Show HkL IIUU R IN 1 THE TARRY 1111St Wonders and Mysteries of the Celestial World f SIGHTS SEEN BY THE AID OF AN OPERA GLASS Good Advice to the Amateurs Fond of Star Gazing Sir Robert Sto > vell Bail Says n Great Observatory niiil Costly Appliances Appli-ances arc Not NcccHMiry to Study the Xebuln Astronomers Often line the Ordinary Opera Glass and IteprluiicrH Should Follow Their Example I I always endeavor to impress on those who are anxious to learn something of the wonders of the heavers that a great observatory ob-servatory fitted with expensive appliances is not absolutely necessary to the would be star gazer No dcubt in one of our great astronomical establishments the visitor 1 vis-itor beholds with astonishment mighty telescopes costing thousands of pounds disposed in special buildings erected at much expense I might therefore not unnaturally be concluded that a instrument instru-ment on a vast scale and of commensurate cost Is Indispensably required whenever celestial work is to be done Of course I need hardly say that there are certain inquiries in-quiries in which these tremendous instru ments cannot be dispensed with There are however many very interesting and Instructive observations possible which only require the very simplest optical assistance On my first visit at night to the observatory obser-vatory of one of the greatest modern astronomers tronomers I was much struck by noticing notic-ing that the instrument he happened to be directing toward the heavens at the time was a common opera glass The beginner be-ginner should follow this example and mace his first acquaintance with the glories glo-ries by the aid of the same familiar form o telescope The special advantage which the oper glass or ordinary binocular possesses pos-sesses for our present purposes consists in the exceptional largeness of the portion o the sky which it permits him to comprehend compre-hend in one glance The beginner who is privileged to explore the begnner through I i rs a mighty telescope often feels I rather disappointed dis-appointed when he finds how small Is the region which Is presented In the field Indeed with one of the greater Instruments Instru-ments It would not be possible 0 exhibit the whole disc of the moon In a single glance The construction of the opera glass Is however such that its held will take In whole constellations at the same time and this is a circumstance which offers a great advantage 0 one who is desirous of obtaining a general notion of the contents of the heavens SEEN IN THE PLEIADES Suppose that the opera glass be turned on any well l known group of stars such for example as en r Y Ke than a most interesting spectacle will be instantly displayed dis-played With the unassisted eye we can interesting spectacle will be Instantly displayed dis-played AVith the unassisted eye we can generally see about half a dozen stars m this group and those persons who aro I endowed with exceptional keen vision can i appears detect as many as ten or a dozen or sometimes even more But the opera glass exhibits to the astonished beholder be-holder thirty or forty or even fifty or sixty stars in this same little constellation constella-tion A glance through it once proves that the stars which we ordinarilv term I the Pleiades are merely the few brightest members among the hundreds 1h constitute con-stitute a mighty I group of glittering points I The great majority uJ this host of stars are too faint to be disclosed to ordinary vision but it only requires such a comparatively com-paratively slight assistance as the opera glass affords to render them conspicuously visible I ought however to add that there are many members of the same cluster clus-ter which are fa to faint to be discernable discern-able even by the most powerful opera glafes but which can be perceived by more efficient telescopes When the full glories glo-ries of the group are displayed by the greatest instruments It is seen to number more than two thousand members WHAT THE TELESCOPE REVEALS The success which the beginner will have had with the Pleiades may it Is to be hoped induce him to direct similar glances to other parts of the sky He will find that whatever part of the heavens he way scrutinize evftganl help l of the opera glass r the field of view Is strewn with a number of stars fa greater than that which his unaided vision ran show in the same region In fact It is not tr much to say that ever the entire heavens a opera glass exhibits a number of stars perhaps ten times n great as can ever be seen with the unaided eye When we remember that each of the stars thus revealed re-vealed Is to be regarded a a sun and that these suns are many of them quite as large and quite n Important as the I sun belonging to our own system then indeed we must admit that the opera gloss has given us a glorious insight into the sublimity of the heavens I But the student who has employed hm self for some nights both pleasantly and profitably I oie studying the different ports I I of the sky with the opera glass will presently feel a desire t see what the stars look like through some more effective I effect-ive instrument I shall therefore suppose sup-pose that he has provided himself with a small telescope which may be let us I I say about three Inches in diameter and ut ti r uf three to four feet in length The young I astronomer will at once notice that his I telescope shows a remarkable advance over the opera glass In power Its capa nllitics will be most easily manifested by the very large number of additional stars I that are disclosed Ihe stars In the sky seem indeed to be almost a far beyond I enumeration n are the sands on the seashore I sea-shore But it Is not only their Increase Iin I numbr which is the specially remarkable remark-able point the beginner will now pay at tentton to the circumstance that manv ob jects wmcn appear to toe unaided vision merely a single stars are really composed com-posed of two or more stars so close together to-gether that the separate points cannot be f discriminated except with telescopic aid The most notable instance of what is called a double star is to be found in MIzar This object may b easily identified identi-fied by observing that It is the middle star of the three wtich form the handle of the constellation known as the dipper or the plow In ordinary language In the language more usual among astronomers Mlzar afe eo middle one of the three