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 London: William Darton; 38. Holborn fill; 7 mo, 2974823. 
 
 
 

 
 
 
 
 
 
 
 
 THE 
 
 WONDERS 
 
 PER PRbsasCOr ws 3 
 
 A DISPLAY 
 
 OF 
 
 THE STARRY HEAVENS, 
 
 
 
 AND OF 
 
 THE SYSTEM OF THE UNIVERSE: 
 
 CALCULATED TO 
 
 PROMOTE AND SIMPLIFY 
 
 
 
 HY H 1 he PT RS ROARS ERT RSLS Teresi 
 
 
 
 
 
 THE STUDY OF ASTRONOMY. 
 
 
 
 WITH COPPER-PLATES. 
 
 —_——— — 
 
 
 
 
 
 
 
 Sree sree ee ae ee SS 
 
 
 
 
 
 od bination ante 
 
 ee ae are 
 a 
 
 PWondon : 
 
 PRINTED (BY ASSIGNMENT) FOR WILLIAM DARTON, 
 58, HOLBORN HILL. 
 
 
 
 
 
 inns 
 
 2 ee = ." 
 
 
 
 
 
 
 
 
 
 OS 
 
 1823. 
 
 a. 
 
Printed by G, SMALLFIFLD, Hackney. 
 
 
 
ADVERTISEMENT. 
 
 THE success of a small Work, published by the 
 same Editor, under the title of The Wonders of 
 the Microscope, has induced him to extend the 
 same plan to the TELEscors, an instrument whose 
 powers have not less contributed to the instruction 
 and amusement of mankind. 
 
 One of these instruments astonishes us by the 
 wonders it displays relative to the infinite divisi- 
 bility of matter and the perfection of ‘objects com- 
 paratively minute, and the other demonstrates our 
 own insignificance, by affording us a glimpse of 
 infinite space, and of the myriads of worlds and 
 systems of worlds by which it is filled. Both are 
 calculated to excite in us sentiments of awe for the 
 Creator of all things, respecting whose omni- 
 potence our ideas are raised a thousand-fold, by the 
 contemplation of the objects to which we are intro- 
 duced by the invention of these two instruments. 
 
 The Author claims the humble merit of intro- 
 ducing his fellow-creatures, in a pleasing and 
 
 
 
popular manner, to the enjoyment of these con- 
 
 templations, which cannot fail at once to make 
 them wiser and better. 
 
 Books of Astronomy have hitherto deterred the 
 inquisitive and young from perusing them, by 
 their technical language, or by the want of those 
 illustrative Plates of which this work proves the 
 subject to be so susceptible. Some of the objects 
 here introduced have never before been drawn, and 
 others are only to be found in the voluminous 
 transactions of learned societies, or in large and 
 expensive works, 
 
 The Author believes, however, that the Plates 
 will be found to be a pleasing, useful, and in- 
 structive part of his work, and, with their aid, he 
 trusts that his Text will prove an agreeable intro- 
 duction to the most sublime of sciences that has 
 hitherto been produced, 
 
 
 
WONDERS 
 
 OF 
 
 THE TELESCOPE. 
 
 Tux Earth, on which we live, is an 
 immense globe or sphere, twenty-five 
 thousand miles round. This is a fact 
 as certain and as well ascertained as 
 any other with which we are acquaint- 
 ed. Standing on the sea-shore, and 
 viewing, with a good telescope, the 
 approach of a vessel, at first its top- 
 mast only is seen; as it approaches 
 nearer, the other parts of the mast will 
 be visible, as if rising out of the-sea-; 
 and at length the whole body of the 
 ship appears. If the sea were an ex- 
 tended plane, the body of the ship, 
 being so much larger than the mast, 
 would be first in view, but, as this is 
 not the case, and the pendant is first 
 A 2 
 
 
 
6 Wonders of the Telescope. 
 
 visible, then the mast, and so on, gra- 
 dually, till the vessel itself comes in 
 sight, it is clear that the Earth and the 
 water are convex, or round. 
 
 A more striking proof is this, that a 
 ship, which sets out from any port, 
 and continues to sail forward in the 
 same direction, will in the course of 
 time come to the same port again; 
 but if the Earth were a flat surface, 
 the farther the ship sailed, the farther 
 would she be from port. Capt. Cook 
 and others have sailed from different 
 parts of Europe, in-a westerly direc- 
 tion, and have, by continuing to sail 
 sn the same direction, after three or 
 four years, found themselves at their 
 own ports again. 
 
 The circular shadow of the Earth, 
 as seen on the Moon during an eclipse 
 of the Moon, isan ocular demonstra- 
 tion of the same principle. 
 
 
 
The Solar System. 7 
 
 The Earth is but one of several other 
 round bodies like itself, called Planets, 
 that circulate or move round the Sun 
 in different periods of time; that is, 
 the nearer a planet is to the Sun, the 
 less time is its period of revolution. 
 
 To the Earth belongs another body, 
 called the Moon, which goes round 
 the Earth, in the same manner as the 
 Earth itself moves about the Sun; and 
 some of the other planets have similar 
 moons. The Sun, the Planets; and 
 their Moons, with other bodies, called 
 Comets, taken together, are called the 
 Solar Systemag 
 
 OF THE SOLAR SYSTEM. 
 
 
 
 Tue Solar System consists of the 
 Sun in the centre; seven-primary pla- 
 nets, viz. Mercury, Venus, the Earth, 
 Mars, Jupiter, Saturn, and the Her- 
 
 ™ 
 
 ~~ 
 
 = reo —5 nant 
 
 — 
 
 : 
 
 | on 
 i 
 ' 
 os 
 "i > 
 Pe 
 oh, 
 if 
 as 
 
 
 
8 Wonders of the Telescope. 
 
 schel, or Georgium Sidus; esghteen 
 secondary planets, viz. the Moon be- 
 longing to the Earth, Jupiter's four 
 satellites, Saturn’s seven, and six be- 
 longing to the Herschel, besides an 
 uncertain number of comets: in addi- 
 tion to these, there have been disco- 
 vered, during the last few years, four 
 other very small planetary bodies. 
 
 The Sun has been properly repre- 
 sented the soul, the animating principle 
 
 of the system, as it not only produces 
 all the necessaries of life, but has a 
 particular influence..in cheering the 
 mind of man. With respect to the 
 system to which we belong, the Sun 
 is that luminary which enlightens all, 
 and his presence constitutes day. 
 
 Great source of day! best image here below 
 
 Of thy Creator, ever pouring wide, 
 
 From world to world, the vital ocean 1ound, 
 
 On nature write with every beam his praise, 
 THOMSON. 
 
 
 
The Solar System. 9 
 
 In the infancy of Astronomy, the 
 Sun was reckoned among the planets, 
 but it is now numbered among the 
 fixed stars. It appears bright and 
 large in comparison of them, because 
 we keep constantly near the Sun, and 
 are at’ immense distances from the 
 stars. For a spectator, placed as near 
 to any star as we are to the Sun, would 
 see that star as large and bright as the 
 Sun appears to us; and toa spectator, 
 as far distant from the Sun as we are 
 from the stars, the Sun would appear 
 as small as the stars seem to us, di- 
 vested of its attendant planets; and in 
 numbering the stars, he would reckon 
 it among them. 
 
 The Sun is about a million times 
 larger than the Earth, and is at the 
 amazing distance of ninety-five mil- 
 lions of miles from us; so that a can- 
 non ball, travelling at the rate of eight 
 
 
 
££ ia 3 
 
 10 Wonders of the Telescope. 
 
 miles in a minute, would, even with 
 that velocity, be more than twenty-Lwo 
 years. in going from the Earth to the 
 Sun. But the rays of light, or the in- 
 definitely small particles that flow from 
 the Sun, travel so fast, that they are 
 only about, eight minutes in coming 
 to us from that body; in other words, 
 they come with a velocity of about two 
 hundred thousand miles in a second of 
 time. What magnificent ideas of the 
 great Creator do the facts, relating to 
 this single body, inspire in the con- 
 templative mind! But when the ef- 
 fects produced by this great Being are 
 but slightly considered, what gratitude 
 should they not call forth from those 
 who daily rejoice under their influence! 
 Let the heart, capable of sublime re- 
 flections, think upon what happens 
 every. bright. morning, 1D the spring. 
 How striking the scene when the glo- 
 
 
 
The Solar System. 11 
 
 nous luminary scatters the clouds with 
 its mild beams! As the illuntination 
 increases, the Earth seems to glow ; 
 darkness and gloom vanish at his ap- 
 pearance; and man, recollecting at 
 the same moment his own weakness 
 and meanness, and, nevertheless, such 
 avast apparatus created for his happi- 
 ness, glories in his habitation, and be- 
 holds it embellished with renovated 
 beauty. The lawn is refreshed by the 
 coolness of the night, and the light of 
 morning displays its increasing yver- 
 dure. The flowers that enamel its 
 surface glitter in the sunbeams, and, 
 like the most brilliant stones, reflect a 
 thousand mingled colours to the eye. 
 The cheerful birds unite in choirs, 
 and hail, in concert, the parent of life: 
 not one is silent; all join, each in his 
 different way, to shout their Maker’s 
 praise. All nature is enlivened by the 
 
 
 
e (Ete hall 
 P VARA ee Cee 
 ; 
 
 ne 
 
 12 Wonders of the Telescope. 
 
 presence of the Sun, and gladdened by 
 his gifts. Millions of glittering insects 
 awake into existence, and flutter in his 
 rays. 
 
 The very dead creation, from thy touch, 
 Assumes a mimic life. 
 
 The bleating flocks and lowing herds 
 salute the welcome blessing. Who 
 can behold with indifference a scene 
 at once so magnificent, so beautiful, 
 and so delightful? ~ Besides all this, 
 
 Bright legions swarm unseen, and sing, unheard 
 By mortalear, the glorious Architect, 
 In this his universal temple, hung 
 With lustres, with innumerable lights, 
 - ‘That shed religion on the soul; at once 
 The temple and the preacher ! 
 
 The nearest planet to the Sun is 
 Mercury, which revolves about him 
 in eighty-eight days: this is the length 
 of his year. Mereury is the smallest 
 of the seven primary planets; and, 
 
 
 

 
 
 
 The Solar System. 13 
 
 being only about thirty-six or thirty- 
 seven millions of miles from the Sun, 
 is rarely seen by the inhabitants of the 
 Earth. The velocity of Mercury about 
 the Sun is at the rate of more than one 
 hundred millions of miles in an hour. 
 The inhabitants of the planet Mercury 
 enjoy a light and heat seven times 
 stronger than what we experience. 
 The second planet in order, 
 
 Fair Venus shines 
 Even in the eye of day; with sweetest beam 
 Propitious shines, and shakes a trembling flood 
 Of soften’d radiance from her dewy locks. 
 
 
 
 
 
 
 
 BARBAULD. 
 
 The distance of this beautiful planet 
 from the Sun is computed at about 
 sixty-six millions of miles. In bulk, 
 Venus is not much less than the Earth. 
 The length of her day and night is very 
 nearly the same as ours, and the length 
 of her year is near two hundred. and 
 B 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 ~~ =, 
 Sa ln SE rE ene er : —<s 
 
 Pipers 
 
 SSS 
 
 =o 
 
 14 Wonders of the Telescope. 
 
 twenty-five of our days ; of course, she 
 travels at the rate of seventy-six thou- 
 sand miles an hour. When this planet 
 appears to the west of the Sun, she 
 rises before him in the morning, and is 
 called the morning star. 
 
 Fair morning star, 
 That leads on dawning day to yonder world, 
 
 The seat of man. 
 MALLET. 
 
 And, when she is east of the Sun, 
 
 she shines in the evening after he is 
 set, and is then called the evening star. 
 She is in each situation, alternately, 
 between nine and ten months, and to 
 these changes Milton alludes : 
 
 Fairest of stars, last in the train of night, 
 
 If better thoa belong not to the dawn, 
 
 Sure pledge of day, that crown’st the smiling 
 morn 
 
 With thy bright circlet. 
 
 The Earta is the next planet in 
 
 
 
The Solar System, 15 
 
 the system, which revolves about the 
 Sun in httle more than three hundred 
 and sixty-five days, at the distance of 
 about ninety-five millions of miles from 
 that luminary. The velocity of this 
 body, in its path round the Sun, though 
 but little more than half the velocity 
 of Mercury, is at the rate of fifty-eight 
 thousand miles an hour, or one hun- 
 dred and twenty times swifter than the 
 velocity of a cannon-ball. The dia- 
 meter of the Earth is nearly. eight 
 thousand miles in length, and she turns 
 on her axis in twenty-four hours, which 
 is the length of our day and night, 
 The equable motion of the Earth about 
 its axis, and the velocity of its course 
 round the Sun, are beautifully described 
 by Milton, in few words : 
 
 
 
 
 
 That spinning sleeps, 
 On her soft axle she paces even, 
 And bears us swift with the smooth air along. 
 
 
 
16 Wonders of the Telescope. 
 
 The rotation of the Earth around 
 her axis every twenty-four hours, from 
 west to east, occasions an apparent 
 
 motion of the heavenly bodies from 
 
 east to west in the same time. 
 
 Beyond the orbit of the Earth is that 
 of Mars, whose distance from the Sun 
 is one hundred and forty-five millions 
 of miles.’ His year is equal to nearly 
 two of our years ; his diameter is more 
 than five thousand miles in length ; 
 his day and night thirty-nine minutes 
 longer than ours; and his_ velocity 
 round the Sun is computed at fifty-five 
 thousand miles an hour. : 
 
 Between the orbits of Mars and Ju- 
 
 piter, the small planetary bodies, lately 
 discovered, revolve: these, on account 
 of their diminutive size, have been 
 termed asteroids by Dr. Herschel. 
 At present, little is known of these 
 bodies ; they have been named Ceres, 
 
 
 
Lhe Solar System. 17 
 
 TFerdinandea, Pallas, Juno, and Vesta. 
 The largest of these, viz. the Ceres, is 
 only about 160 miles in diameter. 
 
 JUPITER is the largest planetin our 
 system; his diameter is more than 
 ninety thousand miles long, and its 
 bulk exceeds the bulk of Venus fif- 
 teen hundred times. Hence he is de- 
 scribed, with regard to magnitude, as 
 travelling 
 
 With kingly state, the rival of the Sun. 
 
 Maver. 
 
 His distance from the Sun is four 
 hundred and ninety-three millions of 
 miles, and he travels at the rate of 
 twenty-nine thousand miles in an 
 hour. His revolution on his axis, or 
 day and night, is not quite equal to 
 ten hours, and his year to nearly twelve 
 of our years. The four satellites of 
 this planet’ are thus referred to by 
 Mallet : 
 
 B2 
 
 \l 
 i 
 
 te AAI ID ~ ceaebaies “ 
 - i = ——s = — 
 
 A - en Sei ee ts 
 
 — —— 
 
 
 
. SSR — eer ee ss 
 FER fo rer get eee 
 
 18 Wonders of the Telescope. 
 
 About him round four planetary moons 
 
 On earth with wonder all night long beheld, 
 
 Moon above moon, his fair attendants dance. 
 
 SaTuRN, next beyond Jupiter, re- 
 volves at almost double his distance 
 from the Sun. His diameter is com- 
 puted at seventy-eight thousand miles, 
 and his diurnal rotation is estimated at 
 
 nearly eleven hours. He travels with 
 
 a velocity of twenty-two thousand 
 miles an hour. This, till the disco- 
 veries of the great Herschel, was sup- 
 posed to be the last planet in our 
 system; its situation as such was beau- 
 
 tifully described by Mallet : 
 
 Last, outmost Saturn walks his frontier round 
 
 The boundary of worlds; with his pale moons 
 
 Faint glimmering through the gloom which night 
 has thrown : 
 
 Deep-dyed and dead o’er this chill globe forlorn: 
 
 An endless desert, where extreme of cold 
 
 . Eternal sits; as in his native seat. 
 
 How much more descriptive must 
 
 
 

 
 The Solar System. 19 
 
 these lines be of the HerscueEt pla- 
 net, which is twice as far from the 
 Sun as Saturn! ‘The diameter of this 
 “ outmost” planet, this “ boundary of 
 worlds,” is something more than thirty- 
 five thousand miles; it travels at the 
 rate of seven thousand miles an hour; 
 and its year is equal to nearly eighty- 
 two of ours. 
 
 Who can contemplate the Power 
 which produced this system, without 
 wonder and admiration ! 
 
 With what an awful, world-revolving pow’r 
 Were first th’ unweildy planets launch’d along 
 Th’ illimitable void!—there to remain, 
 Amidst the flux of many thousand years, 
 That oft has swept the toiling race of men, 
 - And all their labour’d monuments away ! 
 Firm, unremitting, matchless in their course, _ 
 To the kind-tempered change of night and day, 
 And of the seasons ever stealing round, 
  Minutely faithful. Such the all-perfect Hand, 
 That pois’d, impels, and rules the steady whole. 
 Beers haere THOMSON. 
 
 
 
 y 
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20 Wonders of the Telescope. 
 
 Besides the primary planets already 
 noticed, we must not forget their satel- 
 lites, which by astronomers are usually 
 called secondary planets: these revolve 
 round their primaries as centres, in the 
 same manner as the primaries go about 
 the Sun. 
 
 The most conspicuous of the satel- 
 lites is the Moon, “ the beauty of 
 heaven, the glory of the stars.” This, 
 of all the celestial bodies next the Sun, 
 is the most important to us, and has 
 the most beneficial influence upon our 
 globe. 
 
 Array’d in glory, and enthron’d in light, 
 
 She breaks the solemn terrors of the night. 
 
 Broome. 
 
 What a beautiful picture has Mr. 
 
 Pope drawn of a moon-light scene ! 
 
 As when the Moon, refulgent lamp of night, 
 O’er heaven’s clear azure sheds her sacred light, 
 When not a breath disturbs the deep serene, 
 And not a cloud o’ercasts the solemn scene, 
 
 
 
The Solar System. OF 
 
 Around her throne the vivid planets roll, 
 
 And stars unnumber'd gild the glowing pole; 
 O’er the dark trees a yellow verdure shed, 
 
 And tip with silver every mountain’s head ; 
 Then shine the vales, the rocks in prospect rise, 
 A flood of glory bursts from all the skies: 
 
 The conscious swains, rejoicing in the sight, 
 Eye the blue vault, and bless the useful light. 
 
 Such advantages as we derive from 
 our Moon are undoubtedly experienced 
 by the inhabitants of Jupiter, Saturn, 
 and the Herschel, from each of their 
 moons. 
 
 Our Earth is a moon to the Moon, 
 only appearing thirteen times larger 
 to her than she does to us. At new 
 moon to us, the Earth appears to her 
 full. What a majestic sight must that 
 be in the heavens, which would appear 
 from a body of light thirteen times 
 larger than the full moon! The rota- 
 tion of the Moon round the Earth is 
 performed exactly in the same time 
 
 lla 
 
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22 Wonders of the Telescope. 
 
 that she goes round the Earth ; of 
 course, the inhabitants of one-half of 
 the lunar world must be totally de- 
 prived of a sight of the Earth, and 
 remain ignorant of its existence, un- 
 less curiosity should lead them to ex- 
 plore the opposite hemisphere, where 
 they may have a full and glorious 
 sight of our globe, moving majestically 
 through the heavens, and affording as 
 much light to them as thirteen of our 
 moons would at the full. In com- 
 paring it with the Sun, they may well 
 say, 
 +-—__—-— gives us his blaze again, 
 
 Void of its fame, and sheds a softer day. 
 THOMSON, 
 
 Or, according to another poet— 
 
 And see, Day’s amiable sister sends 
 Her invitation, in the softest rays 
 Of mitigated lustre; courts thy sight, 
 - Which suffers from her tyrant brether’s blaze. 
 Youna. 
 
