Astronography, or, Astronomical geography, with the use of globes : arranged either for simultaneous reading and study in classes, or for study in the common method

Front matter

^0*

- iSTRONOGRAPHY,

ASTRONOMICAL GEOGRAPHY,

Preface

fdi I requested by the "Publisher of

this WOck, to write for him | small volume to nceompany and explain the Globes, she undertook the ta>k with pleasure; having, in the long course of her duties ej IVincipal of the Troy Female Seminary, felt the need of new aids in fully understanding them; and she had long entertained the opinion, that a radical error was committed in elementary works on Astronomy M d with Geography, Id put-

ting d«»wn the definitions of the Horizon. Zenith, and other positions depc I fteorror, as some-

thing of the same kind, as the Equator and Pi iaj 1 4 the Earth, and all those definition*, which refer to ohjeota detennin.r nature, and unchangeable in hese, together with

Ecliptic and its accessories being mingled indiscrimin . together. But as ll . :e found her way beset with

dimV i ch could by no other mean- be surmounted

than that the new arrangements I 1, moal have appro-

priate language to express them ; which, not fiffatmg, she was ped to give new and technical significations to such words as most nearly gave her meaning. The first word of the

la, however, a term composed far the occasion.* But be: !v in the ami

mind were fully developed, the nascent subject shot forth new branches, and these still others, until the three B Systems, with each its accessor nd, and their

-ections ehowi ♦•ing permanent or movable

cording to their systems. When the fipirc representing these was completed, the author being asked to explain it. Mid, ' It is three things, instead of three hundred.' 1 ere*

at length in * noU on p*go TIL

8 TBEFACE,

the learned astronomer find that he had gained an advantage, if, in speaking on astronomical subjects, he could use terms so general, and yet so clearly defined to the comprehension of the young, as are the Spherical Systems ?

But in venturing so far from the beaten track, much reading and reflection were required ; lest, in forming a new and useful ladder on which the young might climb to high subjects, the grand edifice of Astronomy should be marred. The growth of the work was therefore slow and laborious.

In the study of the Terrestrial Globe — indispensable on account of the false impressions given by comprehensive maps, especially maps of the world- — the author has also devised some new and useful methods ; particularly, that of the sweeping measurement of all distances from the observer's position, by terrestrial Almacantars.

Since no human production is perfect, notwithstanding care, this work will have its errors ; but the author will correct them as soon as known, whether indicated by friend or foe. She regards herself as peculiarly fortunate, in having written at a time when Herschel's " Outlines of Astronomy" had recently been revised, and Humboldt's " Cosmos" just issued from the press, — the best and most unimpeachable of authorities.

The opening sentence of this work is not an idle flourish ; but a pledge conscientiously redeemed, by so managiDg the subjects as to enlarge and invigorate the mind, and to establish such mental habits and tones of thought, as shall lead the pupils, as they advance into life, to moral as well as intellectual greatness ; — to become the servants of God, and the friends of man.

Contents

GHAPTKB T.

Introduction. — Definition of Astronomic*] Geography. — The

Globe. — (Jravitation. — The Nature and

CHAPTER II. Usee end I ttial and Terrestrial Globes

GHAPTKB III.

vul.ir I be \i> m - li the I arth lim-

ifx-i-

pal Planeti and Satellites, — Comets,—

Dees. — Sir John Hersebel'i Qlostration el the

GHAPTKB IV.

Distinction of Positioni u nent and Movable 41

OHAPTKB v.

The B

- roth, — The Prime Vertical oof an East and W. -t Lino, an .'««r. — 1 >- ftnitions. . ■

GHAPTKB vi.

Earth, Diun ■

CHAPTEB vir.

Sign Ketroccssinn i 'ointl

caused i anon of t]

d of the Bon in

Illustrated by a Father's E Son

10 CONTENTS.

CHAPTER VIII.

Time and Space. — Periodicity. — Secondaries of the Equator. — Terrestrial Globe made for the London Observer. — 24 Semicircles measuring the Equator into 24 equal parts of 15° each — This Unit in Space equal to an hour in Time. — Terrestrial Longitude — How Reckoned — How Calculated. — Circumpolar Stars 82

CHAPTER IX.

Terrestrial Almacantar Circles — How Used to Divide the Earth into Six Belts ; being an Easy Method of obtaining a General Knowledge of the Distances of all Places on the Earth's Surface from our own Position 92

CHAPTER X.

