THE MOON, THE PLANETS, AND THE SUN.
"It is a most beautiful and delightful sight," exclaims Galileo, in
describing the discoveries he had made with his telescope, "to behold
the body of the moon, which is distant from us nearly sixty
semi-diameters of the earth, as near as if it was at a distance of only
two of the same measures.... And, consequently, any one may know with
the certainty that is due to the use of our senses that the moon
assuredly does not possess a smooth and polished surface, but one rough
and uneven, and, just like the face of the earth itself, is everywhere
full of vast protuberances, deep chasms, and sinuosities."
There was, perhaps, nothing in the long series of discoveries with which
Galileo astonished the world after he had constructed his telescope,
which, as he expresses it, "was devised by me through God's grace first
enlightening my mind," that had a greater charm for him than his lunar
observations. Certainly there was nothing which he has described with
greater enthusiasm and eloquence. And this could hardly have been
otherwise, for the moon was the first celestial object to which Galileo
turned his telescope, and then for the first time human eyes may be said
to have actually looked into another world than the earth, though his
discoveries and those of his successors have not realized all the poetic
fancies about the moon contained in the verses that are ascribed to
Orpheus:
"And he another wandering world has made
Which gods Selene name, and men the moon.
It mountains, cities has, and temples grand."
Yet Galileo's observations at once upset the theory, for which
Apollonius was responsible, and which seems to have been widely
prevalent up to his time, that the moon was a smooth body, polished like
a mirror, and presenting in its light and dark spots reflections of the
continents and oceans of the earth. He also demonstrated that its
surface was covered with plains and mountains, but the "cities and
temples" of the moon have remained to our time only within the ken of
romance.
Galileo's telescope, as I have before remarked, was, in the principle of
its construction, simply an opera-glass of one tube. He succeeded in
making a glass of this kind that magnified thirty diameters, a very much
higher power than is given to the opera-and field-glasses of to-day. Yet
he had to contend with the disadvantages of single lenses, achromatic
combinations of glass for optical purposes not being contrived until
nearly a hundred years after his death, and so his telescope did not
possess quite as decided a superiority over a modern field-glass as the
difference in magnifying power would imply. In fact, if the reader will
view the moon with a first-rate field-glass, he will perceive that the
true nature of the surface of the lunar globe can be readily discerned
with such an instrument. Even a small opera-glass will reveal much to
the attentive observer of the moon; but for these observations the
reader should, if possible, make use of a field-glass, and the higher
its power the better. The illustrations accompanying this chapter were
made by the author with the aid of a glass magnifying seven diameters.
Of course, the first thing the observer will wish to see will be the
mountains of the moon, for everybody has heard of them, and the most
sluggish imagination is stirred by the thought that one can look off
into the sky and behold "the eternal hills" of another planet as solid
and substantial as our own. But the chances are that, if left to their
own guidance, ninety-nine persons out of a hundred would choose exactly
the wrong time to see these mountains. At any rate, that is my
experience with people who have come to look at the moon through my
telescope. Unless warned beforehand, they invariably wait until full
moon, when the flood of sunshine poured perpendicularly upon the face of
our satellite conceals its rugged features as effectually as if a veil
had been drawn over them. Begin your observations with the appearance of
the narrowest crescent of the new moon, and follow it as it gradually
fills, and then you will see how beautifully the advancing line of lunar
sunrise reveals the mountains, over whose slopes and peaks it is
climbing, by its ragged and sinuous outline. The observer must keep in
mind the fact that he is looking straight down upon the tops of the
lunar mountains. It is like a view from a balloon, only at a vastly
greater height than any balloon has ever attained. Even with a powerful
telescope the observer sees the moon at an apparent distance of several
hundred miles, while with a field-glass, magnifying seven diameters, the
moon appears as if thirty-five thousand miles off. The apparent distance
with Galileo's telescope was eight thousand miles. Recollect how when
seen from a great height the rugosities of the earth's surface flatten
out and disappear, and then try to imagine how the highest mountains on
the earth would look if you were suspended thirty-five thousand miles
above them, and you will, perhaps, rather wonder at the fact that the
moon's mountains can be seen at all.
It is the contrast of lights and shadows that not only reveals them to
us, but enables us to measure their height. On the moon shadows are very
much darker than upon the earth, because of the extreme rarity of the
moon's atmosphere, if indeed it has any atmosphere at all. By stepping
around the corner of a rock there, one might pass abruptly from
dazzling noonday into the blackness of midnight. The surface of the moon
is extraordinarily rough and uneven. It possesses broad plains, which
are probably the bottoms of ancient seas that have now dried up, but
these cover only about two fifths of the surface visible to us, and most
of the remaining three fifths are exceedingly rugged and mountainous.
