 3rd " = 190 
 
 4th = 425 
 
 5th " = noo 
 
 6th " = 3200 
 
 7th " = 13,000 
 
 8th " = 40,000 
 
 gth " = 142,000 
 
 This matter has been made the subject of estimate by 
 various observers, including especially the late Professor 
 Grant of Glasgow and Karl Von Littrow of Vienna. 
 Their figures, though fairly accordant as regards naked- 
 eye stars in the aggregate, differ a good deal, magnitude 
 by magnitude, owing to there being no recognised defined 
 standards of magnitude. 
 
 As to this, however, it may be remarked as a thing by 
 the way, that Seidel, a German observer who has given 
 much attention to the matter, has suggested the following 
 as standard stars for the first 4 magnitudes : 
 
 ist a Aquilse, a Virginis, a Orionis. 
 
 2nd a Ursse Majoris, 7 Cassiopeiae, Algol (at max.). 
 
 3rd y Lyrae, 8 Herculis, 6 Aquilae. 
 
 , ( p Herculis, A. Draconis (too bright), 
 
 ( H Bootis, 6 Herculis (too faint). 
 
 It may be well to point out that the statistics just given, 
 though necessarily somewhat approximate, are not to be
 
 THE NUMBER OF THE STARS. 45 
 
 regarded as imaginary, though of course to count a num- 
 ber of points of light like stars is not in itself an easy task. 
 It may be worth while, therefore, to carry the foregoing 
 statements a little farther. A very painstaking astrono- 
 mer, also a German, Heis of Miinster, affirmed that it was 
 not possible to count more than about 5000 stars visible in 
 the sky available in Central Europe. Endowed with a sharp 
 sight, and adopting various artifices (such as shutting out 
 all artificial light and marking off by means of a great 
 black tube each region of the sky under examination), he 
 found himself able at Miinster to see 5421 stars. Inas- 
 much as he could from that one place in the course of a 
 year examine in succession T V ns f the heavens, he con- 
 cluded that supposing the portion of the Southern hemi- 
 sphere which he could not see resembled in a sense the 
 rest of the sky which he could see, the sum total of the 
 stars visible to the naked eye would mount up to about 
 6800. But it deserves notice that no possible number of 
 stars which could be counted would represent the stars 
 which an eye could discern. The eye can take notice of 
 more than it can count, because when any given star im- 
 prints itself upon the centre of the retina, others whose 
 images fall upon the corners of the eye, so to speak, seem 
 to vanish. This is a point as to which appearances are 
 apt to be very deceptive. It may be well here to remark 
 that it is important to distinguish clearly in the mind be- 
 tween the results of a single gaze at the sky, the eye being 
 for the while fixed, and a look all round. In the former 
 case it may be taken that no more than a space of 13 or 
 14 can be taken in simultaneously, whilst by moving the 
 eye methodically in successive directions the whole ex- 
 panse of the heavens may be brought under review. 
 
 Secchi noted the following experiment as one that he 
 often tried with interesting results. After taking a glance 
 at some particular part of the heavens he would transfer
 
 46 THE STORY OF THE STARS. 
 
 his eye to the finder of the great telescope at the Roman 
 College at Rome, and would see in this subordinate tele- 
 scope, whose field was no larger than , as many stars as 
 were to be seen in the 13 or 14 grasped by the naked 
 eye. Passing then to his great telescope, armed with an 
 eye-piece showing only an arc of 15', or one-fourth the 
 area of the field of his finder, he would still see as many 
 stars as in the finder ; proceeding yet further to diminish 
 the field by increasing the power, the number of the stars 
 would scarcely diminish, because, though the area was 
 curtailed, yet the increased magnifying power revealed 
 minute stars which had previously escaped notice. Thus 
 it came about that in certain localities it was possible to 
 see in a field no more than ^ in diameter as many stars 
 as were visible to the naked 'eye in a field 13 in diameter. 
 This train of thought will readily enable the general reader 
 to realise the fact that the larger our telescopes become 
 the more stars we can discern ; in other words, that as we 
 cannot say for a certainty how large our telescopes might 
 become, so accordingly we cannot say when stars hitherto 
 unseen will cease to be invisible by becoming visible. So 
 that we may indeed say with Galileo that the stars are in- 
 numerable. 
 
 The heavens are not everywhere equally rich ; in many 
 places even with the largest^ instruments one can find in a 
 field of J scarcely 5 or 6 stars : it would not, therefore, 
 do to judge of the number of the stars by these excep- 
 tional regions. An effort was made by the two Her- 
 schels, Sir William in the Northern hemisphere, and Sir 
 John in the Southern hemisphere, to ascertain the possible 
 number of the stars. It is easy to understand that this is 
 one of the most gigantic tasks which an astronomer could 
 undertake, because it could never be completed in the 
 lifetime of one man. Sir W. Herschel adopted an indirect 
 method to arrive at his results. Making use of his ao-ft.
 
 THE NUMBER OF THE STARS. 47 
 
 reflector, he directed it successively towards certain parts 
 of the heavens, chosen in irregular order, of which he 
 noted the right ascension and declination. These regions 
 were so distributed over the heavens as in a way to result 
 in the sky being dotted over with a network of surveying 
 stations equi-distant from each other. The field of his 
 telescope was just J, and the magnifying power 120. He 
 counted in each field the number of stars visible in it ; in 
 particular places where the number was so great as to 
 render counting impossible he made an estimate. Hav- 
 ing gathered together a certain number of these counts, 
 or estimates, in a particular part of the sky, he summed 
 up the total number of stars seen, and divided this total 
 by the number of the groups. The resulting figure was 
 taken to represent the mean average density of the stars 
 in the neighbourhood of the place examined. This meth- 
 od, the only one possible in practice, has some defects ; 
 still, employed on the large scale carried out by Sir Wil- 
 liam Herschel, it gave results so far conclusive that no 
 more modern effort has yet superseded it. Of course it 
 will often happen that a certain locality will be very rich 
 in stars, whilst in another like area, not far off, there will 
 be a great scarcity of stars ; still, taking rich and poor 
 neighbourhoods together, a fairly trustworthy average re- 
 sult will be obtained. It has already been stated that to 
 take a census of the whole heavens would be a work so 
 vast that no one man could ever hope to accomplish it ; 
 there is, however, now in progress an international photo- 
 graphic survey of the heavens, which, when it is complete, 
 will go far to fill up the void in our knowledge which at 
 present exists ; but before speaking of this it will be bet 
 ter to finish with the work of the Herschels in this depart- 
 ment of astronomy. To obtain an idea of it, it will suffice 
 to remember that Sir W. Herschel dealt with 3400 groups. 
 These were not all completely independent of one another,
 
 48 THE STORY OF THE STARS. 
 
 and they must be reduced to the smaller number of 683 in 
 order to obtain the number of the quite independent 
 groups. Herschel is considered to have examined only 
 yfsth part of the sky ; it would have taken him 83 years 
 to have gone over the entire heavens, allowing that he 
 could have done 100 fields every night, and could have 
 found loo favourable nights in every year. In some re- 
 gions the stars were so numerous that Sir William counted 
 588 in one field of view, and, the telescope remaining sta- 
 tionary, field after field quite as rich passed along as in a 
 panorama for several minutes. At one place he estimated 
 that he had seen 116,000 stars passing before him in a 
 quarter of an hour ; and that on another occasion 258,000 
 stars passed in 41 minutes ; on the other hand, in other 
 parts of the heavens fields presented themselves with only 
 two or three stars in them. The results which Sir W. 
 Herschel arrived at were published in 1785. Nearly 50 
 years later his son, who went out to the Cape of Good 
 Hope for the express purpose of carrying on observations 
 in the Southern hemisphere, took up again this very self- 
 same question of the numbering of the stars. His results, 
 equally as interesting as his father's, differed from them in 
 this particular, that the Southern hemisphere is less uni- 
 formly decked with stars than the Northern hemisphere, 
 and bare places are more common. 
 
 By a computation based on the results of gauging 
 both hemispheres, Sir John Herschel found that the total 
 number of stars visible in an 1 8-inch reflector cannot be 
 less than 5J millions, but Struve, interpreting Sir W. Her- 
 schel's observations in the light of his own, estimated that 
 more than 20 millions of stars were within the grasp of a 
 reflector of the named dimensions. 
 
 The most cursory examination of the heavens will 
 make it clear that the stars are very unequally distributed ; 
 that in some parts they are very much more closely ar-
 
 THE NUMBER OF THE STARS. 49 
 
 ranged than in others, and that this is true whether we 
 consider their absolute number or their individual bright- 
 ness. Various attempts have been made to frame specu- 
 lations as to the causes and meaning of these facts, but it 
 is obvious that all such speculations must be more or less 
 useless and unprofitable. I may have something more to 
 say on this subject when we come to deal with that won- 
 derful mass of stars which we call the Galaxy, or Milky 
 Way, but an investigation as to the " how " or the " why " 
 there are more stars to be seen in some places than in 
 others would, in jthe present state of our knowledge, lead 
 to no very definite or satisfactory results. 
 
 A few words about the International Photographic 
 Survey of the Heavens which is now in progress. This 
 took its origin from a Conference of Astronomers, repre- 
 senting 1 6 different nationalities, which met at the Paris 
 Observatory in April, 1887, on the invitation of the Acad- 
 emy of Sciences of France. The basis on which the 
 undertaking was started was in substance defined as fol- 
 lows : (i) That the progress made in astronomical pho- 
 tography demands that the astronomers of the present 
 day should unite in obtaining a permanent record of the 
 heavens by means of photography. (2) That the work 
 should be carried out at selected stations, and with instru- 
 ments which should be identical in size and other essen- 
 tial features. (3) That the principal object to be aimed 
 at is to secure a chart of the heavens for the present 
 epoch, and therewith data for determining with the great- 
 est possible accuracy the positions and brightness of all 
 stars down to a given magnitude, the ultimate idea being 
 that the information thus obtained should be so preserved 
 as to be available in future years for determining whether 
 changes of position or brightness have occurred in re- 
 spect of any given stars. These preliminary principles 
 having been accepted by the Conference, which comprised
 
 50 THE STORY OF THE STARS. 
 
 20 representatives for France, 8 for England and the 
 British Colonies, 6 for Germany, 3 each for Russia, Hol- 
 land, and the United States, 2 each for Austria, Sweden, 
 and Denmark, and I each for Belgium, Italy, Spain, Portu- 
 gal, Switzerland, Brazil, and Argentina, a committee was 
 appointed to consider and report upon the form and size 
 of the instruments to be used and the range of magnitudes 
 to be embraced. After a large amount of anxious inquiry 
 and debate, it was eventually decided that the instruments 
 employed should be exclusively refractors of 11 inches 
 aperture, and rather more than 1 1 feet fo^al length, giving 
 a field of 2 square, the photographic plates being 6 
 inches square, and showing an effective square (reseau) of 
 
 51 inches, with lines \ inch apart. 
 
 The necessary instruments have been provided, chiefly 
 at the cost of the Governments of the respective countries, 
 and the survey is now well in hand at the following 19 ob- 
 servatories Helsingfors, Potsdam, Oxford, Greenwich, 
 Paris, Vienna, Bordeaux, Toulouse, Catane, Algiers, San 
 Fernando, Chapultepec, Tacubaya, Rio de Janeiro, Santi- 
 ago, Sydney, Cape of Good Hope, La Plata, and Mel- 
 bourne. These observatories range in latitude from 60 
 N. to 38 S., and may be considered as conveniently 
 placed for embracing the whole sky. It is scarcely neces- 
 sary to add that the work undertaken is one of enormous 
 magnitude, and, though not actually difficult, requires in 
 a high degree the services of observers well endowed with 
 the virtues of patience and carefulness. The work will, 
 of course, occupy several years.
 
 DOUBLE STARS. 
 
 CHAPTER VII. 
 DOUBLE STARS. 
 
 WE have hitherto been considering the stars as iso- 
 lated points of light dotted hither and thither all over the 
 heavens and as if they had no connection one with an- 
 other. These suppositions are only true in a qualified 
 
 FIG. 5. o Herculis (double star). 
 
 sense, for the telescope reveals the fact that no inconsidr 
 erable number of the stars which we regard as simple 
 points of light are in reality 2 (or in some cases several) 
 single stars which are so close together as to appear to 
 the naked eye to be one.
 
 52 THE STORY OF THE STARS. 
 
 The proximity of one star to another might in any 
 given case only be an effect of perspective and not an 
 actual fact. For instance, a man standing on the top of a 
 straight road which led up a hill might see 2 men ap- 
 proaching him, seemingly walking shoulder to shoulder, 
 as if they were 2 friends engrossed in conversation, 
 whereas in reality they might be isolated individuals walk- 
 ing up the hill, each on his own account, perhaps 50 yards 
 apart. On the other hand, if the man at the top saw the 
 other 2 men cross from one side of the road to the other 
 simultaneously, and that as one turned his head askew, 
 apparently to look at some distant object, the other did 
 the same thing, he might justly infer that the two were 
 really friends and were really walking side by side. 
 
 The foregoing illustrations will define with perfect ac- 
 curacy the difference between what is called an " optical " 
 double-star (that is, 2 stars which seem to be linked to- 
 gether because of the effect of perspective) and a " binary " 
 double-star ; that is, 2 stars which not only seem to be 
 linked together but truly are so. These last-named are 
 often spoken of as " physical doubles," or 2 stars physically 
 connected. To determine in any given case whether a 
 pair of stars belong to the one class or the other is a mat- 
 ter involving both delicate observations and laborious cal- 
 culations. More than a century and a quarter ago Michell 
 suspected that there might be a physical connection sub- 
 sisting between certain stars by considering the probable 
 chance of producing a purely accidental combination if a 
 batch of stars were, so to speak, promiscuously thrown 
 haphazard into space. He found that the chances of 
 bringing together stars such as the Pleiades, of their 
 brightness and at their distance, was 500,000 to I, of 1500 
 stars visible. The improbability became much greater if 
 the inquiry was based upon the case of stars of the 2nd 
 and 3rd magnitudes and within a few seconds of arc of
 
 DOUBLE STARS. 53 
 
 one another. Yet in point of fact we have several exam- 
 ples of this kind, such as a Centauri and a Geminorum. 
 
 But probability does not suffice to establish the truth 
 of a fact. One draws a much more conclusive argument 
 from a consideration of the actual proper motions of the 
 stars where such can be detected. If the stars were acci- 
 dentally brought together, as they are generally of differ- 
 ent magnitudes, their proper motions, both real and ap- 
 parent, would also differ ; consequently with the lapse of 
 time they ought to separate from one another. Yet it 
 happens that many of these stars, though exhibiting con- 
 siderable actual motion, preserve very much the same dis- 
 tance from one another during an extremely long interval 
 of time. Such are the two stars composing a Centauri, a 
 Geminorum, y Virginis, Ursae Majoris, and a great num- 
 ber of others, pairs of unequal size, a Centauri, the two 
 constituent stars of which were separable with difficulty 
 in a telescope 100 years ago, has such a considerable 
 proper motion that the two stars ought now to have be- 
 come separated by an interval of 6 minutes if the proper 
 motion of the one were not shared in by the other. This, 
 perhaps, would not always be an unfailing criterion, be- 
 cause it might so happen that the proper motions only ex- 
 hibited small differences, notwithstanding the extent and 
 reality of the difference. What, after all, would in any 
 given case plainly decide the question would be the posi- 
 tive fact (where it could be established) that one star 
 turned around the other in a closed orbit in seeming ac- 
 cordance with the recognised principles of the law of 
 gravitation. This great discovery has indeed been made, 
 and we owe it to Sir William Herschel. When that re- 
 markable man had sufficiently perfected his instruments, 
 so that he could penetrate into the depths of space in a way 
 never before attempted by any of his predecessors, he set 
 himself the task of seeking to discover stellar parallax, or
 
 54 THE STORY OF THE STARS. 
 
 the actual distances of the stars from the earth. He se- 
 lected for his purpose certain large stars which were 
 accompanied by small companions at a distance of only a 
 few seconds of arc. He measured these distances with 
 great care by means of an instrument of his own invention 
 called a " micrometer," which also enabled him to deter- 
 mine the angle made by a line passing through two stars 
 with the meridian. He called this angle the "angle of 
 position " of the two stars, regarding the larger of them 
 as the determining centre of the arc on which the meas- 
 urement was founded. If there had been any annual par- 
 allax that is to say, any apparent displacement of the 
 stars with respect to the celestial background, as a result 
 of viewing the stars from opposite points of the earth's 
 orbit at 6-monthly intervals that parallax would have 
 been discoverable because there would have been disclosed 
 a variation in the distance or angle, comparing one time 
 with another separated by the interval of 6 months. How- 
 ever, after numerous and painstaking researches, carried 
 
 IT 
 
 FIG. 6. Herculis (1865). FIG. 7. < Herculis (1871). 
 
 out with every attention to detail, Herschel could not sat- 
 isfy himself that he had obtained any proofs of change,
 
 DOUBLE STARS. 
 
 55 
 
 and .he gave up the work for a time in despair. Having 
 afterwards improved his instrumental means, he resumed 
 his labours, hoping for better results. Great was his sur- 
 prise to find that some of the stars which he had formerly 
 seen double had become single, the junior member having 
 disappeared, whilst others had evidently changed both 
 their angular position and their distance. Though all 
 hope of discovering an annual parallax seemed to have 
 vanished, at least he had obtained traces of a parallax of 
 another sort, due either to a general movement of the 
 whole system or to some special movement appertaining 
 to particular stars. Michell's old idea seems to have re- 
 curred to Herschel's mind and to have stimulated him to 
 further effort, and after several additional years of pains- 
 taking and laborious work, at length in 1802 he found 
 himself in a position to announce to the scientific world 
 his grand discovery that there existed systems formed by 
 pairs of stars revolving about each other in regular elliptic 
 orbits. He coined the word 
 " binary " and gave it to 
 these stars, to distinguish 
 them from mere optical 
 double- stars, which do not 
 exhibit any mutual periodic 
 changes of place. 
 
 The interval that elapsed 
 between Sir W. Herschel's 
 abandonment of his first re- 
 searches and his renewal of 
 work was about 25 years. 
 This is a period quite suffi- 
 cient to enable the motion of 
 many binary stars to become evident to the senses, and 
 accordingly no fewer than about 50 stars were noticed by 
 Herschel to have undergone change during the time that 
 
 FIG. 8. f Herculis (1883).
 
 THE STORY OF THE STARS. 
 
 his operations were suspended. True that his stars had, 
 for the most part, only had time to traverse a portion of 
 their orbits, but more than 90 years having elapsed since 
 Herschel's announcement of 1802, it follows that a certain 
 number of binary stars have not only gone entirely round 
 in their orbits once, but some of them have done so almost 
 twice, and the form and dimensions of their orbits are 
 now fairly well understood. To cut a long story short, it 
 may be stated that fully 200 pairs of stars are now recog- 
 nised to be in motion round one another in obedience to 
 laws probably identical with what are known as the laws 
 of gravitation, though for obvious reasons their orbits have 
 not all been investigated with equal completeness and 
 accuracy. The following are the names and particulars 
 of a few of the binary stars with periods of less than 100 
 years, the nature of whose movements has been ascer- 
 tained with fair certainty : 
 
 NAME OF STAR. 
 
 Period. 
 
 Date of Last 
 Passage. 
 
 
 Years. 
 
 
 42 Comae Berenices 
 
 25 
 
 1870 
 
 Herculis 
 
 34 
 
 1864 
 
 t\ Coronae 
 
 41 
 
 1891 
 
 fjf Herculis 
 
 45 
 
 i860 
 
 Sirius 
 
 49 
 
 1893 
 
 Cancri 
 
 59 
 
 1868 
 
 Ursae Majoris 
 
 60 
 
 1875 
 
 a Centauri 
 
 77 
 
 1875 
 
 y Coronae 
 
 85 
 
 1840 
 
 70 (/) Ophiuchi 
 
 94 
 
 1808 
 
 Sir W. Herschel's original observations had reference 
 only to pairs of stars, but the further attention which has 
 been given to this subject of late years has resulted in 
 the discovery of the fact that in certain cases there exist 
 systems of stars in triplets, each member of which sys-
 
 DOUBLE STARS. 57 
 
 tern has a relation to the other two, which justifies their 
 being called not simply triple stars but " ternary " stars. 
 f Cancri is an object of this type. 
 
 It must be added, by way of caution, that though 
 movement on the part of a pair of stars during a course 
 of years is primd facie a proof of physical connection 
 involving motion in a closed orbit, yet this must not be 
 regarded as a rule of universal application. A mere an- 
 gular displacement may, in a given case, be the effect of 
 individual proper motion on the part of one or both of the 
 stars of a pair, and not the effect of a central force. From 
 this it will follow that sometimes the positions successive- 
 ly occupied by the principal star will not exhibit the line 
 of a sensible curve. Flamsteed's 6ist star in Cygnus 
 seems to be one of this character ; it is moving, but its 
 motion is in a straight line. 
 
 Before passing away from the subject of double stars, 
 a word should be said about the remarkable circum- 
 stances of 2 stars which are well known by reason of 
 their great intrinsic brilliancy Sirius and Procyon. Both 
 these stars are subject to peculiar disturbances of place, 
 which long excited the surprise and curiosity of astrono- 
 mers. It was suggested that these disturbances were due 
 to the presence of some invisible satellite, and in the case 
 of Sirius this surmise has proved well founded. In 1862 
 Alvan Clark, a well-known American optician, found near 
 Sirius a minute companion, the existence of which has 
 enabled astronomers to explain some, though perhaps not 
 all, of the irregularities found to exist in the positions of 
 the primary star at different times. Arising out of this 
 is the further conclusion that this faint attendant, which 
 has only T^^ of the light of Sirius, possesses a mass 
 more than of Sirius. In other words, unless it does 
 thus really approximate in mass to Sirius itself, it is not 
 capable of accomplishing the observed disturbances. 
 5
 
 58 THE STORY OF THE STARS. 
 
 That disturbances are traceable in the movements of 
 Sirius is no new idea, for the great German astronomer, 
 Bessel of Kbnigsberg, as far back as 1844, not only no- 
 ticed their existence but suggested the presence of an in- 
 visible perturbing body, belonging to the system of Sirius, 
 as an explanation of the fact that the proper motion of 
 Sirius takes place not in a regular line, but in an irregular 
 sinuous line. Accordingly, he suggested that this very 
 bright star possessed a dark satellite. Other astronomers 
 worked at the idea, and may be said to have paved the 
 way for the actual discovery of the satellite by Clark. 
 
 A very interesting question often presents itself to 
 students of astronomy, who meditate on what they have 
 seen after they have examined double stars. The ques- 
 tion may be put in this form : We on the earth are 
 placed on a'certain moving body called a planet, which is 
 one of a number of planets circulating round the sun as 
 their chief ruler or centre. Is this state of things unique ? 
 Or, on the other hand, do other suns exist ? Or, to be 
 more precise, do other bodies exist in the universe which 
 are centres of life and motion analogous to our sun ? No 
 one who has seen a bright double star, with its one or 
 more companions, and still more, no one who has seen 
 the many bright stars with companions which are to be 
 found scattered up and down the heavens, can doubt 
 that the answer to the above main question must un- 
 doubtedly be in the affirmative. In other words, that 
 there are in the universe many suns, each with its own 
 cortege of planets, and not one sun only. Much beyond 
 this, however, we cannot go. One thing is not a matter 
 of speculation. Whereas our planets revolve round the 
 sun in orbits, which though not truly circular, are yet not 
 very eccentric ; that is, do not depart much from the cir- 
 cular form, yet in the cases of the binary stars, the orbits 
 of all that are known depart very much indeed from the
 
 FAMILY PARTIES OF STARS. 59 
 
 circle. Secchi has well pointed out that if we consider 
 for a moment what is involved in the existence of lumi- 
 nous systems of stars, we may well be struck with the in- 
 ferences which necessarily follow. In the case of a sys- 
 tem the form of whose orbit is very eccentric (such as 
 a Centauri), any attendant planets must be warmed some- 
 times by 2 suns very near, sometimes by one sun very 
 near, and by another very far off. Who can calculate 
 the transformations of life which go on under such cir- 
 cumstances without remembering the wisdom of Him 
 who often with small apparent means is able to bring 
 about an infinite variety of results ? Add to this the fact 
 that double stars very often exhibit different and comple- 
 mentary colours. The imagination of even a poet would 
 be incapable of describing to us the phases of a day 
 illuminated by, say, a red sun, and of a night illuminated 
 by, say, a green sun ; or of a day in which 2 suns of dif- 
 ferent colours competed with one another, whilst the 
 night was ushered in by a golden twilight and the next 
 morning was preceded by a blue dawn. But I do not 
 wish in this chapter to drift into star colours, for that is a 
 subject of sufficient importance to deserve a chapter to 
 itself. 
 
 CHAPTER VIII. 
 
 FAMILY PARTIES OF STARS. 
 
 THE subject matter of the preceding chapter will nat- 
 urally suggest the idea that if one naked-eye star is found 
 telescopically to consist really of 2 stars, why not another 
 of 3 stars or 4 stars, or more, in close association physic- 
 ally or apparently ? And such, indeed, is the case. We 
 have, accordingly, plenty of triple stars, some quadruples, 
 some quintuples, some sextuples, and so on many of
 
 60 THE STORY OF THE STARS. 
 
 them very picturesque to look at through a telescope. 
 
 Amongst the triple stars within the easy reach of amateurs 
 armed with small telescopes 
 may be mentioned Flamsteed's 
 II Monocerotis, 12 Lyncis, and 
 51 Librae. The following are 
 quadruples : TT' Canis Majoris, 
 8 U Lacertae. /3 Lyras is a quin- 
 tuple. Again there are some 
 stars which comprise so many 
 constituents that they can best 
 be described as " multiples " ; 
 such are e Lyra? and a- Orionis. 
 
 FIG. 9. * Lyrse. - ... , , . 
 