 
 
The Solar System, 93 
 
 Besides the Sun and planets, there 
 are, belonging to the Solar System, 
 other bodies, which are called comets. 
 These are opaque and solid bodies, 
 shining only by the light of the Sun; 
 for when a comet comes to within a 
 given distance from the Earth, it shines 
 much brighter when it is on the same 
 side of the Earth with the Sun, than 
 when it is on the contrary side, which 
 proves that it owes its brightness to 
 that body. The comet which appeared 
 in 1680, was observed to approach so 
 near the Sun, that it became. two thou- 
 sand times hotter than red-hot iron, a 
 heat that would have certainly dissi- 
 pated it, if it had not been a very fixed 
 and solid body. 
 
 A comet thus heated must retain its 
 heat a long time. Fora red-hot globe 
 of iron an inch in diameter, ex posed to 
 the open air, scarcely loses all its heat 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 24 Wonders of the Telescope. 
 
 invan hour, but a larger globe will re- 
 tain its heat much longer ; and it has 
 been calculated that a globe of red-hot 
 iron, as large as our Earth, would 
 scarcely cool in fifty thousand years. 
 
 We shall now proceed to a telescopic 
 view of the principal bodies belonging 
 to the Solar System, beginning with 
 the Sun. 
 
 OF THE SUN, 
 
 AS VIEWED WITH THE TELESCOPE. 
 
 Tue Sun, being evidently the source 
 of light and heat, was considered by 
 the ancients as a globe of pure fire. 
 The discovery of the telescope, how- 
 ever, furnished the means of making a 
 more accurate inquiry ; and, from the 
 dark spots found on many parts of his 
 surface, that opinion was quickly shewn 
 to be ill-founded. 
 
Plate 2 fr 
 
 AS SEEN THROUGH A TELESCOPE, 
 London:William Darton; 58,Holbern fill; 7 Imo. 29% 1823, 
 
 
 

 

 
 
 
 The Sun. 95 
 
 These spots consist, in general, of a 
 nucleus, or central part, which appears 
 much darker than the rest, and seems 
 to be surrounded by a mist, or smoke ; 
 and they are so changeable, in their 
 situation and figure, as frequently to 
 vary during the time of observation. 
 Some of the largest of them, which are 
 found to exceed the bulk of the whole 
 Earth, are often to be seen for three 
 months together ; and when they dis- 
 appear, they are generally converted 
 into faculze, or luminous spots, which 
 appear much brighter than the rest of 
 the Sun. About the time they were 
 first discovered by Galileo, forty or fifty 
 of them might be frequently seen on 
 the Sun at atime; but, at present, we 
 seldom observe many, and there have 
 been periods of seven or eight years in 
 which none could be seen. 
 
 When we look at the Sun through a 
 
 SESS c 
 
 ie 
 ia 
 , a 
 ; 
 
 EEO eT 
 _ — < 
 
 TSS aes 
 
 OE Be = = oa 
 al oe " ee = r= a 2 
 
 te: 
 
 
 

 
 
 
 96 Wonders of the Telescope. 
 
 telescope, even of moderate magnifying 
 power, and sometimes with the naked 
 eye, we discover these black, or rather 
 less bright, spots of various sizes and 
 shapes. They will frequently vanish 
 in a very short time after their first 
 appearance, and sometimes travel over 
 his whole disk, or visible surface, from 
 east to west, when they disappear ; 
 and, after twelve or thirteen days, ap- 
 pear again, so as to be known by their 
 magnitude and figure to be those that 
 had disappeared before. 
 
 These solar spots have occasionally 
 excited the attention of the most cele- 
 brated observers, and have been very 
 differently explained. By some it has 
 been supposed, that they are occasion- 
 ed by the smoke and opaque matter 
 thrown out by volcanoes, or burning 
 mountains of immense magnitude; 
 and that when the eruption is nearly 
 
 4 
 
 -_—~——* 
 
 
 
 : 
 : 
 

 
 
 
 The Sun. 27 
 ended, and the smoke dissipated, the 
 fiery flames are exposed, and have the 
 appearance of the facule, or luminous 
 spots. -.Others have imagined the Sun 
 to be in a continual state of fusion, and 
 that the spots we observe are the emi- 
 nences of large masses of Opaque mat- 
 ter, which, by the wregular agitations 
 of the fluid, sometimes swim on the 
 surface, and at other times sink and 
 disappear. Others havesupposed them 
 to be occasioned by a number of pla- 
 nets which circulate round the Sun, at 
 a small distance from his surface. The 
 Sun itself has been called a globe:of 
 fire, and there have been calculations 
 to ascertain the waste it would undergo 
 by a gradual consumption, and its 1m- 
 mense power of heating the bodies 
 which approach it. . 
 
 A long list of successive eminent 
 astronomers, from Galileo down to the 
 present time, have furnished us with 
 
 
 

 
 28 Wonders of the Telescope. 
 
 materials for a more accurate examina- 
 tion of this subject ; and later obser- 
 vations, made with the assistance of 
 more perfect and powerful telescopes, 
 have determined that most, if not all 
 the spots, are excavations in a coat of 
 luminous matter which environs the 
 Sun’s body, and is probably of no great 
 depth. There have been spots on his 
 face so large as to be seen with the 
 naked eye. In the year 1779, a re- 
 markable one of this kind was dis- 
 tinctly and easily visible, whenever 
 the Sun’s brilliancy was reduced by a 
 fog, or by guarding the eye with a 
 smoked glass: through a telescope of 
 great magnifying power, it appeared to 
 be divided into two parts, the larger of 
 which was calculated to be thirty-one 
 thousand miles in length, and both to- 
 gether must certainly have extended 
 above fifty thousand miles, 
 
 Dr. Herschel, whose immense tele- 
 
 
 

 
 
 
 The Sun. 29 
 scopes gave him so great an advantage 
 in the examination of the heavenly 
 bodies, had made the most accurate 
 research on the nature of the Sun and 
 his spots : he concluded that, in the 
 
 instance of the large spot referred to, 
 
 he viewed the real body of the Sun 
 itself, of which, at other times, more 
 is rarely to be seen than its shining 
 atmosphere. 
 
 Krom a course of highly interesting 
 observations, which this learned astro- 
 nomer had pursued for many years, he 
 wasof opinion that the difference which 
 we have been accustomed to imagine 
 between the Sun and the rest of the 
 planets, is in a considerable degree re- 
 moved. Under these circumstances, 
 said he, ‘‘ the Sun appears to be no- 
 thing else than avery eminent, large, 
 arid jucid planet, evidently the first, 
 or rather the only primary one of our 
 
 c2 
 
 
 
 8 Sw re een ete meena, ene anes 
 RR ST, —— 
 = ad ae ee er ee on 
 

 
 30 Wonders of the Telescope. 
 
 system, all the rest being truly se- 
 condary to it. Its similarity to the 
 other globes of the Solar System, with 
 regard to its solidity, its atmosphere, 
 and its diversified surface ; to the ro- 
 tation upon its axis, and the fall of 
 heavy bodies on its surface, lead us to 
 suppose that it is most probably also 
 inhabited, like the rest of the planets, 
 
 by beings whose organs are adapted to” 
 
 the peculiar circumstances of that vast 
 globe.” 
 
 It may be objected to the idea of the 
 Sun’s being habitable, that, as his heat 
 is so considerable to us, at the distance 
 of ninety-five millions of miles, the sur- 
 face of the globe of the Sun itself must 
 be scorched up beyond all conception. 
 Dr. Herschel answered this, by many 
 
 substantial proofs, drawn from natural 
 
 philosophy, which shew that heat is 
 produced by the Sun’s rays only when 
 
 
 

 
 The Sun. 31 
 
 they act upon a calorific medium: 
 they cause the production of heat, by 
 uniting with the matter of fire which 
 is contained in the substances that are 
 heated, as the collision of flint and 
 steel will inflame a magazine of gun- 
 powder, by uniting with its latent fire, 
 and bringing the whole into action. 
 But a familiar instance or two of the 
 manner in which the solar rays pro- 
 duce their effect, will bring this home 
 to our most common experience. 
 
 ‘‘ On the tops of mountains, and at 
 heights to which the clouds seldom 
 reach to shelter them from the: direct 
 rays of the Sun, we always find regions 
 of ice and snow. Now, if the Sun’s 
 rays themselves conveyed all the heat 
 we find on the Earth, it would of course 
 be hottest in situations similar to the 
 tops of mountains, where their course 
 is least interrupted. But all - those 
 
 : 
 : 
 : 4 
 4 
 i 
 + 
 ) 
 ‘ 
 { 
 : 
 ‘ 
 : 
 , 
 } 
 wg 
 5 
 ‘a 
 , 
 a4 
 a 
 ¥ | 
 4 
 : a 
 
 a I ae 
 are = ——. o 
 
 a es 
 
 — eo 
 - - es = 
 
 ee ete eed 
 mA 
 
 aes 
 
 ern 
 a : = 
 
 ne —_ 
 
 
 

 
 52 Wonders of the Telescope. 
 
 who have ascended in balloons confirm 
 the coldness of the upper regions of 
 the atmosphere; and since, therefore, 
 even on the Earth, the heat of any 
 situation depends upon the facility 
 with which the medium yields to the 
 impression of the Sun’s rays, we have 
 only to admit, that on the Sun itself, 
 the fluids composing its atmosphere, 
 and the matter on its surface, are of 
 such a nature as not to be capable of 
 any excessive heat from its Own rays, 
 
 “ It is alsoa well-known fact, that 
 the focus of the largest burning lens, 
 thrown into the air, will occasion no 
 heat in the place where it has been kept 
 for a considerable time, although its 
 powers of exciting heat when proper 
 bodies are exposed to it, should be suf- 
 ficient to melt or fuse the most refrac- 
 tory metals,” 
 
 Dr. Herschel-shewed that the noid 
 
 
 

 
 The Sun. 33 
 substance of the Sun is not-a liquid, 
 noran elastic fluid, but that it exists in 
 the manner of luminous clouds swim- 
 ming in the transparent atmosphere of 
 the Sun; and he considered that there 
 are two different regions of solar clouds, 
 the lower of which consists of clouds 
 less bright than those which compose 
 the upper stratum. 
 
 Viewed through a telescope of great 
 magnifying power, the Sun’s face ap- 
 pears equally mottled all over, but the 
 little unevennesses which produce this 
 appearance are better seen near the 
 middle of his disk, than towards the 
 circumference, on account of his sphe- 
 rical form. The spots will, from the 
 same circumstance, be seen of around- 
 ish figure when they are near the mide 
 dle of his disk, and oval when they 
 remove towards the edges of it. Some 
 parts will also be obseryed)§ much 
 
 
 
 
 

 
 
 
 
 
 
 34 Wonders of the Telescope.. 
 
 brighter than the general face; these 
 are sometimes disposed in long streaks, 
 and sometimes in small, but highly 
 elevated and luminous spots. 
 
 Dr. Herschel, in consequence of the 
 improvements in his telescope, and the 
 advances in his knowledge of the 
 construction of the Sun, rejected the 
 old_ terms of nuclet, penumbre, and 
 iuculi, by which the spots have been 
 hitherto distinguished, and substituted 
 those of openings, shallows, ridges, 
 nodules, corrugations, indentations, 
 and pores. 
 
 The definitions or meaning of these 
 terms, with an account of the most 
 striking appearances, will direct the 
 young observer to the proper objects 
 of inquiry, and will both give an inte- 
 rest to his own observations, and ena- 
 dle him to understand those of others. 
 Openings are places where the lumi- 
 

 
 
 
 The Sun. 55 
 nous clouds of the Sun are removed, so 
 as to exhibit the opaque globe of the 
 Sun through the aperture. The pro- 
 bable cause of openings is, that a wind, 
 or gas, issues from the Sun’s_ body 
 through the smaller openings, and 
 spreads itself on the luminous clouds, 
 forcing them out of the way, and 
 widening its passage. The direction 
 and operation of this wind are not 
 equally extended on all sides, but are 
 frequently oblique, so that the lumi- 
 nous clouds seem to be driven. and 
 form a large shallow on one side. 
 
 There is sometimes a difference in 
 the colour of openings, apparently from 
 a thin veil of luminous clouds hovering 
 above them; when the openings are 
 decaying, they frequently divide ; the 
 luminous passage across the opening at 
 these times resembles a bridge thrown 
 over a cave or hollow space: witha 
 
 aera 
 
 
 
 J PITTS 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 36 = Wonders. of the Telescope. 
 
 telescope of great power the depth of 
 these openings is easily visible. 
 Shallows are parts depressed below 
 the general surface of the Sun, and are 
 places where the luminous solar clouds 
 of the upper regions are removed, and 
 leave similar clouds visible in the 
 lower regions, still covering the real 
 body of the Sun. Their depth is also 
 visible, and they frequently exist with- 
 Out openings in them. They either 
 begin from the openings, or branch out 
 from shallows already formed, and go 
 forward. They seem to be occasioned 
 by the wind or gas from the openings, 
 which, by its propelling motion, drives 
 away the luminous clouds from the 
 place where it meets with the least 
 resistance, or which, by its nature, dis- 
 solves them as it comes up to them. 
 They have somewhat the appearance 
 of a collection of dense tufted clouds. 
 
 
 
 ; 
 | 
 

 
 The Sun. 37 
 
 Ridges are elevations above the ge- 
 neral surface of the luminous clouds 
 of the Sun. These have been seen of 
 seventy-five thousand miles in length. 
 They generally surround the openings, 
 but are sometimes seen in other parts 
 of the Sun’s surface: they disperse 
 very quickly. 
 
 Nodules are small, but highly ele- 
 vated, luminous places, ‘and, being 
 never seen near the middle of the Sun’s 
 disk, they are supposed to be ridges 
 fore-shortened to our view, by: their 
 situation on the Sun’s spherical sur- 
 face. 
 
 Corrugations are collections of small- 
 er elevations and depressions of ‘the 
 luminous matter. They have a:mot- 
 tled appearance, consisting» :of dark 
 and bright places. Many of the:dark 
 places are not round, but a little ex- 
 tended in different directions, and 
 
 D 
 
 
 

 
 
 
 
 38 Wonders of the Telescope. 
 
 appear to be lower than the bright 
 places; and on favourable days the 
 corrugated surface presents its eleva- 
 tions and depressions as distinctly as 
 the rough surface of the Moon, It 
 generally extends over the whole sur- 
 face of the Sun. The dispersion of 
 ridges and nodules produces the ap- 
 pearance of a corrugated surface. They 
 frequently change their shape and si- 
 tuation, increase and diminish, divide 
 and vanish very quickly. 
 
 The dark places of corrugations are 
 andentations. ‘They are extended over 
 the whole surface of the Sun, and with 
 
 a telescope of moderate magnifying 
 power, they appear like points, or small 
 
 specks, 
 
 Pores are the lowest places of inden- 
 tations. They occasionally increase 
 and become openings, and frequently 
 vanish in a short time. 
 
 
 
 
 
 
 
 
 
 
The Sun. 39 
 The young observer may view the 
 spots and variegated surface of the Sun 
 with a refracting telescope of two or 
 three feet, or a reflecting one of twelve 
 inches, eighteen inches, or two feet, 
 taking the precaution to guard the eye 
 with a smoked or dark-coloured glass, 
 to take off the glaring light; or the 
 image or picture of the Sun with his 
 spots, &c. may be thrown into a dark 
 room by means of a camera-obscura, 
 or scioptric ball and socket, or through 
 a telescope, and received on a semi- 
 transparent screen, or a white sheet. 
 Besides the solar spots, the zodiacal 
 light is a singular phenomenon which 
 accompanies the Sun, and is usually 
 attributed to the atmosphere. It be- 
 gins to appear a little before sun-rise, 
 and seems at first like a faint whitish 
 zone of light, resembling the milky 
 way, with its borders ill terminated, 
 
 4 
 | 
 f 
 
 4 
 
 { 
 
 . ss — n< 
 SSS Se “ 
 
 eee et 
 ; Bart) Baa eS sat 
 Tee eee tee a 
 
 
 

 
 
 
 40 Wonders of the Telescope. 
 
 and scarcely to be distinguished from 
 the twilight which is seen commencing 
 mear the horizon. It is then but little 
 elevated, and its figure nearly agrees 
 with a spheroid seen in profile. As it 
 rises above the horizon, it becomes 
 brighter and larger to a certain point; 
 after which the approach of day renders 
 it grad ually less apparent, till it be- 
 comes quite invisible. 
 Such, then, is the Sun: 
 Soul of surrounding worlds ! in whom best seen 
 Shines out thy Maker! may I sing of thee? 
 "Tis by thy secret, strong, attractive force, 
 As with a chain indissoluble bound, 
 Thy system rolls entire: from the far bourne 
 Of utmost Herschel wheeling wide his round 
 Of eighty years; to Mercury, whose disk 
 Can scarce be caught by philosophic eye, 
 Lost in the near effulgence of thy blaze. 
 Tuomson. 
 
 
 
 
 
 
 
 

 
 OF MERCURY, 
 
 AS SEEN THROUGH THE TELESCOPE. 
 
 
 
 MeERcuRY is a small star, which 
 emits a very bright light ; but on ac- 
 count of his always keeping near the 
 Sun, he is seldom to be seen; and 
 when he does make his appearance, 
 his motion towards the Sun is so swift, 
 that he can only be discerned for a 
 short time. Of course there is but 
 little opportunity given to astronomers 
 to examine it; when, however, it is 
 looked at through a telescope that 
 magnifies two or three hundred times, 
 it appears equally luminous throughout 
 his whole surface, without the least 
 dark spot. He appears to have the 
 same difference of phases, as will be 
 described as belonging to the Moon, 
 being sometimes horned, sometimes 
 
 D; 
 
 
 
yr 
 
 
 
 = = ee = 
 
 ee 
 ae . 
 om a se.. 
 2 ee 
 
 eS 
 
 Re niet 
 Hel 
 r, 
 ; 
 ? 
 
 RLY 
 
 42 Wonders of the Telescope. 
 
 gibbous, and sometimes shining, almost 
 with a round face, though not entirely 
 full, because his enlightened side is 
 never turned directly towards us ; but 
 at all times perfectly defined, without 
 any ragged edge, and perfectly bright. 
 
 The great comet that appeared in 
 the year 1744, came so near Mercury, 
 that it was supposed the planet would 
 have been disturbed by its attraction. 
 Its situation with regard to the Sun is 
 such, that water would be kept con- 
 tinually boiling on that part of its sur- 
 face that is opposite tothe Sun. To 
 this circumstance Baker alludes in his 
 poem, entitled ** The Universe :” 
 
 First Mercury, amidst fali tides of light, 
 Rolls next the Sun, through his small circle bright. 
 All that dwell here must be refin’d and pure ; 
 Bodies like ours such ardour can’t endure ; 
 
 Our earth would blaze beneath so fierce a ray, 
 And all its marble mountains melt away. 
 