Changes of the Seasons, and the Causes 99

CHAPTER XL

Permanent Positions arising from the Intersections of the Systems of the Earth and Heavens. — The Tropics and the Polar Circles. — Different Planets have their Axes at Different Degrees of Obliquity.— The Five Zones 108

CHAPTER XII.

The Intersection of Spherical Systems. — That of the Earth with that of the Observer. — Eight Central Angles of the Intersecting Spheres. — Latitude and Longitude the Foundation of Geography. — Of Navigation. — Means of finding Latitude 119

CHAPTER XIII.

Great Circles can, by their Planes, be transferred from one Sphere to another. — Smaller Circles cannot. — Observer's Line and an Imagined Ray of Solid Light made mediums for transferring Circles of Latitude and of Daily Motion. — Comparative Length of Days and Nights. — Right Sphere. — Parallel Sphere 126

CHAPTER XIV.

Spheres. — A Right Sphere ; a Parallel Sphere ; an Oblique Sphere. — The Atmosphere — Necessary to Man's Respiration; that is, his Life. — Aerial Tides. — Oceanic Mountains 135

CHAPTER XV.

Parallax. — Refraction. — Reflection 145

CHAPTER XVI.

The Moon. — Its Poetic Influence. — Size. — Position. — Three Motions. — Orbit. — Selenography. — Nodes. — Gravitation. — Tides. — Light of the Moon. — Eclipses 153

CHAPTER XVII.

•h.— Tin- Oblique Sphere.— Earth'i rat< >n in her Orbit — Gravitation. — Centrifugal Force.

— Bun'i Altitude, . w York. — Triangle i»t" Time.. .169

GEHAPTBB XVIII.

th of the Daya and Right* — Mia aod Appearance of the Sun.— ►The Obeerrer at N«w rh «.»n the 10th of Ma j. — What the Length ofbii Day, Ac, —

at Stockholm ; at Cape Horn ; at 1S1

CEAPTKB XIX.

therms.— Causes of Exception to the Law that .•!-• 190

CHAPTER XX.

inc. — The Educated live. — Much '203

SB xxi.

.

aeo ad Day, — The Astronomic*]

. Tune "t" the Solar and

BM II Of the Kquinoctial no E<juinoxed 213

CHAPTKB XXII.

Irregularity in S lar Day* — The Mean Day found

by the Clock. — Two

Causes d the In "-Obliquity of the

tnequaJ Motion in herOrbil performing

equal A r — Diapoea] of the odd Bour* and

Mi:. : the Calendar. .

CHAPTER xxill.

Astronomy doubly honors God, in r | < >)>-

•~ and to Mind — l> 1 I the Tana — Nature of Mind,

■ mceni . — taone who tir-t enhtrateo tin- Science. — Ohmcoe, in:..

tone, Pythagoraa, Damo, Philolaua. — School <»f

Arvfttillu*, Timocharia, Ariatarch .

Hij.|.ardiuj.

12 CONTENTS.

CHAPTER XXIV.

History of Astronomy after Christ. — Ptolemy — His System.— The Almagest. — Historical Great Events quicken Inventive Genius. — Discovery of America. — Copernicus — His System : — Compared with Ptolemy's. — Tycho-Brahe. — Kepler — His three Laws. — The Discovery of the Telescope. — Galileo — His Persecution. — Huygens and others. — Sir Isaac Newton — His Excellent Character. — Great Law of Universal Gravitation. . . . .249

CHAPTER XXV.

Astronomy as left by Kepler and Newton. — Mathematical Astronomy. — Optical Astronomy. — Bodies added by Discovery to the Solar System. — Aerolites. — Tremendous Shower at Aigle in France. — Meteoric Shower in North America, 1833. — Terrible Appearance at Crema. — Franklin's Discovery.— Morse's Invention. — Changes in the Stars. — Appearance and Disappearance of the great Star in Cassiopeia. — The two Herschels. — Sir W. Herschel's great Plan and Labors in gauging the Heavens. — Continued by Sir J. Herschel. — The Telescope. — The Discovery of the Southern Heavens. — Great Discoveries of Stars in the Milky Way. — Sublime Hypothesis of Sir "W. Herschel concerning the Motion of the Sun. — The Milky "Way the paramount Circle of the Heavens 264

CHAPTER XXVI.