 It will be seen from the en- 
 gravings that each of these exhibits a double system of 
 stars, so that f Lyras may be called a double-double, whilst 
 <r Orionis is a double-triple. The former object comprises 
 
 FIG. 10. 9 Orionis.
 
 FAMILY PARTIES OF STARS. 
 
 6l 
 
 one pair of stars of mags. 5 and 6$, whilst the second pair 
 are 5 and 5^ respectively. There seems every reason to 
 suppose not only that the 2 stars of each pair constitute 
 a binary system (each star revolving round the other), 
 but that each pair taken together revolves round the 
 other pair, thus constituting a double-binary, or a system 
 
 FIG. IT.* Orionis. 
 
 of mutual association of great complexity. Between the 
 2 main pairs there are several smaller stars. Many tele- 
 scopes will show 3, and Professor Hall, in America, has 
 made the 3 into 7, but his additional stars are very faint 
 indeed, and can only be seen in the very largest telescopes. 
 Lyrae is on the frame of the Lyre, i$ N. E. of the very 
 bright star Vega. 
 
 The group forming tr Orionis, whilst it bears a certain
 
 62 THE STORY OF THE STARS. 
 
 family resemblance to e Lyrae, differs from it in the respect 
 that we have no knowledge of any of the stars being 
 linked together so as to constitute a moving system, a- 
 Orionis may be easily found, as it forms the southern ver- 
 tex of a triangle with the 2 last stars (f and t) in Orion's 
 Belt ; and it is rather less than a degree from f in the 
 direction of ft. 
 
 Orion contains another multiple star of great interest 
 known as 6 Orionis. In this case there are 6 stars, the 
 four most conspicuous of which make a trapezium at dis- 
 tances not very unequal. The $th and 6th stars are fainter, 
 and lie just outside the boundary lines of the trapezium. 
 In this case the component stars are not organised in 
 pairs, and do not appear to constitute a system physically 
 connected. 6 Orionis is in the midst of the " Great Nebula 
 in Orion," of which more anon. Perhaps it might even 
 be said to form a part of the nebula. 
 
 CHAPTER IX. 
 COLOURED STARS. 
 
 MOST persons would say on a casual glance that the 
 stars are specks or points of white light, and so no doubt 
 the majority of them are ; but more attentive examina- 
 tion will disclose the fact that a very considerable number 
 of them exhibit definite colours, though those in which 
 any colour is very pronounced are in a great minority. 
 The student who is familiar with the intense colours of 
 the solar spectrum will be disappointed if he expects to 
 find amongst the stars many colours as pronounced as 
 those which he sees in the solar spectrum. Neverthe- 
 less, it is possible in a general way to find here and 
 there stars which if they were all brought together in
 
 COLOURED STARS. 63 
 
 a row would constitute some similitude of the solar spec- 
 trum. 
 
 There are many difficulties in the way both of observ- 
 ing and of recording the colours of stars, and this ex- 
 plains the discrepancies in the accounts put forth by dif- 
 ferent observers. In the first place, people's eyes are 
 differently constituted ; some eyes are more capable than 
 others of accurately appreciating and describing a colour. 
 Some eyes, indeed, as is well known, are totally incapable 
 of appreciating certain colours at all. Possessors of such 
 eyes are said to be "colour-blind." But, disregarding ex- 
 treme cases of this sort, it is quite certain that ordinary 
 eyes will differ not a little in appreciating a given colour. 
 It suffices to visit a picture gallery and take note of the 
 differences in the copies of one and the same original pic- 
 ture which are being made by different copyists, to realise 
 the fact that particular hues in the original are reproduced 
 in a very different way by the different persons. 
 
 Then, again, the quality of the glass of the telescope 
 employed influences much the apparent colours of the 
 objects looked at ; and still greater is the effect of the good 
 or bad grinding of the lenses. In other words, lenses 
 made of very pure glass and very accurately ground and 
 polished will yield images and indications of colour which 
 will be much more true to nature than the indications 
 afforded by inferior glass inaccurately figured. It is a 
 very noteworthy fact that metallic mirrors always give to 
 objects seen through them a reddish tinge. This is strik- 
 ingly brought out in connection with Sir John Herschel's 
 observations of red stars. To many of these objects he 
 has attached such qualifying words as "carmine," " ruby," 
 "intense crimson," where ordinary observers employing 
 ordinary telescopes would see only ordinary red hues. 
 Nor is magnifying power entirely an unimportant matter ; 
 with a low power white will dominate, and other tints will
 
 64 THE STORY OF THE STARS. 
 
 in a measure be lost, because no star is absolutely mono- 
 chromatic ; on the other hand, a high magnifying power 
 diminishes the total light, and, exaggerating the dimen- 
 sions of the spurious discs, renders the colours more easily 
 distinguishable. Again, the state of the atmosphere and 
 the proximity of a star to the horizon greatly affect its ap- 
 pearance. It is only when a star is well up in the heavens 
 above the horizon that its true colour, whatever it may be, 
 can be noted, because near the horizon all celestial objects 
 apparently acquire red or orange hues, which do not really 
 belong to them. 
 
 Perhaps the greatest of all the difficulties which beset 
 the observer who wishes to make an accurate record of 
 star colours, is the difficulty of providing and using a 
 standard of colour for comparisons. Such a standard is 
 furnished naturally by the solar spectrum ; but astrono- 
 mers have hitherto been altogether baffled in their at- 
 tempts to reproduce the prismatic colours in such a way 
 that they can be rendered practically available in the dark- 
 ness of night, side by side with the image of a star pro- 
 duced at the eye-end of a telescope. There is herein, in 
 point of fact, a double difficulty : that which may be called 
 the manual or mechanical difficulty just alluded to, and 
 that which arises from the fact that the artificial light em- 
 ployed by night being yellow, injures the neutrality of the 
 eye and falsifies all artificial colours. It was with the idea 
 of getting over these difficulties that Secchi proposed to 
 make use of an electric spark, which, if derived from dif- 
 ferent substances, would give for each of them a different 
 hue, but I am not aware that any attempt has ever been 
 made to put this idea into practice. 
 
 Single stars of a red or orange hue are not uncommon, 
 but isolated blue or green stars are very rare. Indeed, 
 ft Librae appears to be the only conspicuous star which is 
 green. In the case, however, of double stars it is much
 
 COLOURED STARS. 65 
 
 more easy to define their colours, for in many instances 
 they exhibit very well-marked colours, and frequently the 
 colours of the 2 stars are what are called " complemen- 
 tary." The reader may be reminded that this is a term 
 applied by physicists to the colours which, when united, 
 make white light. In order to obtain a strictly exact idea 
 of what these colours are recourse must be had to a spe- 
 cial instrument of which several kinds have been con- 
 trived. But for the elementary purposes of this work it 
 will suffice to state that the principal pairs of colours which 
 are mutually complementary are red and green, orange 
 and blue, and yellow and violet. The intermediate tints 
 are too innumerable to be described in words, and they 
 can only be realised by instrumental means. 
 
 When we speak of double stars as exhibiting different 
 colours it is not permissible in all cases to regard the 
 colours as an optical illusion or an effect of contrast, for 
 in some instances certainly the colours are an actual 
 physical reality. We may draw this conclusion in some 
 cases from the circumstance that the colours seen are not 
 always complementary ; and in other cases from the fact 
 that, by concealing the principal star by means of a bar 
 in the eye-piece, formed of watch-spring or something of 
 that sort, we shall notice that the companion star, when 
 thus cleared of the effects of its primary, preserves its 
 colour unchanged. 
 
 The following may be mentioned as good examples of 
 coloured pairs 
 
 Large Star. Companion Star. 
 
 T> Cassiopeise . . . Yellow Purple 
 
 a Piscium . . . Pale Green . . . Blue (or var.) 
 
 7 Andromedse . . . Orange Green 
 
 t Cancri Orange Blue 
 
 e Bootis Pale Orange . . . Sea Green 
 
 fCoronae... ... White Blue
 
 66 THE STORY OF THE STARS. 
 
 a Herculis . . . Orange Emerald Green 
 
 /3 Cygni Yellow Sapphire Blue 
 
 a Cassiopeiae . . . Greenish . . . Bright Blue 
 
 Secchi compiled the following list of conspicuous stars 
 of the colours stated : White, Procyon, Altair ; Blue, 
 Sirius, Vega, Castor, Regulus ; Yellow, Capella, Pollux, 
 a Ceti ; Orange, Aldebaran, Aicturus, Betelguese ; Ruddy, 
 Antares, a Herculis. 
 
 Kriiger, an experienced German observer, has given 
 the following list, which, it will be seen, is not wholly 
 in accord with Secchi's: White, Sirius, Altair, Regu- 
 lus ; Yellow, Capella, Pollux, Arcturus ; Orange or Red, 
 a Herculis, Betelguese. 
 
 All the really red stars that is, stars of pronounced 
 depth of colour are comparatively small in size scarcely, 
 if at all, visible to the naked eye. There are a few per- 
 haps half a dozen to which the designation " carmine " 
 may be applied, but the bulk of the so-called red stars are 
 more orange than red. I shall have something more to 
 say about some of these in the chapter on " Variable 
 Stars." 
 
 The question of whether the stars vary in colour has 
 attracted some attention, but the evidence is on the whole, 
 meagre and inconclusive. From a passage in Seneca, an 
 ancient Roman writer, it has been inferred that he wished 
 it to be understood that in his day Sirius, the Dog Star, 
 was red, whereas now it is white, or bluish-white. Ptolemy 
 seems also to have regarded Sirius as a red star, and to 
 have used a word to describe it which he also applied to 
 Pollux. Now Pollux is certainly a reddish-yellow star in 
 the present day, and if it and Sirius could ever have been 
 appropriately designated by the same adjective of colour, 
 then the conclusion follows as a matter of course that 
 Sirius no longer exhibits the colour it once did. Capella
 
 MOVING STARS. 67 
 
 is perhaps another star which has changed from red, or 
 reddish, to blue but one could have wished for a larger 
 number of instances. At present we can only say 
 that whilst change of brilliancy in the case of stars is a 
 common occurrence, change of colour is not a well-estab- 
 lished fact. 
 
 CHAPTER X. 
 MOVING STARS. 
 
 THE term " fixed stars " is a familiar one, and in a 
 certain sense it is the expression of a truth, but modern 
 science has shown that the term, as applied to the stars, 
 needs to be employed under reserve, for a great many 
 stars are not "fixed." I am not, of course, alluding to 
 their apparent annual or diurnal movements : we have 
 considered that matter in a previous chapter, and I hope 
 the reader understands by this time (at any rate generally) 
 what these apparent movements are and how they arise. 
 What we have now to deal with is actual proper motion, 
 and with this a considerable number of the stars are en- 
 dued. 
 
 It must be understood, of course, that though the an- 
 cients divided the stars into two classes those which 
 were stationary, and those which moved they knew 
 nothing of the stars which form the subject of this chap- 
 ter being moving stars. The objects to which the an- 
 cients applied the designation of " wandering stars " were 
 what we now call Planets, or Comets. Indeed, the very 
 word " planet " itself is derived from a Greek word mean- 
 ing " a wanderer." What we have now to consider are 
 the movements of certain stars, which movements are, as 
 a rule, very small in amount, and proceed very slowly. 
 Sir John Herschel's statement of the case can hardly be
 
 68 THE STORY OF THE STARS. 
 
 improved on. He says : " Motions which require whole 
 centuries to accumulate before they produce changes of 
 arrangement such as the naked eye can detect, though 
 quite sufficient to destroy that idea of mathematical fixity 
 which precludes speculation, are yet too trifling, as far as 
 practical applications go, to induce a change of language 
 and lead us to speak of the stars in common parlance as 
 otherwise than fixed. Small as they are, however, as- 
 tronomers once assured of their reality have not been 
 wanting in attempts to explain and reduce them to gen- 
 eral laws." 
 
 What the expression the " proper motion " of a star 
 means or involves may perhaps be best understood by 
 some such illustration as the following : A man standing 
 in Trafalgar Square and looking down Whitehall may at 
 a given moment see in the direction of the Houses of Par- 
 liament an omnibus, a cab, and a van. After an interval 
 of 2 minutes he may see the same vehicles, but their order 
 may be first the van, then the cab, and lastly the omnibus. 
 This may imply either (i) that the van has remained 
 stationary, the omnibus and the cab having moved for- 
 wards, the omnibus travelling at a more rapid pace than 
 the cab; or (2) that all three have moved somewhat, but 
 each at a different pace ; or (3) that the van has backed 
 towards Trafalgar Square, only the omnibus and the cab 
 going forward. If such a condition of things were con- 
 ceived to be transferred to the heavens, our ideal omnibus, 
 cab, and van being transformed into stars, we should have 
 an analogue of the problem which the astronomer has to 
 solve in detecting and valuing the proper motions of 3 
 neighbouring stars, or, it may be, of only 2, or perhaps 
 even of only i, of such stars. Be it remembered, too, 
 that in the illustration I have given it may well happen 
 that the Trafalgar Square spectator, from his position 
 astride of one of Landseer's lions, though he may be quite
 
 MOVING STARS. 69 
 
 sure that the omnibus and the cab have both moved for- 
 wards, may yet be totally incapable of determining whether 
 their movement amounts to 10 yards or 50 yards, because 
 he is viewing the whole proceeding " end on," or, in as- 
 tronomical language, the 3 vehicles are nearly in his " line 
 of sight." Things would, however, present quite a differ- 
 ent aspect to a second spectator standing, say, in front of 
 the Horse Guards. His would be a " broadside " view of 
 the several vehicles ; and whether they had all moved, or, 
 if only some of them, then which of them, and how much 
 had each moved, would be points upon which he could 
 pronounce an opinion promptly and (let us hope) accu- 
 rately. 
 
 The above simile in each and all its stages and as- 
 pects may be taken to be a counterpart of the problem 
 presented to an astronomer called upon to investigate 
 stellar proper motions. And what Fontenelle once said 
 in respect of the star known as Altair in the constellation 
 Aquila is in keeping with the illustration which I have 
 borrowed from what may be seen any day at Trafalgar 
 Square. Said Fontenelle : " There is a star in the Eagle 
 which, if all things continue their present course, will, 
 after the lapse of a great number of ages, have to the 
 west another star which at present appears to the east of 
 it."* Fontenelle's remark is just such a remark as my 
 ideal spectator at the Horse Guards might make because 
 of his enjoying a " broadside " view of the changes in the 
 positions of the vehicles going down Whitehall. But the 
 
 * Referring to the diagram of the stars in Ursa Major, given on 
 p. 36 (ante), it may be noted that all 7 are endued with proper mo- 
 tion ; but whilst ft, y, 8, , are moving one way, a and 17 are moving 
 the opposite way, and Fontenelle's remark (varied as necessary) 
 finds a further exemplification. Various examples may be found of 
 stars in proximity having common proper motions or, as Miss 
 Clerke words it, having a "gregarious tendency."
 
 70 THE STORY OF THE STARS. 
 
 original spectator at the Nelson Monument has also his 
 circumstances reproduced in the heavens ; for, even though 
 in the case of any given star no indications, or but slight 
 indications, of lateral change of place can be detected, yet 
 such star may nevertheless be endued with a rapid mo- 
 tion of either approach or recession which can be found 
 out by a secondary method. Thanks to the spectroscope 
 and the ingenuity of modern astronomers, motions of ap- 
 proach to or recession from the earth have been discov- 
 ered in the case of certain stars, notwithstanding that 
 those stars, being seen " end on " (alias, in the line of 
 sight), seem on mere visual observation to be practically 
 stationary. 
 
 But I am anticipating too much. The fact that certain 
 of the stars are endued with a proper motion of their own 
 was first ascertained in 1718 by the English astronomer 
 Halley. By comparing the positions of Sinus, Arcturus, 
 and Aldebaran, as laid down in the most ancient cata- 
 logues, with the positions determined by himself in 1717, 
 he found, after making every allowance for the effects of 
 precession and the variation in the obliquity of the ecliptic, 
 that these stars seemed to have got out of place to the 
 extent in each case of more than \, a displacement too 
 considerable to be ascribable to errors of observation or 
 errors of copying. In the case of Aldebaran it was further 
 found that that star had undergone at Athens in 509 A. D. 
 an occultation by the Moon which could not have taken 
 place if the star had occupied 1400 years ago the same 
 or nearly the same place that it occupies at the present 
 time. The utmost that Halley could do was to surmise 
 that the stars in question were affected by proper motion, 
 because in those days no long-continued series of observa- 
 tions of places taken by exact instruments were in exist- 
 ence. Such observations, however, soon began to accu- 
 mulate as the 1 8th century rolled on, and accordingly in
 
 MOVING STARS. 71 
 
 1738 James Cassini was able to say with some confidence 
 that Arcturus had undergone a displacement of 5' in a 
 century and a half, whilst the neighbouring star rj Bootis 
 had been exempt from such displacement. Inasmuch, 
 however, as precise and exact instrumental observations 
 of star places can only be said to date from 1760 (being 
 the epoch of Bradley's Catalogue of important stars) and 
 as that was only a century and a quarter ago it is evidently 
 clear that the study of stellar proper motions must be re- 
 garded as a branch of the science which is still in its in- 
 fancy, especially seeing that in the case of the star having 
 the largest known proper motion (1830 Groombridge Ursaa 
 Majoris), the amount is only 7", and that only in the case 
 of about a dozen stars does the amount exceed 3". It was 
 to a fact such as this that Sir J. Herschel alluded in the 
 paragraph quoted on a previous page, when he spoke of 
 " motions which require whole centuries to accumulate 
 before they produce changes of arrangement such as the 
 naked eye can detect." 
 
 Year by year is adding to the number of the observa- 
 tions, which by their exactitude enable us to detect proofs 
 of proper motion when those observations are placed in 
 juxtaposition with observations of the same stars made in 
 the earlier part of the present century, say between 1800 
 and 1830. The materials already available seem to point 
 to the fact that the proper motions of the brighter stars 
 are, as a rule, greater than those of the fainter stars. The 
 average proper motions of the ist magnitude stars known 
 to possess proper motions has been set down at \" annu- 
 ally, whilst the average displacement of the 6th magni- 
 tude stars known to be affected amounts to no more 
 than 5 y. 
 
 This law, if law it may be properly called, is subject 
 to exceptions, for there are some small stars, such as 1830 
 Groombridge Ursae Majoris, 9352 Lac. Piscis Australis, 61
 
 72 THE STORY OF THE STARS. 
 
 Cygni, 21185 Lalande Ursas Majoris, and 21258 Lalande, 
 which have very considerable proper motions. 
 
 The reader who has followed attentively the Trafalgar 
 Square illustration will have no difficulty in understanding 
 the statement that a knowledge of a star's proper motion 
 conveys very little information as to the said star's real 
 motion reckoned in miles per second. When we say that 
 a star's proper motion amounts to 4" a year (which is 
 about 6V in a century), the record is simply that the star's 
 apparent lateral displacement is so much in such a length 
 of time along a line assumed to run at right angles to the 
 observer's line of sight. But the true direction may not 
 be at right angles as aforesaid ; it may be in a path which 
 the observer may only see foreshortened. Or, in an ex- 
 treme case, if the motion takes place directly in the line of 
 sight so that the star is moving straight towards us, or 
 from us, it may be in rapid motion and yet visually seem 
 to have no motion at all ; that is, to be undergoing no 
 change of apparent place which can be detected by com- 
 paring observations taken at different times. 
 
 Whilst it cannot be said that we know much about the 
 actual motions of many of the stars, yet we do know 
 something. The spectroscope furnishes us with some 
 clue, the basis of which is a principle of physics first enun- 
 ciated by Doppler in 1842. This principle may be thus 
 defined : " When the distance between us and a body 
 which is emitting regular vibrations either of sound or 
 light is decreasing, then the number of pulsations received 
 by us in each second is increased, and the length of the 
 waves is correspondingly diminished." In the case sup- 
 posed the musical pitch rises, and in the same way the 
 refrangibiiity of a wave of light which depends upon its 
 wave length is increased so that it will fall nearer the vio- 
 let end of the spectrum. A practical illustration of this 
 principle may often be had by a person standing on the
 
 MOVING STARS. 73 
 
 platform of a railway station through which a fast train is 
 passing at a high rate of speed, whistling continuously as 
 it passes. It will be noticed in such a case that the pitch 
 of the whistle continuously varies as the train approaches 
 the spectator, whilst it goes on continually varying, but in 
 the opposite direction, after it has passed him and the dis- 
 tance gradually augments. Whatever was the pitch, say, at 
 200 yards, before the engine came up to the platform, the 
 pitch will be the same at 200 yards in the opposite direc- 
 tion after the engine has passed the platform. 
 
 Huggins, in 1868, thought to apply the foregoing prin- 
 ciple by spectroscopic observations on certain stars with a 
 view of seeing whether a particular line in a spectrum un- 
 derwent after an interval any displacement from its nor- 
 mal position towards either end of the spectrum. If in 
 any given case there was a displacement towards the red 
 end of the spectrum, the conclusion would have to be that 
 the star was receding from the earth : if, on the other 
 hand, the displacement was towards the violet end of the 
 spectrum, the conclusion would have to be that the star 
 was approaching the earth. A general deduction to be 
 drawn from the observations of Huggins and of others 
 who have worked in the same field, seems to be that there 
 are several dozen prominent stars in motion at speeds 
 varying from 2 to 50 miles a second. 
 
 When astronomers once came to recognise the fact 
 that certain stars were in motion it naturally followed that 
 there was a desire to ascertain whether any particular 
 consequences, and if so what consequences, were involved 
 in the discovery. Sir W. Herschel in 1783 began by try- 
 ing to classify the proper motions of the stars, so far as 
 known to him at that epoch. Having done this and find- 
 ing evident signs that they converged towards a point in 
 the Constellation Hercules, he was led to conclude that 
 the Solar System as a whole was moving towards a point 
 6
 
 74 THE STORY OF THE STARS. 
 
 in the Celestial Sphere not far from the star X Herculis. 
 The principle involved has been thus defined by Professor 
 Young : " On the whole, the stars appear to drift bodily 
 in a direction opposite to the sun's real motion. Those in 
 that quarter of the sky which we are approaching open 
 out from each other, and those in the rear close up be- 
 hind us. The motions of the individual stars lie in all 
 possible directions, but when we deal with them by thou- 
 sands, the individual is lost in the general, and the pre- 
 vailing drift appears." 
 
 The effect here stated by Young may be seen, and 
 being seen, may be easily realised, by walking through a 
 field dotted over with units of any kind, such as sheaves 
 of corn put up in shocks, or haycocks, or any similar 
 aggregations of produce. As the pedestrian approaches 
 a row of such things, the row which at a distance seemed 
 almost continuous will be found on nearing it to have its 
 units separated by several feet or yards of distance : as he 
 passes forwards across the field the first and subsequent 
 rows will gradually seem to close up behind him into a 
 more or less compact mass. 
 
 Sir W. Herschel's endeavours to find out the " apex " 
 of the sun's way (as it is called) have been followed up by 
 other astronomers since, and about 20 different determina- 
 tions are now available. There is a remarkable general 
 accord between them all. Perhaps on the whole the 
 most trustworthy because it is based upon a very large 
 number of stars is L. Struve's. He has found the point 
 of convergence to be situated in R. A. i8h. 1301. ; and 
 Decl. + 27. Huggins, by spectroscopic observations of 
 an ingenious character, has confirmed the general conclu- 
 sions thus stated. 
 
 A skilful and careful German astronomer, named Mad- 
 ler, at that time employed at the Observatory of Dorpat 
 in Russia, put forth, in 1846, an idea that there exists
 
 TEMPORARY STARS. 75 
 
 some central point in the universe around which the sun, 
 with its bevy of planets and comets, revolves in the course 
 of millions of years ; and he suggested that such centre is 
 situate in the direction of Alcyone, one of the Pleiades. 
 It is difficult to pronounce dogmatically for or against 
 this idea (which, by the way, was rather a revival of a 
 theory put forth by Wright in 1750 than Madler's own), 
 but Grant's remarks may be considered to meet the case : 
 " It is manifest that all such speculations are far in ad- 
 vance of practical astronomy, and therefore they must be 
 regarded as premature." 
 
 CHAPTER XI. 
 
 TEMPORARY STARS. 
 
 HISTORIANS of various dates and nationalities tell us 
 that from time to time stars have blazed forth in the heav- 
 ens in places where no stars had ever been seen before, 
 and that after an existence of, it may be, a few weeks or 
 months, such stars have faded away and been no more 
 seen. It was at one time considered that the authors of 
 these statements had been drawing- upon their imagination 
 for their facts, but the bulk of what has been handed down 
 to us are well founded. About 12 stars in all are recog- 
 nised by astronomers under the designation of " temporary 
 stars." They severally appeared as follows : 134 B. C., 329 
 A. D., 1572, 1600, 1604, 1670, 1848 (Nova Ophiuchi), 1860 
 (T Scorpii), 1866 (T Coronas), 1876 (Nova Cygni), 1885 
 (Nova Andromedas), and 1892 (Nova Aurigas).* The chief 
 difficulty in regard to all the more ancient cases has been 
 
 * Since this chapter was written have appeared : Nova Carinas 
 and Nova Centauri, 1895 ; Nova Sagittarii, 1898 ; Nova Aquillae, 
 1899 ; and Nova Persei, 1901. The latter reached almost the bright- 
 ness of Sirius, February 24, and in some respects was the most re- 
 markable astronomical phenomena of recent years.
 