 
 
: 
 : 
 | 
 N 
 
 
 

 
 Sr EN | ia 
 
 OF VENUS, 
 
 . AS SEEN THROUGH THE TELESCOPE, 
 
 VeENus appears to us the brightest 
 planet of the system ; she is to be dis- 
 tinguished from them all: by a supe- 
 riority of lustre ; her light is of a white 
 colour, and is so considerable, that, in 
 a dusky place, she projects a sensible 
 shadow. She appears to us constantly 
 near the Sun; never farther from him 
 
 ’ 
 : 
 fo. 
 ' = 
 ’ 
 4 
 
 than about forty-seven or forty-eight 
 
 degrees. She is never seen at or near 
 
 =) 
 
 midnight, or in opposition to the Sun, 
 » but is visible to us only for three or. 
 } four hours in the morning, or evening, 
 | according as she is before or after the 
 | Sun; and hence it is that this planet 
 | has Recuired the name of the Morning, 
 and Evening Star, . een cet 
 
 ~ en 
 — —- : {ime 
 £. 
 - ——— 
 
 m= 
 
 
 
me ee | 
 
 ' 
 
 44 Wonders of the Telescope. 
 
 Fair Venus next fulfils her larger round, 
 
 With softer beams and milder glory crown’d : 
 Friend to mankind, she glitters from afar, 
 
 Now the bright Ev’ning, now the Morning Star. 
 
 BAKER. 
 
 If we view Venus through a good 
 telescope of considerable power, when 
 she follows the Sun on the eastern side, 
 and appears above the horizon after 
 sunset, we shall see her nearly round, 
 and but small ; she is, at that time, be- 
 yond the Sun, and presents to us her 
 whole enlightened hemisphere. As 
 she departs from the Sun towards the 
 East, she increases in her apparent 
 size, and is seen to alter her figure, 
 abating of her roundness, and appearing 
 successively like the Moon in the dif- 
 ferent stages of her decrease. At 
 Jength, when she is at her greatest 
 apparent distance from the Sun, she is 
 like the Moon in her first quarter, and 
 
 at 
 fp 
 E a 
 x i 
 ry 
 in 
 | 
 4 ‘ 
 2 i 
 4 4 i 
 2 | = F 
 ce wl 
 ’ a 
 nip | 
 i - 
 ai? 
 a Dp Teen 
 S abe 
 Hh 
 ; 
 Lom 
 ae 
 a ee. 
 rx | 
 + (eal | 
 ay { 
 bee i 
 iy 4 
 Ye. 
 5 
 r te 
 11h om 
 ry 
 | az 
 > aR an: 
 , a} 
 eae | 
 Ht 
 \ Me 
 5 if 
 me oe 
 ‘ ht 4 
 aad 
 vee 
 j { 
 
 75, 
 ef 
 ory) 
 : 
 ii: 
 
 
 
Oe 
 
 Venus. Ad 
 
 appears as she does, when from a full 
 she has decreased to a half moon. 
 
 After this, as she seems to approach 
 the Sun, she appears concave in her 
 illuminated part, as the Moon when 
 she forms a crescent; and she con- 
 tinues thus till she is entirely hidden 
 in the Sun’s rays, and then, presenting 
 to us her whole dark hemisphere, she 
 becomes invisible. 
 
 When she leaves the Sun’s rays on 
 the western side, we see her in the 
 morning just before day-break. In 
 this situation, Venus is called the 
 Morning Star, as in the other, she is 
 called the Evening Star. It is at this 
 time that she appears the most beau- 
 tiful, like a fine thin crescent, of a very 
 bright silver light. From this period 
 she grows more and more enlightened 
 every day, till she is arrived at her 
 greatest apparent distance from the 
 
 a 
 
 2 reer bates 
 Sl a ed Fetes o> 
 
 i 
 4 
 
 ett a emt 
 
 nip vatbactibt Adadiath, 
 — lS eee 
 
 
 
aw, 
 
 AG Wonders of the Telescope. | 
 
 Sun, when she again appears as a half 
 moon, or as the Moon in her first | 
 quarter; if still continued to be ob- 
 served with the telescope, she is found 
 to be more and more enlightened, | 
 though she is all the while decreasing 
 in magnitude, and thus goes on grow- 
 ing smaller and rounder, till she is 
 again hidden, or lost in the Sun’s rays. 
 Venus, when she appears in the 
 shape of a crescent, and at the times 
 of her greatest brightness, affords a 
 more pleasing telescopic view than any 
 other of the heavenly bodies ; her sur- 
 face is diversified with spots, like the 
 Moon, and, by the motion of these, we 
 discover the time she takes up inre-_ , 
 volving upon her axis. With a very 
 powerful telescope, mountains may 
 also be seen, as on the Moon. 
 Both bright and dark spots have 
 occasionally been seen on the face of 
 
 
 
Venus. 47 
 Venus, the most singular of which are 
 represented in the plate. They can 
 only be observed, however, with a very 
 good telescope, and when the air is 
 clear. 
 
 A day and a night in the planet 
 Venus, are about as long as twenty- 
 three days and nights and a half with 
 us ; and from her axis being very con- 
 siderably inclined to her orbit, the 
 variation of her seasons must be very 
 great, and the length of her days and 
 nights differ very much in proportion 
 to each other. She seldom has the 
 forenoon and afternoon of the same 
 day of an equal length, and some parts 
 of her surface enjoy the four. seasons 
 twice every year. 
 
 Venus is occasionally seen to pass 
 over the disk or face of the Sun, 
 having the appearance of a round dark 
 spot. This appearance is called a 
 
 ‘ 
 r / 
 t 
 = 
 : a 
 a 
 } 
 i | 
 i) \ 
 j 
 h : 
 
 Rae TT + repens er 
 
 Wasa a ars ae 
 
 
 
Se 
 
 a eee 
 a 
 
 i 
 ; 
 1 
 | 
 \ 
 
 0 So eee ym 
 es 
 
 ~ ae 
 
 <<) - 3 = 2 Sw - ip eal cl the ns 
 ee ae ee ee ss —— ~ . 
 ee es eels 2 ss > ile =) 
 
 + Penny 
 
 ale asi ie cee ee 
 
 
 
 Facum eee ree 
 = — r sear 
 
 Sees 
 
 = 
 
 =< eS 
 aeons ITE ee 
 
 * 
 
 ~hmwng- a - 
 cat eee SEE 
 
 SS ne “ 
 = ade a Ba ; ; 
 Semareasaemecmae RE se ede 2 RE renee signe = 
 ——._> . : fier 
 x oe 7 
 
 ae See 
 
 48 Wonders of the Telescope. 
 
 transit: it happens but very seldom ; 
 though there have been two within 
 these fifty years, the one in June 
 1761, and the other in June 1769: 
 another will take place in the. year 
 1874. 
 
 The inhabitants of Venus see the 
 planet Mercury always accompanying 
 the Sun; and he is to them, by turns, 
 an evening and a morning star, 
 
 
 
 OF THE MOON, 
 
 AS VIEWED THROUGH THE TELESCOPE. 
 
 
 
 More distant still, our Earth comes rolling on, 
 
 And forms a wider circle round the sun : 
 
 With her the Moon, companion ever dear ! - 
 Her course attending through the shining year. 
 
 | BAKER. 
 Or all the curious discoveries which 
 the telescope has. afforded us, those 
 relating to the ‘Moon are ‘much the 
 

 
 ii, 
 
 . 
 
 
 
 
 
 
 
 y 
 
 ip iT i 
 * " a . 
 y 1 4 a 
 
 
 
 
 
 
 
 
 
 
 
 SSS SSS 
 ———————————SSSTS=— 
 —d === 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 is ti 
 
 Hi 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 or == —— 2 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 THROUGH A TEI 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ANI 
 ith | / HATH 
 HAMM!) Halt eM 
 Hi i v By HY i 
 er TNA 
 Ahi ea 
 WA 
 ; AIAN ue 
 WAT ATT 
 Wal 
 
 i Ns, 
 2% 
 
 ™ 
 hn ane : 
 
 | 
 ii] HI 
 | il iH} 
 
 A 
 
 " i i i ~ 
 | : | | ‘| 
 | S nt sl | 4 / ll a ’ Me e 
 ae f 4 ‘ tH 
 
 Ak aed, 3 A 
 
 il ty 
 
 ay, e 
 a | : .. i. | 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 ——— SSS 
 
 
 
 
 
 
 
 
 
 
 
 HITT Ht | Hi ih { | 
 WHE Heil HH} 
 Wi ai (UHI GHHHI ) Hit 
 WH DAN HINT TL 
 Wt ; i] | : | 
 AANA AA 
 NNT iH} | i} 
 | i HH Hh ) eH 
 WA HAMA . ik 
 1 Hi MATH I tie 
 AN AMG AAA ct ih 
 AAAI A | ! 
 AW AAT AAR 
 Wit i | i | Mi \ H | 
 HH | Hit 
 WA i} / 
 HH} Wh } | 
 ny Wi NN 
 \ | iH Hy 
 1 o | } lj 
 | 
 WT 
 } Wil HHH | 
 st With 
 
 
 
 
 
 
 
 tht | ii 
 i | MUTANT EG HI | ® , 
 HI 
 a | | 
 HN} 
 
 i 
 v il 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 “ 
 
 
 
 ——<————— 
 
 
 
 
 
 = ———— 
 SSS SS = 
 = SSS F 
 SS 
 SSS 
 —S= 
 : === SS 
 
 
 

 
 
 
 
 

 
 St 
 
 The Moon. = GY 
 
 most interesting; she appears to us 
 next in splendour to the Sun, and, 
 being the inseparable companion of 
 our Earth, and considerably nearer to 
 
 us than any other of the heavenly 
 
 bodies, is naturally that to which an 
 observer will direct his chief attention. 
 
 Viewing her with the naked eye, we 
 observe several darkish spots, which, it 
 is easy to imagine, are produced by a 
 breaking up of her surface into irregu- 
 lar portions of land and water, as on 
 our. Earth. These, when examined 
 with the telescope, are prodigiously 
 increased in number, and are found to 
 extend themselves in great variety Over 
 her whole surface; she also appears 
 very plainly to be more protuberant in 
 the: middle than at the edges, or to 
 have the figure of a globe, and not a 
 flat circle, as to the naked eye. 
 
 Some remarkable spots are con- 
 
 E 
 
 
 

 
 
 
 50 Wonders of the Lelescope. 
 
 stantly found, in dark shadows, on 
 the side opposite to the Sun, and light 
 on the side next to him: other spots 
 are as constantly observed to be illumi- 
 nated on the farthest side, and dark on 
 the nearest. Both these shadows be- 
 come shorter, as the Sun shines more 
 directly on her face, or as she ap- 
 proaches the full; and, at the time of 
 complete full moon, they disappear 
 altogether. During the third and last 
 quarters, the shadows appear again ; 
 but all, fall towards the contrary side 
 of the Moon, though still with the 
 same distinction, namely, that one set 
 of spots are dark and shady on the side 
 farthest from the Sun, and the other 
 dark on the side near the Sun. 
 Astronomers infer from hence, that 
 the first sort of spots are hills, and the 
 latter, valleys. Indeed, if we compare 
 these appearances with what we ob- 
 

 
 The Moon. 51 
 
 serve of the effect of sunshine on the 
 hills and valleys of the earth, we shall, 
 without difficulty, agree to their being 
 hills and hollows also. 
 
 When the Moon is horned and gib- 
 bous, one side appears exactly defined 
 and circular, but the other very ragged 
 and uneven. ‘There is, then, no regu- 
 lar line bounding light and darkness, 
 but the confines of these parts appear, 
 as it were, toothed, and cut with innu- 
 merable notches and breaks ; and, even 
 in the dark part, near the borders of 
 the shining surface, small spaces may 
 be seen, which are illuminated by the 
 Sun. About the fourth or sixth day 
 after new Moon, some lucid points 
 may be perceived, like rocks or small 
 islands, within the dark body of 
 the Moon; near the southern edge, 
 other little spaces may be observed, 
 which join to the enlightened surface, 
 
 
 

 
 
 
 
 
 52 Wonders of the Telescope. 
 
 but project into the dark part. These 
 will be found to change their figure 
 gradually, till, at length, they come 
 wholly within the illuminated face, 
 and have no dark parts round them 
 at all. Other shining spaces may be 
 observed to arise in succession, and 
 appear within the darkened part of the 
 Moon, which, before, were totally im- 
 mersed in shadow, and consequently 
 invisible. In the decreasing phases of 
 the Moon, the contrary may be ob- 
 served; the lucid spaces, which were 
 before included in the general illumi- 
 nated surface, gradually recede from 
 it, and, remaining visible for some time 
 in their insulated state, disappear alto- 
 gether. These, also, are facts which 
 tend to prove the shining points to 
 be higher than the Moon’s general 
 surface. 
 
 The appearance of these enlightened 
 
 . hn ee eee 
 

 
 The Moon. - 55 
 spots, before and after the rest of the 
 surface, furnishes an easy method to 
 practical astronomers, to determine the 
 actual height of the mountain to which 
 they belong. Some of them are found 
 to be more than one mile and a half 
 high. 
 
 Where mountains rise, umbrageous dales descend, 
 And caverns deep, as optic tube descries. 
 THOMSON. 
 It has been ascertained, with tele- 
 scopes of great magnifying power, that 
 voleanic eruptions exist in different 
 parts of her surface, similar, in appear- 
 ance and effect, to our volcanic moun- 
 tains of A<tna and Vesuvius. The 
 large masses of stone which are said 
 to fall from the clouds, are imagined 
 by some to be projected with such 
 violence from these lunar volcanoes, 
 as to come within the influence of 
 E 2 
 
 
 
--——= 
 
 rs An - 
 Bs eee me ene ae 
 
 
 
 _ 
 
 ay egg . 
 
 v 
 ~ a 
 et gee 
 
 * 
 — 7 a 
 — a ee eS Sere te Sse Sas re 
 A - — ns ae aniline 
 = 7 a - NO = _ _ 
 ' 
 
 
 
 54 Wonders of the Telescope. 
 
 the Earth’s attractive power, and so 
 brought to her surface. 
 
 The highly-interesting appearance 
 of the Moon, as well from its frequent 
 change of figure as its vicinity to us, 
 naturally made it an object of early 
 examination for the telescope. We 
 find, accordingly, the inventors of the 
 instrument were the first who observed 
 the inequalities of her surface. These 
 discoveries were followed with so 
 much attention and industry, by suc- 
 ceeding astronomers, that drawings, or 
 maps, of her face, were made within a 
 few years; and these have been gra- 
 dually perfected with the improve- 
 ments of the instrument. 
 
 The figure and situation of every 
 spot is delineated as they appear 
 through a telescope, which magnifies 
 about two hundred times, and are 
 
 
 
4 
 
 
 
 The Moon. 55 
 
 each distinguished by a proper name. 
 Riccioli, Cassini, and others, portioned 
 out the lunar regions among those phi- 
 losophers and astronomers who had 
 distinguished themselves in the sci- 
 ence, giving the names of the most 
 celebrated characters to the largest 
 spots, and those of less eminence to 
 the smaller. Another astronomer, 
 Hevelius, denoted the different parts 
 of the Moon by such geographical 
 names as belong to the several islands, 
 countries, and seas, of our Earth; but 
 without regard to similarity of situation 
 or figure. Riccioli’s method, however, 
 is now generally followed: the names 
 of Copernicus, Tycho, Galileo, &c. 
 seeming more appropriate to the sub- 
 ject than those of Egypt, Africa, the 
 Mediterranean Sea, &c. 
 
 The Moon being an opaque body, 
 like the Earth, possessing no native 
 
 en 
 
 SS 
 
 j 
 
 ) 
 | Bi 
 
 \ 
 
 iv 
 
 th 
 
 ; 
 
 ay 
 
 
 

 
 
 
 
 
 56 Wonders of the Telescope. 
 
 light, but shining entirely by light 
 received from the Sun, and reflected 
 to us from her surface, it follows, that, 
 whilst that half of her which is toward 
 the Sun is enlightened, the other half 
 must be dark and invisible; and she 
 disappears when she comes between 
 us and the Sun, because her dark side 
 is then towards us. 
 
 Whilst she is making her revolution 
 round the heavens, she thus undergoes 
 a continual change of appearance. 
 She is sometimes on our meridian at 
 inidnight, and therefore in that part of 
 the heavens which is opposite to the 
 Sun: in this situation she appears 
 with a face completely circular, and 
 is said to be a full Moon. As she 
 ‘moves eastward, a portion of her dark 
 side comes forward on the western 
 side, and, in a little more than seven 
 days, comes to the meridian, at about 
 
 =. 
 
 ae ~ = 4 
 

 
 The Moon. 57 
 
 six in the morning, having the appear- 
 ance of a semicircle, with the convex 
 side turned towards the Sun: in this 
 state we call her a half Moon. Con- 
 tinuing to travel eastward, her defici- 
 ency on the western side increases, 
 and she assumes the form of a crescent, 
 with the convex side still turned to- 
 wards the Sun: this crescent gradually 
 becomes more slender, till, about four- 
 teen days after the full Moon, she is 
 so near the Sun, that she is rendered 
 invisible to us, from the superior splen- 
 dour of that body. About four days 
 after this disappearance, she may be 
 seen in the evening, a little to the 
 eastward of the Sun, in the form of a 
 fine crescent, as before, but having its 
 convex side turned from the Sun. 
 Travelling still towards the east, the 
 crescent becomes wider; and, when 
 the Moon comes to the meridian, 
 
 
 

 
 
 
 58 Wonders of the Telescope. 
 
 about six in the evening, she again 
 bears the appearance of a bright semi- 
 circle, with the same difference that 
 we observed of the crescent: that is, 
 its convex side is now turned from the 
 Sun, Advancing still more to the 
 eastward, the semicircular Moon gra- 
 dually widens into an oval shape, and, 
 at last, in about twenty-nine days and 
 a half from the last opposition to the 
 Sun, she is again in the same situation, 
 and appears a full Moon. 
 
 The full Moon is a very beautiful 
 sight through a telescope of moderate 
 magnifying power, and exhibits a great 
 variety of lustre and colour : 
 
 
 
 
 
 
 
 
 
 The Moon 
 
 Full orb’d, and breaking through the scatter’d 
 clouds, 
 
 Shews her broad visage in the crimson’d east, 
 
 Turn’d to the Sun direct her spotted disk, 
 
 Where mountains rise. 
 
 dg 
 

 
 The Moon. 59 
 The mountains are, however, best ob- 
 served at the time of her increase and 
 decrease. 
 
 Different conjectures have been 
 formed respecting the matter of which 
 the brilliant spots are composed. Some 
 have been so taken with their beauty, 
 as to imagine them to be rocks of 
 diamonds; it seems, however, most 
 reasonable to conclude, that they are 
 the tops of mountains, which, by rea- 
 son of their elevation, are more capable 
 of reflecting the Sun’s light to us than 
 the lower parts. Though philosophers 
 have differed widely in their ideas of 
 the materials of the Moon’s moun- 
 tains, there is fortunately no diversity 
 of opinion respecting their use to us. 
 If she were smooth and polished, like 
 a mirror, or covered with water, she 
 would not reflect and distribute the 
 light she receives from the Sun. In 
 
 
 
= Tes TAL oes 
 TSS See a Fe a ee ET a Ee 
 va 7. > = hy "i =—. 
 
 = >) = 
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 —— a 
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 Set amare = . 5 . - = Wemen 
 A eee er tee ee ert eet 
 
 
 
 
 
 60 Wonders of the Telescope. 
 
 some positions, she would shew us his 
 image no larger than a single point, 
 and with a lustre that would injure 
 our sight; but, roughened by these 
 hills and valleys, her surface returns 
 the Sun’s light to usin an equal and 
 pleasant manner, and enables us to 
 examine her with ease and precision. 
 An observer of the Moon will soon 
 remark, that we see nearly the same 
 face during her whole revolution, or 
 that one-half of ber surface is never 
 visible to us. This arises from her 
 having two motions, which, with re- 
 spect to our view of the Moon, coun- 
 teract each other. Her revolution 
 round the Earth is performed toward 
 the east, in somewhat more than twen- 
 ty-seven days; while a motion she has 
 on her. own axis produces one revolu- 
 tion in the same time, but performs it 
 toward the west, so that one of these 
 
 3 
 
 ] 
 

 
 The Moon. 61 
 motions turns as much of her surface 
 from us as the other turns toward us. 
 If the Moon be observed very atten- 
 tively through a whole lunation, it will 
 yet be found, that, in one part of it, a 
 small portion of her face on the east- 
 ern side will be carried out of sight, as 
 if by the motion on her axis, and a 
 similar portion on the western side 
 will be brought forward. In another 
 part of her revolution, the contrary 
 will be seen; the portion so brought 
 forward on the western side will dis- 
 appear, and the eastern portion be 
 brought in view. ‘This irregularity is 
 called the Moon’s bration an longi- 
 tude. 
 