Atheism Unphilosophical. — God is especially Manifested in Adaptations. — Man is adapted to the Earth, the Air, and the Sun, and they to him. — Man's dignified Position — His Immortality — His high Moral and Religious Duties Illustrated by Gravitation 2*78

NOTE TO TEACHERS.

7%s authors views concerning a Method of Simultaneous Set and Study.

To read with case and tl . LJ •lishment, and

to be acquired by much practice. And whoOTOI wiO look book npon hia cmrly school-days, will And that nothing Ki man indelibly impressed upon his mind than tl. ttnglessons. Following these ideas, the author— an experienced tear: has laid it down as .11. in nil possible oases, be taught to read what they st>< they read. It is a plan which makes important purposes, saving tl. th of the inatz is book is thereforo arranged forma two purposes; iy as

connected with Geo,.- n it

suppose the class to begin the book with I f the

term, and that the Globes stan d in lull view. If

ass understand tha* mence a study, on which

they are, e£ t ran, to be examined, it will qui

their powers of atterr I thai

they | read the lessons

wsU f— distinctly, audibly, and with correct articulation, pronnnolation, and emphasis. og, should,

if possible, be as much as tl I day.

I the common practice with good teaing the meaning of words and

that the pupils understand them. T asizo

prop i

the text will mutual: .-ach other blackboai

Ql having read the lesson, the questions at the I the page, or others, can, at the option of the teacher, be ■

■ books. Thus the knowledge ibjeot will re-

entering their n 'he same t ig the

eorrect manner of reading aloud.

14 NOTE TO TEACHERS.

Towards the close of the term, we recommend that the class give their attention to the subject-matter y as at the first, to the manner of reading.

By proposing this method, with a book designed to afford a connected view of an important subject, we do not expect, or desire to dispense with reading-books in schools. Those are needed for first lessons; and they afford rules and examples for Bhetorical Beading. But the teacher, whose classes read their studies in the method here laid down, will find his pupils prepared to learn rhetorical reading, — as the writing-master, who first teaches a good common hand, finds his scholars prepared to learn the flourishes of ornamental chirography.

In the summer of 1840 the author of this work was elected by the freemen of a parish in her native town, Kensington, in Connecticut, to superintend, for a season, their Common Schools. The classes of the five existing schools were examined together at tho close of the summer term by Henry Barnard, Esq., State Superintendent of Schools, — by the eminent Educator to whom this work in dedicated, and many others. Mr. Barnard's Report of the results, to the State Legislature, was extensively quoted, and referred to as describing an improved method in education. It was thought wonderful that so much was accomplished in so short a time, especially in the use of language, oral and written ; not only in reading naturally and without toning, but in spelling correctly, and in composing off-hand on subjects given at the time by the examiners. Our classes had studied what they read, and they had read what they studied. They read understandingly, and they became familiar with the right spelling of words, and their arrangement in sentences ; and thus time was saved for the practice of off-hand composition, and for other purposes.

The Exercises between the chapters are written in a more free and conversational style than the chapters themselves. The author supposes the teacher will probably give these to the pupils to study between the times of reading the chapters, for the purpose of directing their observations to be made on the Starry Heavens and on the Globes. But every good teacher has his own methods.

ASTRONOGRAPHY,

OR

ASTRONOMICAL GEOGRAPHY.

CHATTER I.

Astih ial Tbuuhtha]

SPHERE, AS Arri.KAIU.K T<» A 1 1 ft '\< >M K \L OEOGRAPQT ; OR, 'I UK. — I'KHMII

1. :' i work of elementary instruction, in any i oe, should perform the <luty

ientiotu teacher, — desirom not npik in that one science, but t<> pro-

iiK-nt; and most, in the beet thi: g

2. which we treat tends to cult i \

and adoration of the (; '"1 of

and in the habit i serving his works,

th and in the 1 1 and, alao, to

re strength and - ning powers, and

ition; — kinds of improvement

. • ion of moral sod intellectual gn

BBS.

describes the ima I. — 1. In what «pi: \v«.rk to

teach any particular asisnoe, perfbra

most I — 'J. In what

rmphy or Astmno^raphy at .• youth f

at arc these two kinds of imj.:

16 man's home, the earth.