 76 THE STORY OF THE STARS. 
 
 to determine how far the celestial objects thus recorded to 
 have burst forth were in any true sense stars, or whether 
 they were comets or mere meteors. The records which 
 we have are of very diverse origin, and some of them 
 2000 years old, handed down to us from times when the 
 scientific precision and verbal accuracy of modern writing 
 and speech were unknown. The fact that the ancient 
 Greeks were a dreamy people, the Romans callous to sci- 
 ence altogether, and the Chinese " flowery " as nowadays, 
 renders it extremely difficult for us to sift the wheat from 
 the chaff, and to prtciser, as the French say, any given 
 statement. For instance, what is one to make out of the 
 following Chinese account of something seen in A. D. 
 173: "On Dec. loth a star appeared between a and /3 
 Centauri, and remained visible for 7 or 8 months ; it was 
 like a large bamboo mat (!), and displayed 5 different 
 colours." Were it not for the fact that on several occa- 
 sions during the present century new stars have burst 
 forth, have shone for a while, and have then either disap- 
 peared absolutely or dwindled almost to invisibility, we 
 should often have to be sceptical as to the tales told us by 
 many ancient chroniclers. 
 
 Our sources of information are twofold European and 
 Chinese. The former are generally very vague as to dates 
 and places ; the latter much more " understandable," 
 though both dates and places are often expressed in a 
 very peculiar fashion. The Chinese observations have 
 the great merit that they are continuous through many 
 centuries, and are expressed in language of very uniform 
 style ; so that once get an insight into the style, and a 
 European astronomer may feel sure that he can interpret 
 with tolerable accuracy the entire series, and this is what 
 has been done. The first workers in this field were cer- 
 tain French Jesuit missionaries, named Couplet, Gaubil, 
 and De Mailla, who lived for a while at Pekin some 1 50
 
 TEMPORARY STARS. 77 
 
 years ago. They made and brought to France copies of 
 various Chinese annals, which somehow or other they got 
 hold of at Pekin. De Mailla's manuscripts were pub- 
 lished at Paris about 100 years ago, but those of Couplet 
 and Gaubil still remain, I believe, unpublished. A very 
 industrious Frenchman named Pingre worked up all these 
 materials in a book on comets which he published in 
 1784, whilst another Frenchman named Biot in 1846 gave 
 to the world a further series of observations. By far the 
 most complete and accurate, however, of all the existing 
 versions of the Chinese astronomical records is the late 
 John Williams's "Observations of Comets from B.C. 611 
 to A. D. 1640," which appeared in 1871. 
 
 All this is a digression from the subject which I wanted 
 to start with, but it is a digression which seemed neces- 
 sary under the circumstances of the case. 
 
 The earliest " new " star appears to have been one ob- 
 served by the Greek astronomer Hipparchus, and a tradi- 
 tion, fathered by Pliny, has always suggested that it was 
 the appearance of this star which prompted Hipparchus 
 to compile his, the first catalogue of stars. This tradition 
 was long regarded as a myth, but as a new star in Scorpio 
 is recorded by the Chinese to have been seen in 134 B.C., 
 a few years before the date commonly assigned to Hippar- 
 chus's Catalogue, there seems now no sufficient reason for 
 rejecting the tradition above referred to. Passing over 
 new stars asserted to have appeared in 945 A. D. and 1264 
 A. D., the authenticity of which is gravely doubtful (the 
 accounts probably referring to the great comets of those 
 years), we come to the year 1 572. In that year there was 
 a celebrated new star with which Tycho Brahe's name is 
 often linked, because he left behind him a particularly full 
 account of it. It was visible for 17 months from Novem- 
 ber, 1572,10 March, 1574. Brighter than Sirius, it rivalled 
 Venus. It changed colour from white to yellow and red
 
 78 THE STORY OF THE STARS. 
 
 and then back again to white, and remained stationary all 
 the while that it was visible. D'Arrest pointed out in 1864 
 that within i' of arc of the place assigned by Argelander 
 to Tycho's star there exists a small star, which Hind and 
 Plummer found in 1873 to be certainly variable in its 
 light. The position for 1890 of Tycho's star is R. A., oh. 
 1 8m. 405.; Decl. + 63 32'.3. Amateurs possessed of 
 telescopes, say of 3 inches aperture, might usefully em- 
 ploy their time in finding and watching this supposed 
 Tycho star. It follows a certain gth mag. star at a dis- 
 tance of 2 1. 6s., and is 10' 4" to the S. This 9th mag. 
 star may itself be identified by reason of the fact that it 
 follows a star known as Flamsteed's 10 Cassiopeia? (mag. 
 6) at a distance of ijm. 125., and is 6.4' to the N. of it. 
 
 In 1604 and in 1670 temporary stars of considerable 
 brilliancy became visible. The star of 1604 appeared in 
 Ophiuchus, and grew to be nearly as bright as Venus, 
 lasting 12 months or longer. The star of 1670, often 
 called " Anthelm's star," appeared in Cygnus, and reached 
 the brightness of a star of the 3rd mag. It lasted alto- 
 gether about 2 years, but faded away and then bright- 
 ened up again more than once before its final disap- 
 pearance. 
 
 In April, 1848, a new star of the 5th mag. was seen in 
 Ophiuchus by Hind. It eventually rose to the 4th mag., 
 and then faded away and became very small, but has 
 never entirely disappeared. This star is now ranked as a 
 recognised variable, but it seems not to have received 
 much notice of late years. 
 
 In 1866 a very remarkable transformation took place 
 in the case of a star which had been previously recorded 
 in 1855 by Argelander as being of the 9th or loth mag. 
 Birmingham at Tuam, on May 12, 1866, found the star 
 shining as of the second mag. Combining the testimony 
 of Birmingham with that of Schmidt of Athens, it would
 
 TEMPORARY STARS. 79 
 
 seem that this star brightened up from the 4th to the 2nd 
 mag. in about 3 hours on the evening of May 12. It 
 soon began to lose light, and after diminishing to below 
 mag. 9 it rose to 7$ in September, and remained at that 
 for the rest of the year. This star also is now treated as 
 a recognised variable, though we have gained very little 
 additional knowledge respecting it. 
 
 In November, 1876, after several days of pronounced 
 bad weather, Schmidt at Athens observed on the 24th a 
 new star of the yd mag., yellow in colour. By the begin- 
 ning of December it had sunk to the 5th mag., and by the 
 end of December to the 7th mag., and now it seems to 
 have disappeared altogether. 
 
 In August, 1885, a new star burst out in, or in front of, 
 the Great Nebula in Andromeda. Though it only reached 
 the 6th mag., yet, owing to the large number of telescopes 
 and spectroscopes brought to bear on it, this nova has a 
 considerable and very interesting history attached to it. 
 
 One moral to be drawn from this is that amateur 
 observers need not fancy that there is no work for 
 them to do in Astronomy. Respecting this star, I 
 will here state historically what seems to have hap- 
 pened. The Great Nebula in Andromeda is one of the 
 largest and most important of the known nebulas, as we 
 shall see when we come to speak of that class of celestial 
 objects. It ordinarily offers the appearance of an exten- 
 sive and dense oval mass of luminous haze. It so pre- 
 sented itself to various observers during the first half of 
 August, 1885. Priority in noticing it to be otherwise 
 that is, as having a star in or on it seems to rest either 
 with the late Mr. Isaac Ward, of Belfast, or with a Hun- 
 garian lady, the Baroness de Podmaniczky, who on 
 August 22 had staying with her at her husband's house 
 a professional astronomer, Dr. De Kovesligethy. There 
 was a telescope of 3$- inches aperture in the house.
 
 8o THE STORY OF THE STARS. 
 
 Hostess and guest several times made use of this 
 telescope, and on August 22 the baroness remarked to 
 the doctor that she saw a little star in the nebula, a state- 
 ment which the visitor confirmed. Yet the phenomenon 
 was so faint that both believed the full moon was the in- 
 direct cause, the moonlight overshadowing the fainter 
 portions of the nebula, and permitting only of the visibil- 
 ity of the bright centre. It was not till more than a week 
 after the above date that the existence of the new star 
 was generally recognised, though there is evidence to 
 show that some days previously to August 22 the nebula 
 as a nebula had exhibited unwonted brightness. To none, 
 however, of the observers who noted this fact does it 
 appear that the thought presented itself that they were 
 gazing on a stellar object. At its brightest this new star 
 seems to have reached the 6th magnitude, and there is 
 reason to suppose that when Mr. Ward and the Baroness 
 de Podmaniczky saw the star it was rising to, but had not 
 reached, its maximum brilliancy. The date of this may 
 perhaps be put at August 31. The star then rapidly de- 
 clined in lustre until the end of September, when it stood 
 at about the loth magnitude. It then further diminished 
 until it became merged in the nebula itself, or rather until 
 its luminosity became lost in the luminosity of the nebula. 
 An interesting question arose as to what were the rela- 
 tions, if any, between the new star and the nebula. A 
 very competent French astronomer named Trouvelot sug- 
 gested the following reasons for concluding that there 
 was no physical connection between the star and the neb- 
 ula. There are a multitude of small stars visually scat- 
 tered all over the nebula. Trouvelot considers these to 
 belong to the Milky Way, of which he traces an extension 
 beyond the nebula, since they increase in number as the 
 Milky Way is approached. They are likewise perfectly 
 sharp and well-defined, which they would not be if they
 
 TEMPORARY STARS. 8 1 
 
 were either in the nebula or behind it. He concludes, 
 therefore, that the nebula lies behind the Milky Way. 
 The well-defined appearance of the new star, and of a 
 small star near it, which he thought was also a new one, 
 seemed to prove that they were both in front of the nebula, 
 and were associated with the Milky Way rather than with 
 the nebula. These surmises, it will be observed, throw 
 no light upon the question why this new star should sud- 
 denly have blazed forth and as suddenly have faded away. 
 I must, however, add my testimony to Trouvelot's so far 
 as to say that when I saw the new star myself on Sep- 
 tember 3, in a 6-inch refractor, I could not refrain from 
 entering in my note-book the thought that " the star had 
 nothing to do with the nebula." 
 
 On December 13, 1885, Mr. J. E. Gore in Ireland no- 
 ticed a new star of the 6th magnitude, reddish in colour, 
 situated some 20' following % l Orionis. It was found to 
 have a beautiful banded spectrum of Secchi's Type III. 
 Six months later it had diminished to below the I2th mag- 
 nitude. It afterwards increased again, and is now recog- 
 nised as a variable going through all its changes of mag- 
 nitude in about 12 months. Why the sudden and special 
 increase of its light in December, 1885, cannot be sur- 
 mised. 
 
 There yet remains another new or temporary star for 
 mention, the history of which is extremely interesting. On 
 February r, 1892, an anonymous postcard was received by 
 Dr. Copeland, the director of the Royal Observatory at 
 Edinburgh, to the effect that a new star of about the 5th 
 magnitude had become visible in the constellation Auriga 
 not far from the star ^. It subsequently transpired that 
 the postcard had emanated from a certain Dr. Anderson, 
 an amateur living in Edinburgh, who had discovered the 
 star by the joint use of a small pocket telescope and Mc- 
 Clure's edition of Klein's " Star Atlas." The history of
 
 82 THE STORY OF THE STARS. 
 
 this star during the weeks immediately preceding its dis- 
 covery by Dr. Anderson became known in a very curious 
 way. Professor Pickering of Harvard College, U. S., had 
 recently conceived the idea of " patrolling the heavens " 
 every fine night by means of a small photographic transit 
 instrument which would automatically sweep the meridian 
 in a series of steps of sufficient exposure to photograph 
 6th magnitude stars, at intervals corresponding to the 
 equatorial breadth of the field. The scheme was well 
 adapted for the detection of strange objects brighter than 
 6th magnitude stars, and so it resulted that Anderson's 
 star was found on 1 3 photographs taken between Decem- 
 ber 10, 1891, and January 20, 1892. As it appeared on 
 all these, which embraced stars down to the 9th magni- 
 tude, but was not to be found on the photograph of De- 
 cember 8th, the presumption is that the new star bright- 
 ened up from below the 9th magnitude between December 
 8th and December loth. After remaining at about the 
 4th or 5th magnitude till the end of February, it dimin- 
 ished somewhat rapidly in brightness, and by the end of 
 March had fallen to below the I2th magnitude. Observa- 
 tions were continued at the Lick Observatory in California 
 till April 26th, when bad weather supervened. It was 
 then of the i6th magnitude, so that it may be said to have 
 practically disappeared. In August, however, it had 
 brightened up again to above the loth magnitude, finally 
 subsiding to about the I2th magnitude. 
 
 I have dwelt somewhat fully on the so-called "tem- 
 porary " stars, because the subject is one which seems to 
 open up opportunities of scientific usefulness to the class 
 of persons under whose notice this volume is likely to fall 
 amateurs possessed of small telescopes, or with no tele- 
 scopes at all, but with many open-air opportunities of 
 becoming familiar with the aspect of the heavens. 
 
 It may have been inferred from various remarks made
 
 VARIABLE STARS. 83 
 
 in this chapter that temporary stars, and variable stars, 
 which will form the subject of the next chapter, are so 
 closely associated as almost to imply that all temporary 
 stars are merely variables of long and irregular periods. 
 There is much to support this idea, as also the correlative 
 idea that many of the -"missing" stars are also variables 
 not yet recognised to be such. But Kirkwood, an ex- 
 perienced and thoughtful American observer, considers 
 that the theory that temporary stars are long-period vari- 
 ables is unsound : that the suddenness of their apparition, 
 the short duration of their maximum brightness, and the 
 great length of their periods, if they are really periodic, are 
 reasons for regarding them as distinct in their nature from 
 the variable stars properly so-called. It is worthy of 
 notice that there is no known instance of a new star 
 appearing and remaining permanently visible. 
 
 CHAPTER XII. 
 
 VARIABLE STARS. 
 
 A LISTLESS observer of the stars will regard them as 
 always preserving their brilliancy, be it much or little, un- 
 changed, but such is not the case with all of them ; a cer- 
 tain number vary from time to time in their light, and are 
 therefore called " variable " stars. The number of those 
 of which it may be said with certainty that they undergo 
 periodical changes of brilliancy amounts to nearly 300 ; 
 but it is probable that as many again may be regarded as 
 possibly subject to fluctuations of light. In the absence 
 of absolute standards for comparison, the systematic study 
 of variable stars is a matter involving much patience on 
 the part of the observer and much refinement in his pro- 
 cedure. Were the number of observers endowed with
 
 84 THE STORY OF THE STARS. 
 
 the requisite patience and experience much increased, 
 there is no doubt that large additions would soon be made 
 to our lists of variable stars. This department of astrono- 
 my is entirely modern, for the ancients have left us merely 
 a few vague statements of stars having disappeared, and 
 we can seldom determine with adequate precision the 
 places occupied by them. 
 
 Professor Young has made some remarks on the 
 method of observation to be resorted to in the case of 
 variable stars, which it may be useful to quote here. He 
 says : " There is no better way than that of comparing 
 the star by the eye, or with the help of an opera-glass, 
 with surrounding stars of about the same brightness at 
 the time when its light is near the maximum or minimum ; 
 noting to which of them it is just equal at that moment, 
 and also those which are a shade brighter or fainter. It 
 is possible for an amateur to do really valuable work in 
 this way, by putting himself in relation with some ob- 
 servatory which is interested in the subject. The observa- 
 tions themselves require so much time that it is difficult 
 for the working force in a regular observatory to attend 
 to the matter properly, and outside assistance is heartily 
 welcomed in gathering the needed facts. The observa- 
 tions themselves are not specially difficult, require no 
 very great labour or mathematical skill in their reduc- 
 tion, and, as has been said, can be made without instru- 
 ments ; but they require patience, assiduity, and a keen 
 eye." 
 
 One of the most celebrated of the periodical stars is 
 o Ceti, otherwise known as Mira (the " wonderful " star), 
 which latter name has been given to it precisely because 
 it undergoes such remarkable changes. Its period is 
 33id. 8h. ; that is to say, it goes through its changes 12 
 times in about 1 1 years. At its maximum brightness it 
 sometimes rises to the 2nd mag., remaining thereat for
 
 VARIABLE STARS. 85 
 
 about a fortnight; it then diminishes during about 3 
 months, becomes invisible except in large telescopes for 5 
 months, and finally requires another 3 months to regain 
 its pristine maximum brilliancy. These may be taken as 
 average intervals, but it does not always diminish or increase 
 by the same gradations ; its maximum brightness is not 
 always the same, nor are the intervals of time between 
 maximum and maximum always identical. These irregu- 
 larities were studied very carefully by Argelander, who 
 came to the conclusion that the period of 33 id. of Mira 
 itself varies in about 88 of such periods, with the result 
 that the single periods gradually lengthen and shorten 
 alternately to the extent of 25 days one way or the other. 
 Moreover, it is not improbable that the irregularities in 
 the star's maximum brilliancy are also periodical, and that 
 at every nth maximum the star attains to a greater de- 
 gree of brilliancy than its usual maximum brilliancy. 
 This supposition would explain the fact that whilst the 
 naked-eye visibility of Mira generally extends to about 18 
 weeks, it was in 1859-60 so observed during 21 weeks, 
 whilst in 1868 the term was but 12 weeks. It was in this 
 year that Heis noted the maximum magnitude to be only 
 the 5th, whilst in 1888 it attained to about the 3rd mag., 
 and therefore of course remained a naked-eye object for 
 a much longer period. The discovery of the variability of 
 this star dates back as far as 1596. On August 13 of that 
 year David Fabricius noted a certain star in Cetus to be 
 of the 3rd magnitude. In the following October he failed 
 to find it. In 1603 Bayer, in preparing his " Star Atlas," 
 assigned the Greek letter o to a star in Cetus occupying 
 the spot where Fabricius's star had disappeared. He 
 noted it to be of the 4th mag., but being either ignorant 
 of, or neglectful of, the earlier observations of Fabricius, 
 he lost the chance of being able to claim the honour of 
 discovering the star's variability. The spectrum of Mira
 
 86 THE STORY OF THE STARS. 
 
 is a remarkable one of Secchi's Illrd Type, in which 
 bright lines have been seen. 
 
 Perhaps Algol (/3 Persei) may be regarded as, after 
 Mira Ceti, the second most remarkable variable in the 
 heavens, or, at any rate, in the Northern hemisphere, as it 
 is second also in point of date of discovery. The fact of 
 its variability was noticed by Montanari in 1669, was con- 
 firmed by Maraldi in 1694, and investigated half a century 
 later by a Saxon farmer named Palitzch, celebrated for his 
 early detection of Halley's Comet in 1758. But it was 
 Goodricke, in 1782, who first determined in full detail the 
 changes of brilliancy which Algol undergoes. It com- 
 monly shines as a star of mag. 2j ; from that it descends 
 to about 3|. Pickering, from photometric measures at 
 Harvard College, finds that the star's light diminishes 
 during 4-h. 23m. before minimum. When the minimum 
 is reached, then 5h. 37m. pass before the star regains its 
 normal maximum. It remains at this for about 2d. loh. 
 The most rapid changes take place during about 100 
 minutes before and 100 minutes after the epoch of mini- 
 mum. Pickering suggests that the range of variability is 
 less than is commonly stated, and does not exceed one 
 whole magnitude. The period in which the entire series 
 of changes take place is about 2d. 2oh. 48m., and is 
 thought by Chandler to have diminished by 8s. since 
 Goodricke's time ; but to talk about 8s. in such a connec- 
 tion is a refinement of precision which savours of affec- 
 tation. 
 
 Another naked-eye variable handy, by reason of its 
 position and magnitude, for observers in the Northern 
 hemisphere is 8 Cephei. Its period is 5d. 8h. 47m. count- 
 ing from minimum to minimum, and its range from about 
 mag. 3f to mag. 4|. The interval between maximum and 
 maximum is not equally divided by the minimum phase, 
 for it takes longer for the star to pass from its maxi-
 
 VARIABLE STARS. 87 
 
 mum to its minimum than it does to regain its maximum 
 after a minimum. The former transformation occupies 
 3d. I ph. but the latter only id. I4h. The variability of 
 8 Cephei was discovered by Goodricke in 1784, and the 
 whole period is put at sd. 8h. 48m. 
 
 Tj Aquilae and /3 Lyras may also be mentioned as short- 
 period variables, which on that account, and because they 
 are visible to the naked eye, are specially suitable for ob- 
 servation by amateurs in England. 
 
 rj Aquilae varies from about mag. 3$ to mag. 4f in a 
 period of about jd. 4h. I4m., but this period itself seems 
 variable. The star is yellow in colour and yields a spec- 
 trum of Secchi's Ilnd Type. 
 
 /3 Lyrae is remarkable as having a double maximum 
 and a double minimum, which together make up a main 
 period of I2d. 2ih. 47m. The variations take the follow- 
 ing form : Starting from a maximum when the star is of 
 mag. 3^, it descends to its first minimum of mag. 4 ; it 
 then rises to the same maximum as before, but in descend- 
 ing to the next minimum it goes down to mag. 4^. Arge- 
 lander ascertained that /3 Lyrae resembles Mira Ceti as 
 regards the circumstances of its period in other words, 
 that its period is itself variable; that down to 1840 the 
 period was increasing, but that after 1840 it began to de- 
 crease, and was decreasing at the time when Argelander 
 made this remark in 1866. Pickering has propounded the 
 idea that this star is a " surface of revolution " or a sphe- 
 roid in form and differently luminous in different parts, 
 and that the epoch of minimum light represents a time 
 when the darker portion at one of the ends is presented 
 to the earth. This seems to be one of those far-fetched 
 fancies which can neither be proved nor disproved. The 
 variability of /3 Lyrae was discovered by Goodricke in 
 1784. 
 
 I have reserved to the last that which is perhaps the
 
 88 THE STORY OF THE STARS. 
 
 most remarkable, as certainly it is the most erratic, of all 
 the prominent variable stars r) Argus. Unfortunately it 
 is not visible in the Northern hemisphere. Halley, on his 
 return from St. Helena, as far back as 1677, frequently ex- 
 pressed doubts as to the constancy of the light of the stars 
 in Argo. Though he seems only to have based his conclu- 
 sions upon Ptolemy's statements of star magnitudes, yet 
 these were generally so accurate that when discrepancies 
 were found to exist between modern and ancient records 
 the idea at once suggested itself that there had been actual 
 change rather than mistakes of observation. Halley, in 
 1677, rated ij Argus as of the 4th magnitude. In 1751 
 La Caille noted it as of the 2nd magnitude. In the next 
 half century it diminished, for Burchell, during his resi- 
 dence and travels in South Africa, between 1811 and 
 1815, saw it as of the 4th magnitude. Fallows, in 1822, 
 at the Cape, and SirT. M. Brisbane, between 1822 and 
 1826, in New South Wales, saw it as of the 2nd magni- 
 tude. In the following year, that is, on Feb. i, 1827, 
 Burchell, then at St. Paul's, in Brazil, saw it as of the ist 
 magnitude, and almost as bright as a Crucis ; but within 
 a year, that is, by Feb. 20, 1828, it had decreased to the 
 2nd magnitude, and as such was entered by M. J. John- 
 son and Taylor in their respective catalogues between 
 1829 and 1833. Sir John Herschel, who started observa- 
 tions at the Cape in 1834, found it then and for several 
 years afterwards to be something between mags, i and 2 
 but nearer 2. It seems to have remained stationary, or 
 nearly so, for well-nigh 3 years, but on December 16, 
 1837, on resuming work after an interval, Sir John was 
 startled to find it had become one of the very brightest 
 stars of the ist magnitude, excelling all belonging to that 
 category except Sirius and Canopus. Sir John Herschel's 
 account of it will bear quoting : " Its light was nearly 
 tripled. ... It very decidedly surpassed Procyon, which
 
 VARIABLE STARS. 89 
 
 was about the same altitude, and was far superior to AI- 
 debaran. It exceeded a Orionis, and the only star (Sirius 
 and Canopus excepted) which could at all be compared 
 with it was Rigel, which it somewhat surpassed. From 
 this time its light continued to increase. On December 
 28 it was far superior to Rigel and could only be com- 
 pared with a Centauri, which it equalled, having the ad- 
 vantage of altitude, but fell somewhat short of it as the 
 altitudes approached equality. The maximum of bright- 
 ness seems to have, been obtained [attained] about Janu- 
 ary 2, 1838, on which night both stars being high and the 
 sky clear and pure, it was judged to be very nearly 
 matched indeed with a Centauri, sometimes the one, 
 sometimes the other, being judged brighter, but on the 
 whole a was considered to have some little superiority. 
 After this the light began to fade." Sir John then goes on 
 to narrate the incidents of the declension of the star's light. 
 His own observations ceased in April, 1838, but the star 
 even then remained bright enough to be compared with Al- 
 debaran. From other sources we learn that the diminu- 
 tion of light went on for 5 years, but that even in March, 
 1843, the star's lustre continued equal to that of an ordi- 
 nary i st magnitude star. At about that time a new outburst 
 took place, and according to the observations of Mackey at 
 Calcutta, and Maclear at the Cape, 77 Argus surpassed 
 Canopus and scarcely fell short of Sirius in brilliancy. 
 This lasted more or less through 1844, when a decline in 
 its brilliancy set in. This proceeded, however, very slow- 
 ly, because in February, 1850, Lieut. Gilliss, then in Chili, 
 reported 17 Argus as being nearly as bright as Canopus 
 but of a reddish-yellow colour, somewhat darker than 
 Mars. In 1856 it was still of the ist mag., but a steady 
 decline was evidently in progress. Hence we find that in 
 1858 it was rated at mag. 2^ by Powell ; in 1860 at mag. 
 3 by Tebbutt; in 1861 at mag. 4J by Abbott; in 1863 at 
 7
 
 90 THE STORY OF THE STARS. 
 
 mag. 5 by Ellery; in 1867 at mag. 6 by Tebbutt. Dur- 
 ing the next 10 years it fell to mag. 7, and in March, 1886, 
 was rated at mag. 7^ by Finlay at the Cape of Good Hope. 
 This appears to have been the lowest point, for by May, 
 1888, the light had increased by fully half a magnitude, 
 so that apparently it is on its way towards another maxi- 
 mum, which perhaps may be expected within the first dec- 
 ade of the 2oth century. From the foregoing account it 
 is, however, clear that we do not possess sufficient infor- 
 mation to assign with any reasonable degree of accuracy 
 a period to TJ Argus, though Wolf has suggested 46 years, 
 and Loomis 67 years. Schonfeld, however, thinks that 
 the star has no regular period at all. At any rate the 
 maximum stage seems very complicated and to consist of 
 3 maxima which jointly occupy 25 years of the period 
 whatever that may be. During this sub-period, the 
 changes may perhaps be regarded as restricted to the ist 
 and 2nd magnitudes, and this sub-period may perhaps be 
 assumed to fall something like in the mid-interval between 
 every 6th or 7th magnitude minimum of the star. 
 