 . There is, besides this, another sort 
 
 of libration, which arises from the axis 
 
 of the Moon being inclined to the 
 
 plane of her orbit; on this account, 
 
 sometimes one of her poles is inclined 
 F 
 
 nn 
 
 eS 
 
 So ~ 
 
 SS SE 
 
 
 
afl 
 62 Wonders of the Telescope. 
 
 toward the Earth, and sometimes the 
 other. In consequence of this, we 
 see more or less of her polar regions in 
 different parts of her revolution, and 
 therefore we can call this irregularity 
 her dibration in latitude. 
 
 Such are the principal phenomena 
 that distinguish the Moon; and it may 
 be worth while to reflect upon some of 
 the signal benefits of which this body 
 is productive to our globe. How 
 cheerless and uncomfortable would be 
 our nights, were we always destitute 
 of the light which this sister-orb, our 
 faithful and inseparable companion, 
 dispenses! How highly useful are 
 even her eclipses, in our astronomical, 
 
 Wa * 
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 geographical, and chronological calcu- 
 lations! How salutary, too, is her 
 
 = <r St 
 eae 
 
 attractive influence, which sways the 
 ocean, and actuates the world of 
 waters: which swells the tides, and 
 
 
 

 
 The Moon. 63 
 
 perpetuates the regular returns of ebb 
 and flow; and which, by these means, 
 not only preserves the liquid element 
 itself from putrefaction, but the sur- 
 rounding continents from infection and 
 disease ! 
 
 ——. ——__-_———. The horned. Moon renews 
 Her waning light, and her whole visage shews: 
 
 Fulfils her course in circles yet unknown, 
 
 And cheers mankind with lustre not her own, 
 
 Pale terror flies before her friendly ray, 
 
 The traveller, benighted, finds his way: 
 
 Her destin’d rule o’er ocean she presides, 
 
 And pours upon the shores the lagging tides. 
 Baker. 
 
 | 
 
 abe os “ 
 
 a ea ae p= = 6 4= Sa SK == a ~ . _ = = ; - ; 
 <—- a ae e eS o aT = avd 
 
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 OF MARS, 
 
 - AS SEEN THROUGH THE TELESCOPE. 
 
 oe ag sea = — —< 
 WS ORR eaes a 
 fhe —— 
 ee —- 
 = Peg ie ee lee at 
 
 
 
 - ieee 45% 
 wae 
 
 See Mars, alone, runs his appointed race, 
 
 And measures out exact the destin’d space : 
 
 Nor nearer does he wind, nor farther stray, 
 
 But finds the point whence first he roll’d away. 
 ; BAKER. 
 
 Wiru thie assistance of the tele- 
 scope, this planet exhibits larger and 
 more remarkable spots than any of the 
 others. This has been examined with 
 great care by Dr. Herschel, for the 
 purpose of determining the figure of 
 the planet, and the position of its 
 aXIs, 
 
 The belts and cloudy appearances 
 on this planet are found to change 
 their shape and arrangement very fre- 
 quently. Very bright and shining 
 spots have been observed about the 
 
 
 
a ee 
 
 Monthy 29.1823 . 
 
 th 
 
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 SS 
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 London:William 
 
 
 

 
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Mars. 65 
 
 poles of Mars; they are supposed to 
 be produced by those parts of his sur- 
 face being intensely frozen, or covered 
 with snow. 
 
 Mars, in, appearance, is the least 
 splendid of all the planets; its orbit 
 lies between that of our Earth and 
 Jupiter; but is very distant from both. 
 By the spots discernible on its surface, 
 by means of a good telescope, the 
 length of its day and night has been 
 ascertained. 
 
 He appears to us of a dusky reddish 
 colour, and, from this, some have sup- 
 posed that he is encompassed with a 
 thick cloudy atmosphere, similar to 
 ours. 
 
 - When in opposition to the Sun, he 
 
 is five times nearer to us than when in 
 
 conjunction. This has a very visible 
 
 effect on the appearance of the planet, 
 
 and causes him to seem much larger 
 F 2 
 
 wl a ain 
 ~ — one - re ro yee — . 
 —= Soe ets + Sra a — -. 
 
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 66 Wonders of the Telescope. 
 
 to us at some periods than at others. 
 In the year 1719, his apparent magni- 
 tude and brightness were so much in- 
 creased, that, by the uninformed, he 
 was taken for a new star. Mars, at 
 its quadratures, appears gibbous, but 
 never horned, like Venus, Mercury, 
 and the Moon, which shews (1) that 
 his orbit includes that of the Earth, 
 and (2) that he shines not by any 
 native light of his own. 
 
 Our observations on this planet are 
 rendered more interesting, from the 
 analogy there is between it and the 
 Earth. The length of his days and 
 nights is nearly the same, nor is its 
 year, though twice as long as ours, 
 very dissimilar, when compared with 
 the long years of Jupiter and Saturn. 
 
 An observer, in this planet, will 
 seldom see, Mercury, except when 
 he sees it passing over the Sun’s 
 

 
 
 
 é 
 
a RT FREES a ee ia ae 
 
 Tanet . Pup and his Four Wet > Datel WEB .as s seen n through a Te les ‘scope Plate ¢ G. “p. G7. 
 
 London: William Darton. 48 
 
 rv Bill, jt At rth ies 
 
 
 

 
 Jupiter. 67 
 disk, Venus will appear to him at 
 about the same distance from the Sun 
 as Mercury appears tous. The Earth 
 willappear about the size of Venus, 
 and constantly near the Sun ; and will 
 be, by turns, a morning and evening 
 starto the inhabitants of Mars, as the 
 planzt Venus is to us. 
 
 
 
 OF JUPITER, 
 
 AS SEEN THROUGH A TELESCOPE. 
 
 
 
 Tue appearance of the planet Jupi- 
 ter, through a telescope, opens a vast 
 field for interesting inquiry. His sur- 
 face is not equally bright, but is va- 
 
 riegited with certain bands or belts, of 
 
 a dakish dusky appearance ; they run 
 parellel to each other, and are conti- 
 nuel. quite round the planet’s body. 
 They are not regular or constant in 
 
 se 
 
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 68 Wonders of the Telescope. 
 
 their appearance: sometimes only one 
 is seen; at other times six, or even 
 eight. The breadth of them is like-: 
 wise variable; one belt sometimes 
 growing narrow, while another, in its 
 neighbourhood, becomes broader, as if 
 one had flowed into the other: in these 
 cases, an oblique belt has been ob- 
 served to lie between them, as if for 
 the purposes of forming a communi- 
 cation. Sometimes one or more spots 
 are formed between the belts, which 
 increase till the whole is united ina 
 large dusky belt. 
 
 There are also bright spots to be 
 discovered on Jupiter's surface ; these 
 are rather more permanent than the 
 belts, and re-appear after unequal in- 
 tervals of time. The remarkable spot 
 by whose motion the rotation of Jupi- 
 ter on his own axis was first ascertain- 
 ed, disappeared in the year 1694, and’ 
 

 
 a - 
 
 he 
 
 Jupiter. 69 
 was not seen again till 1708, when it 
 re-appeared exactly in the same place, 
 and has been occasionally seen ever 
 since. ‘The disappearance and re-ap- 
 pearing of the spots are, however, by 
 no means so curious as the changes 
 that have been observed in the belts. 
 
 Another remarkable telescopic ap- 
 pearance of this planet is produced by 
 four satellites, or moons, which revolve 
 about him at different distances: they 
 are invisible to the naked eye, but 
 through a telescope they make a beau- 
 tiful appearance. As our Moon turns 
 round the Earth, enlightening the 
 nights by reflecting the light she re- 
 ceives from the Sun, so these may also 
 be supposed to enlighten the nights of 
 Jupiter, and move round him in diffe- 
 rent periods of time, proportioned to 
 their several distances; and, as thie 
 Moon keeps company with the Earth 
 
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 70 + Wonders of the Telescope. 
 
 in its annual revolution round the 
 Sun, so these accompany Jupiter in 
 his course. : | 
 
 In speaking of these satellites, we 
 distinguish them according to their 
 places, into the first, the second, and 
 so on. By the first, we mean that 
 which is nearest to the planet, 
 
 Their motion round him is perform- 
 ed inacircular path; but, viewing it 
 edgewise, as we do, it appears an ex- 
 tremely narrow oval, and consequently 
 the apparent path of the bodies differs 
 but little from a straight line ; and we 
 see them move backward and forward 
 on each side of the planet, and occa- 
 sionally pass both before and behind 
 it, 
 
 When a satellite is in its superior 
 semicircle, or that half of its circular 
 path which is more distant from us 
 than Jupiter, its motion appears direct 
 
 So 
 

 
 Jupiter. 71 
 to us; and when it is in its inferior 
 semicircle, or that half of its circular 
 path which is nearer to us than Jupi- 
 ter, ifs motion appears in a contrary 
 direction. Both these motions seem 
 quickest when the satellites are nearest 
 the centre of the planet, and slower 
 when they are more distant: at the 
 greatest distance they appear station- 
 ary for a short time. 
 
 These satellites and their planet mu- 
 tually eclipse each other, in the same 
 manner as do our Earth and the Moon. 
 But there are here three cases in which 
 the satellites disappear to us. 
 
 The one is, when the satellite is 
 directly behind the body of its planet, 
 with respect to the Earth. This is 
 called an occultation of the satellites. 
 
 Another is, when it is interposed 
 between the Earth and its own planet; 
 
 
 
ry < += ee RS, ee > 
 Se ee Re ee ee ee eS Yee a ae yn | 
 oy PE A eats ner ee 
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 a2 Wonders of the Telescope. 
 
 for then it cannot be distinguished 
 from the planet itself, 
 
 The last is, when it is directly be- 
 hind the planet, with respect to the 
 Sun, and so falls into its shadow, and 
 suffers an eclipse similar to that of the 
 Moon when she falls into the shadow 
 of the Earth. 
 
 It is not often that a satellite can be 
 discovered upon the disk of Jupiter, 
 even with powerful telescopes, except 
 at its first entrance, when, from its 
 being more directly illuminated by the 
 rays of the Sun than the planet itself, 
 it appears like a lucid spot upon it. 
 Sometimes, however, a satellite is seen 
 passing over the disk, like a dark spot: 
 this has been attributed to spots on the 
 surface of the satellite, and that with 
 the more probability, as the same sa- 
 tellite has been known to pass over 
 

 
 » . Jupiter. 73. 
 the disk at one time as a dark. spot, 
 and at another time to be so luminous 
 as only to be distinguished from the 
 planet itself at its coming on and going 
 off. 
 
 The beginnings and endings of these 
 eclipses are easily seen by a telescope, 
 when the planet is in a proper situa- 
 tion: but when it is in conjunction, 
 or in the same. quarter of the heavens 
 with the Sun, the brightness of that 
 Juminary renders. both the: planet and 
 satellites totally invisible to us. 
 
 It was by observing these eclipses, 
 that it was discovered that light 1s not 
 progagated instantaneously, though it 
 moves with extreme velocity. A ray 
 of light is found to travel from theSun 
 to the Earth. in about eight minutes of 
 time; thus moving at a rate of two 
 hundred thousand: miles per second, 
 They also furnish astronomers with an 
 
 G 
 
 
 
: . - i — — ——— — F Lo: ——— * 
 OTE = onmemnen — . = : ce ee gree — ~~ F 
 a a ASS 5 Ea ate es a a te Pe Fey = ea >> 
 SR een Ba FEE ae eae ee Seas «PONG SS agp KE TE Ok iy 2 
 TSS ESE ae AST se ss - mh, AE and . ae 
 7 ; : = <—— a aga . - ~ 
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 = - Me Fy 
 
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 74. Wonders of the Telescope. 
 
 easy method of determining the longi- 
 tude. 
 
 Jupiter is situated, in the Solar Sys- 
 tem, between the planets Mars and 
 Saturn, and at a distance of nearly five 
 hundred millions of miles from the 
 Sun. His diameter is ninety-four 
 thousand of our miles; about twelve 
 times greater than our Earth. 
 
 In some parts of his orbit he 1s much 
 nearer to the Earth than im others, and 
 then, of course, appears considerably 
 larger and more luminous than at other 
 times. 
 
 The days and nights of Jupiter are 
 of an equal length, each being about 
 five hours long; and, from the axis of 
 his diurnal motion being nearly per- 
 pendicular to the plane of his annual 
 motion, or path round the Sun, there 
 
 ig consequently very little difference 
 in his seasons, 
 
Jupiter. 75 
 
 To the inhabitants of this planet, 
 his satellites will appear almost as 
 large as our Moon does to us; but the 
 Sun will not appear to be a fifth part 
 of the size he seems to us, The four 
 Moons must afford a very curious and 
 pleasing effect to the inhabitants of 
 Jupiter; for sometimes they rise all 
 together, and sometimes they are all 
 on the meridian together, besides fre- 
 quent eclipses. 
 
 More yet remote from day’s all-cheering source, 
 Vast Juerrer performs his constant course ; 
 Four friendly Moons, with borrow’d lustre, rise, 
 Bestow their beams benign, and light his skies. 
 BAKER. 
 
 An observer, in Jupiter, will never 
 see either Venus, Mercury, the Earth, 
 or Mars, because, from the immense 
 distance at which he is placed from 
 them, they must appear to accompany 
 the Sun, and to rise and set with him. 
 
 “4 
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| 
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 76 Wonders of the Telescope. | 
 The heavenly bodies which ‘he will 
 havé for the objects of observation; 
 are, his own four Moons, the planet 
 
 Saturn, with his ring and satellites, 
 and probably the Herschel planet. 
 
 OF SATURN, 
 
 AS SEEN THROUGH A TELESCOPE. 
 
 
 
 Trix Sir Wm. Herschel’s discovery 
 of the planet called after himself, forty- 
 two years ago, Saturn was considered 
 the most remote planet in our system. 
 He shines with a pale and feeble light, 
 less bright than Jupiter. 
 
 Farthest and last, scarce warm’d by Pheebus’ ray, 
 Through his large orbit Saturn wheels away: 
 How great the change, could we be wafted there! 
 How slow the seasons! and how long the year ! 
 
 BAKER, - 
 
 The uninformed eye does not ima- 
 

 
 OO a ae 
 
 the I lanet Satwnnis RAG. na Deven 
 
 | Sate Ate, as seen through a Telescope. Plate7, p, 
 
 SS = 
 
 
 
 London: Willian Darton, 8,Tretborn Jt on Morttde 29. 7822. 
 
 | 
 7 
 

 
 
 
Saturn. 77 
 gine, when it is directed to this little 
 speck of light, that it is viewing a large 
 and glorious globe, one of the most 
 stupendous of the planets, whose dia- 
 meter is seventy-eight taousand of our 
 miles. age 
 
 One of the first discoveries of the 
 elescope, when brought to a tolerable 
 degree of perfection, was, that Saturn 
 did not appear globular like the other 
 planets. Galileo, in the year 1610, 
 imagined it to be composed of three 
 stars or globes, a largerin the middle, 
 and a smaller on each side; and he 
 continued his observations till what 
 he thought the two lesser stars disap- 
 peared, and this planet looked like the 
 others. Farther observation shewed 
 that what Galileo took for two stars 
 were parts of a ring. This singular 
 and curious appendage to the planet 
 Saturn is a broad, opaqie ting, encom- 
 
 G2 
 
 
 
 
 
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 init ginagpinre aiheigipheeeemen 
 : : a asi ete 
 
 ee one Ses 
 
 : ee ee Sa 
 
 yy 
 
 78 Wonders of the Telescope. 
 
 passing the body of the planet without 
 touching it: like the horizon of an 
 artificial globe, it appears to be sus- 
 pended round the planet, and to keep 
 its place without any immediate con- 
 
 nexion with it. But 
 
 ~———— even here the sight, 
 
 
 
 Amid these doleful scenes, new matter finds 
 Of wonder and delight !—a mighty ring / 
 
 MALLET. 
 
 This appendage to the planet Saturn 
 is still one of the most curious astro- 
 nomical phenomena with which we 
 are acquainted. 
 
 By what means it is suspended, or 
 of what it is composed, we yet remain 
 ignorant. It has been supposed by 
 some to be a bright and permanent 
 cloud, and by others, a vast number 
 of satellites disposed in the same plane, 
 and which, at this immense distance, 
 appears as a mass of light. 
 
 a 
 
Saturn. 79 
 
 Of its use to the inhabitants of the 
 planet, we are as uninformed as of its 
 nature, though perhaps it might be 
 reasonably imagined to be intended to 
 afford them light. 
 
 The space between the ring and the 
 globe of Saturn is supposed to be ra- 
 ther more than the breadth of the ring 
 itself; the greatest diameter of the ring 
 is in proportion to that of the globe, as 
 seven to three; and its breadth is about 
 twenty-one thousand of our miles. It 
 puts on different appearances to us, 
 sometimes being seen quite open, or 
 as a wide oval, and at others, only as 
 a single line. 
 
 When our eye is in the plane of the 
 ring, or looking at it directly on the 
 edge, it is invisible to us; and it is in 
 this situation twice in each revolution 
 of the planet ; that. is, once in about 
 fifteen years ; at these times, he appears 
 
 paternal 
 
 Sn lee 
 
 } 
 ; 
 k 
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 t 
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 4 
 
 - Le ae 
 . — Po IO r- = —Z 
 
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 a eee - a 
 
 eo 
 
 = ree 
 
 q — 
 
 
 
ho. 
 
 a 
 
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 aaa wears er 
 Pre ae a ee ee a ae | 
 = 
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 = gee MS 
 OL Semmes ee. a, <n 
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 >: w= wae ot eS = 
 
 = + A eS seat: 
 S FT RE Ne SR ETI ST I a : 
 een 
 
 
 
 ——_ 
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 80 Wonders of the Telescope. 
 quite round for nine or ten months 
 together. 
 
 The ring was invisible to us in the 
 year 1818, and has, since that time, 
 been gradually increasing in light and 
 breadth, and presenting a beautiful 
 object for the telescope. This will 
 continue for a year or two longer, 
 after which both will again decrease, 
 till, as before, after an interval of fif- 
 teen years, in the year 1833, the ring 
 will be again edgewise to us, and invi- 
 sible. 
 
 When the ring appears of an oval 
 shape, the parts about the ends, which 
 project, as it were, on each side of 
 him, are called the anse. 
 
 With telescopes of great magnifying 
 power, two belts or stripes have been 
 discovered on Saturn: they appear pa- 
 rallel to the ring, and are supposed to 
 be permanent. | 
 
a 
 
 Saturn. 81 
 
 Besides the ring, Saturn is also equip- 
 ped with seven attendant moons or 
 satellites, which move about him at 
 different distances in a way similar to 
 those of Jupiter; in reference to which, 
 the poet says, 
 
 One Moon on us reflects its cheerful light ; 
 
 There, seven attendants brighten up the night: 
 
 Here, the blue firmament bedecked with stars ; 
 There, over head a lucid arch appears. 
 