Many of the mountains of the moon are, foot for foot, as lofty as the
highest mountains on the earth, while all of them, in proportion to the
size of the moon's globe, are much larger than the earth's mountains. It
is obvious, then, that the sunshine, as it creeps over these Alpine
landscapes in the moon, casting the black shadows of the peaks and
craters many miles across the plains, and capping the summits of lofty
mountains with light, while the lower regions far around them are yet
buried in night, must clearly reveal the character of the lunar surface.
Mountains that can not be seen at all when the light falls
perpendicularly upon them, or, at the most, appear then merely as
shining points, picture themselves by their shadows in startling
silhouettes when illuminated laterally by the rising sun.
But at full moon, while the mountains hide themselves in light, the old
sea-beds are seen spread out among the shining table-lands with great
distinctness. Even the naked eye readily detects these as ill-defined,
dark patches upon the face of the moon, and to their presence are due
the popular notions that have prevailed in all quarters of the world
about the "Man in the Moon," the "Woman in the Moon," "Jacob in the
Moon," the "Hare in the Moon," the "Toad in the Moon," and so on. But,
however clearly one may imagine that he discerns a man in the moon while
recalling the nursery-rhymes about him, an opera-glass instantly puts
the specter to flight, and shows the round lunar disk diversified and
shaded like a map.[E]
[E] I should, perhaps, qualify the statement in the text
slightly in favor of a lunar lady to whom Mr. Henry M.
Parkhurst first called my attention. About nine days
after new moon a rather pretty and decidedly feminine
face appears on the western half of the disk. It is
formed by the mountains and table-lands embraced by
the Sea of Serenity, the Sea of Tranquillity, the
Sea of Vapors, etc., and is best seen with the aid
of an opera-glass of low power. The face is readily
distinguishable on Rutherfurd's celebrated photograph
of the full moon. It is necessary for this purpose
to turn the photograph upside down, since it is a
telescopic picture, and consequently reversed. The
crater Tycho forms a breastpin for the lady, and
Menelaus glitters like a diamond ornament in her hair,
while the range of the Apennines resembles a sort of
coronet resting on her forehead. This same woman in
the moon, it appears, was described by Dr. James
Thompson years ago, and, for aught I know, she may be
the Diana to whom Herrick sang:
"Queen and huntress chaste and fair,
Seated in thy silver chair,
Now the Sun is laid to sleep,
State in wonted manner keep.
Hesperus entreats thy light,
Goddess excellently bright."
A feature of the full moon's surface that instantly attracts attention
is the remarkable brightness of the southern part of the disk, and the
brilliant streaks radiating from a bright point near the lower edge. The
same simile almost invariably comes to the lips of every person who sees
this phenomenon for the first time--"It looks like a peeled orange." The
bright point, which is the great crater-mountain Tycho, looks exactly
like the pip of the orange, and the light-streaks radiating from it in
all directions bear an equally striking resemblance to the streaks that
one sees upon an orange after the outer rind has been removed. I shall
have something more to say about these curious streaks further on; in
the mean time, let us glance at our little sketch-map of the moon.
[Illustration: MAP OF THE MOON.]
The so-called seas are marked on the map, for the purpose of reference,
by the letters which they ordinarily bear in lunar maps. The numerals
indicate craters, or ring-plains, and mountain-ranges. The following
key-list will enable the reader to identify all the objects that are
lettered or numbered upon the map. I have given English translations of
the Latin names which the old astronomers bestowed upon the seas:
_Seas, Gulfs, and Marshes._
A. The Crisian Sea.
B. Humboldt Sea.
C. The Sea of Cold.
D. The Lake of Death.
E. The Lake of Dreams.
F. The Marsh of Sleep.
G. The Sea of Tranquillity.
H. The Sea of Serenity.
I. The Marsh of Mists.
K. The Marsh of Putrefaction.
L. The Sea of Vapors.
M. The Central Gulf.
N. The Gulf of Heats.
O. The Sea of Showers.
P. The Bay of Rainbows.
Q. The Ocean of Storms.
R. The Bay of Dew.
S. The Sea of Clouds.
T. The Sea of Humors.
V. The Sea of Nectar.
X. The Sea of Fertility.
Z. The South Sea.
_Mountains and Crater Rings._
1. Grimaldi.
2. Letronne.
3. Gassendi.
4. Euclides.
5. Bullialdus.
6. Pitatus.
7. Schickhard.
8. Longomontanus.
9. Tycho.
10. Maginus.
11. Clavius.
12. Newton.
13. Maurolycus.
14. Stoefler.
15. Walter.
16. Regiomontanus.
17. Purbach.
18. Arzachel.
19. Alphonsus.
20. Ptolemaus.
21. Hipparchus.
22. Albategnius.
23. Theophilus.
24. Cyrillus.
25. Catharina.
26. The Altai Mts.
27. Piccolomini.
28. Petavius.
29. Langrenus.
80. Proclus.
31. Cleomedes.
32. Atlas.
33. Hercules.
34. Posidonius.
35. Plinius.
36. Menelaus.
37. Manilius.
38. The Caucasus Mts.
39. Eudoxus.
40. Aristotle.
41. The Alps.
42. Plato.
43. Archimedes.
44. The Apennines.
45. Eratosthenes.
46. Copernicus.
47. The Carpathian Mts.
48. Timocharis.
49. Lambert.
50. Euler.
51. Aristarchus.
52. Kepler.
53. Flamsteed.
The early selenographers certainly must have been men of vivid
imagination, and the romantic names they gave to the lunar landscapes,
and particularly to the "seas," add a charm of their own to the study of
the moon. Who would not wish to see the "Bay of Rainbows," or the "Lake
of Dreams," or the "Sea of Tranquillity," if for no other reason than a
curiosity to know what could have induced men to give to these regions
in the moon such captivating titles? Or who would not desire to visit
them if he could? though no doubt we should find them, like the
"Delectable Mountains" in the "Pilgrim's Progress," most charming when
seen from afar.
The limited scale of our map, of course, renders it impossible to
represent upon it more than a comparatively small number of the lunar
mountains that have received names. In selecting those to be put in the
map I have endeavored to choose such as, on account of their size, their
situation, or some striking peculiarity, would be most likely to attract
the attention of a novice. The observer must not expect to see them all
at once, however. The lunar features change their appearance to a
surprising extent, in accordance with the direction of their
illumination. Some great mountain-masses and ring-plains, or craters,
which present scenes of magnificence when the sun is rising or setting
upon them, disappear under a perpendicular light, such as they receive
at full moon. The great crater-plain, known as Maginus, numbered 10 in
our map, is one of these. The broken mountain-wall surrounding this vast
depressed plain rises in some places to a height of over fourteen
thousand feet above the valley within, and the spectacle of sunrise upon
Maginus, seen with a powerful telescope, is a most impressive sight, and
even with a field-glass is very interesting. Yet, a few days later,
Maginus vanishes, as if it had been swallowed up, and as Beer and Maedler
have expressed it, "the full moon knows no Maginus." The still grander
formation of mountain, plain, and crater, called Clavius (11 in the
map), disappears almost as completely as Maginus at full moon, yet,
under the proper illumination, it presents a splendid pageant of light
and shadow.
On the other hand, some of the lunar mountains shine vividly at full
moon, and can be well seen then, though, of course, only as light spots,
since at that time they cast no shadows. Menelaus (36 in the map),
Aristarchus (51), Proclus (30), Copernicus (46), and Kepler (52), are
among these shining mountains. Aristarchus is the most celebrated of
them all, being the brightest point on the moon. It can even be seen
glimmering on the dark side of the moon--that is to say, when no light
reaches it except that which is reflected from the earth. With a large
telescope, Aristarchus is so dazzlingly bright under a high sun, that
the eye is partly blinded in gazing at it. It consists of a
mountain-ring surrounding a circular valley, about twenty-eight miles in
diameter. The flanks of these mountains, especially on their inner
slopes, and the floor of the valley within, are very bright, while a
peak in the center of the valley, about as high as Storm-King Mountain
on the Hudson, shines with piercing brilliancy. Sir William Herschel
mistook it for a volcano in action. It certainly is not an active
volcano, but just what makes it so dazzling no one knows. The material
of which this mountain is formed would seem to possess a higher
reflective power than that of any other portion of the moon's surface.
One is irresistibly reminded of the crystallized mountains described in
the celebrated "Moon Hoax" of Richard Adams Locke. With an opera-glass
you can readily recognize Aristarchus as a bright point at full moon.
With a field-glass it is better seen, and some of the short, light rays
surrounding it are perceived, while, when the sun is rising upon it,
about four days after first quarter, its crateriform shape can be
detected with such a glass.