 17 Argus is in the field with the celebrated "Great 
 Nebula in Argo," and some remarkable circumstances 
 bearing alike on the star and on the nebula will come 
 under consideration in a later chapter in which the nebula 
 will be described. 
 
 The reader who has followed me thus far in trying to 
 pick up some ideas about the peculiarities of the stars 
 called " variable " will very likely wish now to put the 
 question, "What is a variable star?" It is impossible to 
 answer such an inquiry with any confidence. It seems, 
 however, likely that the variability of the stars which are 
 known to be variable may be due to one of two causes, 
 one of which applies to one class of star and the other to 
 another class. It is generally accepted by astronomers 
 that Algol is a type of a small number of stars which owe
 
 VARIABLE STARS. 91 
 
 their peculiarity to a cause quite different from that which 
 applies to the vast majority of these objects. The idea 
 was started by Pigott in 1783, and has met with much 
 acceptance, that the periodical fluctuations in the light of 
 Algol are due to the revolution round it of an opaque 
 satellite smaller than itself yet large enough to eclipse 
 partially the primary. With respect to the general run of 
 variables it is thought that we may draw some inferences 
 respecting them from what we know of the physical con- 
 stitution of the sun and of what happens in or upon that 
 luminary. Now we know that from time to time, and ac- 
 cording to a period which is recognised to amount to 
 about 1 1 years, dark spots of various sizes and shapes and 
 of different depths of shade break out upon the sun. The 
 solar spots which we are accustomed to see, even the very 
 largest of them, are too small relatively to the size and 
 brilliancy of the sun to cause any measurable depreciation 
 in the aggregate of the sun's light, but let us suppose it 
 were otherwise, and that every 1 1 years masses of spots 
 so extensive as to represent one-half or even one-fourth of 
 the apparent surface of the sun, burst forth, we should 
 then have the great centre of our system converted from 
 a permanently bright star into a variable star. I speak of 
 our sun as a bright star because probably it represents for 
 us on the earth neither less nor more than what Sirius or 
 other bright stars * represent to the inhabitants of other 
 worlds in far-off regions of space. If we could travel from 
 the earth a long way towards Sirius we should probably 
 find Sirius to grow into what we should without reserva- 
 tion call a sun, whilst our sun would deteriorate into what 
 we now call a star. 
 
 So much for the possible circumstances of those stars 
 which undergo periodic changes of light. But this expla- 
 
 * See p. 58 (ante).
 
 92 THE STORY OF THE STARS. 
 
 nation, even if accepted so far, does not meet the case of 
 those temporary outbursts of stellar light which we con- 
 sidered in Chapter XI. (ante). Here again, however, solar 
 history may be brought in. It is now quite recognised as 
 a fact that the red flames seen during total eclipses of the 
 sun are outbursts of glowing hydrogen gas emanating 
 from the interior of the sun ; nay, more, that such emana- 
 tions of burning hydrogen are constantly occurring on the 
 sun. Now in the case of the temporary star in Corona 
 Borealis which became visible in 1866, Huggins's observa- 
 tions tended to show that there happened in that star a 
 sudden and extraordinary outburst of glowing hydrogen, 
 which by its own light, as well perhaps as by heating up 
 the whole surface of the star, caused the unwonted in- 
 crease in its brilliancy which then took place. These 
 ideas find confirmation in other directions, but it seems 
 hardly within the design of this work to go further into 
 details of this character. 
 
 There are, however, some miscellaneous facts con- 
 nected with variable stars which are too interesting to be 
 passed over. For instance, it is an undoubted fact that 
 the vast majority of the variable stars are red or reddish 
 in colour ; and so general is this rule that whenever a new 
 star is found it is a safe presumption to start with that if 
 its colour is red it has hitherto escaped observation be- 
 cause of its being variable. Hind has noticed that vari- 
 able stars when at minimum often appear hazy or foggy, on 
 which Arago suggested the idea that the diminution of 
 brilliancy might be due to the interference of clouds. It 
 is an undoubted fact that in the case of red variable stars 
 as they diminish in brilliancy they deepen in colour, whilst 
 as their light increases their hue becomes paler. 
 
 An experienced American observer, Chandler, has 
 evolved a connection between the colours and periods of 
 variable stars. He not only subscribes to the opinion
 
 VARIABLE STARS. 93 
 
 that variable stars are generally red, but he finds that the 
 more red they are the longer their periods. Of 1 1 2 vari- 
 ables whose colours and periods are fairly well estab- 
 lished, classifying them in groups having periods of under 
 i oo days, of 100 days but under 200, and so on up to 
 over 400, he finds that whilst of those under 100 days 
 barely one-half are red, of those over 100 days three- 
 fourths are red ; whilst those over 400 days are all red. 
 His statistics arranged in another form show that whilst 
 the periods of the white and yellow stars average 125 
 days, the periods of the red stars average 288 days, and of 
 the intense red 477 days. 
 
 Espin has arrived at some curious statistics concern- 
 ing the distribution of variable stars in the heavens, and 
 also concerning their periods. He finds that they are 
 especially numerous in a zone of the heavens inclined 1 5 
 or 20 to the equator ; that this zone crosses the preced- 
 ing side of the Milky Way on the N. side of the equator, 
 and the following side of the Milky Way on the S. side of 
 the equator ; that the northern portion of the zone is not 
 many degrees broad and is clearly marked, but that the 
 southern portion is split into 2 streams of stars and that 
 the place where this occurs is near the place where the 
 Milky Way is also divided ; that hereabouts the variables 
 seem connected with the Milky Way, often occurring in 
 the gaps and constantly on the edges of the gaps, but 
 rarely in the centre of the star sprays from the Milky 
 Way ; whilst the northern stream of variable stars is 
 sharply defined by itself and seems unconuected with the 
 Milky Way. Espin adds that with one or two exceptions 
 all the temporary stars have appeared in the region where 
 the Milky Way and the variable star zone are both 
 broken into two streams ; and that stars which do not 
 belong to the above-named zone are chiefly the bright 
 and short-period variables. Espin's statistics in detail
 
 94 THE STORY OF THE STARS. 
 
 are too elaborate for embodiment in these pages in their 
 entirety, but some further general conclusions are of 
 sufficient interest and importance to be reproduced. 
 Writing in 1882 he found that the variables then known 
 readily fell into two classes : (i) those with periods of 
 less than 70 days ; and (2) those with periods of more 
 than 135 days ; there being none with periods between 71 
 and 135 days. Of the former group it might be said 
 that they were in colour white or red in tolerably even 
 numbers, and large in magnitude ; whilst the latter group 
 were mainly red and small in magnitude. 
 
 Some other conclusions which he arrived at were that 
 if the variation of. light be small in extent, or if the star be 
 bright, the period will probably be short ; on the other 
 hand, where the period ranges from 135 days up to 420 
 days the number of stars increases with the length of the 
 period ; also, that between a range of i magnitude up to 
 6 magnitudes the number of stars increases with the vari- 
 ation in magnitude. These rules seem, however, to fail 
 where the stars have periods of more than 420 days, or 
 where the range extends beyond 6 magnitudes. 
 
 The foregoing statistics are based upon only a minority 
 of the known variables, and therefore cannot yet be put 
 forward as disclosing a series of general laws. Neverthe- 
 less, they are sufficiently interesting and pronounced to de- 
 serve attention now, as well as to encourage further in- 
 quiry in the future. 
 
 The following classification of variable stars has met 
 with some acceptance in America, and therefore it may be 
 given here, but it is open to the objection that it assumes 
 that temporary stars are merely long-period variables, 
 which at present is, at the best, an assumption : 
 
 (1) Stars showing slow continuous change. 
 
 (2) Stars exhibiting irregular fluctuations of light : al-
 
 THE STARS IN POETRY. 95 
 
 ternately brightening up and becoming dim with- 
 out any apparent law. 
 
 (3) Temporary stars, which blaze out suddenly and 
 
 then disappear. 
 
 (4) Periodic stars of the type of o Ceti, usually of long 
 
 period. 
 
 (5) Periodic stars of the type of /3 Lyrae, of short 
 
 period. 
 
 (6) Periodic stars of the type of Algol, in which the 
 
 variation of light is such as would result from 
 some intervening body eclipsing the primary 
 star. 
 
 It is evident from all that has gone before that variable 
 stars form a very interesting branch of observational as- 
 tronomy. 
 
 CHAPTER XIII. 
 
 THE STARS IN POETRY. 
 
 As the previous chapter concludes what I have to say 
 respecting the stars taken individually, and the remainder 
 of this volume will be occupied with the stars in masses 
 under the designations Clusters and Nebulae, the present 
 seems a convenient point at which to withdraw the reader's 
 thoughts for a while from the technicalities of science to 
 things more light and sentimental. Hence it has occurred 
 to me to try and enliven my pages by a few citations from 
 English classical poetry a field which has been worked 
 with great assiduity, from an astronomer's standpoint, by 
 Mr. J. E. Gore.* 
 
 Shakespeare of course occupies the front rank amongst 
 the great English writers who have brought the facts of 
 
 * In his Scenery of the Heavens.
 
 96 THE STORY OF THE STARS. 
 
 science, astronomical and general, into line with their or- 
 dinary musings. Unfortunately he lived at a period when 
 the so-called science of astrology flourished side by side 
 with astronomy, and trading as it did on the credulity of 
 man it overshadowed but too successfully the sister science 
 of astronomy, if such a bracketing together of fraud and 
 humbug with true learning can be tolerated. Perhaps, 
 after all, we of the igth century must not be too hard on 
 our forefathers of the Elizabethan epoch, for figures of 
 speech implying a belief in the tenets of astrology and in 
 many other ridiculous beliefs and practices hold sway in 
 these closing years of the century, and they are not re- 
 stricted to ignorant and unlettered dwellers in remote 
 agricultural villages. 
 
 And now to Shakespeare. In Julius Ccesar (Act i., 
 scene 2) Cassius says 
 
 " Men at some times are masters of their fates ; 
 The fault, dear Brutus, is not in our stars 
 But in ourselves, that we are underlings." 
 
 The idea that the stars exercise some influence, for weal 
 or woe, over the birth of individuals was widely prevalent 
 300 years ago, and Shakespeare does no more than con- 
 form to the ideas of the times when he makes Richard III. 
 say (Act iv., scene 4) 
 
 ' ' Lo, at their births good stars were opposite ; " 
 or Jupiter, in Cymbeline, say (Act v., scene 4) 
 " Our Jovial star reign'd at his birth ; " 
 
 whilst Romeo (Act v., scene 3) speaks in the Churchyard 
 scene of shaking 
 
 " The yoke of inauspicious stars."
 
 THE STARS IN POETRY. 97 
 
 Malvolio, in Twelfth Night (Act ii., scene 5), expresses 
 the popular sentiment in words most clear 
 
 " In my stars I am above thee ; but be not afraid of great- 
 ness ; " 
 
 and then follow immediately the familiar sentiments 
 
 " Some are born great, some achieve greatness, and some have 
 greatness thrust upon them." 
 
 Particular constellations or groups of stars are occa- 
 sionally referred to by Shakespeare. Thus in Othello 
 (Act ii., scene i) the sea, stirred by the wind, is said to 
 
 " Seem to cast water on the burning Bear, 
 And quench the Guards of the ever-fixed Pole." 
 
 What idea underlies the application of the term " burning " 
 to Ursa Major does not appear. 
 
 The Pole Star receives elaborate treatment in Julius 
 Casar (Act iii., scene i). Cassar himself thus speaks 
 
 " But I am constant as the northern star, 
 Of whose true-fix'd and resting quality 
 There is no fellow in the firmament. 
 The skies are painted with unnumber'd sparks, 
 They are all fire, and every one doth shine ; 
 But there's but one in all doth hold his place." 
 
 In the letter read by Polonius {Hamlet, Act ii., scene 2) 
 we come upon an idea which is alike ancient (for Stoics 
 and Epicureans held it) and modern 
 
 " Doubt thou the stars are fire : 
 Doubt that the sun doth move." 
 
 Milton is another of our great national writers who 
 makes various allusions to celestial objects. In the Para, 
 dise Lost (Book vii.) he refers to the moon and stars
 
 98 THE STORY OF THE STARS. 
 
 "... then formed the moon 
 Globose, and every magnitude of stars, 
 And sowed with stars the heavens, thick as a field ; " 
 
 and to the Pleiades (in the same book) 
 
 "... the gray 
 
 Dawn, and the Pleiades, before him danced, 
 Shedding sweet influence." 
 
 Young's Night Thoughts is peculiarly rich in its ref- 
 erences to astronomy. Perhaps the best-known passage 
 of all is that in the " gth Night," which runs as follows : 
 
 '' Devotion ! Daughter of Astronomy, 
 An undevout Astronomer is mad. 
 True ; All Things speak a God ; but in the Small 
 Men trace out Him ; in Great He seizes Man." 
 
 In the following passage (" 8th Night ") we come upon 
 the idea already mentioned in these pages as being a sober 
 astronomical probability 
 
 " These sparks of night, these stars shall shine, 
 Unnumber'd Suns." 
 
 Again, the following passage referring to the distances of 
 the stars contains, as we have seen, true astronomical 
 teaching 
 
 " How distant some of these nocturnal Suns ! 
 So distant (says the Sage) 'twere not absurd 
 To doubt, if Beams set out at Nature's Birth, 
 Are yet arrived at this so foreign World 
 Tho' nothing half so rapid as their Flight." 
 
 Truly indeed may it be said that the stars serve the pur- 
 pose thus suggested by Young
 
 THE STARS IN POETRY. 99 
 
 " One Sun by Day, by Night ten thousand shine 
 And light us deep into the Deity." 
 
 In Byron's Childe Harold's Pilgrimage (Canto III., 
 v. Ixxxviii.) we find the following striking passage : 
 
 "Ye stars ! which are the poetry of heaven ! 
 If in your bright leaves we would read the fate 
 Of men and empires 'tis to be forgiven 
 That in our aspirations to be great, 
 Our destinies o'erleap their mortal state 
 And claim a kindred with you ; for ye are 
 A beauty and a mystery, and create 
 In us such love and reverence from afar, 
 That fortune, fame, power, life, have named themselves a 
 star." 
 
 Shelley in his Prometheus Unbound (Act iv.), speak- 
 ing of an astronomer in his observatory, says 
 
 " Heaven's utmost deep 
 Gives up her stars, and like a flock of sheep 
 They pass before his eye, are number'd, and roll on." 
 
 Moore in his Light of the Haram thus brings in the 
 Pole Star 
 
 " Whose light, among so many lights, 
 Was like that star, on starry nights 
 The seaman singles from the sky, 
 To steer his bark for ever by ! " 
 
 Elsewhere (Sacred Songs) he makes a further allusion to 
 the Pole Star 
 
 "As still to the star of its worship, though clouded, 
 The needle points faithfully o'er the dim sea."
 
 100 THE STORY OF THE STARS. 
 
 By the way, this allusion is not scientifically accurate, 
 for the compass-needle does not point to the Pole Star, 
 but to the earth's magnetic pole. 
 
 The stars naturally find a place in Thomson's Seasons. 
 He says 
 
 " Snatch me to heaven ; thy rolling wonders there, 
 World beyond world, in infinite extent, 
 Profusely scatter'd o'er the blue immense, 
 Show me : their motions, periods, and their laws, 
 Give me to scan." 
 
 Longfellow remarks 
 
 " Wondrous truths, and manifold as wondrous, 
 God hath written in those stars above." 
 
 Wordsworth, in The Excursion (Book IV.) thus 
 brings in the uses of the Pole Star 
 
 " Chaldean shepherds, ranging trackless fields, 
 Beneath the concave of unclouded skies 
 Spread like a sea, in boundless solitude 
 Looked on the polar star, as on a guide 
 And guardian of their course, that never closed 
 His steadfast eye." 
 
 And in Poems of the Imagination (Part II., xxv.) 
 
 " The stars are mansions built by Nature's hand 
 And, haply, there the spirits of the blest 
 Dwell clothed in radiance, their immortal vest." 
 
 Tennyson is very astronomical. In The Princess we 
 find 
 
 "And the shining daffodil dies, and the Charioteer 
 And starry Gemini hang like glorious crowns 
 Over Orion's grave low down in the west."
 
 GROUPS OF STARS. 101 
 
 Tennyson has a very good conception of a binary star 
 when he speaks of 
 
 " those double stars 
 Whereof the one more bright 
 Is circled by the other." 
 
 CHAPTER XIV. 
 GROUPS OF STARS. 
 
 THE thing to do in order to be able to realise to the 
 utmost the marvellous beauty of the starry heavens, is to 
 obtain an opportunity of gazing at some of those crowded 
 fields of stars bordering on the Milky Way, in which the 
 stars are so close together that though they hardly consti- 
 tute a " cluster " technically so-called, are yet so numer- 
 ous that the whole circular field of the telescope is one 
 shining mass of bright points. There is such a field, 
 favourably circumstanced for observers in England in the 
 constellation Perseus (R. A. 2h. iim. 203. Decl. + 56 38'), 
 and I would urge every reader of this book to take the 
 first opportunity open to him of viewing this in a telescope 
 of, -if possible, not less than 3 inches aperture. Doing 
 this he will, I am confident, be more inspired to dedicate 
 to astronomy some of his time, thoughts, and money, than 
 by doing anything else which I could suggest. This par- 
 ticular object is sometimes called " The Cluster in the 
 Sword Handle of Perseus." 
 
 Starting with the stars as single stars we have seen 
 that a considerable number go together in pairs; that a 
 smaller number are associated in triplets ; and so on, till 
 we come to a principal star having, it may be, half a dozen 
 companions gathered round it. The transition from such
 
 102 THE STORY OF THE STARS. 
 
 a group to what is called a "cluster," and so on to a "re- 
 solvable nebula," is a gradual one which, however, may 
 be said to come about in the nature of things almost as a 
 matter of course. The lines of demarcation between 
 these different classes of objects are naturally not very 
 pronounced, and must be laid down in a rather arbitrary 
 manner. However, I think that for our present purpose 
 we may conveniently range the celestial objects now 
 about to be described under the three following heads : 
 
 (1) Irregular groups more or less visible to the naked eye ; 
 
 (2) Clusters of stars resolvable into their constituent stars, 
 with the aid of a telescope ; (3) Nebulae for the most part 
 irresolvable with the telescopes we at present possess ; 
 either because the telescopes are deficient in the neces- 
 sary optical power, or because the objects themselves are 
 not stellar at all, but are something else gaseous or what 
 not. 
 
 Of the groups of stars which may be considered to be 
 incipient clusters there are several visible to the naked 
 eye, not counting certain true nebula? which can be de- 
 tected by the naked eye by reason of their great size. 
 Three of these clusters were noticed and recorded by the 
 ancients, namely, the " Pleiades " and " Hyades " in Tau- 
 rus, and " Praesepe " in Cancer. The Pleiades are men- 
 tioned twice in the Book of Job, and once in the prophecy 
 of Amos, and also in Homer, who likewise names the 
 Hyades. The passages in Job and Amos have already 
 been quoted.* The passage in Homer (Odyssey Lib. v. 
 ver. 270) runs thus in Pope's version : 
 
 " With beating heart Ulysses spreads his sails ; 
 Plac'd at the helm he sat, and mark'd the skies, 
 Nor clos'd in sleep his ever-watchful eyes. 
 
 * Ante, p. 40.
 
 GROUPS OF STARS. 103 
 
 There view'd the Pleiads, and the northern team, 
 And great Orion's more refulgent beam, 
 To which, around the axle of the sky 
 The bear revolving, points his golden eye." 
 
 The Pleiades were always supposed to be 7 in num- 
 ber; then one was said to have disappeared, so that 6 
 only remained. This transaction appears to be lost in 
 obscurity ; I had even said is unhistoric. Yet Ovid has 
 recorded it in the famous line : 
 
 " Quse Septem dici, sex tamen esse solent." 
 
 However, whilst ordinary eyes can, as a rule, only grasp 
 6 stars, the 7th is still there, and can be seen with the 
 slightest optical help ; whilst very good eyes can make out 
 several more. Miss Airy, indeed, has noted 12. With a 
 small telescope any number (say at least 50) may be seen, 
 and photography has recorded over 2000 stars. The 
 brightest in the group is Alcyone, otherwise rj Tauri, of 
 the 3rd magnitude ; next in order come Electra and Atlas, 
 both 3!, Maia 4, Merope 4^, Taygeta 4^ ; whilst Celeno, 
 Asterope, and Pleione are all smaller and of much the 
 same brightness, say mag. 6. Then follows a miscellane- 
 ous crowd of smaller stars. 
 
 A passing allusion must be made to certain modern 
 discoveries connected with the Pleiades, the exact import 
 of which is at present very imperfectly understood. On 
 October 19, 1859, Tempel, a German observer resident in 
 Italy, observed an object which he took to be a telescopic 
 comet. On the following evening he found it in the same 
 position, and therefore not a moving comet, but a station- 
 ary nebula. It was seen subsequently by other observers. 
 Auwers noted it to be about i in extent, but thought 
 that it might have escaped notice owing to its proximity to 
 Merope, one of the Pleiades, the bright light of which
 
 104 THE STORY OF THE STARS. 
 
 would overshadow the nebula. Schiaparelli in 1875 saw 
 the nebula very clearly, and was much surprised at its 
 
 FIG. 12. The Pleiades. 
 
 size and apparent ramifications in different directions, 
 Hind had stated that he had often suspected nebulosity 
 around some of the smaller outlying stars of the Pleiades. 
 The earlier observations of this nebula (or these nebulas)
 
 GROUPS OF STARS. 105 
 
 in the Pleiades were by no means very consistent, and the 
 idea of variability suggested itself ; some even regarded 
 the whole thing as a myth. But later researches by the 
 aid of photography have not only established the reality 
 of Tempel's discovery, but have done a good deal more ; 
 for it is now certain that no fewer than five of the chief 
 stars in the Pleiades (Pleione, Atlas, Asterope, and Tay- 
 geta being the exceptions) are involved in a mass of nebu- 
 lous matter, the extent of which was never suspected 
 until the photographic proof was obtained at Paris in 
 1885. It is satisfactory, under the circumstances, to know 
 that a general confirmation of the photograph has been 
 obtained by the direct testimony of the telescope in the 
 shape of eye-views at the Russian observatory at Pul- 
 kowa, with the gigantic refractor of 30 inches aperture 
 there in use. 
 
 The Hyades form a more open and less interesting 
 group, also in the constellation Taurus, and near Alde- 
 baran; but the stars are too scattered to make a very 
 striking field. 
 
 Praesepe in Cancer is altogether a more effective group ; 
 one, however, which should be looked at through a tele- 
 scope with a low power and large field. This object, long 
 called the " Bee-hive," appears to have been the first ob- 
 ject to which the term " nebula " was applied in bygone 
 days, its component stars not being separately distinguish- 
 able. We have it on record that Prassepe was taken 
 account of by the ancients 2000 years ago ; for both 
 Aratus and Theophrastus tell us that its dimness and dis- 
 appearance during the progressive condensation of the 
 atmosphere were regarded as the first sign of approaching 
 rain. Galileo with his baby telescope counted 36 stars. 
 To find Prassepe, carry an imaginary line from Spica 
 Virginis under Regulus in Leo, and about 22 beyond it 
 will strike Prassepe.
 
 106 THE STORY OF THE STARS. 
 
 The group of stars forming the constellation Coma 
 Berenices is cited by Webb as " a gathering of small stars 
 which obviously at a sufficient distance would become a 
 nebula to the naked eye." By the way, this constellation 
 is said to have been instituted by the astronomer Conon 
 in honour of the Queen of Ptolemy Soter, who dedicated 
 her splendid tresses to the gods to secure her husband's 
 safety in war ! 
 
 CHAPTER XV. 
 CLUSTERS OF STARS. 
 
 WE have now to consider the clusters of stars which, 
 though seemingly nebulous in very small telescopes, be- 
 come immediately resolved into individual stars on the 
 application of a very slight additional amount of optical 
 power. A select number of these are put together in the 
 Appendix for the use of those readers of this book who, 
 possessing telescopes, would wish to know whither to 
 direct them profitably. It will suffice, therefore, to allude 
 here to only a few of these clusters. 31 ip VI. Cassiopeiae 
 is a somewhat conspicuous object and readily seen with a 
 telescope of 2 inches aperture. Perhaps the best known 
 of all the so-called globular clusters is 13 M. Herculis, that 
 is to say, the I3th in Messier 's Catalogue and in the con- 
 stellation Hercules. This is commonly regarded as the 
 finest of the globular clusters. Smyth called it " an ex- 
 tensive and magnificent mass of stars with the most com- 
 pressed part densely compacted and wedged together 
 under unknown laws of aggregation." Sir J. Herschel 
 spoke of its thousands of stars and " hairy-looking curvi- 
 linear branches," which features the Earl of Rosse inter- 
 preted as indicative of a spiral tendency ; he also perceived
 
 CLUSTERS OF STARS. 107 
 
 several dark rifts in the cluster. Beautiful as it is one 
 might even say magnificent yet J. P. Nichol goes a little 
 too far in asserting that " perhaps no one ever saw it for 
 the first time through a telescope without uttering a shout 
 of wonder." 
 