 The plane on which they move is 
 so considerably inclined to the plane 
 of the planet’s path about the Sun, 
 that they very seldom appear to us to 
 pass either across or behind him; so. 
 that their eclipses are not near so fre- 
 quent as those of Jupiter. They are 
 so small, with respect to their distance 
 from us, as not to be easily visible, 
 even with a good telescope, unless the 
 air is exceedingly clear. 
 
 The Sun’s disk appears ninety times 
 
 
 

 
 
 
 
 
 
 82 Wonders of the Telescope. 
 
 less to an inhabitant of Saturn than it 
 does to us; but yet the quantity of 
 light he affords them is more consi- 
 derable than the great distance of the 
 planet would lead us to suppose: it is 
 at least five hundred times stronger 
 
 than the light which. we receive from 
 
 the full Moon. 
 
 OF THE HERSCHEL PLANET, 
 
 AS SEEN THROUGH THE TELESCOPE. 
 
 
 
 Wirnour the assistance of the tele- 
 scope, the wonders of which we endea- 
 vour to set forth and illustrate in this 
 little work, this planet would certainly 
 
 never have been discovered. It was 
 first observed by Mr, (late Sir W.) Her- 
 schel, on the 13th of March, 1781, 
 near the foot of Castor, and his atten- 
 tion was arrested by its steady light. 
 
 
 
wee 
 
 Herschel Planeé. 83 
 
 On applying to the observation a high- 
 er magnifying power to the telescope, 
 it appeared to increase in diameter, 
 which was a certain proof that it could 
 not be a fixed star. The news of the 
 discovery was spread in a short time 
 over the whole of Europe. Many fo- 
 reign astronomers contended that it 
 was a comet; but, by our own coun- 
 trymen, it was very soon ascertained 
 to be a new planet; and the circum. 
 stances which led to the discovery 
 were, its vicinity to the ecliptic, and 
 the direction of its motion, It is found 
 to revolve in an orbit that is nineteen 
 times farther from the Sun than the 
 Earth’s orbit; of course, it enjoys 
 three hundred and sixty-one times 
 less light and heat from the Sun than 
 we experience. Still the proportion 
 of light is considerable; it has been 
 calculated, and found to be equal to 
 
 i | 
 ; ic 
 Bel 
 Tt 
 mir 
 mt 
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 iS 
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 LT 3 t aas 
 EEE 
 
 
 
— eee = 
 
 
 
 = 
 Se eee eee ame 
 
 ae ae xo: ~ 
 iaeiemehaletdsathdiansis cies Lilia hailed tenner saeneeas : a . ~~ 
 ia b ateeeene = See ee r . nant a a r ee 
 
 ——— = ee el 
 
 Be Seg rh aed 
 Se 
 
 ——— 
 
 aT Ra er 
 
 Sa ES 
 SO SE ES VE 
 Soi aay 
 
 ee ee 
 
 eee ern dnt ae , 
 
 
 
 i 
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 ey 
 y 
 gf 
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 84 Wonders of the Telescope. 
 
 the effect of two hundred and forty- 
 eight of our full moons. In reference 
 to its remote situation, when compared 
 with our own, we may well say, 
 
 From earth, how large, how strong the Sun’s 
 bright ball ! 
 
 But seen from thence, how languid and how small! 
 
 When the keen north, with all its fury blows, 
 
 Congeals the floods, and forms the fleecy snows, 
 
 Tis heat intense to what can there be known; 
 
 Warmer our poles than is ifs burning zone: 
 
 Who there inhabit, must have other powers, 
 
 Juices, and veins, and sense, and life, than ours. 
 
 One moment’s cold like theirs would pierce the 
 bone, 
 
 Freeze the heart-blood, and turn us all to stone. 
 
 Yet there is every reason to believe 
 that even this planet is inhabited by 
 some race of beings; that the Her- 
 schel, as well as our own globe, is the. 
 abode of happiness to. millions, who 
 rejoice in the Creator’s goodness ; not, 
 indeed, by means that we can compre- 
 
 
 
Comeis. 85. 
 
 hiend, nor by laws that we can describe: 
 but He who formed the world, and 
 who has given to it six Moons, to en- 
 lighten it during the Sun’s absence, 
 ean adapt the inhabitant to the habi- 
 tation. 
 
 Strange and amazing must the difference be, 
 
 *Twixt this duil planet and bright Mercury : 
 
 Yet reason says, nor can we doubt at all, 
 
 Millions of beings dwell on either ball, 
 
 With constitutions fitted for that spot 
 
 Where Providence, all-wise, has fix’d their lot. 
 
 BAKER, 
 
 OF THE TELESCOPIC APPEARANCE 
 OF COMETS. 
 
 
 
 Comets, seen through a telescope, 
 have a very different appearance from 
 any of the planets; they also differ 
 much among themselves. A comet 
 seems to consist of a body which shines 
 
 H 
 
 nape: a ies 
 
 — 
 
 = Se = 2 T. 
 
 alae ee RT oi a 
 a ~ ee ? 
 
 ) 
 ‘ 
 } 
 
 ——— - —* 
 
 a cee sare 
 ti Ie 
 
 
 
ee 
 
 } 
 ‘ 
 \ 
 : 
 
 pion ante Cee 
 Lees ae 
 
 —— 
 Mage oa29 5 
 
 — 
 Ce aied 
 
 eT ie 
 ee 
 
 
 
 \ 
 
 36 Wonders of the Telescope. 
 
 by the reflected light of the Sun, and 
 is encompassed with an atmosphere of 
 apparently fine matter, resembling that 
 of the Aurora Borealis: this is called 
 the head of the comet, and the inter- 
 nal part, the nucleus. 
 
 When a comet arrives at a certain 
 distance from the Sun, an exhalation 
 arises from it: this is called the tail, 
 and is always directed to that part of 
 the heavens opposite to the Sun, and 
 increases in dimensions and brightness 
 as it approaches that luminary. 
 
 These singular bodies traverse the 
 heavens in every direction, and have 
 been seen so frequently, and under so 
 many different appearances, that their 
 number is not correctly ascertained ; it 
 is supposed, however, to exceed five 
 hundred. | 
 
 The velocity with which they seem 
 to move is variable in every part of 
 
=. 
 
 Ly i 
 Aegan) 
 bs 
 é : 
 ° _ 
 
 ~~ 
 
 Se hey 
 
 
 
 a el 
 
 “ 
 
 
 
 = 
 
The WON of ™ Cit BYU TCU and thi) D . Plate 8. p. 87. 
 
 Lonidon:Witham Darton: 58, Ze lbern Hill, * Monthy 29,1823. 
 
 
 
NP oc ce ae 
 
 
 
 Comets. Ae 8y 
 
 their path about the Sun: when they 
 are near the Sun, they appear to move 
 with great swiftness, and, when very 
 remote from him, their motion is in- 
 conceivably slow. 
 
 Various different opinions have been 
 entertained of their nature; but it is 
 now generally allowed that they are a 
 sort of planets, which move about the 
 Sua in very long and narrow ovals, or 
 ‘Agama! : 
 
 The figure in Plate 7, is 4 repre- 
 sentation of the great comet which 
 appeared in the year 1680: this is re- 
 markable from its near approach to the 
 Sun. Sir Isaac Newton calculated 
 that it came so near to it, as at one 
 time to be only one-sixth part of the 
 Sun’s diameter from his surface ; its 
 rate of travelling was, in that situation, 
 also caleulated to be above eight hun- 
 dred and eighty thousand miles per 
 hour. 
 
 =- 
 
 i 
 
 so ETE 
 
 SSS - 
 —— Pred — ona", 
 
 se 
 
 = 
 
 . 
 : 
 i i 
 iS 
 : 
 i 
 { 
 
 
 
ae 
 
 “yen aes nat = 2 = AEs x KS EP RN i 
 
 pecs 
 ee 
 
 aad ee ee. ee i ee a 
 tS Pee - Pag ee ee etree 
 Ree ST | 
 
 Wonders of the Telescope. 
 
 Will it not astonish the youthful 
 reader, that, though this body travelled 
 almost two thousand times faster than 
 a cannon-ball, yet it drew after it a 
 tail of fire estimated at eighty millions 
 of miles in length? How amazing is 
 it, that this stupendous body, travers- 
 ing the immensity of the creation with 
 such a rapidity, and at the same time 
 wheeling about in that line which its 
 great Creator prescribed to it, should 
 move with such inconceivable velocity, 
 
 and likewise with such exact regula- 
 
 rity! How spacious must the universe 
 be, that gives such bodies as these 
 their full play, without suffering the 
 Jeast disorder or confusion by it! With 
 what a glorious exhibition must those 
 beings be entertained, that can look 
 into this great theatre of nature, and 
 see myriads of these tremendous ob- 
 jects wandering through those immea- 
 surable depths of ether, and running 
 
 
 
 : 
 
Comets. 89 
 
 their appointed courses! Our eyes 
 may hereafter be strong enough to 
 command this magnificent prospect, 
 and our understandings able to find 
 out the several uses of these immense 
 parts of the universe. In the mean 
 time, they are very proper objects for 
 our imagination to contemplate, that 
 we may form more extensive notions 
 of Infinite Wisdom and Power, and 
 learn to think humbly of ourselves, 
 and of all the little works of human 
 invention.—Guardian, No. 103. 
 
 It is true that comets have been 
 looked upon as forerunners of some 
 dreadful calamity ; of some terrible 
 destruction which awaits a guilty na- 
 tion; and when once such a fancy 
 takes possession of the vulgar, nothing 
 is more easy than to find some event 
 to correspond with the superstitious 
 notion. Philosophers now know bet- 
 
 H 2 
 
 
 
90 Wonders of the Telescope. 
 
 ter; but poets have, in all ages, taken 
 advantage of the credulity of the com- 
 mon people. Thus Dr. Young: 
 
 Hast thou ne’er seen the comet’s flaming flight ? 
 
 Th’ illustrious stranger passing terror sheds 
 
 On gazing nations, from his fiery train 
 
 Of length enormous. 
 
 And Milton compares his Satan to 
 a comet; and its tail is described as 
 setting fire to the sky: 
 
 Incens’d with indignation, Satan stood 
 
 Unterrified, and like a comet burn’d, 
 
 That fires the length of Ophiucus huge 
 
 In th’ arctic sky, and from his horrid hair 
 Shakes pestilence and war. 
 
 SS 
 
 se TE BS. 
 
 erage = 
 es 
 
 oO EE ETE Oo a a pe 
 
 mee D 
 4 | 
 m : 
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 Pe 
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 3 
 pean 
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 ter 
 HRS 
 Fe 
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 esa 
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 eS 
 
 > 
 
 More of the properties of these 
 blazing stars are beautifully recounted 
 by Savage: 
 
 In fancy’s eye, encountering armies glare, 
 
 a ae Se 
 Sn oS 
 a a I: BT pe tl art OA — —— 
 
 And sanguine ensigns wave unfurl’d in air; 
 Hence the deep vulgar deem impending fate,’ 
 A. monarch ruin’d, or unpeopled state. 
 
 
 
* ae 
 ae ee : — - RTS : 
 
 Comets. Ol 
 
 Thus comets, dreadful visitants! arise 
 
 To them wild omens, science to the wase / 
 These mark the comet to the Sun incline, 
 While deep-red flames around its centre shine ! 
 While its fierce rear a winding trail displays, 
 And lights all ether with the sweeping blaze ! 
 Or, when compelled, it flies the torrid zone, 
 And shoots by worlds unnumber’d and unknown, 
 By worlds, whose people, all aghast with fear, 
 May view that minister of vengeance near ! 
 
 Till now, the transient glow, remote and lost, 
 Decays and darkens ’mid involving frost ! 
 
 Or when it, sun-ward, drinks rich beams again, 
 And burns imperious on th’ ethereal plain! 
 The learn’d one, curious, eyes it from afar, 
 Sparkling through night, a new illustrious star ! 
 
 From the beginning of the Christian 
 era till now, there have appeared about 
 five hundred comets. Before that time, 
 we have accounts of about one hun- 
 dred others. But, when it is consi- 
 dered that there may have been many 
 that have not been seen, from being too 
 near the Sun, from appearing in moon- 
 
 
 

 
 
 
 
 
 
 ~ 7 5 
 i 
 He 
 : aie! 
 F 4 
 vs wf 
 3 ( 
 i 
 i 
 i 
 S } 
 f 
 
 il 92 Wonders of the Teleseope. 1A 
 | ili light, from being in the other hemi- 
 
 il) sphere, or from being too small, or from 
 
 i not being recorded, the number is pro- 
 
 I bably much greater, Miss Herschel 
 | | has discovered several comets within 
 4 ih the last thirty years, by means of the 
 tt telescope.—See Pail. Trans. 
 Wl OF THE FIXED STARS AND 
 ay SYSTEMS OF SUNS. 
 | Rie | 
 ii. To form clear ideas in astronomy, | 
 ay and especially to make observations 
 | on the planets with any precision or 
 i satisfaction, it is needful that we obtain 
 H \ a tolerably correct knowledge of the { 
 1 principal fixed stars. It is evident, 
 ‘ i that the better we are acquainted with 
 I the appearance and places of these 
 
 ! stars, which always remain at the same 
 || 4listance from each other, the more 
 
Stars and Suns. 93 
 
 readily we shall know the planets, 
 which are continually altering their 
 situations, by journeying, in their re- 
 spective. years, round the Sun. It 
 must be premised, that the fixed stars 
 shine by their own native light, and 
 are, probably, suns to other systems of 
 planets, of which we are and must 
 remain ignorant : 
 
 
 
 
 
 Ten thousand Suns appear, 
 Of elder beam ; which ask no leave to shine 
 Of our terrestial star, nor borrow light 
 
 From the proud regent of our scanty day. 
 BaRBAULD, 
 
 To obtain this information, then, we 
 begin with learning how to distinguish 
 the pole of the world, or that point of 
 the heavens, round which all the rest 
 appears to move, while itself remains 
 fixed. There is a tolerably bright star 
 situated very near this point, and it 
 is, therefore, called the polar star, it 
 never departs from its situation, with 
 
 H 
 Bilt 
 ar 
 r 
 ; 
 4 
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 it 
 ; 
 iin 
 1p St) 
 A 
 a4 
 Sa! 
 : 
 4 
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 eu 
 ihe 
 Eb, 
 pet 
 
 — -s 
 Rees Ore ete. ee 
 
 PP eh = SEAS Oe 
 
 Sa 
 Fr etter ee TTS 
 acm) —— — = 
 
 n Sys ots 
 le eee 
 
 Fa SS Aad an Si 
 
 
 

 
 
 
 penorringr aaa ~~ 
 
 
 
 94 Wonders of the Telescope. 
 
 regard to the other fixed stars, and at 
 every hour of the day and night, and 
 in every season of the year, is to be 
 found in the same position, 
 
 The general appearance, therefore, 
 of the starry heavens, is that of a vast 
 concave sphere, turning slowly round 
 this polar star. 
 
 This star is more or less elevated, 
 according to the part of the earth from 
 which it 1s viewed : thus, more north- 
 ward, as in Lapland, it appears much 
 higher, or nearer the point over our 
 heads, than it does with us, If we 
 travel southward, it will appear lower 
 than with us: we see it more elevated 
 than the inhabitants of the south of 
 France and Spain; and these again see 
 it higher than those of Barbary, and 
 the countries south of them. By 
 continually travelling southward, we 
 should see the pole star depressed to 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Stars and Suns. 95 
 
 the horizon, and the other pole would 
 appear opposite to it, in the southern 
 part of the horizon, round which the 
 stars in that part would revolve. If we 
 were still to travel onward to the south, 
 the north polar star would disappear, 
 and the whole hemisphere would ap- 
 pear to turn round a single point in the 
 south, as our. northern hemisphere 
 appears to turn round the pole star in 
 the north. 
 
 The polar star may be discovered by 
 observing the motions of the stars, 
 as already described; but there is a 
 readier method, by a little attention to 
 that collection of stars which astrono- 
 mers distinguish by the name of the 
 Great Bear. It principally consists of 
 seven very conspicuous stars: four of 
 these make an irregular kind of square, 
 and represent the body of the beast, 
 and the other three the tail, whichis 
 curved, or convex on one side, and 
 
 se ee 
 ——— _ 
 ———— = = a = 
 
 | 
 h 
 
 Sh awe coq 
 a 
 
 == —= 
 eset 
 a a 
 
 
 

 
 on ay _ 
 
 a) 
 ' 
 Caen ope eae ean - 
 eet an 2 
 
 ia Bel aN 
 ——— ae 
 
 See ae 
 
 
 
 96 Wonders of the Telescope. 
 
 concave on the other. If a straight 
 line be imagined to pass through those 
 two stars of the body, which are far- 
 thest from the tail, and towards that 
 part of the heavens to which the curve 
 of the tail is convex, it will, at some 
 little distance, pass very near to the 
 bright star which we have described to 
 be the north polar star. Knowing the 
 polar star, it will be easy to distin- 
 guish the cardinal points, viz. the 
 north, south, east, and west: the north 
 is the side to which we are turned 
 when we look at the pole; the south is 
 the opposite side, or that on which the. 
 Sun appears at noon; the easé lies 
 directly on the right hand, when we 
 look towards the north, and is: that 
 side on which the Sun appears to rise; 
 
 the wes is directly opposite to this, on. 
 the left hand, and is that side on which. 
 the Sun seems to set. 
 
 The time at which the greatest 
 
 
 

 
 Stars and Suns. 97 
 
 number of stars are visible to the 
 naked eye, is on a winter's evening, 
 when the air is clear, and our Moon is 
 not present. But even then a good 
 eye can scarcely distinguish more than 
 one thousand at a time; for though, 
 at such a time, they seem almost innu- 
 merable, the appearance arises only 
 from our viewing them altogether, and 
 in a confused manner. But if we 
 consider them distinctly, and only a 
 small portion of the heavens at a time; 
 and if, after some attention to the 
 situation of the larger stars contained 
 in that part, we begin to count them, 
 we shall find they may be enumerated 
 with considerable ease. 
 
 To avoid confusion in description, 
 and to be able to point out any par- 
 ticular star, without being obliged 
 to give a name to each, astronomers 
 divide them into several parcels, or 
 
 I 
 
 
 

 
 ee i ee , P > 
 
 Ene SR Meine Bt ine 
 = SLT: I ~ ae = aS — ae — 
 - a os 
 
 or ae —— = 
 ae - - 
 
 whe 7 - (hey Z> a - =" PKI + oe eone - ed ie Aad 
 ne a ee a ee A Sei. 5 
 
 
 
 95 
 
 ws 
 
 
 
 Wonders of the Telescope. 
 
 groups, and to each of these is assigned 
 a figure ; these assemblages, or groups 
 of stars, 
 Thus, a number of stars, near the 
 
 are called constellations. 
 
 north pole, is called the Bear, because 
 the stars which compose it, happen'to 
 be at such distances from each other 
 that they fall within the figure of that 
 beast: and so of the rest. And, in 
 order that the memory may not be 
 burdened, even with the small num- 
 would 
 eccur in one constellation, astrono- 
 
 ber of distinct names which 
 
 mers mark the stars of each group with 
 a letter of the Greek alphabet, deno- 
 ting those which are the most conspi- 
 cuous by the first letter, the next by 
 the second letter, and so on in succes- 
 sion, By this means, they can be 
 spoken of with as much ease as if each 
 had a separate name. 
 