The visibility of Aristarchus on the dark side of the moon leads us to a
brief consideration of the illumination by the earth of that portion of
the moon's surface which is not touched directly by sunlight at new and
old moon. This phenomenon is shown in the accompanying illustration. Not
only can the outlines of the dark part of the moon be seen under such
circumstances, but even the distinction in color between the dusky
"seas" and the more brilliant table-lands and mountain-regions can be
perceived, and with powerful telescopes many minor features come into
sight. A little consideration must convince any one, as it convinced
Galileo more than two hundred and seventy-five years ago, that the light
reflected from the earth upon the moon is sufficient to produce this
faint illumination of the lunar landscapes. We have only to recall the
splendors of a night that is lighted by a full moon, and then to
recollect that at new or old moon the earth is "full" as seen from our
satellite, and that a full earth must give some fourteen times as much
light as a full moon, in order to realize the brilliancy of an earth-lit
night upon the moon. As the moon waxes to us, the earth wanes to the
moon, and _vice versa_, and so the phenomenon of earth-shine on the
lunar surface must be looked for before the first quarter and after the
last quarter of the moon.
[Illustration: SUNRISE ON THE SEA OF SERENITY, AND THEOPHILUS AND OTHER
CRATERS.]
The reader will find it an attractive occupation to identify, by means
of the map, the various "seas," "lakes," and "marshes," for not only
are they interesting on account of the singularity of their names, but
they present many remarkable differences of appearance, which may be
perceived with the instrument he is supposed to be using. The oval form
of the Crisian Sea (A), which is the first of the "seas" to come into
sight at new moon, makes it a very striking object. With good
telescopes, and under favorable illumination, a decidedly green tint is
perceived in the Crisian Sea. It measures about two hundred and eighty
by three hundred and fifty-five miles in extent, and is, perhaps, the
deepest of all the old sea-beds visible on the moon. It is surrounded by
mountains, which can be readily seen when the sun strikes athwart them a
few days after new or full moon. On the southwestern border a stupendous
mountain-promontory, called Cape Agarum, projects into the Crisian Sea
fifty or sixty miles, the highest part rising precipitously eleven
thousand feet above the floor of the sea. I have seen Cape Agarum very
clearly defined with a field-glass. Near the eastern border is the
crater-mountain Proclus, which I have already mentioned as possessing
great brilliancy under a high sun, being in this respect second only to
Aristarchus.
From the foot of Proclus spreads away the somewhat triangular region
called the Marsh of Sleep (F). The term "golden-brown," which has been
applied to it, perhaps describes its hue well enough. With a telescope
it is a most interesting region, but with less powerful instruments one
must be content with recognizing its outline and color.
The broad, dark-gray expanse of the Sea of Tranquillity (G) will be
readily recognized by the observer, and he will be interested in the
mottled aspect which it presents in certain regions, caused by ridges
and elevations, which, when this sea-bottom was covered with water, may
have formed shoals and islands.
The Sea of Fertility (X) is remarkable for its irregular surface, and
the long, crooked bays into which its southern extremity is divided.
The Sea of Nectar (V) is connected with the Sea of Tranquillity by a
broad strait (one would naturally anticipate from their names that there
must be some connection between them), while between it and the Sea of
Fertility runs the range of the Pyrenees Mountains, twelve thousand feet
high, flanked by many huge volcanic mountain-rings.
The Sea of Serenity (H), lying northeast of the Sea of Tranquillity, is
about four hundred and twenty miles broad by four hundred and thirty
miles long, being very nearly of the same area as our Caspian Sea. It is
deeper than the Sea of Tranquillity, and a greenish hue is sometimes
detected in its central parts. It deepens toward the middle. Three
quarters of its shore-line are bordered by high mountains, and many
isolated elevations and peaks are scattered over its surface. In looking
at these dried-up seas of the moon, one is forcibly reminded of the
undulating and in some places mountainous character of terrestrial
sea-bottoms, as shown by soundings and the existence of small islands in
the deep sea, like the Bermudas, the Azores and St. Helena. The Sea of
Serenity is divided nearly through the center by a narrow, bright
streak, apparently starting from the crater-mountain Menelaus (36 in the
map), but really taking its rise at Tycho far in the south. This curious
streak can be readily detected even with a small opera-glass. Just what
it is no one is prepared to say, and so the author of the "Moon Hoax"
was fairly entitled to take advantage of the romancer's license, and
declare that "its edge throughout its whole length of three hundred and
forty miles is an acute angle of solid quartz-crystal, brilliant as a
piece of Derbyshire spar just brought from the mine, and containing
scarcely a fracture or a chasm from end to end!" Along the southern
shore, on either side of Menelaus, extends the high range of the Haemus
Mountains. South and southeast of the Sea of Serenity are the Sea of
Vapors (L), the Central Gulf (M), and the Gulf of Heats (N). The
observer will notice at full moon three or four curious dark spots in
the region occupied by these flat expanses. On the north and northwest
of the Sea of Serenity are the Lake of Death (D), and the Lake of Dreams
(E), chiefly remarkable for their names.