 Before offering any further remarks on the larger clus- 
 ters it will be convenient to explain the word "globular," 
 
 FIG. 13. 13 M. Herculis. 
 
 and seemly to say something about the French astrono- 
 mer Messier, whose name is so closely associated with 
 these objects. "Globular," as a word, of course needs 
 no explanation, but it was first applied to star clusters, I 
 believe, by Sir W. Herschel, in order to convey to the 
 mind the idea that, when looking at them, the eye is gaz- 
 ing not on a flat background sprinkled with stars, but on 
 a veritable ball of stars. Without saying that all or even 
 any of the clusters so called are truly such, yet undoubt- 
 edly an ordinary eye will readily appreciate them as balls 
 of stars.
 
 108 THE STORY OF THE STARS. 
 
 Messier was a Frenchman who dedicated himself about 
 a century ago to the task of hunting for comets. In car- 
 rying out this work he was so far very successful that be- 
 tween 1760 and 1798 he found no fewer than 13. He 
 was, however, much bothered by constantly coming upon 
 objects in his small telescope which, whilst they looked at 
 first like comets, were only clusters and nebulae ; so in 
 1758 he thought to guard against being taken in any more 
 by forming a permanent catalogue of nebulas, including 
 clusters, by collecting together all that had been found by 
 himself, La Caille, and Mechain. This catalogue was 
 published (but whether for the first time or not I am not 
 sure) in 1784, and is alike a monument of its author's 
 shrewdness and of his industry, for it embraces, with 
 scarcely an exception, the whole of the conspicuous clus- 
 ters and nebulas visible in the latitude of Paris. 
 
 We will now resume our consideration of the clusters 
 by mentioning a few more of them. Next after the clus- 
 ter in Hercules comes perhaps 5 M. Libras, which, in the 
 words of Webb, is a " beautiful assemblage of minute 
 stars greatly compressed in the centre." Sir W. Herschel 
 with his 4O-ft. reflector made out about 200 stars, though 
 the middle of it was so compressed that it was impossible 
 to individualise the components. Smyth says that : 
 "This superb object is a noble mass, refreshing to the 
 senses after searching for faint objects, with outliers in all 
 directions and a bright central blaze." Messier, however, 
 " assured himself that it did not contain a single star," 
 but this unsound statement was the unwise result of dog- 
 matising, on the strength of a telescope 2 feet long. 
 
 80 M. Scorpii is a compressed globular cluster which 
 Messier, who found it in 1780, described as resembling 
 the nucleus of a comet ; and indeed its blazing centre and 
 attenuated disc give it a very cometary aspect. Sir W. 
 Herschel pronounced it to be the richest and most con-
 
 CLUSTERS OF STARS. 109 
 
 densed mass of stars which the firmament can offer to 
 the contemplation of astronomers, albeit that Messier had 
 
 FIG. 14. 5 M. Librae. 
 
 registered it as Ntbuleuse sans Jtozles. Near the centre of 
 this object, or, as Webb suggested, " between it and us," 
 there burst forth in 1860 a remarkable temporary star. 
 Pogson had been familiar with the cluster because two 
 variable stars, R and S Scorpii, were in the field with it, 
 and he had frequently been in the habit of viewing them. 
 On May 28, 1 860, while seeking for these variables, his at- 
 tention was arrested by the fact that a star of about the 
 7th magnitude had appeared in the place previously occu- 
 pied by the cluster. He had seen the cluster as recently 
 as May 9, and was positive that it had appeared exactly the 
 same as usual without anything stellar about it. The 
 same instrument and power had been employed on both 
 occasions. A fortnight later, that is, on June 10, using a 
 lower power, the stellar appearance had nearly vanished, 
 but the cluster still shone with unusual brilliancy and a
 
 110 THE STORY OF THE STARS. 
 
 marked central condensation. Pogson's observations were 
 fully confirmed by two German observers, E. Luther and 
 Auwers. Pogson thus summed up the circumstances of 
 this curious case : " It is therefore incontestably proved 
 upon the evidence of 3 witnesses that between May 9 and 
 June 10 [1860] the cluster known as 80 Messier changed 
 apparently from a pale cometary-looking object to a well- 
 defined star fully of the yth magnitude, and then returned 
 to its usual and original appearance. It seems to me ab- 
 surd to attribute this phenomena to actual change in the 
 
 FIG. 15. 80 M. Scorpii. 
 
 cluster itself, but it is very strange if a new variable star, 
 the 3rd in the same field of view, should be situated be- 
 tween us and the centre of the cluster." At the time 
 when this was written the incident thus narrated was 
 unique, but the more recent case of Nova Andromedas ap- 
 pears to present various analogies to the case of 80 M. 
 Scorpii in 1860. Schonfeld thought he saw some trace of 
 the star in June, 1869, but, barring this, I am not aware of 
 any further information being on record. There are many
 
 CLUSTERS OF STARS. in 
 
 other globular clusters to be met with in the heavens, 
 some which will be found referred to in the List in the 
 Appendix, but 2 more only need be mentioned here. 
 These are both in the southern hemisphere, and surpass, 
 it would seem in the matter of size and brilliancy, anything 
 visible in England. 
 
 47 Toucani was described by Sir J. Herschel as a su- 
 perb globular cluster " very visible to the naked eye and 
 one of the finest objects in the heavens. It consists of a 
 very condensed spherical mass of stars of a pale rose- 
 colour concentrically enclosed in a much less condensed 
 globe of white ones 15' or 20' in diameter." Herschel, in 
 speaking of this cluster, made the very curious and sig- 
 nificant remark that he could not remember a single ellip- 
 tical nebula which is resolvable, all the resolvable clusters 
 being more or less circular in form. He then goes on to 
 add : " Between these two characters then (ellipticity of 
 form and difficulty of resolution) there undoubtedly exists 
 some physical connection ... it deserves also to be no- 
 ticed that in very elliptic nebulas which have a spherical 
 centre (as in 65 M.) a resolvable or mottled character of- 
 ten distinguishes the central portion, while the branches 
 exhibit nothing of the kind." This was written prior to 
 the construction of Lord Rosse's great telescope, and 
 therefore it is no reflection on Sir John's accuracy to point 
 out that the " Crab Nebula " in Taurus is an exception to 
 the above rule. 
 
 Respecting the cluster surrounding 03 Centauri, Sir John 
 Herschel says that " it is visible to the naked eye as a dim, 
 round, cometic object about equal to a star of 4^ magni- 
 tude, though probably if concentrated in a single point the 
 impression on the eye would be much greater. Viewed 
 in a powerful telescope it appears as a globe of fully 20' 
 in diameter, very gradually increasing in brightness to the 
 centre, and composed of innumerable stars of the I3th
 
 112 THE STORY OF THE STARS. 
 
 and 1 5th magnitudes, the former probably being two or 
 more of the latter closely juxtaposed." 
 
 This chapter may appropriately be concluded with a 
 mention of some large clusters not specifically globular in 
 form. 67 M. Cancri is a rich but loose cluster at the root 
 of the Crab's southern claw. Smyth noted it as consist- 
 ing principally of a mass of stars of the pth and loth mag- 
 nitudes, gathered somewhat in the form of a Phrygian 
 
 FIG. 1 6. 67 M. CancrL 
 
 cap, followed by a crescent of stragglers. W. Herschel 
 saw above 200 stars at once in the field of view. This ob- 
 ject precedes a Cancri by about 2. 
 
 77 M. Ceti is a round stellar object near f in the con- 
 stellation named. It is small, bright, and exactly on a 
 line with 3 small stars, one preceding and 2 following ; of 
 which the nearest and largest is of the pth magnitude.
 
 CLUSTERS OF STARS. 
 
 Sir W. Herschel made this object a peg on which to hang 
 the following remark : " We may conclude that the pro- 
 fundity of the nearest part is at least of the 9ioth order." 
 By this Sir William meant that this object is 910 times as 
 
 S 
 
 FIG. 17. 77 M. Ccti (nebulous star). 
 
 far off as stars of the first magnitude ; but, to say the 
 least of it, this is a highly imaginative thought one of a 
 type which I think is too common and rather apt to 
 make astronomy and astronomers look ridiculous in the 
 minds of matter-of-fact people. 
 
 The cluster u M. AntinoT is an interesting cluster of 
 uncommon form. Smyth likened it to a flight of wild 
 ducks, a simile more appropriate than many of those met 
 with in astronomical writings. There is an 8th magni- 
 tude star in the middle, and two outside its limits and 
 preceding it. Smyth remarks : " By all analogy these 
 are decidedly between us and the cluster." This, how-
 
 114 THE STORY OF THE STARS. 
 
 ever was not the opinion of Kirch, its discoverer, who, in 
 1 68 1, described it as a small, obscure spot, with a star 
 shining through and rendering it more luminous. 
 
 In the field with, and adjacent to, the star K Crucis 
 there is a large and loose cluster, described by Sir John 
 Herschel as one of the most beautiful objects of its class. 
 It comprises more than 100 stars from the yth magnitude 
 downwards, 8 of the more conspicuous of them being 
 coloured various shades of red, green, and blue. This 
 object was very carefully surveyed in 1872 by Russell at 
 Sydney, who remarked that many of the stars had drifted 
 (presumably in consequence of proper motion) in the 40 
 years which had elapsed since Sir John's drawing was 
 made. Russell adds : " The colours of this cluster are 
 very beautiful, and fully justify Herschel's remark that it 
 looks like a ' superb piece of fancy jewellery.' " 
 
 CHAPTER XVI. 
 
 NEBULA. 
 
 IN the present chapter we shall consider the Nebulas 
 commonly so called those celestial objects of very diverse 
 sizes, shapes, and brilliancy, of which many or most are 
 probably stellar in their constitution, though some of 
 them, however, may be not such but gaseous. At the 
 outset I will deal with them merely descriptively. Mes- 
 sier's catalogue, to which such frequent allusions have 
 been made, embracing as it did only those larger and 
 brighter objects which were within reach of a mere hand 
 telescope, does in no way indicate the present state of our 
 knowledge respecting the nebulae. The bulk of the ob- 
 jects enrolled by Messier eventually proved to be resolvable 
 star clusters, though a residue were veritable nebulae^
 
 NEBULA. 115 
 
 faint, misty objects, many of them not unlike specks of 
 luminous fog. Of these nebulae some have yielded to the 
 larger telescopes of modem days, and have proved to be 
 masses of stars too closely aggregated together to be re- 
 solved by the puny telescopes which only were available a 
 century or more ago. Since Messier's days, and as a re- 
 sult of so many large telescopes having been set to work 
 during the second half of the nineteenth century, the num- 
 ber of observed nebulas has become so great that upwards 
 of 8000 are now on record. By far the greater number of 
 these are, however, irresolvable, and therefore it is an 
 open question what they are. 
 
 The nebulae generally may be conveniently classified 
 under six general heads, it being understood of course 
 that this classification only has regard to form or size : 
 (i) Annular nebulas; (2) elliptic nebulas ; (3) spiral nebu- 
 las ; (4) planetary nebulae ; (5) nebulous stars ; (6) large 
 nebulas of irregular form. 
 
 The annular nebulas hitherto recognised scarcely num- 
 ber a dozen, and of these one only is large or bright 
 enough to have obtained much notoriety. This is Mes- 
 sier's 57th in the constellation Lyra. If it be realised that 
 the word " annular " is derived from the Latin word an- 
 nulus, a ring, a ready clue will be had as to the general 
 form of these bodies. The annexed engraving indicates 
 it, but only that simple conception which is obtainable by 
 means of a moderate-sized telescope say an instrument 
 of 4 inches aperture. With instruments of much larger 
 size the individuality of the ring disappears, and the cen- 
 tral space, black or nearly so in a small telescope, shows 
 evident indications of nebulous matter, which Lord Rosse 
 found to be distributed, not uniformly, but in streaks ; 
 whilst the external edge of the ring was broken by pro- 
 jections of various sizes and shapes. All these particulars 
 will be better understood from a picture than from any
 
 116 THE STORY OF THE STARS. 
 
 written description. There is considerable conflict of 
 opinion as to the ultimate account which ought to be ren- 
 dered of this object when the largest available telescopes 
 
 FIG. 18. The ring nebula in FIG. 19. The ring nebula in 
 
 Lyra. (SirJ.Herschel.) Lyra. (Earl o 
 
 are brought to bear upon it ; Rosse, Chacornac, and 
 Secchi all claimed to have resolved it into stars. Hug- 
 gins, on the other hand, insists that it is merely a mass of 
 glowing gas. The Lick observers find its structure to be 
 very complex, but seem unwilling to commit themselves 
 to a very definite opinion on the subject. At the same 
 time they make mention of the existence of, and describe 
 the position of, numerous individual stars. 
 
 Elliptic nebulas of various degrees of eccentricity, from 
 a common oval to a long streak, are met with in various 
 parts of the heavens. As a rule they are very bright, and 
 several of them are remarkable as having double stars at 
 or near each of their foci. There is one elliptic nebula 
 which stands out beyond all the rest, yet its great size, 
 brilliancy, and peculiar features forbid its being regarded 
 as a typical elliptic nebulae. I am here alluding to the 
 " Great Nebulae in Andromeda," Messier's 3ist. Its ellip- 
 ticity is considerable ; it is likewise very long, and has a 
 bright central condensation which renders it readily dis-
 
 NEBULAE. 117 
 
 coverable by the naked eye on a clear night not far from 
 the star rj Andromeda of magnitude. 4$-. Sir John Her- 
 schel's drawing is well known, having obtained wide cir- 
 culation through his own and other people's books. G. 
 P. Bond was the first to improve upon it, which he did 
 when he published, more than 40 years ago, an engraving 
 exhibiting much more internal detail than Herschel had 
 shown. In particular two curious black streaks or longi- 
 tudinal vacuities, which run nearly parallel to the major 
 axis of the oval on the south side. Bond traced the neb- 
 ula to a length of 4 and a breadth of 2^. 
 
 Roberts (see Frontispiece) has carried the matter still 
 further than Bond had done, for he finds traces of a dark 
 ring separating the central parts of the nebula from an 
 outer brighter portion, the whole yield- 
 ing traces of what may indicate a 
 spiral structure. No telescope has 
 yet resolved this object distinctly into 
 stars, though several hundred stars 
 have been counted within its limits. 
 This object is, however, probably 
 stellar, and may one day be proved to 
 be such; certain is it that it is not FIG. 20. The neb- 
 gaseous. The other extreme of ellip- ^ is 43 # L vir ' 
 tic nebula is illustrated in Fig. 20, 
 which represents 43 jp I. Virginis, a long, narrow wisp 
 of luminous matter with a slight condensation in the 
 centre. 
 
 " Spiral," or, as they are sometimes called, " Whirl- 
 pool " nebulae first had that special feature of them brought 
 out by the late Earl of Rosse. The best known is Mes- 
 sier's 5 1st in the constellation Canes Venatici. To Sir J. 
 Herschel it presented the appearance of a bright globular 
 cluster encompassed at some distance by a bright nebu- 
 lous ring, which varied very much in brightness in its
 
 n8 
 
 THE STORY OF THE STARS. 
 
 different parts. It seemed as if it was split through for 
 about fths of its circumference into 2 laminae, one of 
 which gave the impression that it was turned up towards 
 the eye, out of the general plane. Sir John saw, seem- 
 
 FIG. 21. The spiral nebula 51 M. Canum Venaticorum. 
 (SirJ. Herschel.) 
 
 tngly detached from the main object, a small, bright, 
 round nebula. Lord Rosse's telescope entirely altered 
 the aspect of the whole group. The ring was found to 
 pass into a distinct spiral coil of nebulous matter, and the 
 outlying portion to be connected with the main mass by
 
 NEBULA. 
 
 a curved band, the whole showing indications of resolvabil- 
 ity into stars. No ordinary telescope affords even suspicion 
 of these details. The spectrum appears to be non-gaseous. 
 " Planetary " nebulae are objects first so designated by 
 Sir W. Herschel because they exhibited a fairly well defined 
 outline as of a disc, circular or slightly oval. The most 
 
 FIG. 22. The spiral nebula 51 M. Canum Venaticorum. (Earl o/Rosse.) 
 
 striking of these is Messier's p7th in Ursa Major, 2 south 
 and following the star /3. It has been described as " a 
 very singular object, circular and uniform, and after a long 
 inspection looks like a condensed mass of attenuated light." 
 It has a diameter of 2' 40". The late Earl of Rosse de- 
 tected perforations and a spiral tendency in it. He found
 
 120 THE STORY OF THE STARS. 
 
 a star in about the centre of each main perforation and 
 called it the " Owl " nebula, from its appearance. One of 
 the stars seems to have disap- 
 peared since 1850, or, as a 
 thoughtful writer suggests, the 
 owl has closed one of his eyes ! 
 Huggins has found the spec- 
 trum gaseous. 
 
 The planetary nebulas are 
 not very numerous and not very 
 bright, which is a matter for re- 
 gret, because it would seem that 
 FlG< 23 i7ura jypalor.' nebula thev possess interesting features 
 entitling them to the special at- 
 tention of astronomers but needing large telescopes. For 
 instance, there is one in the constellation Draco, No. 
 37 in Sir W. Herschel's IVth class, which, according 
 to Professor Holden, who has studied it with the Lick 
 telescope, possesses an extraordinary structure. He says 
 that it " is apparently composed of rings overlying each 
 other, and it is difficult to resist the conviction that these 
 are arranged in space in the form of a true helix." At 
 the first glance the nebula appears to Holden to consist 
 of 2 circles which intersect, a central star being within 
 the area, resulting from the intersection of the 2 circles. 
 At the S. point of intersection the brightness is ap- 
 proximately twice the average brightness of the circum- 
 ference ; at the N. point it is less bright relatively. A 
 little attention, however, seems to show that these rings 
 are so arranged that one complete ring lies on the upper 
 or hither side (nearer the eye) of the other complete ring 
 which is undermost or farther from the eye. There is 
 another peculiar feature. The nebula itself is unmistak- 
 ably blue in colour, whilst the star is yellowish-red. Star 
 and nebula yield different spectra, and require for accu-
 
 NEBULA. 121 
 
 rate definition the telescope to be brought to a different 
 focus according as it is desired to obtain a good image 
 of the one or the other. All these facts point to remark- 
 able intrinsic peculiarities in this object. Holden finds 
 the nebula I ip IV. Aquarii to possess some analogies 
 with the nebula in Draco just described. 
 
 Before passing away from the planetary nebulas some 
 further peculiarities appertaining to them deserve a pass- 
 ing notice. According to the spectroscope, they are most- 
 ly gaseous, and several are noticeably bluish in hue. 
 Three-fourths of them are in the southern hemisphere, 
 and the greater number are in, or very close to, the Milky 
 Way. 
 
 " Nebulous stars," according to their name, are ordi- 
 nary stars with a faint nebulosity surrounding them ; but 
 the term does not seem altogether a happy one. Hind 
 remarks that the nebulosity is in some cases well defined, 
 but in other cases is quite the reverse ; that " the stars 
 thus attended have nothing in their appearance to dis- 
 tinguish them from others entirely destitute of such ap- 
 pendages ; nor does the nebulous matter in which they 
 are situated offer the slightest indication of resolvability 
 into stars with any telescopes hitherto constructed." 
 
 Perhaps the most striking nebulous star is No. 45 in 
 Sir W. Herschel's IVth class, in the constellation Gemini. 
 Sir John Herschel speaks of it as an 8th magnitude star 
 which lies "exactly in the centre of an exactly round, 
 bright atmosphere 25" in diameter." Key described it as 
 " a bright but somewhat nebulous star closely surrounded 
 by a dark ring ; this again by a luminous ring ; then an 
 interval much less luminous, and, finally, at some distance 
 an exterior luminous ring." This description accords well 
 with the late Earl of Rosse's. 
 
 The brightest nebulous star certainly recognised as 
 such appears to be i Orionis, a triple star of mag. 3^. 
 9
 
 122 THE STORY OF THE STARS. 
 
 f Orionis, of mag. i\, is often spoken of as a star sur- 
 rounded by a nebulosity, but the evidence is very contra- 
 dictory, and inclines on the whole to the negative. 
 
 The last class of nebulae remaining to be described 
 are some of very diverse size and shape, which cannot be 
 brought under any general denomination. 
 
 The " Crab nebula " in Taurus bears a popular and 
 familiar designation, but it does not seem to rest on a 
 very satisfactory foundation. In all ordinary telescopes 
 this object exhibits a simple oval outline, but the special 
 title was based on the late Lord Rosse's early description 
 of it, which Sir John Herschel thought justified by the 
 facts, though the later Parsonstown observations seem to 
 negative the claw features. It was the discovery of this 
 object in 1758, when he was following a comet, which led 
 Messier to form his well-known catalogue of nebulae. 
 
 All things considered, it seems probable that the 
 " Great Nebula in Orion " must be regarded as the 
 grandest and most interesting of all the nebulae. I have 
 in a previous chapter mentioned it in connection with the 
 multiple star 6 Orionis, which it surrounds ; and the dia- 
 gram already given, rough though it is, affords an idea of 
 the prominent feature of the nebula which presents itself 
 in every small telescope, namely, the " Fish's mouth." 
 Sir John Herschel's general description, written a great 
 many years ago, still in the main holds good, though 
 modern observations, when 'made with the large tele- 
 scopes of the present day, bring out many features not 
 recognised half a century ago ; and in particular exhibit 
 very distinctly what may be called the flocculent charac- 
 ter or structure of the nebula. 
 
 Sir John Herschel's account runs as follows : " In its 
 more prominent details may be traced some slight resem- 
 blance to the wings of a bird. In the brightest portion 
 are four conspicuous stars, forming a trapezium. The
 
 NEBULAE. 123 
 
 nebulosity in the immediate vicinity of these stars is floc- 
 culent and of a greenish-white tinge ; about half a degree 
 northward of the trapezium are 2 stars involved in a 
 branching nebula of singular form, and southward is the 
 star t Orionis, also situated in a nebula. Careful exam- 
 ination with powerful telescopes has traced out a contU 
 nuity of nebulous light between the great nebula and both 
 these objects, and there can be but little doubt that the 
 nebulous region extends northwards as far as in e the belt 
 of Orion, which is involved in a strong nebulosity, as well 
 as several smaller stars in the immediate neighbourhood." 
 
 Secchi thought that this nebula must be considered as 
 extending far beyond the limits usually assigned to it, and 
 that there exist in various directions, and remote from the 
 principal centre, scattered fragments of nebulous matter 
 which all really belong to the main mass. He ascribed to 
 the whole, speaking roughly, a triangular outline with a 
 base of 4 and a height of about 5J, reaching downwards 
 from in Apex (with a break, however, at <r) almost as 
 far as . Photographic and spectroscopic observations 
 have been carried out on a considerable scale of late years. 
 The latter are thought to indicate that the nebula consists 
 of incandescent hydrogen gas. The multiplication of pho- 
 tographs spread over a term of years may lead to a better 
 understanding of the circumstances and conditions of this 
 nebula than is at present possible. The existing drawings 
 of it, extending over nearly a century, are so much want- 
 ing in consistency one with another as to have led many 
 persons to surmise that it has undergone distinct change, 
 but the evidence to support this theory falls far short of 
 what is necessary to sustain such a suggestion. 
 
 30 Doradus is a nebula in the Southern hemisphere 
 which, from Sir John Herschel's description and engraving 
 of it, must be a very remarkable object. Sir John speaks 
 of it as " one of the most singular and extraordinary ob-
 
 124 THE STORY OF THE STARS. 
 
 jects which the heavens present." Strange to say, he 
 does not describe it in detail, contenting himself by saying 
 that the engraving (in his Outlines of Astronomy) is so 
 satisfactory as to render further description superfluous. 
 The special feature of this nebula is the wonderful series 
 of convolutions which it exhibits masses of nebulous 
 matter twisted in and out in singular fashion with num- 
 berless black, or more or less starless, interstices. 
 
 Another Southern nebula not entirely unlike the fore- 
 going is that surrounding the strange variable star j Ar- 
 gus already described. Sir John Herschel's account of it, 
 penned at the Cape of Good Hope some 60 years ago, 
 runs as follows: "Viewed with an 1 8-inch reflector, no 
 part of this strange object shows any sign of resolution 
 into stars, nor in the brightest and most condensed por- 
 tion, adjacent to the singular oval vacancy in the middle 
 of the figure, is there any of that curdled appearance, or 
 that tendency to break up into bright knots with interven- 
 ing darker portions, which characterise the nebula of 
 Orion, and indicate its resolvability. ... It is not easy for 
 language to convey a full impression of the beauty and 
 sublimity of the spectacle which this nebula offers, as it 
 enters the field of the telescope (fixed in R. A.) by the 
 diurnal motion, ushered in as it is by so glorious and in- 
 numerable a procession of stars, to which it forms a sort 
 of climax." 
 
 Some mystery hangs over this nebula and its central 
 star. Much excitement was caused in 1863 by the publi- 
 cation of an announcement by Abbott, of Hobart Town, 
 Tasmania, that, whereas Sir John Herschel had noticed 
 near the centre of the nebula a lenticular sort of space de- 
 void of stars, ?; being some distance from this void and 
 closely encompassed by nebulous matter, the void space 
 had altered in form, and the star (which had dwindled 
 down to the 6th mag.) no longer had nebulous matter
 
 NEBULA. 125 
 
 close up to it. These assertions, indicative, if true, of ma- 
 terial changes in the appearance of the nebulas having 
 taken place between 1883 and 1863, were reviewed by 
 Captain J. Herschel, in India, and Dr. B. A. Gould, in 
 South America, and others, and the general verdict was 
 that the allegations of Abbott were unfounded, and that 
 Sir John Herschel's drawing of 1833 continued in 1882 to 
 represent the details of the nebula as they were to be seen 
 at the later date. 
 