 The arrangement of the stars into 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Stars and Suns. 99 
 
 constellations is of the highest anti- 
 quity, as we may easily imagine, when, 
 in the Bible, we find Job speaking 
 of the constellations Orion and the 
 Pleiades, 
 
 The fixed stars appear of different 
 degrees of magnitude and_ brightness, 
 and are, therefore, for farther dis- 
 tinction, divided into six different 
 classes. Those, which seem the larg- 
 est and brightest, are called stars of 
 the first magnitude; and the smallest 
 that we can see with the naked eye, 
 are called stars of the sixth magnitude; 
 the intermediate ones, according to 
 their different apparent sizes, are called 
 of the second, third, fourth, or fifth 
 magnitudes. Those stars which can- 
 not be seen without the assistance of 
 the telescope, are not placed in any of 
 
 these classes, but are called Telescopic 
 Stars. . 
 
 TET A ES 
 
 Se SS 
 
 = 
 iw ——— 
 a eee ETI Rm ae 
 
 F 4 
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 eesietriecter oy 
 
 
 
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 100 Wonders of the Telescope. 
 
 An ordinary telescope will discover, 
 in many parts of the heavens, more 
 than ten times as many stars as are 
 visible to the naked eye. With pow- 
 erful telescopes, seventy-eight stars 
 have been counted in the group called 
 the Pleiades, which, to the naked eye, 
 appears to consist of not more than 
 six or seven.* The astronomer Gali- 
 leo reckoned eighty in a small space 
 of the constellation Orion, and above 
 five hundred more in another part, 
 within a very small compass. In the 
 whole of this constellation, above two 
 thousand stars have been counted. 
 Iuture improvements in telescopes 
 may enable us to discover many stars 
 that are now invisible to us; and there 
 are, doubtless, many more which are 
 
 * See the plate representing this constellation, 
 and the curions light space in the Sword of Orion, 
 drawn as they appear in a good telescope, 
 
——_ aD Te 
 . bos 
 
 UMANOUS SPACE IN THE SWORD OF ORION 
 
 I00. 
 
 
 
 
 
 B.7he 4 Stars in the Center, in an ordinary Telescope, 
 appear as a Sing le Star but in one of a greater 
 
 Magnifying power they are Seen Seperated. 
 London: Waa arion 58. Holborn. Fill; 7 mo. 29 298-23. 
 
 
 
| 
 | 
 | 
 : 
 
 aan, d 
 
 
 
 
 
 
 and the curious li 
 drawn as they ap 
 
Suns and Stars, 101 
 even too remote to be seen through 
 telescopes, when they have received 
 their greatest improvement. 
 
 Sir W. Herschel, to whose science 
 and industry astronomy is so much 
 indebted, shewed, by his own labaurs, 
 what great discoveries may yet be 
 made by improving the instruments 
 of observation. 
 
 The immense number of stars which 
 were rendered visible with his large 
 telescope, within a small space, make 
 it reasonable to conclude, that in the 
 whole heavens there are above eighty 
 millions of stars! He also shewed, 
 that many stars which, to the eye, or 
 through ordinary telescopes, appear 
 single, do, in fact, consist of two or 
 more stars, 
 
 The luminous appearance of the 
 milky way is shewn to be produced 
 
 TQ? 
 
 Ad 
 
 
 
102 Wonders of the Telescope. 
 
 by a multitude of small stars, placed 
 so close to each other, as not to be 
 entirely discernible even with the 
 telescope. The nebule, or small 
 cloudy specks, which are to be seen 
 in different parts of the heavens, with 
 a telescope, are also determined to be 
 occasioned in the same way. 
 
 [t is the general opinion, as it has 
 already been observed, that each fixed 
 star not only shines by its native and 
 unborrowed light, but is a Sun to some 
 other system of planets unknown to 
 us, around which they revolve, as our 
 Earth and its sister planets revolve 
 about*our Sun. For, it is not to be 
 imagined that the Almighty, who ever 
 acts with wisdom, and who creates 
 nothing in vain, should have created 
 so many~ glorious’ Suns, adapted to 
 such important purposes, without pro- 
 
 
 
bY 
 Suns and Stars. 103 
 
 per objects to be benefited by their 
 influence: 
 
 
 
 Can those everlasting founts of light, 
 Bodies immensely vast! divinely. bright ! 
 
 Serve for no end at all? or, but to blaze 
 
 Through empty space, and useless spend their rays ? 
 Consult with reason. Reason will reply— 
 
 4 
 
 Each lucid point, which glows in yonder sky, 
 Informs a system in the boundless space, 
 And fills with glory its appointed place : 
 With beams unborrow’d, brightens other skies, 
 And worlds, to thee unknown, with heat and life 
 supplies. BAKER. 
 It is certain that they shine by their 
 own light, for it is impossible that rays 
 from our Sun should be sent to them, 
 and then transmitted to us. How 
 faintly does Saturn shine, notwith- 
 standing his immense bulk! and yet 
 his distance from the Sun is almost 
 nothing compared with that of the 
 nearest fixed star. Their distance is 
 so great, that the best telescopes ex- 
 
 es te 
 
 \ 
 
 _ 
 
 ?. 
 *¥ 
 y 
 i 
 ¥ 
 ; 
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 at er 
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 Leni Bee 
 
 joe 
 
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 ee ae 
 
 
 
104 Wonders of the Telescope. 
 
 hibit. them as mere points, instead 
 of magnifying them, as they do any 
 objects within a measurable distance. 
 Mr. Huygens computed, that the dis- 
 tance of the nearest fixed star from us 
 was so great, that a cannon-ball would 
 spend nearly seven hundred thousand 
 years in passing through this space, 
 with the same velocity with which it 
 first sets out. The same illustrious 
 astronomer thinks there may be stars 
 at such inconceivable distances from 
 our Earth, that their light, though it is 
 known to travel at the rate of about 
 twelve millions of miles in a minute, 
 has not reached us since the creation: 
 
 How distant some of the noctural Suns! 
 
 So distant, says the sage, ’twere not absurd 
 
 To doubt, if beams, set out at Nature’s birth, 
 
 Are yet arriv’d at this our foreign world ; 
 
 Yet nothing half so rapid as their flight. 
 
 Younes, 
 
 
 
Stars and Suns. 105 
 
 Every star, then, may be considered 
 as the centre of some magnificent 
 System, irradiated by its beams, and 
 revolving about it by its’ influence. 
 Thus the empire of God is magnified, 
 his power, and wisdom, and goodness, 
 made manifest. He is not glorified in 
 one earth, or in one system of worlds, 
 but in an indefinite number. — Could 
 we dart to the loftiest apparent star, 
 we should there see other skies ex- 
 panded ; other suns distributing their 
 inexhaustible beams of day; other 
 stars decorating the hours of night; 
 and other systems established in un- 
 known profusion, through the bound- 
 less dimensions of space. And, as a 
 good writer observes, ‘* the dominion 
 of the universal Sovereign does not 
 terminate there: even at the end of 
 this vast tour, we shall find ourselves 
 
 
 
q 
 { 
 
 “ a>} 
 ey 
 
 
 
 A ee + mera 2 et Fo. 5 - ==: 
 
 a Se = 
 7 = = 
 cae Ss 
 
 106 Wonders of the Telescope. 
 advanced no farther than the suburbs 
 of creation, the frontiers of the great 
 Jehovah’s kingdom.” 
 
 A WALK ON A STARRY 
 NIGHT. 
 
 
 
 THE student in astronomy, who 
 takes an evening’s walk to admire the 
 magnificence and the glory of the starry 
 heavens, and who desires to profit by 
 his observations, should learn to class 
 the heavens into particular divisions, 
 and fix on certain points, as a sort of 
 land-marks to direct his attention. 
 
 By knowing the part of the heavens 
 in which the Sun rises, he is able to 
 determine the eastern side ; by attend- 
 ing.to its situation at noon, he ascer- 
 Aains the south; and by noticing the 
 
 ) 
 
Tage 
 
 
 
 A Walk on a Starry Night. 107 
 place of its setting, he determines the 
 western side of the horizon. He need 
 not be told that the north is opposite 
 to the south. 
 
 The moment, then, in which he 
 casts his eyes on the sparkling expanse 
 6f heaven, he is supposed to be sensi- 
 ble of the bearings north, south, east, 
 and west. 
 
 The next principle to be recognized 
 is, that he sees above his horizon % 
 one-half of the whole heavens ; that 
 is to say, one-half of the heavens are 
 always visible, or above the horizon, 
 and the other half is below the horizon, 
 He must not expect, therefore, to see 
 all the constellations and planets at 
 once, but only that half which at the 
 
 * The horizon is the part all round, where the 
 
 sky and the earth seem to meet. 
 
 .. : aie nao = , ——* - ERS Te , 
 
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 7a “1 a] ~ ses SE SITs PT ETE Ty “ 
 
 
 
 Se 
 
 
 
 108 Wonders of the Telescope. 
 
 time of observation is above the hori- 
 zon. 
 
 For the sake of precision and accu- 
 rate reference, astronomers have sup- 
 posed the 360 degrees into which geo- 
 graphers divide the surface of . the 
 earth, to be extended. to the heavens ; 
 so that the whole round of the horizon 
 of the heavens is supposed to be 360 
 degrees, or proportional parts ; half is 
 180 degrees, and a quarter is 90 de- 
 grees. And as we see one-half of the 
 heavens above the horizon, it is. of 
 course 180 degrees from one. side of 
 the horizon, in a line passing over our 
 heads, to the directly. opposite side; 
 and of course from the point over our 
 heads, called the zenzth, it.is 90 de- 
 grees to the horizon on every side. 
 
 Remember, then, that the whole hea- 
 vens are 360 degrees or proportional. 
 
A Walk ona Starry Night. 109 
 
 parts round, and that it is always 90 
 of these degrees from the point directly 
 over your head down to the horizon. 
 
 An observer of the heavens will 
 discover the progression of the whole, 
 from..east to west, by a quarter of an 
 hour's attention. Let him bring a 
 star, in any part between the zenith 
 and the southern part of the horizon, 
 into apparent contact with the end ofa 
 house, steeple, or other fixed object, 
 and he will in a few minutes perceive 
 the motion of that star, and of the 
 whole heavens, from east to west. 
 
 It may be proper for him at this 
 time to consider, that this, general mo- 
 tion of the whole heavens is merely 
 apparent, and is occasioned by the 
 rotation of the earth on its axis in a 
 contrary direction, Of course, if the 
 spectator is moving from west to east, 
 the distant stars will appear to move 
 
 K 
 
 
 

 
 110 Wonders of the Telescope. 
 
 from east to west. The rising and 
 setting of all the distant heavenly 
 bodies will hence be easily under- 
 stood. The earth turns completely 
 round every twenty-four hours : every 
 inhabitant: of it will therefore be 
 carried round. towards all the bodies 
 out of it, and distant from it, every 
 twenty-four hours. Hehce the rising 
 and setting of the Sun, the succession 
 of day and night, and all the depen- 
 dent phenomena. 
 
 This progression of the whole hea- 
 vens from ‘east to west, the rising of 
 some stars in the east, and the setting 
 of others in the west, are objects 
 which, viewed in this manner, will 
 leave impressions much stronger than 
 the mimic representation of the same 
 phenomena on ‘the celestial globe. 
 The immensity of the great vault of 
 heaven; the still, solemn, uniform 
 
 
 
A Walk on a Starry Night. 411 
 
 motion ; the accompanying association 
 of the immeasurable distances, the 
 apparent perpetuity, and the countless 
 numbers of the stars, will fill the mind 
 with reverence and devotion towards 
 the omnipotent, infinite, and eternal 
 Author of the whole! 
 
 Having thus obtained ocular demon- 
 stration of the motion of the stars from 
 east to west, or rather of the motion of 
 the earth in the contrary direction, it 
 will then be necessary to attend toa 
 circumstance which is a consequence 
 of that motion. A slight considera- 
 tion will prove, that the stars imme- 
 diately above the axis on which the 
 earth may be supposed to turn, will 
 appear to remain stationary over those 
 places, at both ends of the axis. In 
 turning a wheel on a fixed axis, all the 
 parts of the circumference will succes- 
 sively present themselves to different 
 
 
 
— 
 a 
 > > ET aa se eee : 
 Soy Se SS Se 
 - = + _— er 
 
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 sok awe, = 
 
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 gE 
 
 Sr SRS 
 
 LS ee 2S LS s 
 — 
 
 112 Wonders of the Telescope. 
 
 objects, but the axis will continue to 
 point to the same place. Ifthe wheel 
 be supposed to bea globe revolving on 
 an axis, the effect will be the same ; 
 the point of the axis, called the pole 
 of the globe, will point to the same 
 spot, while all the parts will perform 
 smaller or larger circuits, in proportion 
 as they are removed in a greater or 
 less degree from the poles. It is im- 
 portant then to be able to determine 
 the points in the heavens which are 
 opposite to the poles of the earth ; 
 these always appear to stand still, 
 while the other stars appear to make 
 a daily circuit round them. As, how- 
 ever, we can only see 90 degrees from 
 the point over our own heads, the 
 inhabitants of no part of the earth can 
 see both poles, except those who live 
 at the equator, from which both poles 
 are distant 90 degrees. The poles of 
 

 
atk CONSTELLATION OF THE PLEIADES OR SEVEN STARS. 
 
 ee ko a — i ieee 
 ge sé . aa | rd1f,,,de oth de 
 N3.The Grele represents the Field of a Telescope of nearly 2 Degrees diameter The Stars are reversed and re ns Res 2 = 
 : > 4 Mag? o 7 Mag” 
 
 the middle Star Alcion would implay 4 minutes to pass_trom the Center to the extremity of the Field. * ss 
 -  London:William Darton; 58 Holborn till; 7'mo. 29% T823. We? preg: 
 
 
 
—————— ee — oe 
 
 A Walk on a Starry Night. 118 
 the heavens may therefore be seen at 
 the equator, exactly in the horizon, in 
 the north and the south; but if you 
 travel or sail one degree to the north 
 of the equator, so as to be within 89 
 degrees of the north pole, you will of 
 course see one degree beyond the 
 north pole, and not so far as the south 
 pole by one degree ; because, as before 
 stated, you can always see 90 degrees 
 in the heavens, from your zenith, or 
 place over your head. In England, 
 therefore, which lies between 50 and 
 60 degrees from the equator, or within 
 40 or 50 degrees of the north pole; we 
 always see 50 or 60 degrees beyond the 
 north pole; or in other words, the 
 north pole in the heavens, or the stars 
 immediately above the north pole of 
 the earth, will be 50 or 60 degrees 
 high, es 
 
 Rather above midway, between the 
 K 2 
 
 
 
a 
 
 114 Wonders of the Telescope. 
 
 horizon and the zenith, in the northern 
 part of the heavens, we are to look for 
 the north pole of the heavens, or the 
 part which never appears tomove. It 
 happens that there is’a star so near the 
 north pole, that for all ordinary pur- 
 poses it may be taken for the north 
 pole itself, and this star may always be 
 found very easily by means of two 
 other stars which point to it in a right 
 line. During the winter months these 
 stars, which are in the constellation of 
 the Great Bear, are to be found with 
 the other starsof that remarkable con- 
 stellation on the eastern side of the 
 pole. They are about six degrees 
 asunder, and the nearest is five times 
 that space, or thirty degrees from the 
 polar star, at which they seem to point, 
 and are thence called the Poznters. 
 The north pole star being thus found, 
 it will be a pleasing employment to 
 
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 a 
 
 SLR eelap 
 
 oS eee 
 
 
 
rt 
 
 
 
 A Walk on a Starry Night. 116 
 
 observe that all the stars appear to 
 move round it, according to their seve- 
 ral distances, while it constantly stands 
 still. An hour’s contemplation of this 
 star, and of the motions of the rest of 
 the heavens while it remains an 1m- 
 moveable centre, will teach more to the 
 uninformed in astronomy than.a thou- 
 sand lessons or lectures 1n the closet. 
 On a winter’s evening, the other 
 remarkable objects in view will be the 
 Pleiades, or seven stars, in the south- 
 east ; and below them, a little to the 
 east, the grand constellation of Orzon ; 
 and still lower, the dog-star Syraws, the 
 brightest of all the fixed stars. The 
 three bright stars together in a line, 
 called the Belt of Orion, are at about 
 equal distances from the Pleiades and 
 Syrius, that is, about twenty-five de- 
 orees fromeach, Besides remembering 
 this: distance, and: that of the Pozers 
 
 
 
 li 
 
 ——— ae 
 63 eee 
 
 =e Wika 2 SS 
 _— - “ee : ween es 
 
116 Wonders of the Telescope. 
 
 before-mentioned, for the sake of occa- 
 sional comparisons, it will be useful to 
 ih recollect that the most northern of the 
 Hi H three stars in the belt of Orion is ex- 
 
 ‘ actly over the equator, so that from 
 that star to the north pole star is ex- 
 actly ninety degrees. 
 
 The Pletades are in the Zodiac, on 
 the south side, and so is the red star, 
 Aldebaran, near them; and the two 
 bright stars about 40 degrees to the 
 left, called Castor and Pollux, or the 
 Twins, are also in the Zodiac, and 
 about five degrees north of the Sun’s 
 place on the 12th of July, 
 
 On such an evening the milky-way 
 will be seen in the west, as a light 
 cloud, but in. truth a mass or shoal of 
 stars, almost infinite in number, but 
 indistinct from their distance. 
 
 A celestial globe, rectified to the 
 day and hour, will point to other ob- 
 
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 et el ow 
 
 Sg SSE SF LL 
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 a, Ser egos: 
 
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 A Walk on a Starry Night. 117 
 
 jects ; an ephemeris will indicate the 
 names or places of the planets which 
 may be above the horizon ; anda tele- 
 scope will render visible other interest- 
 ing and wonderful phenomena. 
 
 Should the Moon be visible, the mo- 
 tion in her orbit may be rightly traced 
 by her approximating to, or receding 
 from, certain stars ; and the same may 
 be observed in the motion of the pla- 
 nets in their orbits. 
 
 One, two, or three evenings, spent 
 in making and in repeating these and 
 similar observations, will bring into 
 familiar use all the other facts and prin- 
 ciples detailed in the several chapters 
 of this Work ; and if a celestial globe 
 should not be at hand, our projection 
 of the heavens will be found a tolerable 
 substitute for that useful and elegant 
 
 machine. 
 
 Rin ae 
 
 = hips ae a ey 
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 ( 118) 
 
 OF THE CONSTELLATIONS, 
 
 OR IMAGINARY DIVISIONS OF THE STARS. 
 
 THE general splendour of a bright 
 star-light night elevates the mind of the 
 observer, while the seeming irregularity 
 confounds it. In order to bring this 
 vast collection into arrangement, it will 
 be found needful to fix on some of the 
 most distinguishable groups, and to 
 make use of those as marks to conduct 
 him among the rest, and to each group 
 to assign the name given to it by the 
 ancients. 
 
 The reader is supposed to be already 
 sufficiently acquainted with the Great 
 Bear, to be able to find it in the heavens 
 without difficulty ; and as this is the 
 first constellation he is familiar with, 
 and it is always visible to us, and al- 
 
Constellateons. 119 
 
 ways seen in the same quarter of the 
 heavens, it is evidently the most pro- 
 per with which to begin his operation 
 of arrangement. ) 
 
 Let him, then, place himself in an 
 open situation, on a clear evening of the 
 month of January. 
 
 If now a straight line may be ima- 
 gined to extend from the middle of the 
 Great Bear through the polar star to an 
 equal distance on the opposite side, it 
 will pass through a group of eight or 
 ten tolerably bright stars, which form a 
 figure something like the letter Ww. 
 This is the constellation called Casseo- 
 peia ; it has no stars either of the first 
 or second magnitude, five of the third 
 magnitude, six of the fourth, twelve of 
 the fifth, and thirty-of the sixth. 
 