Earth ; and to us, whose home is in this planet, no knowledge can be more interesting. But the condition of the Earth, signally depends upon the Sun, is much influenced by the Moon, and in a lesser degree affected by the other heavenly bodies. So that the very foundation of Geography is laid in Astronomy.* This science treats of the heavenly bodies, and of the Earth, as composing one of their number; so that there is one portion of Geography which is Astronomy, and one portion of Astronomy which is also Geography :\ and these parts of the two sciences, together compose Astronomical Geogkaphy ; or, in one word, Astronography.

4. The Artificial Terrestrial Globe represents the great globe, or Earth, which man inhabits. To the centre of the Earth all things upon its surface tend, being drawn towards that point by a force, called the Attraction of Gravitation. An Artificial Globe cannot, in this respect, be made to resemble that on which we live ; but it must itself, with whatever is upon it, be attracted to the Earth. With regard to every individual of the human race, down, signifies directly towards the centre of the JUarth ; and up, directly away from that centre ; and this is the case on whatever part of its surface any one may live ; whereas, on this Artificial Globe, there is but one position, which we term the Upper Vertex, where a little figure, representing a man, could be made to stand. His feet would, in that place alone, point towards the centre of the artificial globe, and, as ours do, towards the centre of the

* Astronomy, from two Greek words, asrep, a Star, and vo^ a law.

f Geography, from ys, the Earth, and ypa<pe, description.

3. Define Geography : On what does the Earth's condition depend ? Define Astronomy : What, in view of these definitions, is Astronomical Geography ? — 1 What is represented by the Artificial Terrestrial Globe ? What force is here spoken of ? What effect, with respect to the Earth, is produced by the Attraction of Gravitation ? In what respect is it impossible that an Artificial Globe should truly represent the Earth ? With regard to mankind, what direction is down ? What direction is up ? What difference is there between the Earth and the Artificial Globe, in regard to a position on which to stand ?

m i>r.su;\ IK. 17

arranged, bo thai we on

make the Upper Vertd the plaos of the ftnai

Observer.

5. r is an imaginary personage, to

d on the Earth many of the definitions of

For the place of this

ire ftnall continue to dm the term Upper

ir first lessons in this science, should

r kept in their new, with his place of

: it is intelligent mind beholding things

rtain place on the Earth's may slone be used, ss circum-

stances dictate : u nr u the Meridian of Lou-

don.'" lias of the Observer at London; u the

Zenith of the ( observer at Boston.

6. mous; but in th lifier-

ence. The n £ used in IfathemaJ

and the port f die

properties of t he & 1 Spht r

• swe hare the phrase "the Doctrine of the Bph< Without som< I doctrine, 11 no

can be made in A graphy. A Globe or

Sphere is a solid b<>< wk iek il

• i this, thai

7. ps as to be in

• line, coi

the Sphere.

5. What is ■ -»'. What <lif-

fercooe w * be terms

br Spheric* f What can you ■ f thi BoIm

this « 1* - ti f i : What is a Radius < : v may we sup

pose the Diameter of a Sphere to be constituted I

18 DOCTRINE OF THE SPHERE.

to two of its radii. Any straight line passing through the centre of a Sphere, and cutting the surface in opposite points, is a diameter. The diameter is the longest straight line which can be included in a Sphere, All the diameters of a perfect Sphere are equal.

8. The Earth is not a perfect Sphere. Its diameter at the Equator is longer by 26 miles than that from north to south, which is identical with the Earth's axis. By being thus a little flattened at the poles, the Earth approaches in form to an oblate spheroid. Yet its variation from a perfect sphere is so little, that for any purpose, appertaining to our present study, it is not necessary to notice the difference ; but we are to study the Globe as if the Earth, which it represents, were a perfect sphere.

9. We find drawn around artificial globes many circles, some of which are great circles, and some small or lesser circles. A Great Circle is one whose plane divides the Sphere into two equal parts, or Hemispheres. A Lesser Circle is that whose plane divides the sphere into two unequal parts. To understand this, we must consider that to every circle belongs a plane, as well as a circumference and a centre.

10. For illustration, suppose I take this round apple to represent a Sphere. Any Sphere, cut by a plane which passes through its centre, will be divided into two equal half-spheres, or Hemispheres ; and the meeting of the plane with the surface of the Sphere will be a great circle of that Sphere. I hold my knife level, and cut the apple through the centre. The line of the divided skin represents the circumference of a great circle of the little Sphere, and the plane within, is the plane of that circle; the middle point being the centre. Suppose the halves of the

T. What further may be said of the Diameter of a Sphere ? — 8. What is said on the que stion whether or not the Earth is a perfect Sphere ? What kind of Sphere is it ? — 9. What are the two equal parts or halves of Spheres called ? What are Great Circles of Spheres? What are Lesser Circles? What three things belong to every circle ? — 10. How may the circumference, plane, and centre of a circle be illustrated ?