 The constellation Sagittarius contains 2 large nebulous 
 masses of considerable interest at no great distance from 
 each other. 20 M. Sagittarii is the chief member of an 
 important group respecting which Sir John Herschel 
 writes as follows : " One of them is singularly trifid, con- 
 sisting of 3 bright and irregularly formed nebulous masses, 
 graduating away insensibly externally, but coming up to a 
 great intensity of light at their anterior edges, where they 
 enclose and surround a sort of three-forked rift or vacant 
 area, abruptly and uncouthly crooked, and quite void of 
 nebulous light. A beautiful triple star is situated precisely 
 on the edge of one of these nebulous masses, just where 
 the interior vacancy forks out into two channels." 
 
 8 M. Sagittarii, not far from the last named, is another 
 remarkable object, perceptible to the naked eye, and show- 
 ing effectively, even in a telescope as small as a 3-inch. 
 Sir John Herschel thus speaks of it : " A collection of 
 nebulous folds and masses, surrounding and including a 
 number of oval dark vacancies, and in one place coming 
 up to so great a degree of brightness as to offer the ap- 
 pearance of an elongated nucleus. Superposed upon this 
 nebula, and extending in one direction beyond its area, is 
 a fine and rich cluster of scattered stars, which seem to 
 have no connection with it as the nebula does not, as in 
 the region of Orion, show any tendency to congregate 
 about the stars."
 
 126 THE STORY OF THE STARS. 
 
 The small constellation Scutum Sobieskii contains a 
 rather famous object sometimes (but not very judiciously) 
 
 FIG. 24. The " Omega" nebula in Scutum Sobieskii. 
 
 called the " Horse-shoe " nebula, or by others (and with 
 more propriety) the " Omega " nebula. From the engrav- 
 ing annexed it will be seen that, as regards at any rate a 
 small telescope, the idea conveyed is more that of a swan 
 as seen floating on the surface of water. As in the case 
 of 77 Argus, allegations have been made, and apparently 
 with better foundation in this case, that important changes 
 have taken place in the appearance of this nebula since the 
 first drawings of it were made. Weighty names are at- 
 tached to these conclusions, and Holden, who has investi- 
 gated with much care and detail its history, as recorded 
 between 1833 and 1875, concludes that " the ' Horse-shoe ' 
 has moved with reference to the stars," and that therefore 
 " we have evidences of a change going on in the nebula. 
 This may be a veritable change in the structure of the neb- 
 ula itself, such as was suspected by Schroter, confirmed 
 by O. Stuve, and again confirmed by myself in the nebula
 
 NEBULA. 127 
 
 of Orion ; or it may be the bodily shifting of the whole 
 nebula in space." 
 
 The " Dumb-bell " Nebula (27 M. Vulpeculae) is too 
 well known to need a lengthened description in this place. 
 The records of its appearance during more than a century 
 past, as telescopes of successively increasing power have 
 been brought to bear on it, constitute a weighty warn- 
 ing to those who, on the strength of seeming discrepancies 
 in verbal descriptions and drawings, choose to infer that 
 absolute changes have taken place in the appearance or 
 circumstances of celestial objects. It is not too much to 
 say that whilst the designation " Dumb-bell " is fairly ap- 
 propriate in describing this object as seen in telescopes 
 up to 6 or 8 or more inches of aperture, yet this feature 
 becomes inappreciable altogether in the giant telescopes 
 of the present day, which run to 20, or 30, or 40 inches of 
 aperture. Roberts's photograph of this object is visually 
 almost irreconcilable with the older drawings, in which 
 the " Dumb-bell " idea is the dominant one. 
 
 The Southern hemisphere contains two objects which 
 must not be passed over in treating of nebulas. These 
 are the " Magellanic Clouds," or the " Nubecula Major " 
 and " Nubecula Minor " both of them terms recalling the 
 cloudlike appearance of these objects, the words " major " 
 and " minor " relating of course to their size. Both are 
 at no great distance from the Pole, the " Greater Cloud " 
 being in the constellation Dorado, and the " Lesser 
 Cloud " in Toucan. They are of a somewhat oval shape 
 and visible to the naked eye, but the smaller one disap- 
 pears in strong moonlight. Sir John Herschel describes 
 them as consisting of swarms of stars, clusters, and 
 nebulae. 
 
 The distribution of the nebulae in the heavens is a sub- 
 ject which has attracted the attention of many astrono- 
 mers who have had theories to advance respecting such
 
 128 THE STORY OF THE STARS. 
 
 topics, or who have written on the constitution of the 
 Universe. But I do not know that it can be said that 
 very much light has been thrown upon the questions of 
 this character which have presented themselves for solu- 
 tion. One thing is very noteworthy, and no doubt is sig- 
 nificant, but we do not know of what it is significant. The 
 distribution of the nebulae over the heavens is extremely 
 unequal. They congregate in a zone which crosses the 
 Milky Way at right angles. The majority are to be 
 found in a zone which scarcely embraces an eighth part 
 t of the heavens. The constellation Virgo is where they 
 are gathered together in greatest number, and they abound 
 also in the neighbouring constellations of Leo, Ursa 
 Major, Camelopardus, Draco, Bootes, Coma Berenices, 
 and Canes Venatici. In the part of the heavens almost 
 exactly opposite to these constellations that is to say, in 
 Pegasus, Andromeda, and Pisces they are also numer- 
 ous. The inequality in the distribution of the nebulae 
 will perhaps be best brought home to the reader by con- 
 sidering how they are distributed in hours of Right As- 
 cension. Of the 5079 clusters and nebulas entered in Sir 
 John Herschel's Catalogue of 1864 whilst the XlXth and 
 XXth hours contain only 79 and 90 objects respectively, 
 the Xlth hour contains 421 and the Xllth 686. The 
 last-named hour is that which embraces a large part of 
 Virgo. The regions of the heavens which lie nearest to 
 the Milky Way are the poorest in nebulae, while they 
 are most abundant around the Poles of that great and 
 mysterious belt. In the Southern hemisphere the nebulas 
 are more uniformly spread over the zone which surrounds 
 the South Pole. On the other hand, their aggregate num- 
 ber is smaller; nevertheless there are 2 magnificent re- 
 gions there which alone contain nearly 400 nebulae and 
 star clusters. 
 
 It is a remarkable fact that almost all the nebulae in-
 
 THE MILKY WAY. 129 
 
 dicated by the spectroscope to be gaseous are situated 
 either within the Milky Way or closely adjacent thereto ; 
 whilst in the regions near the poles of the Milky Way 
 gaseous nebulae are wanting, though other nebulas are 
 abundant. 
 
 The reader will remember what has already been said 
 respecting the alleged variability of great nebula in Orion, 
 of the nebula surrounding rj Argus, and of the " Omega " 
 nebula in Vulpecula. Subject to the remarks already 
 made in dealing with those 3 nebulas, it is to be consid- 
 ered that, though there are such things as variable stars, 
 no variable nebulas are known to exist. 
 
 CHAPTER XVII. 
 
 THE MILKY WAY. 
 
 THOUGH when one gazes at the Milky Way there is, 
 in a certain sense, not much to see (or at least not much 
 which one can realise), yet an attentive consideration of it 
 with the assistance of a telescope brings to light a vast 
 variety of details of the highest interest. How it pre- 
 sented itself to our English forefathers is sufficiently 
 shown by Milton's well-known description of it (Paradise 
 Lost, bk. vii. v. 577-81) as 
 
 " A broad and ample road, whose dust is gold 
 And pavement stars, as stars to thee appear, 
 Seen in the Galaxy, that Milky Way 
 Which nightly, as a circling zone, thou seest, 
 Powdered with stars." 
 
 From the foregoing it will appear that Wordsworth 
 was not displaying his own original genius when (in Dion) 
 he spoke of
 
 130 THE STORY OF THE STARS. 
 
 " Heaven's broad causeway paved with stars." 
 
 Perhaps before I recount any further speculations of 
 this character we had better consider the Milky Way de- 
 scriptively. So far as I know the only astronomer who 
 has written on it, and been able to do so from personal 
 study of it in both hemispheres of the earth, is Sir John 
 Herschel. It is obvious that no description of such an 
 object can be adequately framed merely by the colloca- 
 tion of accounts prepared piecemeal, but that there is re- 
 quired the pen of a man who has taken notes of it at first 
 hand round its entire circumference. I make no apology, 
 therefore, for borrowing, in a simplified and condensed 
 form, Sir John Herschel's description of the Milky Way. 
 
 Following the line of its greatest brightness, as well as 
 its varying breadth permits, its course conforms as nearly 
 as may be to that of a great circle inclined about 63 to 
 the equinoctial, and cutting that circle in R. A. 6h. 47m., 
 and i8h. 47m., so that its poles are in R. A. I2h. 47m., 
 Decl. N. 27 and R.A. oh. 47., Decl. S. 27. Through- 
 out the region where it is sub -divided this great circle 
 runs as it were in between the 2 great streams of galaxy 
 matter, with a nearer approximation, however, to the 
 brighter and continuous stream. If we trace the Milky 
 Way in the order of R. A., we find it traversing Cassi- 
 opeia, its brighter part passing about 2 to the North of 
 8. Passing thence between y and e it sends off a branch, 
 southwards and preceding, towards a Persei, conspicuous 
 as far as that star, prolonged faintly towards e Persei, and 
 possibly traceable towards the Hyades and Pleiades. The 
 main stream, however (which is here very faint), passes 
 on through Auriga over t, (, rj, preceding Capella, between 
 the feet of Gemini and the horns of Taurus (where it in- 
 tersects the ecliptic nearly in the solstitial colure), and 
 thence over the club of Orion to the neck of Monoceros,
 
 THE MILKY WAY. 131 
 
 intersecting the equinoctial in R.A. 6h. 54m. Up to this 
 point, from the offshoot in Perseus, its light is feeble, but 
 thenceforward it gradually brightens up, and from the 
 shoulder of Monoceros and over the head of Canis Major 
 it presents a broad, moderately bright, very uniform and, 
 to the naked eye, starless stream up to the point where it 
 enters the prow of Argo nearly on the Southern Tropic. 
 Here it again subdivides (about the star m Puppis), send- 
 ing off a narrow and winding branch on the preceding 
 side as far as y Argus, where it abruptly terminates. 
 
 The main stream pursues its southward course to the 
 33rd parallel of South Declination, where it diffuses itself 
 broadly and again subdivides, opening out into a wide 
 fan-like expanse, nearly 20 in breadth, formed of inter- 
 lacing branches, all of which terminate abruptly, in a line 
 drawn nearly through X and y Argus. 
 
 Here the continuity of the Milky Way is interrupted 
 by a wide gap, and where it recommences on the oppo- 
 site side it is by a somewhat similar fan-shaped assem- 
 blage of branches which converge upon rj Argus. Thence 
 it crosses the hind feet of the Centaur, forming a curious 
 and sharply defined semicircular cavity, and enters the 
 Cross by a bright isthmus not more than 3 or 4 wide 
 this is the narrowest portion of the Milky Way. After 
 this it immediately expands into a bright mass, enclosing 
 a and $ Crucis and Centauri, extending almost up to 
 a Centauri. In the midst of this bright mass, and occu- 
 pying about ^ its breadth, occurs a singular dark pear- 
 shaped vacancy about 8 long and 5 broad, very con- 
 spicuous, and for several centuries past called the " Coal- 
 sack " a name given to it by the early navigators. In 
 this vacancy there is only one very small naked-eye star, 
 though there are telescopic stars. The striking blackness 
 is the effect of contrast with mass of bright matter by 
 which the black area is surrounded. This is the place of
 
 132 THE STORY OF THE STARS. 
 
 the nearest approach of the Milky Way to the South 
 Pole. Throughout all this region its brightness is very 
 striking, and when compared with the more Northern 
 portion, the course of which has been already traced, con- 
 veys strongly the idea of greater proximity, and would 
 almost lead to a belief that our situation as spectators is 
 separated on all sides by a considerable interval from the 
 dense body of stars composing the Galaxy, which in this 
 view would have to be considered as a flat ring of im- 
 mense and irregular breadth and thickness within which 
 we are eccentrically situated, nearer to the Southern than 
 to the Northern part of its circuit. 
 
 At a Centauri the Milky Way again subdivides, send- 
 ing off a great branch of nearly half its breadth, but 
 which thins off rapidly, at an angle of 20 with its gen- 
 eral direction, towards the preceding side to ij and d Lupi, 
 beyond which it loses itself in a narrow and faint stream- 
 let. The main stream passes on, increasing in breadth, 
 to y Normae, where it makes an abrupt elbow and again 
 subdivides into one principal and continuous stream of 
 very irregular breadth and brightness on the following 
 side, and a complicated system of interlaced streaks and 
 masses on the preceding, which covers the tail of Scorpio, 
 and terminates in a vast and faint effusion over the whole 
 extensive region occupied by the preceding leg of Ophiu- 
 chus, extending northwards to a parallel of 1 3 of South 
 Declination, beyond which it cannot be traced, a wide in- 
 terval of 14 free from all appearance of nebulous light 
 separating it from the great branch on the North side of 
 the equinoctial of which it is usually represented as a con- 
 tinuation. 
 
 Returning to the point of separation of this great 
 branch from the main stream at a Centauri, let us now 
 pursue the course of the latter. Making an abrupt bend 
 to the following side it passes over t Aras, 6 and i Scorpii,
 
 THE MILKY WAY. 
 
 133 
 
 and y Telescopii to y Sagittarii, where it suddenly collects 
 into a vivid oval mass about 6 in length and 4 in breadth, 
 so excessively rich in stars that a very moderate calcula- 
 tion makes their number exceed 100,000. Northward of 
 this mass this stream crosses the ecliptic in longitude 
 about 276, and proceeding along the bow of Sagittarius 
 into Antinoiis, has its course rippled by 3 deep concavi- 
 ties separated from each other by remarkable protuber- 
 ances, of which the larger and brighter (situated between 
 the stars 3 and 6 Aquilae) forms the most conspicuous 
 patch in the Southern portion of the Milky Way visible in 
 English latitudes. 
 
 Crossing the equinoctial at the XlXth hour of R. A. 
 it runs in an irregular, patchy, and winding stream through 
 Aquila, Sagitta, and Vulpecula up to Cygnus. At e Cygni 
 its continuity is interrupted, and a very confused and 
 irregular region commences, marked by a broad, dark 
 vacuity not unlike the " Coal-sack " of the Southern hemi- 
 sphere, occupying the space between , a and y Cygni, 
 which serves as a kind of centre from which 3 great 
 streams diverge. Of these streams one has been already 
 traced ; a second, which is a continuation of the first 
 (across the interval) from a Cygni northwards, between 
 Lacerta and the head of Cepheus to the point in Cassio- 
 peia, whence we set out ; and a third branching off from 
 y Cygni, very vivid and conspicuous, running off in a 
 southerly direction through /3 Cygni and s Aquilae, almost 
 to the equinoctial, where it loses itself in a region thinly 
 sprinkled with stars, where in some maps the modern 
 constellation Taurus Poniatowskii is placed. This is the 
 branch which, if continued across the equinoctial, might 
 be supposed to unite with the great southern effusion in 
 Ophiuchus already noticed. A considerable offshoot or 
 protuberant appendage is also thrown off by the northern 
 stream from the head of Cepheus directly towards the
 
 134 THE STORY OF THE STARS. 
 
 Pole occupying the greater part of the trapezium formed 
 by a, |3, i and 8 of that constellation. 
 
 In connection with the Milky Way a large amount of 
 speculation has been indulged in, but as Gore well re- 
 marks : " Many attempts have been made to form a sat- 
 isfactory theory of the construction of the Milky Way, but 
 these efforts have been hitherto attended with but little suc- 
 cess. This is not surprising, as the problem is evidently 
 one of great difficulty." Thomas Wright, of Durham, was 
 the first modern speculator. He started, about 1734, a 
 theory which, in a more matured form and worked out 
 with better materials, was put forward by Sir W. Herschel 
 about 1784 and became widely known as the " Stratum 
 theory " of the Milky Way, or, as some have called it, the 
 " Cloven disc theory." Briefly, his idea was that the stars 
 were not indifferently scattered through the heavens, but 
 were rather arranged in a certain definite stratum, com- 
 prised between 2 plane surfaces parallel to and near each 
 other but prolonged to immense distances in every direc- 
 tion, the thickness of which stratum, as compared with 
 its length and breadth, was inconsiderable ; and that the 
 Sun occupies a place somewhere about the middle of its 
 thickness, and near the point where it subdivides into 2 
 principal streams inclined to each other at a small angle. 
 This theory is not accepted in the present day,* and other 
 theories have been put forth. Proctor, whose strong 
 point was running down his rivals, suggested that the 
 form of the Milky Way was that of a spiral, but this no- 
 tion has been demolished by Sutton. Gould is disposed 
 to consider the Milky Way to be " the resultant of two or 
 
 * Proctor asserted that it was even given up by its author, but 
 Sir John Herschel, writing more than half a century afterwards, 
 reproduced it without any hint that it had been abandoned by his 
 father, and a son is a better authority as to his father's opinions 
 than a mere stranger, as Proctor was.
 
 THE MILKY WAY. 135 
 
 more superposed galaxies," whatever that may mean. All 
 things considered, Gore's words are eminently wise : 
 " The Copernicus of the sidereal system has not yet ap- 
 peared, and it may be many years, or even centuries, be- 
 fore this great problem is satisfactorily solved." In point 
 of fact, for more than 2000 years astronomers (and others) 
 have been speculating as to the origin and nature of the 
 Milky Way. Metrodorus considered it to be the original 
 course of the Sun abandoned by him after the bloody 
 banquet of Thyestes ; others thought that it pointed out 
 the place of Phaeton's accident, whilst yet another class 
 regarded it as being made up of the ears of corn dropped 
 by Isis in her flight from Typhon. It seems hardly con- 
 sonant with our prosaic nineteenth-century thoughts to 
 transcribe such rubbish as this, yet these and kindred fa- 
 bles and fancies have taken deep root in the human mind, 
 though probably it is true that they do not possess the 
 ascendancy which they did even fifty years ago. There 
 were, however, others of the ancients who, though no 
 doubt painfully ignorant of physical science, as tested by 
 our modern standards, and impregnated with ideas of the 
 most ridiculous and fantastic character, did, at any rate, 
 do their best, according to their lights. For instance, 
 when Aristotle imagined the Milky Way to be the result 
 of gaseous exhalations from the earth which were set on 
 fire in the sky, who shall say that he did not prefigure 
 Huggins's conclusion that certain of the nebulas are 
 nought else but blazing masses of hydrogen or other ter- 
 restrial gases? It is more difficult, however, to find a 
 modern counterpart for the idea of Theophrastus, that it 
 is the soldering together of 2 hemispheres ; or for the con- 
 ception of Diodorus, that in gazing at the Milky Way we 
 see a dense celestial fire which shows itself through the 
 clefts which indicate that 2 hemispheres are about to burst 
 apart. It is, however, interesting to come upon specula-
 
 136 THE STORY OF THE STARS. 
 
 tions by Democrates and Pythagoras that the galaxy was 
 neither more nor less than a vast assemblage of stars. 
 Ovid speaks of it as a high-road " whose groundwork is 
 stars." Manilius, who posed as an astronomical writer 
 about the first century of the Christian Era, and who was 
 probably a Roman, uses similar language. In a poem 
 which he wrote called the " Astronomicon," and which 
 has been more than once, I think, rendered into English, 
 we find the following allusion to the Milky Way : 
 
 " Or is the spacious bend serenely bright 
 From little stars, which there their beams unite, 
 And make one solid and continued light ? " 
 
 It is not a little curious how widely spread, both as 
 regards time and place, is the association of the idea of 
 milk with the Milky Way ; and though, no doubt, it may 
 be a case of one language supplying a word which others 
 borrowed and translated, yet this would hardly have been 
 done if the underlying idea had not proved acceptable. 
 The Greek name was Ta\aias or KVK\OS yakaKTiKos, which 
 the Romans converted into Circulus Lacteus or Orbis 
 Lacteus, whence no doubt our "Milky Way." At the 
 same time our English ancestors had several independent 
 names of their own. Amongst these were "Jacob's Lad- 
 der," "The way to St. James's," and " Watling Street." 
 The existence of these names supplies another proof, if 
 one were wanted, that the cardinal facts and features of a 
 science like astronomy often take a much deeper hold 
 over the popular mind than might be expected.
 
 APPLICATION OF SPECTROSCOPE TO STARS. 137 
 
 CHAPTER XVIII. 
 
 THE APPLICATION OF THE SPECTROSCOPE TO THE 
 STARS AND NEBULAE. 
 
 THE subject covered by the above heading has of late 
 years grown to be a very large one, and it will only be 
 possible to exhibit here a bare outline. The spectroscope 
 was first applied to the stars by Fraunhofer about 1814. 
 His apparatus consisted only of a small prism placed in 
 front of the object glass of a telescope belonging to a 
 theodolite. The intervention of the prism changed the 
 image of the star from the bright point which it showed 
 when viewed by the telescope alone, into a narrow, bright 
 line which exhibited all the colours of the rainbow in their 
 customary order, from red at one end to blue at the other. 
 The formation of the spectrum, as this many-coloured line 
 is called, is easily understood. The light from a star con- 
 sists, not of rays of one colour alone, but of rays of an 
 infinite number of different colours. These, in the ordi- 
 nary course of things, follow the same path, enter the 
 telescope together, come practically to the same focus, or 
 nearly so, and produce a single and colourless image of 
 the star, because the combination of all the different col- 
 ours yields the sensation which we term white light. But 
 when the light of a star passes through a prism it becomes 
 bent out of its course, and the several different colours are 
 each differently affected, some being more bent from the 
 original straight line than others. Each separate coloured 
 ray then produces a separate coloured image of the star, 
 and these images no longer converge together to the same 
 point, but fall into position side by side, overlapping each 
 other. 
 
 Fraunhofer found, however, in the case of the stars, as 
 he had previously found on examining the light of the sun, 
 10
 
 138 THE STORY OF THE STARS. 
 
 that the spectra of the stars were not quite complete, and 
 instead of the coloured line being absolutely continuous 
 from the red end to the violet end, it was interrupted here 
 and there by narrow dark spaces. These spaces, in the 
 case of the planets Mars and Venus, corresponded pre- 
 cisely with those spaces which he had already detected in 
 the spectrum of the sun, and this was natural, since the 
 planets only reflect to us the light which they receive from 
 the sun. But the gaps or dark lines in the spectra of dif- 
 ferent stars were not precisely identical with those to be 
 traced in the solar spectrum, and, moreover, the spectra 
 of different stars were different. 
 
 This was an important discovery, for it proved that the 
 source and cause of these dark lines depended on the sun 
 or on the various stars themselves, as the case might be ; 
 and was not due to anything in our atmosphere, or in ce- 
 lestial space, for in such case all the lines would have 
 been alike. Certain particular lines were indeed traced to 
 our atmosphere as they were invariably seen in the spec- 
 trum of any celestial body when it was near the horizon, 
 and was therefore being viewed through a great thickness 
 of terrestrial atmosphere. 
 
 Fraunhofer did not arrive at any explanation of the 
 cause of these lines, and a generation passed away before 
 Kirchhoff, in 1859, proved that a number of the solar lines 
 were due to the presence in the sun's atmosphere of the 
 glowing vapours of various metals, of which sodium and 
 iron seemed to be the chief. 
 
 The presence of a pair of bright lines in the orange- 
 yellow portion of the spectrum of a candle flame had long 
 been noticed. It had been proved that these were due to 
 sodium, and it had been shown that they corresponded 
 precisely in position to a pair of dark lines known as the 
 D lines in the spectrum of the sun. Kirchhoff succeeded 
 in showing that a glowing gas which, at a given tempera-
 
 APPLICATION OF SPECTROSCOPE TO STARS. 139 
 
 ture, gives off light of a particular tint (or rather of a par- 
 ticular wave-length) possesses also at that temperature the 
 power of absorbing light of that same wave-length. The 
 surface of the sun (the " photosphere," as it is technically 
 called) emits light of every colour, but superposed on it 
 are the luminous vapours of various metals. These va- 
 pours, could we but see them alone, would give us only 
 light of certain particular colours their spectra would be 
 spectra of bright lines. But, looking through them at the 
 solar photosphere (which lies below), these gases shut off 
 from us light emanating from the photosphere of precisely 
 the same quality as they themselves emit. We find, 
 therefore, the solar spectrum crossed by dark lines, which 
 correspond to the bright lines of the gases of the solar at- 
 mosphere. The conclusion of the whole matter is that 
 whilst the two D lines show the presence of sodium, other 
 lines, known as C, F, G 1 , and h show the presence of hy- 
 drogen ; whilst iron, magnesium, and other elements have 
 also been severally detected in turn. 
 
 The same principle has now been applied to the spectra 
 of stars. In their case, as in the case of the spectrum of 
 the sun, the bright background of the continuous spec- 
 trum shows the presence of a stellar photosphere, the dark 
 lines crossing it the presence of particular gases in the 
 stellar atmosphere. But the work of identifying these 
 gases in connection with the stars was one of far greater 
 difficulty than it had been in the case of the sun, owing to 
 the light even of the brightest stars being comparatively so 
 feeble. This task was, however, undertaken by Huggins 
 and Miller with the utmost skill and patience, and hydro- 
 gen, sodium, magnesium, iron, calcium and other elements 
 which had been previously detected in the sun were shown 
 to exist in the atmospheres of Arcturus, Aldebaran, and 
 several other stars. 
 
 For such researches as those of Huggins and Miller
 
 140 THE STORY OF THE STARS. 
 
 the object-glass prism of Fraunhofer was quite unsuited, 
 and a slit spectroscope was adopted. In this a very nar- 
 row slit occupies the focus of the telescope, so that the 
 image formed by the telescope falls upon it. The slit is 
 also in the focus of a small' object-glass placed behind it, 
 called the collimator, which renders the rays of light com- 
 ing from the star parallel to each other. The rays then 
 pass through one or more prisms and so become dis- 
 persed, the differently coloured rays undergoing a different 
 amount of bending out of their course. Finally the spec- 
 trum thus produced is viewed by means of a small tele- 
 scope. As the normal image of a star is only a point the 
 resulting spectrum is only a line, and a small breadth has 
 to be imparted to it by means of a cylindrical lens before 
 it can be successfully observed. 
 