 A constellation, called the Lzééle 
 Bear, may be known from its being 
 nearly of the same figure as the Great 
 
 
 
Sea 
 
 —— 
 Sal ni tel 
 pet ed 
 
 ws ~ 
 
 Se SSE eae ST NS ge een < 
 —————ee ——_ ee er Ete im we 
 Seite tallltssbuswedesumssenebaaenetinniantineenes > 
 a 
 
 — 
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 nt 
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 — oe eR Ny 
 
 oe RSS Be eet 
 PE ee ete en gg go re + 
 
 aS a a 
 
 ; A thy Deeg 
 Sore ia Senter 
 
 120 Wonders of the Telescope. 
 
 Bear; it is parallel to it, but in an 
 
 the polar star forms 
 It has no stars of 
 
 inverted position ; 
 the tip of the tail. 
 the first magnitude, one of the second, 
 (the pole star,) two of the third, three 
 of the fourth, five of the fifth, and two 
 of the sixth. 
 
 Ifa line be imagined to pass through 
 the two last stars in the tail of the 
 Great Bear, and continued beyond the 
 tail, about twice its length, it will pass 
 through the constellation Bootes, and 
 very near a very bright and very beau- 
 tiful star of the first magnitude called 
 Arcturus. Thisisa very brilliant group 
 of stars: it: contains one of the. first 
 magnitude, seven of the third, fourteen 
 of the fourth, sixteen of. the fifth, and 
 thirty of the sixth: it has none of the 
 second magnitude, 
 
 Turning towards the south, we ob- 
 serve ‘the splendid constellation of 
 
Constellations. 191 
 
 Orion; it is composed of nine or ten 
 very bright stars, four of which. form 
 an irregular square: within these are 
 three others, placed near each other ; 
 and in a straight line below them are 
 three others of inferior lustre, which 
 seem, as it were, to hang from them. 
 The two higher stars in this square 
 form the arms or shoulders of the 
 figure ; the two lower, his legs or feet ; 
 the three bright stars in the middle 
 represent his girdle; and the three 
 smaller, which are below them, his 
 sword. The constellation Orzon is by 
 far the most brilliant and beautiful of 
 any in our hemisphere, both. with re- 
 spect to the number of bright stars and 
 the beauty of their arrangement. It 
 contains two stars of the: first magni. 
 tude, four of the second, three of the 
 third, sixteen of the fourth, nineteen 
 L 
 
 
 
129 Wonders of the Telescope. 
 
 of the fifth, and above thirty of the 
 sixth. 
 
 If a straight line be drawn through 
 the three stars which form Orion’s belt, 
 and continued on each side of that 
 constellation, it will lead on one side 
 to the star Sirius, or the Dog Star, and 
 on the other to the Pleiades. 
 
 Sirius is a remarkably bright star of 
 the first magnitude, and is nearer to us 
 than any other of the fixed stars ; it is 
 easily distinguished from the rest by 
 
 
 
 — _ atm ~aes 
 members yee “ + - 
 MEETS ON EE ee ee 
 eS ee ee 
 
 —— 
 ee 
 ee — = 
 ee ee et = == 
 
 > oe 
 
 its superior lustre. 
 
 The Pleiades, or what are commonly 
 called the seven stars, are on the north- 
 west side of Orion. It isrecorded that 
 there were formerly seven of these 
 stars; to the naked eye, however, they 
 are now but six: they form part of a 
 constellation called the Budd. 
 
 A very large star, which lies about 
 
 ee ee ae ee eae eee - 
 eee Se SS 
 
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 Constellations. 123 
 
 half. way between the Pleiades and the 
 western shoulder of Orion forms the 
 Bull’s eye ; it is a star of the first mag- 
 nitude, and is called Aldebaran. The 
 constellation of the Bull contains this 
 star.of the first magnitude, one of the 
 second, four of the third, ten of the 
 fourth, twenty of the fifth, and forty- 
 six of the sixth. 
 
 A large bright star, which forms a 
 triangle of equal sides with Sirius and 
 Orion’s belt, is also a star of the first 
 magnitude, and is called Procyon, or 
 the Lesser Dog; it lies to the north of 
 Sirius, and to the east of Orion. 
 
 If a straight line be imagined to ex- 
 tend from the star Procyon, towards 
 the north, the first bright star it meets 
 with is Castor, a star of the first mag- 
 nitude, and belonging to the constella- 
 Jation of the Twins; near this, to the 
 south-east, is another bright star of the 
 
 
 
124 Wonders of the Telescope. 
 
 same constellation ; it is of the second 
 magnitude, and is called Pollux. Four 
 stars, which lie at equal distances in a 
 straight line, and about half way be- 
 tween the eastern shoulder of Orion 
 and the Twins, form the four feet of 
 the Twins. This constellation con- 
 tains one star of the first, one of the 
 second, four of the third, ten of the 
 fourth, twenty of the fifth, and forty- 
 five of the sixth. 
 
 A line drawn from the western foot 
 of Orion, through the star Procyon, will 
 lead to a very bright star of the first 
 magnitude, in the constellation of the 
 
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 Lion ; it is called Regulus. If a line 
 be drawn from a star in the middle of 
 the Twins, through the star Regulus, it 
 will, at a very little distance from it, 
 pass below a square of bright stars, 
 which form the rest of the constellation. 
 The first bright star lying in a line, 
 
 a 
 
 ee See TN Ge EN ROE Se ees 
 
 nl nae me 
 os 
 
 
 
Constellations. 795 
 
 almost east from Regulus, forms the 
 tail of the Lion: the star is also of the 
 first magnitude, and is called Dened. 
 The constellation contains two stars of 
 the first magnitude, two of thesecond, 
 six of the third, thirteen of the fourth, 
 fourteen of the fifth, and forty-four of 
 the sixth. 
 
 A line drawn from the star Rigel in 
 Orion, through the star which forms 
 his western shoulder, will, at about the 
 length of Orion from him pass near 
 a very bright and beautiful star in the 
 constellation Auriga: the star is of the 
 first magnitude, and is called Capella, 
 or the Goat. This constellation has 
 Capella, of the first, one of the second, 
 nine of the fourth, twenty-one of the 
 fifth, and twenty-four of the sixth 
 magnitude. | 
 
 The Crab is a constellation composed 
 of small stars, difficult to distinguish ; 
 
 L 2 
 
 ee eee 
 
 ee : 
 a a bs els en a 
 
 << oat a a —— . 
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 = pes 
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 126 Wonders of the Telescope. 
 
 a line drawn from the star Procyon to 
 the tail of the Great Bear will pass 
 through it. This consteliation has no 
 star either of the first, second, or third 
 magnitude; it has seven of the fourth, 
 eight of the fifth, and forty-three of the 
 sixth. 
 
 A line drawn from the star Procyon, 
 by Aldebaran to the westward, leads 
 to the constellation of the Ram, This 
 is called by astronomers the first con- 
 stellation in the heavens, in point of 
 order, because the group of stars which 
 form its head lies nearest to that point 
 where the Sun equally divides the 
 year, making the nights equal to the 
 days. The first star in the Ram’s horn, 
 which is the star astronomers reckon 
 from, lies considerably more to the west 
 than Aldebaran. This constellation 
 has no star of the first magnitude, one 
 of the second, one of the third, four of 
 
Constellations. 197 
 
 the fourth, six of the fifth, and thirty- 
 two of the sixth. 
 
 Now, draw a line from the Pleiades, 
 in a direction north west, and the first 
 bright star it meets is the first star in 
 the constellation Perseus: the star to 
 the north-west of this is his right shoul- 
 der, the star to the west is the left ; and 
 the brilliant star nearly south of the 
 first star, is a star of the second magni- 
 tude, and this is the first of a group of 
 stars in this constellation, called Me-+ 
 dusa’s Head: next to this, there are 
 three others very near, which form the 
 whole head ; they lie something in the 
 form of a square. The constellation 
 has no star of the first magnitude, two 
 of the second, four of the third, twelve 
 of the fourth, thirteen of the fifth, and 
 twenty-seven of the sixth. 
 
 A line drawn from the star Castor, 
 through the pole star, and continued to 
 
 crepe 
 
 ah cern = 
 
 a 
 
 4 
 i 
 Bl 
 \ 
 i 
 q 
 
 
 

 
 128 Wonders of the Telescope. 
 
 about the same distance on the other 
 side, will meet the constellation of the 
 Swan ; its principal stars are disposed 
 nearly in the form ofa large cross, It 
 has one star of the first magnitude, 
 which is called Arzded, six of the third, 
 eleven of the fourth, fourteen of the 
 fifth, and forty-nine of the sixth ; it 
 has no star of the second. 
 
 If a line be imagined to extend from 
 the northern side of the square of the 
 Great Bear, through the pole star, it 
 will pass through the middle of the 
 constellation Pegasus. Its three prin- 
 cipal stars, which are of the second 
 magnitude, form an equal square, with 
 a bright star of the same magnitude in 
 the head of its neighbouring constella- 
 tion Andromeda: this last forms the 
 northern corner of the square. A line 
 drawn from the Pleiades, through the 
 principal star of the Ram, will fall 
 
Constellations. 129 
 
 upon the star Algenzd : this is the sou- 
 thern corner of the square. The stars 
 which mark the other two cormers are 
 called Markab and Scheat, of which 
 Scheat lies to the north, and Markab 
 to the south. This constellation has: 
 no star of the first magnitude, three of 
 the second, three of the third, nine of 
 the fourth, thirteen of the fifth, and 
 fifty-one of the sixth. 
 
 The constellation Cepheus is con-: 
 tained between the Lesser Bear, Cas- 
 siopeia, and the Swan. A line drawn 
 from the pole star to the star Arided in 
 the Swan, will pass through the two 
 principal stars in this constellation, 
 It has no stars either of the first or 
 second magnitude, three of the third, 
 six of the fourth, twelve of the fifth, 
 and thirty of the sixth. | 
 
 These are the constellations which 
 are the most conspicuous. during -the 
 
 
 
pe 
 
 moo OES Sr oe 
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 pepe ve ~ 
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 i 
 Hh 
 
 130 Wonders of the Telescope. 
 
 winter months: those which shew 
 themselves during the nights of sum- 
 mer, are not quite so important, or so 
 distinctly marked ; but after practising 
 the method of finding the former with 
 a little attention, these will also by the 
 help of a globe, become easily distin- 
 guishable. 
 
 When the star in the middle of the 
 tail of the Great Bear ison the meri- 
 dian, ahd above the pole star, which 
 takes place about nine o'clock in the 
 evening towards the end of May, a 
 very bright star may be observed to-+ 
 wards the south, and in the meridian: 
 this is the principal star in the constel- 
 lation of the Virgin ; it is of the first 
 magnitude, and is called Sprca, or the 
 ar of Corn: it will also be found to 
 form a triangle of equal sides with the 
 star Arcturus, and Deneb in the Lion’s 
 tail. The Vergim has one star of the 
 

 
 — 
 
 Constellations. 131 
 
 first magnitude, six of the third, nine 
 of the fourth, sixteen of the fifth, and 
 seventy of the sixth; it has none of 
 the second. 
 
 A little more to the right, but lower 
 
 than the star Spica, a kind of square 
 
 may be observed formed by four prin- 
 cipal stars: this constellation is called 
 the Crow. At has no stars either of the 
 first or second magnitude, three of the 
 third, two of the fourth, one of the 
 fifth, and three of the sixth, 
 
 A line drawn through the two most 
 eastern stars of the square of the Great 
 Bear and the star Regulus, and con- 
 tinued a little farther south, will pass 
 through a bright star of the second 
 magnitude, called the Heart of Hydra. 
 It is the principal star in the constel- 
 lation Hydra, which extends from the 
 Lesser Dog, under the Crow, to the 
 lower part of the Ear of Corn, It has 
 
 
 
132 Wonders of the Telescope. 
 
 no star of the first magnitude, one of 
 the second, two of the third, twelve of 
 the fourth, thirty-seven of the fifth, and 
 forty-three of the sixth. 
 
 The constellation Lyra is marked by 
 a very brilliant star of the first magni- 
 tude ; it lies in the north-east quarter 
 of the heavens, and forms a right-an- 
 gled triangle with Arcturus..and the 
 pole star. This constellation has one 
 star of the first magnitude, two of the 
 third, three of the fourth, five of the 
 fifth, and eleven of the sixth. 
 
 The Northern Crown is a small con- 
 stellation, situated: near to the’ star 
 -Arcturus, on a line: drawn. from that 
 star to the Lyre; it is easily known, 
 by its being composed of seven oreight 
 pretty visible stars, disposed in.a semi- 
 circle,or rather: semi-oval,. and one of 
 which is.of the second magnitude. 
 This constellation. js also pornted out, 
 
 SE ts 
 
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Constellations. 133 
 
 by a line carried from the two first stars 
 in the tail of the Great Bear. It has 
 no star either of the first or third mag- 
 nitude, one of the second, sixteen of 
 the fourth, ten of the fifth, and fifteen 
 of the sixth. 
 
 A very bright star which lies a little 
 way south of Lyra and the Swan, is 
 the principal star of the Eagle, It is 
 easily known, by observing that it lies 
 jn a straight line, between’ two bright 
 stars of the third magnitude, and very 
 nearthem. The small groups of stars, 
 that lie to the south of, and next to 
 the Eagle, is called Antinous. ‘This 
 has one star of the first, ten of the third, 
 six of the fourth, fourteen of the fifth, 
 and thirty-seven of the sixth. 
 
 A line drawn through the stars Re- 
 gulus and Spica, will lead in a direction 
 east-south-east to Anéares, a star of tlre 
 
 M 
 
 
 
 
 

 
 134 Wonders of the Telescope. 
 
 first magnitude, and the principal star 
 in the Scorpion. This constellation 
 is very remarkable; for, to the south 
 of Antares, there is an arch of stars, 
 with its convex side towards the south; 
 this forms the tail of the Scorpion, 
 and seems as if it were a centre to the 
 circle of stars round it. The Scorpion 
 has one star of the first magnitude 
 (Antares), one of the second, ten of the 
 third, seven of the fourth, nine of the 
 fifth, and thirty of the sixth, 
 
 A bright star, which lies about half 
 way between Spica and Antares, is 
 the southern scale of the constellation 
 called the Balance: the next bright 
 star to this, in a north-east direction 
 from it, is the northern scale of that 
 small constellation ; they are both of 
 the second magnitude. The Balance 
 has no star of the first, two of the 
 
Constellations. 135 
 
 second, three of the third, ten of the 
 fourth, four of the fifth, and twenty- 
 three of the sixth. 
 
 The constellation Sagittarius follows 
 the Scorpion to the eastward; a line 
 drawn through the Swan and the Eagle 
 will lead directly to it. It has no stars 
 of the first or second magnitude, five of 
 the third, ten of the fourth, twelve of 
 the fifth, and sixty-four of the sixth. 
 
 A line drawn from Antares to the 
 polar star, will first pass through the 
 constellation Ophiucus, or Serpenta- 
 rius, and a little higher through that 
 of Hercules. A line from Antares 
 to Lyra passes betwixt the heads 
 of Hercules and Ophiucus; they 
 lie very near to each other, and are 
 stars of the second magnitude. The 
 most eastern and southern of the two 
 is the head of Ophiucus. The stars 
 which lie to the north of the head of 
 
 ———— eS Cer ee 
 
 Le , : 
 on ra ra pln See: 
 
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 = 
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 xs = 
 
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 SS ee by eee a Ss ey ae a ng a } - £ 
 — 34 > ” 
 owe 
 — ~20 - — --e -— 
 
 
 
136 Wonders of the Telescope. 
 
 Hercules, form the rest of that constel- 
 lation; and those which are to the 
 south of the head of Ophzucus, consti- 
 tute that constellation. 
 
 Hercules has no stars of the first or 
 second, seven of the third, twenty-six 
 of the fourth, the same number of the 
 fifth, and forty of the sixth. Ophiucus 
 has no star of the first, one of the 
 second, seven of the third, nine of the 
 fourth, fourteen of the fifth, and thirty- 
 six of the sixth. 
 
 A line drawn through Lyra and the 
 Eagle, towards the south-east, leads to 
 two stars of the third magnitude, and 
 pretty near each other, which form the 
 head of the constellation Capricorn; 
 another star of the same magnitude, at 
 about the same distance from the head 
 that Lyra is from the Eagle, and lower 
 towards the south, forms the tail of 
 Capricorn. It has no stars of the first 
 
 al 
 AVY 
 mae et 
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 ber 
 py 
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 ny 
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 ees eS aie Soa 
 
 - —— 
 
 
 
Constellations. 157 
 
 or second, three of the third, four of 
 the fourth, six of the fifth, and thirty- 
 four of the sixth. 
 
 A line drawn from Lyra through the 
 tail of Capricorn, will point out a very 
 bright star of the first magnitude, called 
 Fomalhaut ; it is in the mouth of the 
 constellation called the Southern Fish. 
 
 The group of five stars, of which four 
 are very near each other, and in a 
 lozenge-shaped figure, and lie next to 
 the Eagle, ina direction nearly north- 
 east from it, forms the constellation of 
 the Dolphin. 
 
 It has no stars of the first or second 
 magnitude; the five principal stars just 
 mentioned are of the third; it has none 
 of the fourth, two of the fifth, and ele- 
 ven of the sixth. 
 
 A line drawn from the Dolphin to 
 the star Fomalhaut will pass directly 
 below the square of bright stars in 
 
 M 2 
 
 
 

 
 Pa . 
 _ 
 PRA, a eee 2 —— 
 Ei I ES a 7 > ete 
 
 eos et 
 
 SI ee ee 
 
 138 Wonders of the Telescope. 
 
 Pegasus, and will then pass through 
 the whole length of the constellation 
 Aquarius. It has nostars of the first 
 or second magnitude, four of the third, 
 seven of the fourth, twenty-five of the 
 fifth, and sixty-two of the sixth. 
 
 A line drawn through the star Ca- 
 pella and the Pleiades will, at about 
 the same distance, pass a bright star of 
 the second magnitude, which is the 
 first in the head of the constellation 
 Cetus, or the Whale; a line drawn 
 from the star Aldebaran, in Taurus, 
 through this star, will pass through the 
 whole constellation, It has no star of 
 the first magnitude, one of the second, 
 ten of the third, eleven of the fourth, 
 nine of the fifth, and sixty-three of the 
 sixth. 
 
 A line drawn from the Whale’s Head 
 to the middle of the square of stars in 
 Pegasus, will have passed through the 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

 
 
 
We 
 
 mM MTT 7 
 
 
 
 MATT 
 
 TT 
 
 —s ~ 
 
Vee 1 AN WANS a =. 
 
 Constellations. 139 
 
 constellation Pisces, or the Fishes. It 
 has no stars of the first or second, one 
 of the third, five of the fourth, twenty- 
 five of the fifth, and sixty-two of the 
 sixth. 
 
 We have now mentioned all those 
 constellations which are ever visible in 
 this part of the Earth, except a few of 
 such as for the present purpose are of 
 less importance, as containing no Te- 
 markable stars. 
 
 The principal stars and coustellations ; 
 
 being known, it will be easy to trace 
 the path, or to find any of the planets 
 
 which may be at any time above our. 
 
 horizon. Besides this, the examina- 
 tion of the fixed stars with the tele- 
 scope, will open.a new source of 
 amusement and instruction ; many of 
 those which appear single to the naked 
 eye, are, with the telescope, discovered 
 to be double... Many stars are found 
 
 ~ 
 —- . 
 
 _— 
 == 
 ee ee 
 ey de eet 
 
 ee 
 —— . 
 - ~* 
 
 tne _ 
 
 —< 
 
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 Boi 
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 —— 
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 — ——_— SR OE RS eS : : 
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 140 Wonders of the Telescope. 
 
 to change their brightness and colour 
 at certain periods, and in some parts of 
 the heavens, spots are found of a size 
 and appearance which give them the 
 effect of openings through the confines 
 of our system into ‘some region of 
 light. 
 