stars which form the tai of the great bear So far as the unaided vision Is concerned the only clrcumtstjnce which might attract at-tract particular attention to this object Is the presence of another small star named Alcor quite close to the brighter object The telescope will however at once demonstrate the remarkable fact that Mlzar is composed of two bright stars quite close together The spectacle Is in deed a singularly pleasing one for i shows that the object before us is no less than I pair of twin stars obviously related and associated by invisible bonds How Intrinsically great this double star is may be appreciated from the fact that the larger of the two components r rla nents of Mizar has been guYOt weigh more than ten million times as much a the earth After a little experience the observer will discern that other wi many oter Interesting double stars are else within I the range of the small telescope ei have supposed him to be using Let him observe Castor for instance when he will see a noble pair of suns which revolve each around the other I In a period of a few centuries He must I also look at the wonderful star Theta In the sword handle of the constellation ot Orion There he will be delighted to behold I be-hold a splendid cluster of four bright stars and two smaller points the whole six being so close together as to appear lie a single star except when the power of the telescope is applied DOUBLE STARS But perhaps the most beautiful feature InB l whole of ed ggfe star astronomy i ha yet to be mentioned The wellknown bright stars are usually of a white color I I There are however certain stars more or less tinged with red with yellow or with I orange I happens from some cause or other that in many of the double stars the hues of the components a exceptionally vivid The beauty and delicacy of the spectacle thus presented isnot Infrequently Infrequent-ly enhanced by the circumstances that the tints of eb allied objects are strangely contrasted Here is indeed one of the most pleasing displays which the heavens offer to our contemplation Turn the telescope tel-escope for instance on that famous object ob-ject which indicates the bill of the swan 1 refer to the star called Beta Cygni 0 give it the exact designation which the astronomers tronomers generally employ There will be found a double star of which the larger lar-ger member r 1s truly a gem glittering with the hue of a beautiful topaz while the smaller star associated therewith displays an emerald blue The fact that genuine t o = blue stars a very Infrequent In the heavens makes this exquisite object all the mor worthy of the astronomers attention at-tention teton In spending an hour among the stars we must take core to allot sufficient time for the examination of some of those sub exainaton lime spectacles presented In the great spctaces star clusters By fa the most remarkable te able of the objects so named is that In the sword handle of Perseus This cluster can just be discerned by the unaided eye a a dull point of light When however how-ever the telescope Is directed upon the spot the light is seen t emanate from a myriad of brilliant points which form a miniature richly wrought with beautiful gems I is obvious that all these stars or suns we may perhaps call them are c allied to constitute some mighty system I mghty systm f t esme I In far distant space In the case of other clusters such as the superb globular cluster in Hercules the several stars seen from our point of view appear to be individually fainter than the stars in the cluster of Perseus But what the stars in Hercules group lack in individual indi-vidual brightness they make up for by abundant number This wondertul object consists veritably of a bal of stars so numerous and s close together that in the centl portion we are not able to die porton tinguish the several points We nOn sea the light dispersed from them collectively On the out r regions of this astonishing the stars ore association of stellar paint ac more naturally stelar ly distributed and the different we are thus able to discriminate ferent individuals In this cluster of Hercules Her-cules we have a collection of thousands of stars which occupy only I a very small spot on the sky and are entirely invisible t the unaided eiN STTTTJTKS IN NEBULA Lastly the observer during his hour with the stars should study some of the nebulae both great and small which are so liberally strewn over the heavens No doubt most of these objects are so extremely faint that we have to invoke in-voke the help of really powerful telescopes tele-scopes when we want to do justice to the delicacy and to perceive the full extent of such light stains on the sky The most beautiful of these objects as well as the most celebrated is the great nebula In Orion which lies beneath the well known belt in that constellation and serves as a glorious setting halo around the remarkable multiple star to which I have already referred The great nebula is evidently a stupendous mass of gas which has been heated to a temperature tem-perature so elevated that it glows with a bluish hue characteristic of the particular partic-ular materials of wnlch it Is composed Indeed the light of the nebula when suitably examined discloses to the astronomer as-tronomer the actual elements from which this great structure Is composed I appears ap-pears that the light which this glowing gas yields is of the same character as the light given off by incandescent hydrogen We thus infer that hydrogen is an important im-portant constituent In the composition of this remote celestial body Another object of the same class which which will naturally attract attention is the great nebula in Andromeda this also appears to be a gaseous object but I is plainly of a very different character from the great nebula In Orion The nebula neb-ula In Andromeda is so vast that the whole solar system including all the planets placed at their true distances would form an inappreciable speck i plunged In the mighty glowing mass The owner of a telescope will erelong discover that the heavens contain abundant abun-dant materials for many an hour of delightful de-lightful watching Indeed we may say that years of assiduous labor would be necessary for the diligent observer to make himself fully acquainted with even n small part of the objects which call for his admiration SIR ROBERT STAWELL BALL Royal Astronomer of Ireland Dublin Ireland |