 A labour of a different character was being undertaken 
 by Secchi at about the same time that Huggins and Miller 
 were at work. This distinguished Italian physicist found 
 that though the spectra of different stars differed in charac- 
 ter, these differences might easily be reduced to no more 
 than 3 or 4 simple types. Rutherfurd had made a similar 
 suggestion a little earlier, but Secchi was the first to carry 
 out a systematic spectroscopic examination of any con- 
 siderable number of stars. More recently, other and more 
 detailed classifications have been proposed by Vogel and 
 by Lockyer and as regards the photographs of stellar 
 spectra by Pickering, but these have in no way super- 
 seded Secchi's scheme of classes ; they have supplemented 
 it rather than replaced it. 
 
 Secchi divided the stars into 4 principal groups, which 
 he designated " Types " : (I.) The white or bluish stars, 
 of which Sirius may be taken as the type. These stars 
 yield spectra with the lines of hydrogen very broad and 
 dark, but the lines of the metals faint and difficult to see, 
 or altogether absent. (II.) The yellow stars, of which
 
 APPLICATION OF SPECTROSCOPE TO STARS. 141 
 
 our Sun, Arcturus, and Capella may be taken as the chief 
 types. The spectra of these show the lines of hydrogen, 
 but not so broadly or prominently as in the case of the 1st 
 type ; the metallic lines are, however, on the other hand, 
 numerous and distinct. (III.) The orange stars, of which 
 a Orionis, a Herculis, and the variable star Mira Ceti are 
 types. This class also includes divers variable stars of 
 long or irregular period. The spectra are crossed by a 
 number of dark, bands, very dark and sharp on the side 
 nearest the blue, and shading off gradually towards the 
 red end. (IV.) The red stars, none of which are brighter 
 than 5th magnitude. These have spectra crossed princi- 
 pally by 3 dark bands, due to the absorption of carbon, 
 and shaded the reverse way to those of the Illrd type. 
 
 A number of small stars, distributed along the axis of 
 the Milky Way, and commonly called the " Wolf-Rayet " 
 stars, from the two French astronomers who found the 
 first examples, are now considered, in accordance with a 
 suggestion of Pickering's, to form, together with the 
 planetary nebulas, a Vth general type. These show very 
 characteristic spectra, the background being of irregular 
 brightness and crossed by two bright lines in the yellow, 
 by another in the light green, and by a distinctive bright 
 band in the blue. 
 
 There are also a few stars which can scarcely be 
 brought under any of the foregoing five heads. For in- 
 stance, many of the stars in Orion have the hydrogen as 
 well as the metallic lines narrow and faint ; they can 
 therefore hardly be placed under either the 1st or Ilnd 
 types. And it may be added that y Cassiopeias, /3 Lyras, 
 and a few other stars show the hydrogen lines bright. 
 
 Secchi's catalogue contained about 500 stellar spectra, 
 but this number has been very largely increased by Vogel, 
 who has informed us concerning the spectra of about 
 4000 stars ; whilst Konkoly has dealt with about 2000
 
 142 THE STORY OF THE STARS. 
 
 stars. All the foregoing were the result of direct eye ob- 
 servation, but a fuller survey has since been accomplished 
 by means of photography. Huggins at an early period 
 applied photography to the study of stellar spectra, and 
 discovered thereby a remarkable series of broad, dark 
 lines in the ultra-violet region of spectra of stars of the 
 Sirius type. Dr. Henry Draper worked on similar lines at 
 about the same time, and after his death his widow placed 
 ample funds at the disposal of the Harvard College ob- 
 servatory for further researches to be carried on in memory 
 of her late husband. One of the results of her generosity, 
 and of Pickering's skilful use of it, is the " Draper Cata- 
 logue," a classified catalogue of the photographed spectra 
 of more than 10,000 stars. The classification adopted is 
 somewhat more detailed than Secchi's, but proceeds on 
 essentially the same lines. 
 
 In a previous chapter (XII.) I have said a good deal 
 about that remarkable class of objects commonly called 
 the temporary stars, or Nova stars which have suddenly 
 come into view and have then rapidly faded away. Only 
 a few instances have occurred since the application of the 
 spectroscope to stellar observation, and the stars have all 
 been much less bright and enduring than Tycho's famous 
 star of 1 572, but striking characteristics have been exhib- 
 ited by each of those which have been spectroscopically 
 treated. 
 
 The spectrum of T Coronas in 1866 showed, besides 
 a continuous spectrum crossed by dark lines, a number 
 of bright lines, amongst which those of hydrogen were 
 clearly to be noticed. In Nova Cygni in 1876, again, a 
 number of bright lines were seen superposed on a con- 
 tinuous spectrum. These bright lines appeared on the 
 whole to correspond to those of the solar chromosphere 
 (the narrow red fringe seen surrounding the sun's disc 
 during a total solar eclipse). The hydrogen lines, and a
 
 APPLICATION OF SPECTROSCOPE TO STARS. 143 
 
 characteristic line in the yellow, near the D lines of so- 
 dium, and called Da (or the " Helium " line), were the 
 most conspicuous. It must be noted in this connection 
 that the hydrogen lines with the D 3 line are also the chief 
 lines exhibited by the "red flames," or "prominences," 
 which are often seen to rise from the solar chromosphere 
 to heights of 100,000 miles or more. It follows from this, 
 therefore, that T Coronae and Nova Cygni seemed to offer 
 evidence that stars are not only sometimes composed of 
 the same elements as the sun, and, like it, possess pho- 
 tospheres surrounded by absorbing gases, but also that 
 they possess chromospheres and prominences, so that, in 
 point of fact, the sudden development of brilliancy re- 
 corded in the case of these 2 stars was really in the 
 nature of a prodigious chromospheric outburst. 
 
 Nova Cygni, however, underwent further changes. 
 When its continuous spectrum had nearly faded out the 
 aspect of the spectrum that remained greatly resembled 
 that of the Wolf-Rayet stars. Later still, in the autumn 
 of 1877, the light of the star appeared concentrated in a 
 single bright line, apparently the line characteristic of the 
 nebulas. 
 
 Near the centre of the great nebula in Andromeda a 
 new star became visible in August, 1885. Its spectrum 
 was practically continuous. 
 
 Two other Nova have yet to be mentioned, Nova Au- 
 rigas and Nova Normas, the last named apparently a faint 
 copy of the first. Nova Aurigae stands out as perhaps 
 the most interesting and most perplexing object yet stud- 
 ied by aid of the spectroscope. Discovered by Dr. Thomas 
 Anderson on January 24, 1892, but recorded by the auto- 
 matic stellar camera of Harvard College on December 10, 
 1891, it showed, when subjected to spectroscopic analysis, 
 the twofold spectrum seen in T Coronas and Nova Cygni, 
 a continuous spectrum crossed by dark lines, and a spec-
 
 144 THE STORY OF THE STARS. 
 
 trum of bright lines, amongst which those of hydrogen 
 were conspicuous, together with many of the principal 
 lines of the solar chromosphere. 
 
 The star diminished in brightness very quickly after 
 March 16, 1892, and was unfavourably placed for some 
 months. When it was examined afresh on August 17 by 
 the Lick observers, it was found to have undergone a par- 
 tial revival, and, as in the case of Nova Cygni, they 
 thought its spectrum closely resembled that of a planet- 
 ary nebula. Huggins, however, did not regard this con- 
 clusion as fairly established. The spectrum showed, it is 
 true, two bright bands near the positions of the two chief 
 nebular lines, but the bands were really groups of bright 
 lines, extending over a- considerable length of the spec- 
 trum. The most striking feature of the spectrum of 
 Nova Aurigae was the displacement of its lines. As first 
 seen, the bright hydrogen lines were accompanied by 
 dark absorption lines, manifestly due to the same element, 
 but displaced towards the violet as compared with the 
 bright lines. Photographs of the spectrum revealed 
 further details. Many of the dark lines carried a fine 
 bright line upon them ; many of the bright lines could be 
 resolved into two or three components. Here, then, 
 there was at least a double hydrogen spectrum : one of 
 dark lines, the other of bright lines, the two displaced 
 with regard to each other. Possibly there were several 
 such distinct spectra. How were their displacement with 
 regard to each other to be explained ? 
 
 Doppler, in 1843, had shown that the motion of a 
 source of light towards the observer must cause a short- 
 ening of the intervals between the waves of light. In 
 other words, light of a given special wave-length would 
 have that wave-length diminished, and the light would 
 appear to have shifted its place in the spectrum towards 
 the blue end if the source of the light were in motion
 
 APPLICATION OF SPECTROSCOPE TO STARS. 145 
 
 towards us. If we adopt this explanation of the com- 
 posite spectrum of Nova Aurigas it follows that that star 
 must have consisted of two or more bodies moving in 
 different directions in the line of sight with the most 
 amazing velocity. The body giving the dark absorption 
 lines would appear to have been approaching our system 
 at a speed of 400 or 500 miles a second, and the body 
 giving the bright lines to have been receding at a speed 
 of about 300 miles a second. 
 
 This is scarcely the place to bring forward in detail 
 theories to explain these complicated spectra. The two 
 most favoured are the " tidal theory," which supposes 
 that the near approach of two great stars to each other 
 has given rise to immense tidal waves of highly heated 
 gas, and the " cosmical cloud theory," according to 
 which these Nova are due to the rush of a swiftly moving 
 star through a nebula. 
 
 Doppler's principle (as has already been briefly men- 
 tioned in a previous chapter) had been applied to a differ- 
 ent problem by Huggins in 1867, who carefully compared 
 the position of the green line of hydrogen as given by a 
 vacuum tube, with that of the same line in the spectrum 
 of Sirius. Later on he examined the spectra of a number 
 of stars, and calculated from the amounts and direction of 
 the displacement of the lines in their spectra, the speed at 
 which the separate stars were moving towards us, or 
 away from us in the line of sight. This research was 
 then taken up at Greenwich and at Rugby, but with in- 
 sufficient means. Lastly, Vogel pressed photography 
 into the service, and made some very successful observa- 
 tions on about 50 stars. 
 
 One result of Vogel's work was the discovery of " spec- 
 troscopic double stars." The variable star, Algol, had 
 long been suspected to have a dark companion, which by 
 transiting before its primary caused a partial eclipse every
 
 146 THE STORY OF THE STARS. 
 
 69 hours. Vogel now conclusively showed that this was 
 the case, for Algol was moving round the centre of gravity 
 of the pair in precisely the time required, and the diame- 
 ter, mass, distance from its primary, and speed in its orbit, 
 of the unseen companion, were all computed. 
 
 Spica Virginis proved to be another close double, 
 though in this case the companion does not obscure the 
 bright principal star. Indeed, it is possible that it is as 
 bright as the 3rd magnitude. 
 
 In some cases a " spectroscopic double " is composed 
 of two stars of nearly equal brightness. This is the case 
 with f Ursae Majoris and /3 Aurigae, which were discovered 
 by Pickering a little before Vogel's proof of the existence 
 of the companion of Algol. The two stars which make 
 up /3 Aurigas revolve in an orbit which is but little inclined 
 to the line of sight. Consequently at one time one star 
 will be approaching us in its orbit whilst the other is re- 
 ceding. The lines due to the first star are displaced 
 towards the blue, and those of the second towards the 
 red, and the lines in the compound spectrum are therefore 
 double. A little later both bodies are moving across the 
 line of sight, and therefore are neither approaching us nor 
 receding from us, so that the lines of the two stars exactly 
 coincide. The period in the case of this star is nearly 4 
 days. 
 
 Another probable " spectroscopic double " is the vari- 
 able star (3 Lyrse. This star (as we have already seen) 
 goes through its changes in a little less than 13 days, hav- 
 ing two maxima and two minima. Its spectrum shows 
 broad, dark bands, due to hydrogen, besides bright lines, 
 which change their appearance and position from time to 
 time. It has been suggested that the system consists of 
 two stars of unlike spectra revolving round each other, 
 and partially eclipsing each other as they cross the line of 
 sight. The changes of the spectrum are, however, very
 
 APPLICATION OF SPECTROSCOPE TO STARS. 147 
 
 complicated, and have not yet been completely studied, 
 and so simple an explanation appears scarcely adequate. 
 
 A very promising and important study is that of the 
 distribution of the different types of stellar spectra. For 
 this the available material is as yet insufficient. Never- 
 theless, the Draper catalogue, and the catalogues of Vogel 
 and Konkoly, have enabled some first approximations to 
 be made. It appears, from a consideration of such binary 
 stars as have been spectroscopically examined, that the 
 1st or Sirius type of stars are much less dense relatively 
 to their brightness than the Solar stars, or are intrinsically 
 brighter relatively to their density. The Ilnd type of 
 stars, i. e., the Solar stars, and to a less degree the Illrd 
 type of stars, appear to be pretty evenly distributed over 
 the sky. The 1st, or Sirius type, shows a distinct disposi- 
 tion to aggregation towards the Milky Way, whilst, as 
 already pointed out, the Wolf-Rayet stars cluster along its 
 axis. The proper motions of the Sirius stars appear to be 
 smaller than those of the Solar stars, which from this 
 and other reasons may be supposed to be on the average 
 nearer to us than the Sirius stars. If the Solar type stars 
 be divided into two classes, according to their greater 
 resemblance to Capella and Arcturus respectively, the for- 
 mer class appears to have a larger average proper motion 
 than the latter, and may therefore be supposed to be the 
 nearer stars. The entire subject, however, needs much 
 fuller investigation before any great weight can be at- 
 tached to these provisional conclusions. The completion 
 of the Draper catalogue by the publication of the results 
 of the survey of the southern heavens carried out at Are- 
 quipa, in Peru, under the direction of the Harvard astrono- 
 mers, will constitute the next important forward step. 
 
 The first observation of the spectrum of a nebula was 
 made by Huggins in August, 1864. The object examined 
 was the small, bright, planetary nebula in the pole of the
 
 148 THE STORY OF THE STARS. 
 
 ecliptic, 37 ip IV Draconis, to which some allusion has 
 already been made. The first scrutiny revealed the fact 
 that there existed an immense difference between its 
 spectrum and an ordinary stellar spectrum. In place of 
 the usual continuous spectrum only three isolated bright 
 lines were seen a proof of the presence of luminous gas. 
 In other words, the object was a true nebula, that is, a 
 mass of glowing gas, and not a star cluster, seeming to be 
 nebulous only on account of its distance. 
 
 Of the three lines, one, the faintest, was evidently due 
 to hydrogen. The other two have not yet been identified, 
 but the brightest is very near one of a pair of green lines 
 in the spectrum of nitrogen, and has hence been sometimes 
 spoken of as the "nitrogen line." Other lines due to 
 hydrogen have since been observed in various nebular 
 spectra, together with the well-known chromospheric line 
 Da, A number of other lines have also been detected in 
 the visual spectrum with extreme difficulty by different 
 observers, and many more by means of photography in 
 the violet and ultra-violet regions. The sources of these 
 lines have not yet been ascertained, and in a great number 
 of the fainter spectra the line in the green near the nitrogen 
 pair, which is especially to be regarded as the typical 
 nebular line, is alone visible. 
 
 The problem of the motions of the nebulas in the line 
 of sight has been attacked by Keeler at the Lick Observa- 
 tory. He has measured the displacement of the chief 
 nebular line in the spectra of the nebulae, and has obtained 
 evidence of movements varying from a speed of about 40 
 miles per second of approach, to about 30 miles per 
 second of recession. 
 
 Several of the nebulae, as, for example, the great nebula 
 in Andromeda, show continuous spectra. But many of 
 those that give a spectrum of bright lines give also a faint, 
 continuous spectrum. The great nebula of Orion is one
 
 APPLICATION OF SPECTROSCOPE TO STARS. 149 
 
 of the latter class, though Huggins considers that the 
 seemingly continuous spectrum is resolvable into lines. 
 Other nebulas show bright lines only, without any trace of 
 continuous spectrum. 
 
 In the case of the great nebula in Orion Huggins has 
 secured some photographs of exceptional interest, which 
 show that the stars of the "trapezium " are not merely 
 apparently in the nebulae, but really so, for a number of 
 bright lines (one in particular, with a wave-length of 3730 
 " tenth metres ") were observed both in the continuous 
 spectrum of two of the trapezium stars, and in the spec- 
 trum of the nebulae in their immediate neighbourhood. A 
 later photograph, taken in 1889, in which the slit of the 
 spectroscope was pointed near to the trapezium, but not 
 actually across it, failed to shew the 3730 line, which 
 would thus appear to be typical only of the regions of the 
 nebulas close to the stars. It would seem probable, there- 
 fore, that these stars are involved in the nebulae. 
 
 The subject of spectroscopic observations of the stars 
 and nebulae is a growing one, but we have yet much 
 more to do before we can much more learn.
 
 APPENDIX I. 
 
 TABLE OF THE CONSTELLATIONS. 
 
 BY the entries in the column headed " Centre " it is 
 meant to be inferred that a line of Right Ascension and a 
 line of Declination taken off the map will intercept at a 
 point which may be regarded as about the centre of the 
 constellation. This, however, is only true of the more 
 compact constellations, for there are some, like Draco, 
 Cetus, and Argo, which are so long and straggling that 
 they extend over several hours of R.A. When, therefore, 
 I state that the constellations are here arranged in the 
 order of R.A., the statement must be regarded as need- 
 ing some qualification in many cases. In the column of 
 " Declination " + means North, and South. 
 
 NAME OF CONSTELLATION. 
 
 CENTRE. 
 
 R.A. 
 
 Decl. 
 
 Pisces . 
 
 h. m. 
 O 2O 
 
 o 30 
 o 40 
 
 I 
 I O 
 
 i 45 
 
 2 
 2 25 
 2 30 
 2 40 
 3 20 
 
 + 10 
 
 -35 
 
 + 38 
 - 4 8 
 + 60 
 12 
 
 432 
 
 33 
 
 + 20 
 -72 
 
 + 42 
 
 Sculptor [Apparatus Sculptoris] 
 
 Andromeda 
 
 Phoenix 
 
 Cassiopeia 
 
 Cetus 
 
 Triangulum 
 
 Fornax [Chemical 
 
 
 
 Perseus 
 
 150
 
 THE CONSTELLATIONS. 
 
 NAME OF CONSTELLATION. 
 
 CENTRE. 
 
 R.A. 
 
 Decl. 
 
 
 h. m. 
 3 20 
 3 50 
 3 5 
 4 30 
 4 40 
 5 o 
 5 20 
 5 25 
 5 30 
 5 40 
 5 40 
 5 40 
 6 o 
 6 40 
 7 o 
 7 o 
 7 30 
 7 40 
 7 50 
 8 o 
 8 30 
 8 40 
 8 40 
 9 o 
 9 30 
 
 10 O 
 10 10 
 10 20 
 
 10 30 
 10 40 
 
 II 
 II 
 II 20 
 12 2O 
 12 30 
 12 30 
 12 40 
 13 
 11 20 
 
 -52 
 -63 
 30 
 
 + 18 
 -42 
 
 60 
 
 + 3 
 
 20 
 
 52 
 
 -77 
 -34 
 -f 70 
 + 42 
 -24 
 + 24 
 
 3 
 + 6 
 -32 
 +45 
 40 
 + 20 
 62 
 -69 
 30 
 -45 
 -35 
 i 
 
 + 33 
 + 15 
 
 -78 
 
 12 
 
 + 5 8 
 
 15 
 60 
 
 -18 
 
 -68 
 -27 
 + 40 
 
 47 
 
 Reticulum fRhomboidalisl 
 
 
 
 
 Dorado 
 
 
 Lepus 
 
 Pictor [Equleus PictorisJ 
 
 Mensa TMons Mensa] .. 
 
 Columba [Noachil 
 
 Camelopardus 
 
 
 
 
 
 Canis Minor 
 
 
 Lynx 
 
 
 Cancer 
 
 Argo [Carina] 
 
 Volans [Piscis Volans] 
 
 Argo [Malus] 
 
 Argo [Vela] 
 
 Antlia Pneumatica 
 
 Sextans 
 
 
 Leo 
 
 
 Hydra 
 
 Ursa Major 
 
 
 Crux 
 
 Cor/us 
 
 
 
 Canes Venatici 
 
 Centaurus.. .
 
 '52 
 
 APPENDIX I. 
 
 NAME OF CONSTELLATION. 
 
 CENl 
 
 RE. 
 
 
 R.A. 
 
 Decl. 
 
 
 h. m. 
 11 2O 
 
 2 
 
 Bootes 
 
 14 IS 
 
 -4-7O 
 
 Circinus 
 
 14 So 
 
 _6i 
 
 
 is o 
 
 4O 
 
 
 15 10 
 
 I/I 
 
 
 IS IO 
 
 76 
 
 Serpens . 
 
 IS TS 
 
 f 8 
 
 Corona Borealis 
 
 I S .IO 
 
 4- IO 
 
 Triangulum Australe 
 
 IS: 4O 
 
 6s 
 
 Ursa Minor 
 
 IS 4O 
 
 + 78 
 
 Norma 
 
 16 o 
 
 d.O 
 
 Draco 
 
 16 o 
 
 + 60 
 
 
 16 20 
 
 26 
 
 
 16 50 
 
 ss 
 
 Ophiuchus 
 
 17 10 
 
 4, 
 
 
 17 10 
 
 + 27 
 
 Corona Australis 
 
 18 30 
 
 41 
 
 
 18 10 
 
 IO 
 
 Telescopium 
 
 18 40 
 
 S2 
 
 Lyra 
 
 18 dc. 
 
 + ^6 
 
 
 IQ O 
 
 2S 
 
 Pavo 
 
 IQ IO 
 
 6s 
 
 Aquila (with Antinoiis) 
 
 IO ^O 
 
 + 2 
 
 Sapitta. . . 
 
 IQ SO 
 
 -fiS 
 
 Vulpecula et Anser 
 
 2O IO 
 
 + 2S 
 
 
 2O V3 
 
 + 4O 
 
 
 2O IS 
 
 4-12 
 
 
 2O 5O 
 
 2O 
 
 
 21 O 
 
 "37 
 
 
 21 IO 
 
 4- 6 
 
 
 21 2O 
 
 s8 
 
 
 21 4.O 
 
 ^2 
 
 
 22 O 
 
 + 70 
 
 Grus 
 
 22 2O 
 
 47 
 
 
 22 2O 
 
 1^ 
 
 
 22 2S, 
 
 + 41 
 
 
 22 ^O 
 
 + 17 
 
 
 23 45 
 
 68 
 
 Octans 
 
 Polar 
 
 (South)
 
 APPENDIX II. 
 
 LIST OF CELESTIAL OBJECTS FOR SMALL TELE- 
 SCOPES.* 
 
 IT is here assumed that a certain number of the read- 
 ers of this volume may happen to possess a small tele- 
 scope, and would be glad to direct it on celestial objects 
 of interest if they knew where to look for some which 
 were within the reach of their instruments. Hence the 
 motive for the compilation of this catalogue, which may 
 be said to represent the capacity of portable refracting 
 telescopes of about 2 inches in aperture. 
 
 (l) DOUBLE OR COMPOUND STARS. 
 
 
 
 Right 
 
 Declina- 
 
 Magnitudes 
 
 Distance 
 
 No. 
 
 NAME OF STAR. 
 
 Ascen- 
 
 tion, 
 
 of Com- 
 
 between the 
 
 
 
 sion, 1890. 
 
 1890. 
 
 ponents. 
 
 Components. 
 
 
 
 h. m. s. 
 
 o / 
 
 
 // 
 
 I 
 
 Toucani 
 
 o 26 30 
 
 -63 34 
 
 Both 5 
 
 28 
 
 2 
 
 TJ Cassiopeiae 
 
 o 42 26 
 
 + 57 13 
 
 4 and 7$ 
 
 5 
 
 3 
 
 7 Arietis 
 
 I 47 29 
 
 + 18 45 
 
 4i and 5 
 
 8 
 
 4 
 
 7 Andromedee 
 
 I 57 8 
 
 + 41 48 
 
 3| and 5$ 
 
 ( 10 : B. 
 
 ( double. 
 
 5 
 
 Eridani 
 
 2 54 5 
 
 40 44 
 
 5 and 6 
 
 8 
 
 6 
 
 14 Aurigae 
 
 5 8 14 
 
 -1-32 33 
 
 5 and 7^ 
 
 14 
 
 7 
 
 23 Orionis 
 
 5 17 3 
 
 + 3 26 
 
 5 and 7 
 
 
 8 
 
 8 Orionis 
 
 5 26 23 
 
 O 22 
 
 2 and 7 
 
 53 
 
 * For a comprehensive general catalogue of objects of this kind, 
 with full descriptions of each, see Admiral W. H. Smyth's " Cycle 
 of Celestial Objects," 2nd ed., Oxford, 1881, price 125. 
 II 'S3
 
 APPENDIX II. 
 
 No. 
 
 NAME OF STAR. 
 
 Right 
 _Ascen- 
 sion, 1890. 
 
 Declina- 
 tion, 
 
 1890. 
 
 Magnitudes 
 of Com- 
 ponents. 
 
 Distance 
 between the 
 Components. 
 
 
 
 h. m. s. 
 
 / 
 
 
 // 
 
 9 
 
 <r Orionis 
 
 5 33 3 
 
 2 38 
 
 4, 8 and 7 
 
 ( 12 and 42 : 
 / multiple. 
 