 Plate 9 represents all those constel- 
 lations which are visible to us, with 
 their principal stars as far as the fourth 
 magnitude. This chart of the stars 
 will prove of considerable use and 
 amusement, to practise the finding the 
 constellations from each other, as we 
 have directed, at those times when the 
 circumstances of the weather prevent 
 our consulting the heavens themselves. 
 An admirable contrivance for obtain- 
 ing a correct knowledge of the constel- 
 lations is an optical apparatus, on the 
 principle of the Phantasmagoria, con- 
 structed by Mr. Blunt, of Cornhill. 
 
 Sie 4 ws 
 

 
 ; pe tie are 
 aie See : ae 
 ped Cele ahd ieee err oor 
 
 Rm ; Sr re re 
 
 id — 
 
 
 
 ——— — a el 
 &- ae = " 
 
 me 
 

 
 A Refracting or Achromatic Telescope . 
 
 
 
 
 cat wD . a 
 
 
 
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 SS a ey a EE 
 Sees Se SS = ee Ee 
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 eer ere a ee x me => SE a Te! — —, eee eas Se a 
 ee ee ae a a ee SSS at a De eee 6 eT yer) ee 
 
 a a a we - 
 
= 141 
 
 
 
 ~ OF THE CONSTRUCTION 
 
 USING THE DIFFERENT SORTS OF TELE- 
 SCOPES, 
 
 —_——_s—_ oo 
 
 TELEscopEs are divided into two 
 classes, the. reflecteng and the. refract- 
 ung. Reflecting telescopes are those, 
 in the. construction of which coneave 
 mirrors are used, which reflect the 
 appearance of the object to the eye of 
 the observer. Refracting telescopes 
 are those which are composed of con- 
 vex lenses: through these the images 
 of the objects seen are refracted, or 
 bent towards the eye of the observer. 
 
 The reflecting telescope is generally 
 preferred for astronomical purposes, 
 because the principles of its construc- 
 tion admit of its being made to magnify 
 
 ~_ 
 
 en ee na — are preeminent NS 3 0g RE TIER etn tot =: 
 * pe Sor ~ 
 - iskt-aae t - 
 ger te eae ee : ee ers rtm a4 
 oe eee a 7 
 es A — nd 
 
 eA? selene pr sag 
 
 eS 
 
 | 
 aiE 
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 = xtioe Sew ers : are Rai 
 ae = = aa —. 
 
 a —— + 
 
 
 
 
 
 
 te ee a oe 
 
 tae we 
 
 
 
 
 
 co emits 5 a eeree ies ape weer ae aecine 
 
 142 Wonders of the Telescope. 
 
 more than a refracting telescope of the 
 same length. 
 
 The refracting telescope is preferred 
 for the common uses of the instrument, 
 because it is of a more simple con- 
 struction, and therefore less liable to 
 accident or derangement ; it is, for this 
 reason, constantly used by seamen. 
 
 The night telescope is a refracting 
 telescope, constructed in the common 
 way, but of a small magnifying power, 
 and large or wide glasses; it is used 
 principally by seamen. It must not 
 be supposed that this instrument ac- 
 tually enables us to see in. the dark, 
 The effect of all telescopes is, that we 
 are enabled to see a distant object with 
 them as large and distinctly as if we 
 were much nearer to it; and this is in 
 proportion to what is called the magni- 
 fying power of the telescope ; so that 
 if an object be at a distance of eighteen 
 
 
 
 
 
ee 
 
 « = 
 Nig tickle ets a ee 
 allies baie eer - . = ~ 
 
 gsagense = 
 
 4 
 
 i 
 , 
 4 
 
 
 
oes a ee ne hae eee 
 2 - Se il ae ee EB. 
 
 CN tee ee 
 
 
 
Telescopes. 143 
 
 hundred yards from us, and we look at 
 it with a telescope, which magnifies 
 eighteen times, it will appear as large 
 and distinct as it would to the naked 
 eye, if it were only one hundred yards 
 distant from us. 
 
 Now, if we suppose a night only so 
 dark as that we could just perceive a 
 inan at one hundred yards distant, he 
 would of course be totally invisible to 
 us, 1f he were eighteen hundred yards 
 from us; but if, at that distance, we 
 look towards him with a telescope 
 which magnifies eighteen times, he 
 will, in effect, be brought eighteen 
 times nearer to us, and become as visi- 
 ble as he would have been to the naked 
 eye at a distance of one hundred yards; 
 and so of any other distance, 
 
 The telescope represented in Plate 
 10 is a refracting telescope, mounted 
 on a brass tripod stand, as. it generally 
 
 
 

 
 
 
 144 Wonders of the Telescope. 
 
 is for astronomical uses, and provided 
 with two tubes of eye glasses, to 
 change occasionally when it is wished 
 to alter the magnifying power ; when 
 in use, they are screwed into a short 
 tube at the smaller end of the tele- 
 scope; when the shorter of the two 
 sets of eye-glasses is used, the tele- 
 scope magnifies the most. To use 
 this instrument, there is nothing more 
 to be done than to set it on its legs, as 
 in the figure, and having uncovered 
 the object-glass, (that at the larger 
 end,) screw in one of the sets of eye- 
 glasses, and, looking through the tele- 
 scope, turn the brass button at the 
 side of it, until the object you look at ~ 
 is seen distinctly. 
 
 Plate 11 represents a reflecting tele- 
 scope, mounted as it generally is for 
 astronomical purposes. This telescope 
 “is also provided with more than one 
 
Te lescopes. 145 
 
 Set of eye glasses, to change occasion- 
 ally: they are screwed into the end of 
 the jarge tube, as in the figure. The 
 reflecting telescope has also the ap- 
 pendage of a small telescope, which is 
 fixed to its side; it is of small magni- 
 fying power, and lies parallel to the 
 tube of the large telescope ; it is called 
 the finder telescope, from its use being 
 to point the large telescope to the ob- 
 ject which is to be viewed. To un- 
 derstand the operation, it is necessary 
 to know that the field of view of every 
 telescope becomes smaller as the mag- 
 nitying power is increased. Now, if 
 the large reflecting telescope magnifies 
 very considerably, its field of view will 
 be small, and it will therefore be diffi- 
 cult to point it exactly to the object 
 without many trials; but with a tele- 
 scope of very small magnifying power, 
 N 
 
 
 

 
 —-. =e 
 
 SESS SEE ee OO re 
 ee re Mehta ew 
 
 
 
 
 
 
 
 
 
 
 Sr ao 
 
 ~~ SIore 
 
 tox: 
 er x 
 34, : 
 
 sa ae 
 
 — 
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 i 
 
 BS gt 
 
 146 Wonders of the Telescope. 
 
 and whose field of view is proportion- 
 ably extensive, the object would be 
 caught with much more facility. Such 
 a telescope is therefore fixed to the 
 large one, in such a manner, that it 
 always moves with it, and points the 
 same way. To set the large telescope 
 correctly to any object, we avail our- 
 selves of the above-mentioned property 
 of the small one, and, bringing the ob- 
 ject to the centre of its field of view, it 
 will also be found at the centre of the 
 other. Distinct vision is produced 
 with this telescope by the screw, which 
 is fixed to its side ; the turning of this, 
 by its button, alters the distance of its 
 mirrors from each other: it must be 
 performed while the observer is look- 
 ing through the telescope. 
 
 Plate 12 represents Dr. [Sir Wil- 
 liam] Herschel’s great telescope. 
 
 
 
 
 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 VIEW OF ILE RSCHELs FORTY FOOT REFLECTING TELESCOPE. 
 
 London: William Parton : 58 Holborn Hill; 7 Fm 29% 1823. 
 
 
 

 
 
 
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 147 
 
 OF THE MAGNIFYING POWER OF 
 TELESCOPES. 
 
 
 
 Many methods have been contrived 
 to determine the magnifying power ot 
 any telescope by easy experiment. The 
 late Mr. Ramsden, an eminent opt 
 cian, invented a small instrument to 
 measure the diameter of the pencil, or 
 cone, which is formed by the rays of 
 light passing through the telescope, 
 and may be seen at the extremity of 
 the eye-tube. If we divide the dia 
 meter of the large mirror in a reflect- 
 ing telescope, or the diameter of the 
 object-glass in a refractor, by the dia- 
 
 meter of this cone of rays, as measured 
 
 by the instrument, the quotient will 
 express the magnifying power of thé 
 telescope: it is, however, expensive, 
 and therefore not often used. A very 
 
 
 

 
 148 Wonders of the Telescope. 
 
 ingenious and simple apparatus has 
 been contrived, to answer the purpose 
 of this instrument, by Mr, Varley. It 
 possesses the important advantage of 
 being extremely easy of construction: 
 indeed, any person, who can use a pair 
 of drawing compasses with tolerable 
 precision, may make it for themselves, 
 and it is found sufficiently accurate for 
 the common purposes of the experi- 
 ment. His description of it is as fol- 
 lows :¥*—‘“* Take a piece of thin writing- 
 paper, rather more than two inches in 
 length, and about half an inch in 
 breadth, draw with a pen, or other 
 proper instrument, the line a, b, in the 
 lower figure of plate 12, and then, with 
 a pair of compasses, set off one-tenth 
 of an inch from 6 to c, with the same 
 extent divide the line a, b, into twenty 
 
 * Philosophical Magazine, Vol. LV. 
 
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 SS eee 
 
 
 

 
 Telescopes. 149 
 
 equal parts, making visible marks or 
 punctures at each division: then draw 
 the line a, c, and make the divisions, 
 1, 2,3, 4, &c. to 10, at every other 
 point made with the compasses, and 
 put a small quantity of sweet-oil upon 
 the paper to make it more transparent. 
 These numbers are to express, in hun- 
 dredths of an inch, the distance of the 
 lines a, b, and a, c, at the points where 
 they are placed. The divided paper 
 being provided, adjust the telescope 
 to distinct. vision, by looking at some 
 distant object, and then take off the 
 brass cell which covers the end, or 
 eye-glass: now direct the telescope to 
 the open day-light, and take ‘the di- 
 vided paper in one hand, and a‘small 
 magnifying-glass to view it with in the 
 other; apply the proper scale to ‘mea- 
 sure the diameter of the bright pencil, 
 N 2 
 
 3 
 
 | : 
 j 
 f 
 | 
 il 
 i 
 
 . eg pe EL LEE OA LOG COOGEE . 
 ’ a. eee ——-- = ( 
 , 
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 ayer > 
 
 
 

 
 150 - Wonders of the Telescope. 
 
 or cone of light, as it proceeds from 
 the eye-glass, and at that distance 
 where it appears of the smallest dia- 
 meter. This place, where the paper | 
 is to be applied, will be easily known, ay 
 by observing, with the magnifying- | 
 glass, where the bright spot appears 
 distinct and well defined at the edges, 
 and, at the same time, the filament of 
 the paper distinctly seen. By moving 
 the paper slowly from side to side, or 
 from the wide end of the scale towards 
 the narrow, a part of it may be found, 
 where the bright spot will just fill up 
 "the space between the lines a, 6, and 
 | a,c. Suppose this to take place near 
 || the third division, when, of course, it 
 will be three-hundredths of an inch in 
 
 es 5 
 
 it 
 
 | 
 
 ee Y 
 
 Dig 
 t 
 
 bia] 
 
 ely. 
 
 ie: 
 ‘fh 
 mi 
 
 q. 
 
 e == — Ss 
 SS Se SS 
 
 diameter ; and suppose the diameter 
 “of the object-glass of your telescope 
 to be two inches and one-tenth, or two 
 
 
 

 
 
 
 151 
 hundred and ten such divisions, these 
 divided by three, the diameter of the 
 spot will give seventy for the magnify- 
 ing power, 
 
 ‘* Again, suppose that, with another 
 tube of eye-glasses, the cone of light 
 fills the lines at the fourth division, 
 divide the two hundred and ten by 
 four, and it will give fitty-two—five, or 
 fifty-two and a half, for the magnifying 
 power.” 
 
 Mr. V. also describes another me. 
 thod, which may be used in confirma- 
 tion of the former, and is more simple, 
 and well calculated to produce convic- 
 tion. 
 
 Telescopes. 
 
 ‘‘ First, measure the space occupied 
 by a number of the courses, or rows of 
 bricks, in a modern building, which, 
 upon an average, is found to have eight 
 courses in two feet, so that each course, 
 
 
 

 
 
 
 
 
 
 
 
 
 
 
 
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 152 Wonders of the Telescope. 
 
 or row, is three inches: then cut a 
 piece of paper three inches in height, 
 and of the length of a brick, which 1s 
 about nine inches, so that it may re- 
 present a brick, and, fixing the paper 
 against the brick wall, place the tele- 
 scope to be examined at the distance 
 of fifty or a hundred yards from it; now 
 looking through the telescope at the 
 paper with one eye, and at the same 
 time with the other eye looking past 
 the telescope, observe what extent of 
 wall the magnified image of the paper 
 appears to cover, then count the courses 
 of bricks in that extent, and it will 
 give the magnifying power of the tele- 
 scope,” 
 
 Le 
 ana’ | 
 

 
 DESCRIPTION OF THE PLATES. 
 
 PLaTE I. to face the Title-—The Solar System consists 
 of the Sun, S. in the centre, round which the planets 
 move in the following order: Mercury is nearest the Sun, 
 and goes round it in the orbit @; Venus performs her 
 revolution in the circle 8; next to this comes the Earth 
 at c; then Mars in the orbit d; Ceres follows in the path 
 e; beyond her come Jupiter and Saturn in the orbits F 
 and G. Besides these, the bodies w and <z represent 
 comets in their very eccentric orbits. Our Plate does 
 not admit of a representation of the orbit of the Herschel 
 planet, which is much beyond that of Saturn. 
 
 PLATE II, p. 24, the Sun, as seen through a Telescope.— 
 We have here a good representation of the solar spots, 
 which appear to be of very different magnitudes; some 
 have been calculated to be five times greater than the 
 whole surface of the Earth. The diameter of a Spot is 
 measured by comparing the time it takes in passing over 
 a cross hair in the telescope, with the time in which the 
 whole disk of the Sun passes over the same hair. 
 
 Pate III. p.43, Venus, as seen through a Teleseope.— 
 This is a representation of Venus when seen in her qua- 
 drature, or in a position similar to that of the Moon when 
 she is about seven days old. ‘The spots marked on the 
 surface are such as have been seen on it by astronomers 
 at different periods. 
 
 PLATE IV. p. 48, the Moon; &c.—This is an exact re- 
 presentation of the face of the Moon, as she is seen 
 
 
 

 
 
 
 15% Description of the Plates. 
 
 through a telescope that magnifies between two and three 
 hundred times. ‘The dark parts are supposed to be water, 
 as lakes, seas, &c., and the lighter parts, land; and, for 
 the sake of distinguishing them, each of the parts has 
 been marked by astronomers with a proper name, Thus 
 No. 3, is called Aristarchus; No. 11, Copernicus ; No. 
 18, Archimedes. A is called Mare Humorum ; B, Mare 
 Nubium, and so of the rest, 
 
 PiaTE V. p. 64, Mars, as seen through a Telescope.— 
 The dark parts on the surface of Mars exhibit the occa- 
 sional changes of the partial belts which are sometimes 
 visible on this planet. The variations noticed on the 
 surface of this planet have been ascribed to clouds and 
 vapours floating in its atmosphere. 
 
 PLATE VI. p. 67, Jupiter and his Four Satellites, as 
 seen through a Telescope.—Besides the satellites which 
 accompany this planet, and which move in orbits, that 
 make a small angle with the planet’s orbit, the surface of 
 Jupiter is frequently surrounded with belts of various sizes, 
 and in various positions. Their number is variable from 
 one to eight. ‘They are usually parallel to one another. 
 The time of their continuance is very uncertain ; some- 
 times they remain unchanged three months together, and, 
 at others, only a few hours. 
 
 PLATE VIL. p. 76, Saturn and his Seven Satellites, as 
 seen through a Telescope.—This is a beautiful representa- 
 tion of Saturn, with his ring. The distance of the ring 
 from the body of the planet is about equal to the breadth 
 of the ring itself. There are also two belts on the sur- 
 face of this planet parallel to one another, and to the 
 ring. 
 
 . Piate VU. p. 87, the Comet of 1680.—This Comet 
 appeared, through a telescope, like a coal dimly glowing; 
 
 
 

 
 | 
 
 Description of the Plates. 155 
 
 or a rude mass of matter illuminated with a dusky light. 
 The plate represents the tail as it appeared when it was 
 nearest the Sun. The tail increased in length and bril- 
 liancy as it approached the Sun, and grew shorter and 
 fainter as it went farther from him and from the Earth, 
 
 PLATE IX. p. 100, the bright Space in the Sword of 
 Orion. 
 
 PLATE X, p. 115, the Constellation of the Pleiades, or 
 Seven Stars, as seen through a. Telescope. 
 
 PiaTE XI. p. 139, Constellations, §c.—This is a chart 
 in plano of the principal stars visible in our hemisphere, 
 and they may be easily known by attending to the fol- 
 lowing directions : 
 
 A line drawn from the centre of the plate (¢ of Ursa 
 Minor, the third from the pole star) through the plate 
 towards the edges, and through the capital letter on its 
 border, will respectively pass through all the stars of the 
 first magnitude. Thus a line from centre of plate drawn 
 to A, passes through Fomalhaut, the principal star in the 
 southern fish ; through B, Aldebaran, the principal of the 
 Pleiades in the constellation of the Bull. 
 
 Through C, ———— Rigel, in Orion. 
 
 D. ———— Capella, in the constellation Auriga, 
 ——— E, ———— Betelguer, in Orion. 
 ——— FF, ———— Sirius, in the Great Dog. 
 ——. G. ——_—— Castor, in Gemini. 
 H Procyon, in the Lesser Dog. 
 ——- |, ———— Regulus, in Leo. 
 K, ———— Dubhe, the Upper Pointer, in the 
 Great Bear. 
 ——— L, ———— Deneb in Leo. 
 M, ———— Spica Virginis, in Virgo. 
 
 
 
 
 
 
 
ia 
 
 
 
 
 
 
 
 
 
 
 
 
 a4 
 i 156  Descripteon of the Plates. 
 a Through N. — Arcturus, in Boites. 
 } — O. — Antares in Scorpio. 
 
 1a ——— P, —+—— Lyra, in the Lyre. 
 
 iti } ——— kh. — Arided, in the Swan. 
 
 Te Piaves XII. and XIII. p. 141 and p.142, exhibit the 
 
 A Hi figures of telescopes. properly. mounted, for, viewing the 
 
 | | MI heavenly bodies. Long handles seen under the reflecting 
 
 A telescope, are attached to certain screws, by turning of 
 Bit i which the instrument.is pointed to the object. 
 bh ld PLatrE XIV. p. 146, Herschel’s Refiecting Telescope.— 
 i | it ‘This instrument; the-latgest ever constructed, is a curious 
 i i specimen of astupendous machiné, father than of an useful 
 i . one. We believe it has been little used, it being found 
 | that the*great mirror bent under its own weight, and 
 . q consequently produced a: distorted image. © All the dis- 
 ) i coveries'of Dr. [Sir W.] Herschel were: made with a six- 
 ie feet achromatic, but he constructed. useful. instruments of 
 Bat twenty and ‘twenty-five: feet-in length, to which the same 
 
 Woe apparatus ‘of motion*.was appended as is here -repre- 
 
 i si reseyt cys * 
 i ; SCHTEG, 
 
 
 
 G. SMALLFIELD, Printer, Hackney. 
 
 
 
 
 

 
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