DEFICIT!

appl< ^ether, so that no plane can be soon,

the plane to be attended out to any listanoe from the apple; like this paper circle which i> inserted between its two halves.

1.4

11. Tl 'V an<l DiomtUr of any Great

and diameter of that 5 uneter may be termed an

ra; farif about which it might revolfo,

if there ' i m| it in motion. Any axis of a

• ■ and Polei eonn< with that axis may be (bond. For the meeting of the axis with I two opposite points of the Sphere

68 of that axis. And /

A line it at right angles, oi Licnlai to a plane, when it does not in-

cline to either

T€ y are those which the axis cuts v .-S between the Gh

10. How can yon f«»rm an Kdeaof tl. lacing

led \ — 11. W I any

Sphere equal to I sphere be \

f.-r it- fi\i- f BuppoM an axis of a Sphen to bi L-iv.ii.uh.it may be known f I beloogiqg to any

It. Define the Leuer oxia.

OIECLES THEIR MEASURE.

Circle and the Poles. Of the axis of the Earth, the Equator is the Great Circle; the two Tropics and the two Polar Circles, and all circles of latitude are Lesser Circles; and its poles are the Poles of the Earth.

13. Angles are measured by arcs of circles.

An arc is any part of a circle less than the whole, and is said to be an arc of a certain number of degrees. To find the measure of arcs and angles it becomes necessary to divide the circle (that is, any or all circles) into a certain number of equal parts. By common consent every circle, whether great or small, is divided into 360 equal parts, called degrees. For the purpose of exact measurement, degrees are divided into minutes and seconds. A minute is the 60th part of a degree, and a second, a 60th part of a minute. A degree of a Great Circle of the Earth is 60 geographical miles, or 69* English miles. Hence a minute and a geographical mile are the same measure, but both exceed the English mile.

* When the circumference of the Earth was estimated at 25,000 miles, it was usual to state the number of statute miles of a degree 69-J-, which number was, even at that calculation, a little too large ; since 360° X 69i=25,020. But taking the number now more generally adopted from Sir John Herschel, 24,856, the nearest approach to correctness, without running into inconvenient fractions, is 69 statute miles to a degree; since 360° X 69 =24,840, which approaches within 16 miles of the present calculations of the Earth's mean circumference.

12. What is the Great Circle belonging to the Earth's axis? "What the Lesser Circles? — 13. How are angles measured? What is an arc of a circle ? What must be done in order to obtain a method by which the measure of arcs can be determined ? How are circles divided ? What more minute divisions are used ? If we take a Great Circle of the Earth (which is the measure of the Earth's circumference), to what is each degree, or 360th part, equal ? How is this reckoned ? (See Note.)

MUTUALITY OF ANGLES A5P ARCS.

14. We insert a diagram to illustrate the division of I the measures of iDgl68. The circle A.BCD

is divided by two diarn* ft r.s A and B D, so crossing each xioother at : I >UT equal

- at th»- et-ntre are equal, and Uiey are all r Sii •• the measure of the circle is

860 degrees, that of a quarter of a aide b ^ (| An i subtends half a right angle, and an an of ally, all angles are mscwtred ty tts ares

and it makes no difference whetb r

• nee of the circle, whose fcrc measures the

an^le, be great or small. The two circles of the diagram

ag a common centre, are ( tf

I* ),l>irt,l at tf ■

oriiono0jf« It'

1 t If n dnle i- dividbd by two diameter**, centre, making equal angles, what are those angles f

! i th«- circlr witi- dn • qual angle a, \ 1 these angles be »iil»t»n I. -1 }

t bese angles f — I onfoana] principle

angle be placed at a common las I

22 A SPHERICAL SYSTEM.

its sides include 90 degrees in the smaller, they will include 90° in the larger circles, and so of any number of circles and any number of degrees.

16. When a Convex Sphere is so inclosed by a Concave Sphere or hollow Globe, that the centre of the Convex is also the centre of the Concave Sphere, then these two Spheres are Concentric ; and the axis of the Convex and the plane of its Great Circle may be produced to the Concave Sphere, becoming its axis and Great Circle, — the Poles in each being, by definition, the extremities of the axes. This is the case with the Convex Terrestrial and the Concave Celestial Sphere by which it is surrounded.