 10 
 
 ii Monocerotis 
 
 6 23 29 
 
 - 6 57 
 
 6J, 7 and 8 
 
 j 7,9 = 
 1 (B.C.=2. 5 ) 
 
 ii 
 
 7 Volantis 
 
 7 9 40 
 
 -70 19 
 
 5 and 7 
 
 13 
 
 12 
 
 a Geminorum 
 
 7 27 35 
 
 + 32 7 
 
 3 and 3-^ 
 
 5 
 
 13 
 
 7 Argfis 
 
 868 
 
 47 o 
 
 2 and 6 
 
 42 
 
 14 
 
 54 Leonis 
 
 10 49 39 
 
 +25 20 
 
 4i and 7 
 
 6 
 
 15 
 
 a Crucis 
 
 12 20 28 
 
 62 29 
 
 ii, 2 and 5 
 
 5,90: 
 quintuple 
 
 16 
 
 17 Comae Ber. 
 
 12 23 25 
 
 + 26 30 
 
 4-J and 6 
 
 . 145 [use 
 low power] 
 
 17 
 
 7 Crucis 
 
 12 25 2 
 
 56 29 
 
 2 and 5 
 
 1 20 
 
 18 
 
 7 Virgin is 
 
 12 36 5 
 
 o 50 
 
 both 4 
 
 5 
 
 19 
 
 a Can. Venat 
 
 12 50 53 
 
 + 38 54 
 
 2-J and 6 
 
 20 
 
 
 
 
 
 
 514 ; Alcor, 
 
 20 
 
 Ursse Maj. 
 
 13 19 29 
 
 + 55 30 
 
 3 and 5 
 
 mag. 5, is 
 
 
 
 
 
 
 distant nf 
 
 21 
 
 a Centauri 
 
 14 32 7 
 
 DO 22 
 
 I and 2 
 
 14 
 
 22 
 
 IT Bootes 
 
 14 35 33 
 
 + 16 53 
 
 3i and 6 
 
 5 
 
 
 
 
 
 
 7 * A. nlso 
 
 23 
 
 Scorpii 
 
 15 58 19 
 
 ii 4 
 
 4^ and "]\ 
 
 double 
 
 
 
 
 
 
 T . A 1 _ 
 
 24 
 
 j8 Scorpii 
 
 15 59 2 
 
 -19 30 
 
 2 and si 
 
 13 i ** aiso 
 double 
 
 
 
 
 
 
 I 40 ; both 
 
 25 
 
 v Scorpii 
 
 16 5 36 
 
 19 10 
 
 4 and 7 
 
 -| double 
 
 
 
 
 
 
 ( 0.7, 2 
 
 26 
 
 36 (A) Ophiuchi 
 
 17 8 34 
 
 26 25 
 
 4i and 6i 
 
 4 
 
 27 
 
 a Herculis 
 
 17 9 38 
 
 + 14 30 
 
 3-J and si 
 
 4 
 
 28 
 
 CLyne 
 
 18 40 59 
 
 + 37 29 
 
 S and s 
 
 44 
 
 29 
 
 Serpentis 
 
 18 50 49 
 
 + 43 
 
 4-J- and 5 
 
 21 
 
 30 
 
 /3 Cygni 
 
 19 26 17 
 
 + 27 43 
 
 3 and 7 
 
 34 
 
 31 
 
 a 9 Capricorn! 
 
 20 ii 57 
 
 -12 53 
 
 3 and 4 
 
 j 376 [use 
 ( low power] 
 
 32 
 
 /S 2 Capricorni 
 
 25 14 5 
 
 -15 7 
 
 3i and 7 
 
 205 
 
 33 
 
 7 Delphini 
 
 20 41 33 
 
 + 15 43 
 
 4 and 6J- 
 
 ii 
 
 34 
 
 /3 Cephei 
 
 21 27 14 
 
 + 70 43 and 8 
 
 13 
 
 35 
 
 8 Cephei 
 
 22 25 5 
 
 + 57 5i4i and 7 
 
 40 : A. var.
 
 LIST OF CELESTIAL OBJECTS. 
 
 '55 
 
 (2) CLUSTERS OF STARS AND NEBULAE. 
 
 No. 
 
 DESIGNATION OF OBJECT. 
 
 Nature of 
 Object. 
 
 Right As- 
 cension. 
 
 Declina- 
 tion. 
 
 
 
 
 h. m. s. 
 
 / 
 
 I 
 
 47 Toucani 
 
 Cluster 
 
 o 19 9 
 
 -72 41 
 
 2 
 
 31 M. Andromedae 
 
 Nebula 
 
 o 36 47 
 
 + 40 40 
 
 3 
 
 The Nubecula Minor 
 
 
 o 48 41 
 
 -73 58 
 
 4 
 
 103 M. Cassiopeiae 
 
 Field of stars 
 
 i 25 56 
 
 + 60 7 
 
 5 
 
 33 ]$. VI Persei 
 
 Double cluster 
 
 2 II 2O 
 
 + 56 38 
 
 6 
 
 i\ Tauri 
 
 Group of stars 
 
 3 40 56 
 
 + 23 45 
 
 7 
 
 Nubecula Major 
 
 
 5 24 6 
 
 69 34 
 
 8 
 
 I M. Tauri [" Crab "] 
 
 Nebula 
 
 5 27 51 
 
 + 21 56 
 
 9 
 
 42 M. Orionis 
 
 Nebula 
 
 5 29 52 
 
 5 27 
 
 10 
 
 35 M. Geminorum 
 
 Cluster 
 
 624 
 
 + 24 26 
 
 ii 
 
 41 M. Canis Majoris 
 
 Cluster 
 
 6 42 13 
 
 -20 37 
 
 12 
 
 " Praesepe " in Cancer 
 
 Cluster 
 
 8 33 55 
 
 + 20 19 
 
 13 
 
 i) Argus 
 
 Nebula 
 
 10 40 47 
 
 59 6 
 
 14 
 
 K Crucis 
 
 Cluster 
 
 12 47 7 
 
 -59 45 
 
 15 
 
 o> Centauri 
 
 Cluster 
 
 13 20 10 
 
 46 44 
 
 16 
 
 3 M.Canum Venaticorum 
 
 Cluster 
 
 13 37 3 
 
 + 28 55 
 
 I? 
 
 5 M. Librae 
 
 Cluster 
 
 15 12 57 
 
 + 2 30 
 
 18 
 
 80 M. Scorpii 
 
 Cluster 
 
 16 10 26 
 
 -22 43 
 
 19 
 
 13 M. Herculis 
 
 Cluster 
 
 16 37 45 
 
 + 36 39 
 
 20 
 
 92 M. Herculis 
 
 Cluster 
 
 17 13 46 
 
 + 43 15 
 
 21 
 
 14 M. Ophiuchi 
 
 Cluster 
 
 17 31 50 
 
 - 3 ii 
 
 22 
 
 8 M. Sagittarii 
 
 Cluster 
 
 17 57 8 
 
 24 22 
 
 23 
 
 24 M. Scuti Sobieskii 
 
 Cluster 
 
 18 ii 44 
 
 18 26 
 
 24 
 
 17 M. Scuti Sobieskii 
 
 Nebula 
 
 18 14 16 
 
 16 14 
 
 
 [" Horse-shoe "] 
 
 
 
 
 25 
 
 22 M. Sagittarii 
 
 Cluster 
 
 18 29 28 
 
 23 59 
 
 26 
 
 II M. Antinoi 
 
 Cluster 
 
 18 45 13 
 
 6 24 
 
 27 
 
 57 M. Lyrae 
 
 Annular neb. 
 
 18 49 28 
 
 + 32 53 
 
 28 
 
 27 M. Vulpecula 
 
 Nebula 
 
 19 54 48 
 
 + 22 25 
 
 
 [" Dumb-bell "] 
 
 
 
 
 2 9 
 
 15 M. Pegasi 
 
 Cluster 
 
 21 24 38 
 
 + 11 40 
 
 30 
 
 2 M. Aquarii 
 
 Cluster 
 
 21 27 44 
 
 - I ig
 
 i 5 6 
 
 APPENDIX 11. 
 
 (3) SPECIAL STARS. 
 
 No. 
 
 NAME OF STARS. 
 
 Right 
 Ascension, 
 
 1890. 
 
 Declina- 
 tion, 
 1890. 
 
 Mag. 
 
 Notes. 
 
 
 
 h. m. s. 
 
 / 
 
 
 
 I 
 
 oCeti 
 
 2 13 47 
 
 3 28 
 
 Var. 
 
 Max. mag. 2 : 
 
 
 
 
 
 
 Fiery red. In- 
 
 
 
 
 
 
 visible at Min. 
 
 2 
 
 aCeti 
 
 2 56 31 
 
 + 3 39 
 
 2i 
 
 Orange colour 
 
 3 
 
 $ Persei 
 
 312 
 
 + 40 31 
 
 Var. 
 
 Max. 2 : Min. 4 
 
 4 
 
 5 Lyncis 
 
 6 17 12 
 
 + 8 28 
 
 5i 
 
 Fiery red 
 
 5 fj. Canis Majoris 
 
 6 51 3 
 
 13 54 
 
 Sir 
 
 Fiery red 
 
 6 
 
 20918 Lai. Hydrae 
 
 10 46 16 
 
 20 37 
 
 7 
 
 Copper coloured 
 
 7 
 
 /3 Librae 
 
 15 ii 5 
 
 8 58 
 
 2* 
 
 Pale green 
 
 8 
 
 a Scorpii 
 
 16 22 39 
 
 26 ii 
 
 I 
 
 Fiery red 
 
 9 
 
 xCygni 
 
 19 46 20 
 
 + 32 38 
 
 Var. 
 
 Max. 4: Min. in- 
 
 
 
 
 
 
 visible 
 
 10 
 
 /* Cephei 
 
 21 40 8 
 
 + 58 16 
 
 Var. 
 
 Max. 4 : Min. 6 : 
 
 
 
 
 
 
 Deep garnet 
 
 
 
 
 
 
 colour 
 
 ii 
 
 5 Cephei 
 
 22 25 5 
 
 + 57 5i 
 
 Var. 
 
 Max. 3^: Min. 4^ 
 
 12 
 
 8 Andromedae 
 
 23 12 38 
 
 + 48 24 
 
 5 
 
 Fiery red 
 
 13 
 
 30 Piscium 
 
 23 56 ig 
 
 - 6 37 
 
 4i 
 
 Fiery red
 
 GENERAL INDEX. 
 
 A. 
 
 Achernar (a Eridani), 24. 
 
 Airy, Miss, 103. 
 
 Alcyone, one of the Pleiades, 103. 
 
 Aldebaran (o Tauri), 23, 24, 32, 33, 
 
 Algol 03 Persei), 32, 33, 86, 145. 
 Almanacks, based on astronomy, 10. 
 Altair (a Aquilse), 24, 25. 
 Amos. Prophecy of, cited, 40, 102. 
 Andromeda (constellation), 32, 34, 
 
 Great Nebula in, 79. 116, 148. 
 
 Angle of position of double star, 54. 
 
 Annular Nebulaej 115. 
 
 An tares (a Scorpii), 23, 24, 25, 34. 
 
 Antinous, 152. 
 
 Antlia Pneumatica (constellation), 
 
 151. 
 Apparatus Sculptoris (constellation), 
 
 150. 
 Apparent movement of the heavens, 
 
 n. 
 
 Apus (constellation), 152. 
 Aquarius (constellation), 35. 
 Aquila (constellation), 34. 
 Ara (constellation), 152. 
 Arago, 92. 
 Aratus, 42. 
 Arcturus (a Bootes), 23, 24, 34, 70, 
 
 71, 141. 
 
 Argelander, F. G. A., 43, 85. 
 Argo (constellation), 151. 
 
 Great Nebula in, 124, 129. 
 
 jf. Variable in, 88. 
 
 Aries (constellation), 33, 35, 39. 
 
 First point of, 37. 
 
 Aristotle, 135. 
 Ascension, Right, 37. 
 Atlases, Celestial, 39. 
 Auriga (constellation), 151. 
 Auwers, A, 103. 
 
 Axis of the heavens, 15. 
 Azimuth, 18. 
 
 B. 
 Bayer, J., his Atlas, 85. 
 
 his lettering of the stars, 23. 
 
 Bessel, F. W., 58. 
 Betelgeuse (a Orionis), 24. 
 Bible, References to, 40, 102. 
 Binary stars, 55. 
 Biot, E., 77. 
 Birmingham, J., 78. 
 Bond, G. P., 117. 
 Bootes (constellation), 152. 
 Bradley, J., 71. 
 Brisbane, Sir T. M., 88. 
 Burchell, his observations of ij Ar- 
 gus, 88. 
 Byron, Lord, Quotation from, 99. 
 
 C. 
 
 Caela Sculptoris (constellation), 151. 
 Camelopardus (constellation), 151. 
 Cancer (constellation), 35. 
 Canes Venatici (constellation), 151. 
 Canis Major (constellation), 33. 
 Canis Minor (constellation), 33. 
 Canopus (a Argus), 24. 
 Capella (a Aungae), 24, 25, 32, 167. 
 Capricornus (constellation), 34. 
 Cassiopeia (constellation), 31-, 32. 
 Castor (o Geminorum), 34, 35. 
 Centaurus (constellation), 151. 
 Central sun hypothesis, Madler's, 
 
 Cepheus (constellation), 31, 32. 
 Cetus (constellation), 34, 35. 
 
 Mira, Variable in, 84, 141. 
 
 Chacomac, 116. 
 Chaldean astronomy, 41. 
 Chamaeleon, 151. 
 Chandler, 86, 92. 
 
 157
 
 158 
 
 GENERAL INDEX. 
 
 Chinese observations referred to, 41, 
 
 >7 6. 
 
 Circinus (constellation), 152. 
 Clusters of stars, 101. 
 
 List of, for small telescopes, 155. 
 
 Coal Sack. The. 131. 
 Coloured stars, 62. 
 Columba Noachi (constellation), 33. 
 Coma Berenices (constellation), 106. 
 Compass, Points of, 17-20. 
 Complementary colours, 65. 
 Constellations, 28. 
 Constellations, List of, 150. 
 
 Brief account of, 30. 
 
 Corona Australis (constellation), 152. 
 Corona Borealis (constellation), 34. 
 Corvus (constellation), 151. 
 Crab Nebula in Taurus, 122. 
 Crater (constellation), 151. 
 Crux (constellation), 151. 
 Cygnus (constellation), 32. 
 
 D. 
 
 Declination, 36. 
 
 Delphinus (constellation), 34. 
 
 Deneb (a Cygni), 24. 
 
 Diodorus, 135. 
 
 Diurnal Movement, 13. 
 
 Doppler, 72, 144. 
 
 Dorado (constellation), 151. 
 
 Nebula in, 123. 
 
 Double stars, 51, 65. 
 Draco (constellation), 32, 42. 
 Draper, Dr.. 142. 
 ''Dumb-bell" Nebula, 127. 
 
 E. 
 
 Egyptian Astronomy, 40. 
 Elliptic Nebulae, 115, 116. 
 Eriqanus (constellation), 151. 
 Espin, T. E., 93. 
 
 F. 
 
 "Fixed" stars, 12. 
 Fomalhaut (a Piscis Australis), 23, 
 
 24, 25. 34- 
 Fontenelle, 69. 
 
 Fornax Chemica (constellation), 150. 
 Fraunhofer, 137. 
 
 G. 
 
 Galaxy, 49 (see Milky Way). 
 Gauging the heavens, 47. 
 Gemini (constellation), 33, 35. 
 Genesis xv, 5 cited, 43. 
 Globular clusters, 107. 
 
 Goodricke, 86, 87. 
 
 Gore, J. E., 81, 95, 135. 
 
 Gould, B. A., 134. 
 
 Grant, R., 44. 
 
 Gravitation as applied to binary 
 
 stars, 56. 
 
 Greenwich Observatory, 10. 
 Grus (constellation), 152. 
 Greek alphabet, 23, 30. 
 
 H. 
 
 Halley, E., 70, 88. 
 Hercules (constellation), 34. 
 
 cluster 13 M. in, 106, 155. 
 
 cluster 92 M. in, 155. 
 Herschel, Sir W., 46, 53, 55, 73, 74, 
 
 107, 108, 113, 119, 134. 
 Herschel, Sir J. F. W., 46, 63, 67, 88, 
 
 106, III, 114, 117, 121, 122, 123, 
 124, 125. 
 
 Herschel, Capt. J., 125. 
 
 Hesiod, 42. 
 
 Hjnd, J. R., 78, 92, 104, 121. 
 
 Hipparchus, 77. 
 
 Holden, E., 120. 
 
 Huggins, W., 73, 74, 92, 116, 135, 
 
 139, 140, 144, 147. 
 
 Hyades, The, in Taurus, 33, 102, 105. 
 Hydrus (constellation), 150. 
 
 I. 
 Indus (constellation), 152. 
 
 J- 
 Jacob's Ladder, name for Milky 
 
 Way, 136. 
 Job ix, 9 cited, 40, 102 ; xxxviii. 
 
 31-2, 40, 102. 
 
 K. 
 
 Key, Rev. H. C., 121. 
 Kirchhoff, 138. 
 Klein, H. J., his Atlas referred to, 
 
 39- 
 Konkoly, 141. 
 
 L. 
 
 La Caille, N. L., 88, 108. 
 Lacerta (constellation), 152. 
 Leo (constellation), 33, 35. 
 Leo Minor (constellation), 151. 
 Lepus (constellation), 151. 
 Libra (constellation), 35. 
 Lockyer, J. N., 140. 
 Longfellow, Quotation from, ico. 
 Lupus (constellation), 152.
 
 GENERAL INDEX. 
 
 159 
 
 Lynx (constellation), 151. 
 Lyra (constellation), 152. 
 
 quadruple star, e, 60. 
 
 Annular Nebula in, 115. 
 
 M. 
 
 Madler, J. H., 74- 
 Magellanic Clouds, 127. 
 Magnitudes of stars, ai. 
 
 , List of stars of the first, 24. 
 
 Maia (one of the Pleiades), 103. 
 Manilius, his description of the 
 
 Milky Way, 136- 
 Mazzaroth, Meaning of, 41. 
 Mechain, 108. 
 Meridian, 17, 37. 
 Messier, his catalogue of nebulae, 
 
 108, 122. 
 
 No. i, 122, 155. 
 
 No. 5, 108. 
 
 No. n, 113, 155. 
 
 No. 13, 106. 
 
 Metrodorus, his idea of the Milky 
 
 Way, 135. 
 Micromete_r, 54. 
 
 Microscopium (constellation), 152. 
 Milky Way, its course amongst the 
 
 stars, 80, 129. 
 
 Theories of, 134. 
 
 Various old names of, 136. 
 
 Miller, W. A., i3Q t 140. 
 Milton, J., Quotations from, 97. 
 Mira (o) Ceti, 84, 156. 
 Monoceros (constellation), 151. 
 Mons Mensae (constellation), 151. 
 Montanari, 86. 
 
 Moore, T., Quotations from, 99. 
 Motions of the stars, apparent, n. 
 
 in the line of sight, 146. 
 
 Multiple stars, 62. 
 
 Musca Australis (constellation), 151. 
 
 N. 
 Naked eye, Number of stars visible 
 
 to, 12, 43, 45. 
 
 Nautical Almanac referred to, 10. 
 Nebulae, 114. 
 Spectroscopic observations of, 
 
 129, 147. 
 
 , alleged to be variable, 129. 
 
 for small telescopes, 155. 
 
 Nebulous stars, xai. 
 
 New stars, 142. 
 
 Norma (constellation), 152. 
 
 Nubecula Major, 127. 
 
 Nubecula Minor, 127. 
 
 Number of the stars visible to the 
 
 naked eye, 12, 43. 
 
 O. 
 
 Octans (constellation), 152. 
 " Omega" Nebula, 126, 129. 
 Ophiuchus (constellation), 34. 
 
 Hind's Nova in, 78. 
 
 " Orbis Lacteus," 136. 
 Orbits of double stars, 56. 
 Orion (constellation), 33. 
 
 Great Nebula in, 122, 129, 149. 
 
 Ovid, Quotations from, 103, 136. 
 
 P. 
 
 Palitzch, observes Algol, 86. 
 Parallax, Stellar, 26. 27, 55. 
 Pavo (constellation), 152. 
 Pegasus (constellation), 32, 34, 35. 
 Perpetual apparition, Circle of, 14. 
 Perpetual occultation. Circle of, 14. 
 Perseus (constellation), 150. 
 
 Cluster in, 101. 
 
 Phoenix (constellation), 150. 
 Photography as applied to stars, 49. 
 Pickering, E. C., 22, 82, 86, 140. 
 Pictor (constellation), 151. 
 Pigott, his theory of variable stars, 
 
 91. 
 
 Pingre, A. G., 77. 
 Pisces (constellation), 35. 
 
 Australis (constellation), 152. 
 
 Volans (constellation), 151. 
 
 Planetary nebulae, 118. 
 Pleiades, 32 34, 35, 102. 
 referred to in Job and Amos, 
 
 102. 
 possibly the centre of the Solar 
 
 System, 75. 
 
 mentioned by Homer, 102. 
 
 nebulae in, 103. 
 
 Pogson, N., Account of nebula in 
 
 Scorpio, 109. 
 Pole-star, Polaris (a Ursae Minoris) 
 
 12, 3 1 . 33, 34- 
 Pole, North, 13. 
 
 , South, 13. 
 
 Pollux 03 Geminorum), 24, 34. 
 Position, Angle of, 54. 
 Prxsepe in Cancer, 102, 105. 
 Precession of the Equinoxes, 37. 
 Pritchard, Rev. C., 22. 
 Proctor, R. A., 134. 
 Procyon (a Canis Minoris), 24, 33, 57. 
 Proper motions of stars, 67. 
 Pythagoras, his speculations as to 
 
 the Milky Way, 136. 
 
 Q. 
 Quadruple stars, 60.
 
 i6o 
 
 GENERAL INDEX 
 
 R. 
 
 Red stars, 63, 66 { 141. 
 
 Regulus (a Leoms), 24, 25, 33, 34, 35. 
 
 Rigel O Orionis), 24. 
 
 Right Ascension, 36. 
 
 Rooerts, I., his photographs, 117, 127. 
 
 Rosse, Earl of, various observations 
 
 by, 106, 115, 117, 118, 119, 121. 
 Russell, H. C., his account of K Cru- 
 
 cis, 114. 
 
 S - 
 
 Sagitta (constellation), 152. 
 Sagittarius (constellation), 35. 
 
 nebulae in, 125. 
 
 Schiaparelli, 104. 
 Schmidt, J. F. )., 78. 
 Schonfeld, E., no. 
 Scorpio (constellation), 35. 
 
 cluster 80 M, 108. 
 
 Sculptor alias Apparatus Sculptoris 
 
 (constellation), 150. 
 Scutum Sobieskii (constellation), 152. 
 
 Nebula in, 126. 
 
 Secchi, A., 45, 116, 123, 140. 
 
 his classification of star spectra, 
 
 140. 
 
 Seidel, 22, 44. 
 
 Serpens (constellation), 152. 
 Sextant (constellation), 33. 
 Shakespeare, W., Quotations from, 
 
 95- 
 
 Shelley, Quotations from, 99. 
 Signs of the Zodiac, 38 (see Zodiac). 
 Sinus (a Canis Majoris), 24, 25, 27, 
 
 57, 70, 91, 140. 
 Smyth, Admiral W. H., 106, 108, 112, 
 
 "3- 
 Spectroscopic observation of stars, 
 
 I 37- 
 
 of nebulae, 147. 
 
 Spica (a Virginis), 24, 25, 34, 35. 
 Spiral Nebulae, 115, 117. 
 Stars, Double, 51, 52, 64. 
 
 Binary, 55. 
 
 Triple, 56, 59. 
 
 Multiple, 62. 
 
 Coloured, 62. 
 
 Variable, 83. 
 
 Temporary, 75, 109, 142. 
 
 Brilliancy of, 21. 
 
 Motions of, 67. 
 
 Names given to, 23. 
 
 Struve, F. G. W.. 48. 
 
 - L T. 
 Taurus (constellation), 33, 34, 35. 
 " Crab " Nebula in, 122. 
 
 Telescopes, List of objects for, 153. 
 
 Telescopium (constellation), 152. 
 
 Tempel, W., 103. 
 
 Temporary stars, 75, 109. 
 
 Tennyson, Quotations from, 100. 
 
 Ternary stars, 57. 
 
 Theophrastus, hislidea of the Milky 
 
 Way, 135. 
 
 Thomson, Quotations from, 100. 
 Time, Measurement of, 9. 
 Toucan (constellation), 152. 
 
 globular cluster in, in. 
 Trapezium in Orion, 62. 
 Triangulum (constellation), 151. 
 Australe (constellation), 152. 
 Triple stars, 60. 
 Tycho Brahe, 77. 
 Types, Secchi's four, 140, 147. 
 
 Ursa Major (constellation), 14, 29, 31. 
 
 - planetary nebula 7 M in, 119. 
 Ursa Minor (constellation), 31. 
 
 V. 
 
 Variable stars, 83, 145, 146. 
 
 - nebulae, alleged, 129. 
 Vega (a Lyrse), 24, 25, 34. 
 Vertical, t6. 
 
 Virgo ^constellation), 33, 35. 
 
 Vitruvius cited, 15. 
 
 Vogel, 140, 145. 
 
 Volans alias Piscis Volans (constel- 
 
 lation), 151. 
 Vulpecula (constellation), 132. 
 
 - " Dumb-bell" Nebula in, 127. 
 
 W. 
 
 "Watling Street," name of the 
 
 Milky Way, 136. 
 " Way to St. James's," name of 
 
 Milky Way, 136. 
 Webb, Rev. T. W 108, 109. 
 Whirlpool or Spiral Nebulae, 117. 
 Williams, J., 77. 
 Wolf-Rayet stars, 141. 
 Wordsworth, Quotations from, 100. 
 Wright, T., 134. 
 
 Y. 
 
 Young, C. A., 74, 
 - (P 
 
 oet), Quotations from, 98. 
 Z. 
 
 Zenith, 16. 
 
 Zodiac, Signs of, 37.
 
 DATE DUE 
 
 PRINTED IN U A
 
 3 1970 00258 1848 
 
 A 000459657 3