The Sea of Showers (O) is a very interesting region, not only in itself,
but on account of its surroundings. Its level is very much broken by
low, winding ridges, and it is variegated by numerous light-streaks. At
its western end it blends into the Marsh of Mists (I) and the Marsh of
Putrefaction (K). On its northeast border is the celebrated Sinus
Iridum, or Bay of Rainbows (P), upon which selenographers have exhausted
the adjectives of admiration. The bay is semicircular in form, one
hundred and thirty-five miles long and eighty-four miles broad. Its
surface is dark and level. At either end a splendid cape extends into
the Sea of Showers, the eastern one being called Cape Heraclides, and
the western Cape Laplace. They are both crowned by high peaks. Along the
whole shore of the bay runs a chain of gigantic mountains, forming the
southern border of a wild and lofty plateau, called the Sinus Iridum
Highlands. Of course, a telescope is required to see the details of this
"most magnificent of all lunar landscapes," and yet much can be done
with a good field-glass. With such an instrument I have seen the capes
at the ends of the bay projecting boldly into the dark, level expanse
surrounding them, and the high lights of the bordering mountains sharply
contrasted with the dusky semicircle at their feet, and have been able
to detect the presence of the low ridges that cross the front of the bay
like shoals, separating it from the "sea" outside. Two or three days
after first quarter, the shadows of the peaks about the Bay of Rainbows
may be seen. The Bay of Dew (R) above the Bay of Rainbows, and the Sea
of Cold (C), are the northernmost of the dark levels visible. It was in
keeping with the supposed character of this region of the Moon that
Riccioli named two portions of it the Land of Hoar Frost and the Land of
Drought.
Extending along the eastern side of the disk is the great Ocean of
Storms (Q), while between the Ocean of Storms and the middle of the moon
lies the Sea of Clouds (S). Both of these are very irregular in outline,
and much broken by ridges and mountains. The Sea of Humors (T), although
comparatively small, is one of the most easily seen of all the lunar
plains. To the naked eye it looks like a dark, oval patch on the moon.
With a telescope it is seen, under favorable conditions, to possess a
decided green tint. Humboldt Sea (B) and the South Sea (Z) belong
principally to that part of the moon which is always turned away from
the earth, and only their edges project into the visible hemisphere,
although, under favorable librations, their farther borders, lined as
usual with mountain-peaks, may be detected. For our purposes they
possess little interest.
Let us now glance at some of the mountains and "craters." The dark oval
called Grimaldi (1) can be detected by the naked eye, or at least it has
been thus seen, although it requires a sharp eye; and perhaps a shade or
a pair of eye-glasses of London smoke-glass, to take off the glare of
the moon, should be used in looking for it.[F] It is simply a plain,
containing some fourteen thousand square miles, remarkable for its dark
color, and surrounded by mountains. Schickhard (7) is another similar
plain, nearly as large, but not possessing the same dark tint in the
interior. The huge mountains around Schickhard make a fine spectacle
when the sun is rising upon them shortly before full moon.
[F] There are other uses to which such eye-glasses may be put
by sky-gazers. I habitually carry a pair for studying clouds.
It is wonderful how much the effect of great cloud-masses is
heightened by them, especially when seen in a bright light.
Delicate curls and striae of cirrus, which escape the uncovered
eye in the glare of sunlight, can be readily detected and
studied by the use of neutral-tinted eye-glasses or spectacles.