17. A Spherical System, as we shall use the term, is composed of the Axis, Poles, and Great Circle of a Sphere ;* and may be accompanied with certain adjuncts ; as the 'parallels of the Great Circle, which are small circles, lessening towards, and finally vanishing in the Poles ; and the secondaries of the Great Circle, which are great circles cutting it at right angles, and crossing each other at the Poles. Thus the Axis, Poles, and the Equator of the Earth, are a Spherical System, which may be considered with or without the adjuncts or accessories, which are parallels of latitude and circles of longitude, or hour circles. . . . When any body is in circular motion around a central point, that motion is reckoned according to the degrees of the circle passed over, and is called angular motion. The distance between any two bodies, or between any two points situated on the same circle, is the number of degrees of the part of the circle intercepted between them. This is called angular distance.

* See Fig. 1.

16. What are Concentric Spheres? — 17. What is here called s Spherical System ? What is angular motion ? What is angular distance ?

ITIE FIRST PROBLEM.

l — W« reeoanMod that Ihese

.

and tin* i

Igfjd if in In- tir.-t §j

wrong line often shows whefj

It is * an auth. I

that :i b.*.k should b»* bled with be-lit1

r<.->cntat;

e Nn.k on i cramped .

an;." ii so fundamental, ti. at w» recommend that questions on t}>> Hibjed be frequ< ntly given to the class.

•

i »xpe< t tl - rson will

i map

the brazen mer will find, direct!-.

Philadelphia M from tin I place sought is in north latitude) as i

will than be m | .ally

how many will be as circle be to IS equal parts, of

how many degrees will be each part ? If into 24 equal pal how many degrees will be ea< - .t a part I

of a circle is 4 degrees! How greai a p S0° f How great a part is 15° t How great a par I 90° f ;

be, define the position of tho Earth- Equator, as to the oceans, seas, continents, countries, and islands through which it i

CHAPTER II.

Uses and Differences of the Celestial and Terrestrial Globes. — The Fixed Stars. — Their Distances. — The Constellations. —-Antiquity of Astronomy.

1. While the two Globes, the Celestial and Terrestrial, are placed together before a class, who are more or less acquainted with geography, the pupils are easily made to conceive, that the Terrestrial Globe, covered as it is by a continuous map, represents the Earth ; and thus they readily understand its use. But they find difficulties in the study of the Celestial Globe, which partly arise in consequence of its differences from the Terrestrial.

2. The Celestial Globe is made of the same size as its mate, the Terrestrial ; whereas, the Sphere which it represents is immeasurably larger than the Earth. The Terrestrial Globe is convex, as is the Earth which it represents. But the Celestial Globe, while it is convex, repreresents the vast concave of the Starry Heavens, which concentrically surrounds the Earth.

3. While the Terrestrial Globe presents a familiar map, dividing its surface into oceans, seas, islands, and continents, the Celestial Globe is covered with uncouth figures of all monstrous things — strange men and women, mingled with beasts, birds, fishes, and serpents. These grotesque figures represent the Constellations, into which the surface of the concave Heavens is divided, — as is the convex surface of the Earth into seas and countries ; and as the Geographer learns them, and the cities which they contain, from the Terrestrial Globe, so does the Astronomer learn the names and places of the Constella-

Chapter II. — 1. Which of the two globes is most easily understood, and why ? — 2. In what respects are the two globes different ? What is here said of the concave of the Heavens ? — 3. What do the uncouth figures on the Celestial Globe represent ? What are Constellations ?

thi: ICRB0FQLIXAH COM S6

tions, and the principal stars which they include, from the

4. Of the E o first division is into fixed and wane' >\ of which our Sun is regarded as one, ;. which do DOJ tiMy change their

with regard to each other. The wandering la, are Plan eU and OomeU* The Earth ie a planet The wandering Btan have do place giren them on a Map: the Constellation* which till it, being

who] I etare. But as the

journey of a traveller can be made known to ■ reader who

tphical map of the fixed p] through which h an the course of a wander-

tly intelligible to the person who

deal map, with which the Centered.

5. The Sun ap pear * to ohang rition in regard to the fixed stars, but does nd in n-ality. I lis appa