Tycho (9) is the most famous of the crater-mountains, though not the
largest. It is about fifty-four miles across and three miles deep. In
its center is a peak five or six thousand feet high. Tycho is the radial
point of the great light-streaks that, as I have already remarked, cause
the southern half of the moon to be likened to a peeled orange. It is a
tough problem in selenography to account for these streaks. They are
best seen at full moon. They can not be seen at all until the sun has
risen to a certain elevation above them, 25 deg. according to Neison; but,
when they once become visible, they dominate everything. They turn aside
for neither mountains nor plains, but pass straight on their courses
over the ruggedest regions of the moon, retaining their brilliancy
undiminished, and pouring back such a flood of reflected light that they
completely conceal some of the most stupendous mountain-masses across
which they lie. They clearly consist of different material from that of
which the most of the moon's surface is composed--a material possessing
a higher reflective power. In this respect they resemble Aristarchus and
other lunar craters that are remarkable for their brilliancy under a
high illumination. Tycho itself, the center or hub, from which these
streaks radiate like spokes, is very brilliant in the full moon. But
immediately around Tycho there is a dark rim some twenty-five miles
broad. Beyond this rim the surface becomes bright, and the bright region
extends about ninety miles farther. Out of it spring the great rays or
streaks, which vary from ten to twenty miles in width, and many of which
are several hundred miles long--one, which we have already mentioned as
extending across the Sea of Serenity, being upward of two thousand miles
in length. It has been truly said that we have nothing like these
streaks upon the earth, and so there is no analogy to go by in trying to
determine their nature. It has been suggested that if the moon had been
split or shattered from within by some tremendous force, and molten
matter from the interior had been thrust up into the cracks thus formed,
and had cooled there into broad seams of rock, possessing a higher
reflective power than the surrounding surface of the moon, then the
appearances presented would not be unlike what we actually see. But
there are serious objections to such a view, which we have not space to
discuss here. It is enough to say that the nature of these streaks is
still a question awaiting solution, and here is an opportunity for an
important discovery, but not one to be achieved with an opera-glass.
I may add an interesting suggestion as to the nature of these streaks
made by the Rev. Mr. Grensted. He holds that the air and water of the
moon were chemically, and not mechanically, absorbed in the process of
oxidation which went on at the time when her surface temperature was
above a red heat. Having a much larger surface in proportion to her bulk
than the earth, the oxidation of the moon has, he thinks, extended much
deeper than that of the earth, and her atmosphere and oceans have been
exhausted in the process. Both the earth and the moon, he maintains,
have metallic nuclei, and the streaks about Tycho and Copernicus, and
some other lunar craters, may be dikes of pure and shining metal, which
have escaped oxidation owing to the comparatively small supply of lunar
oxygen. Upon this theory Aristarchus must be a metallic mountain.
[Illustration: SUNRISE ON CLAVIUS, TYCHO, PLATO, ETC.]
Clavius (11) is one of the most impressive of all the lunar formations.
There probably does not exist anywhere upon the earth so wild a scene
upon a corresponding scale of grandeur. Of course, its details are far
beyond the reach of the instrument we are supposed to be using, and yet,
even with a field-glass, or a powerful opera-glass, some of its main
features are visible. It is represented in our picture of the half-moon,
being the lowest and largest of the ring-like forms seen at the inner
edge of the illuminated half of the disk; the rays of the rising sun
touching the summits of some of the peaks in its interior have brought
them into sight as a point of light, and at the same time, reaching
across the gulf within, have lighted up the higher slopes of the great
mountain-wall on the farther or eastern side of the crater-valley,
making it resemble a semicircle of light projecting into the blackness
of the still unilluminated plains around it. I should advise every
reader to take advantage of any opportunity that may be presented to him
to see Clavius with a powerful telescope when the sun is either rising
or setting upon it. Neison has given a spirited description of the
scene, as follows:
The sunrise on Clavius commences with the illumination of a few peaks
on the western wall, but soon rapidly extends along the whole wall of
Clavius, which then presents the appearance of a great double bay of
the dark night-side of the moon penetrating so deep into the
illuminated portion as to perceptibly blunt the southern horn to the
naked eye. Within the dark bay some small, bright points soon
appear--the summits of the great ring-plains within--followed shortly
by similar light-points near the center, due to peaks on the walls of
the smaller ring-plains, these light-islands gradually widening and
forming delicate rings of light in the dark mass of shadow still
enveloping the floor of Clavius. Far in the east then dimly appear a
few scarcely perceptible points, rapidly widening into a thin bright
line, the crest of the great southeastern wall of Clavius, the end
being still lost far within the night-side of the moon. By the period
the extreme summit of the lofty wall of Clavius on the east becomes
distinct, fine streaks of light begin to extend across the dark mass
of shadow on the interior of Clavius, from the light breaking through
some of the passes on the west wall and illuminating the interior; and
these streaks widen near the center and form illuminated spots on the
floor, when both east and west it still lies deeply immersed in
shadow, strongly contrasting with the now brightly illuminated crest
of the lofty east wall and the great circular broad rings of light
formed by the small ring-plains within Clavius. The illumination of
the interior of Clavius now proceeds rapidly, and forms a magnificent
spectacle: the great, brightly illuminated ring-plains on the
interior, with their floors still totally immersed in shadow; the
immense steep line of cliffs on the east and southeast are now
brilliantly illuminated, though the entire surface at their base is
still immersed in the shades of night; and the great peaks on the west
towering above the floor are thrown strongly into relief against the
dark shadow beyond them.
Newton (12) is the deepest of the great crateriform chasms on the moon.
Some of the peaks on its walls rise twenty-four thousand feet above the
interior gulf. Its shadow, and those of its gigantic neighbors--for the
moon is here crowded with colossal walls, peaks, and craters--may be
seen breaking the line of sunlight below Clavius, in our illustration. I
have just spoken of these great lunar formations as chasms. The word
describes very well the appearance which some of them present when the
line separating day and night on the moon falls across them, but the
reader should not be led by it into an erroneous idea of their real
character. Such formations as Newton, which is one hundred and forty
miles long by seventy broad, may more accurately be described as vast
depressed plains, generally containing peaks and craters, which are
surrounded by a ring of steep mountains, or mountain-walls, that rise by
successive ridges and terraces to a stupendous height.
The double chain of great crater-plains reaching half across the center
of the moon contains some of the grandest of these strange
configurations of conjoined mountain, plain, and crater. The names of
the principal ones can be learned from the map, and the reader will find
it very interesting to watch them coming into sight about first quarter,
and passing out of sight about third quarter. At such times, with a
field-glass, some of them look like enormous round holes in the inner
edge of the illuminated half of the moon. Theophilus (23), Cyrillus
(24), and Catharina (25), are three of the finest walled plains on the
moon--Theophilus, in particular, being a splendid specimen of such
formations. This chain of craters may be seen rapidly coming into
sunlight at the edge of the Sea of Nectar, in our picture of "Sunrise on
the Sea of Serenity," etc. The Altai Mountains (26) are a line of lofty
cliffs, two hundred and eighty miles in length, surmounting a high
table-land.
The Caucasus Mountains (38) are a mass of highlands and peaks, which
introduce us to a series of formations resembling those of the
mountainous regions of the earth. The highest peak in this range is
about nineteen thousand feet. Between the Caucasus and the Apennines
(44) lies a level pass, or strait, connecting the Sea of Serenity with
the Sea of Showers. The Apennines are the greatest of the lunar
mountain-chains, extending some four hundred and sixty miles in length,
and containing one peak twenty-one thousand feet high, and many varying
from twelve thousand to nearly twenty thousand. It will thus be seen
that the Apennines of the earth sink into insignificance in comparison
with their gigantic namesakes on the moon. As this range runs at a
considerable angle to the line of sunrise, its high peaks are seen
tipped with sunlight for a long distance beyond the generally
illuminated edge about the time of first quarter. Even with the naked
eye the sun-touched summits of the lunar Apennines may at that time be
detected as a tongue of light projecting into the dark side of the moon.
The Alps (41) are another mountain-mass of great elevation, whose
highest peak is a good match for the Mont Blanc of the earth, after
which it has been named.
Plato (42) is a very celebrated dark and level plain, surrounded by a
mountain-ring, and presenting in its interior many puzzling and
apparently changeable phenomena which have given rise to much
speculation, but which, of course, lie far beyond the reach of
opera-glasses. Plato is seen in the picture of "Sunrise on Clavius,"
etc., on page 133, being the second ring from the top.
If Ariosto had had a telescope, we might have suspected that it was this
curious plain that he had in mind when he described that strange valley
in the moon, in which was to be found everything that was lost from the
earth, including lost wits; and where the redoubtable knight Astolpho,
having been sent in search of the missing wit of the great Orlando, was
astonished to find what he sought carefully preserved in a vial along
with other similar vials belonging to many supposedly wise people of the
earth, whom nobody suspected of keeping a good part of their sapience in
the moon.
Copernicus (46) is the last of the lunar formations that we shall
describe. It bears a general resemblance to Tycho, and is slightly
greater in diameter; it is, however, not quite so deep. It has a cluster
of peaks in the center, whose tops may be detected with a field-glass,
as a speck of light when the rays of the morning sun, slanting across
the valley, illuminate them while their environs are yet buried in
night. Copernicus is the center of a system of light-streaks somewhat
resembling those of Tycho, but very much shorter.
We must not dismiss the moon without a few words as to its probable
condition. It was but natural, after men had seen the surface of the
moon diversified with hills and valleys like another earth, that the
opinion should find ready acceptance that beings not unlike ourselves
might dwell upon it. Nothing could possibly have been more interesting
than the realization of such a fancy by the actual discovery of the
lunar inhabitants, or at least of unmistakable evidence of their
existence. The moon is so near to the earth, as astronomical distances
go, and the earth and the moon are so intimately connected in the
companionship of their yearly journey around the sun, and their greater
journey together with the sun and all his family, through the realms of
space, that we should have looked upon the lunar inhabitants, if any
had existed, as our neighbors over the way--dwelling, to be sure, upon a
somewhat more restricted domain than ours, vassals of the earth in one
sense, yet upon the whole very respectable and interesting people, with
whom one would be glad to have a closer acquaintance. But, alas! as the
powers of the telescope increased, the vision of a moon crowded with
life faded, until at last the cold fact struck home that the moon is, in
all probability, a frozen and dried-up globe, a mere planetary skeleton,
which could no more support life than the Humboldt glacier could grow
roses. And yet this opinion may go too far. There is reason for thinking
that the moon is not absolutely airless, and, while it has no visible
bodies of water, its soil may, after all, not be entirely arid and
desiccated. There are observations which hint at visible changes in
certain spots that could possibly be caused by vegetation, and there are
other observations which suggest the display of electric luminosity in a
rarefied atmosphere covering the moon. To declare that no possible form
of life can exist under the conditions prevailing upon the lunar surface
would be saying too much, for human intelligence can not set bounds to
creative power. Yet, within the limits of life, such as we know them, it
is probably safe to assert that the moon is a dead and deserted world.
In other words, if a race of beings resembling ourselves, or resembling
any of our contemporaries in terrestrial life, ever existed upon the
moon, they must long since have perished. That such beings may have
existed, is possible, particularly if it be true, as generally believed,
that the moon once had a comparatively dense atmosphere and water upon
its surface, which have now, in the process of cooling of the lunar
globe, been withdrawn into its interior. It certainly does not detract
from the interest with which we study the rugged and beautiful scenery
of the moon to reflect that if we could visit those ancient sea-bottoms,
or explore those glittering mountains, we might, perchance, find there
some remains or mementos of a race that flourished, and perhaps was all
gathered again to its fathers, before man appeared upon the earth.
That slight physical changes, such as the downfall of mountain-walls or
crater-cones, still occasionally occur upon the moon, is an opinion
entertained by some selenographers, and apparently justified by
observation. The enormous changes of temperature, from burning heat
under a cloudless sun to the freezing cold of space at night with no
atmospheric blanket to retain heat (which has generally been assumed to
be the condition of things on the moon), would naturally exert a
disintegrating effect upon the lunar rocks. But the question is now in
dispute whether the surface of the moon ever rises above the
freezing-point of water, even under a midday sun.
Mankind has always been a little piqued by the impossibility of seeing
the other side of the moon, and all sorts of odd fancies have been
indulged in regard to it. Among the most curious is the ancient belief
that the souls of the good who die on earth are transported to that side
of the moon which is turned away from the earth; while the souls of the
wicked sojourn on this side, in full view of the scene of their evil
deeds. The visible side of the moon--with its tremendous craters, its
yawning chasms, its frightful contrasts of burning sunshine and
Cimmerian darkness, its airless and arid plains and dried-up sea-bottoms
exposed to the pitiless cold of open space, and heated, if heated at
all, by scorching sunbeams as fierce as naked flame--would certainly
appear to be in a proper condition to serve as a purgatory. But we have
no reason to think that the other side is any better off in these
respects. In fact, the glimpses that we get of it around the corners, so
to speak, indicate that the whole round globe of the moon is as ragged,
barren, and terrible as that portion of it which is turned to our view.
THE PLANETS.--In attempting to view the planets with an opera-glass,
too much must not be expected; and yet interesting views can sometimes
be obtained. The features of their surfaces, of course, can not be
detected even with a powerful field-glass, but the difference between
the appearance of a large planet and that of the stars will at once
strike the observer. Mercury, which, on account of its nearness to the
sun and its rapid changes of place, comparatively few persons ever see,
can perhaps hardly be called an interesting object for an opera-glass,
and yet the beauty of the planet is greatly increased when viewed with
such aid. Mercury is brilliant enough to be readily distinguishable,
even while the twilight is still pretty bright; and I have had most
charming views of the shy planet, glittering like a globule of shining
metal through the fading curtain of a winter sunset.
Venus is, under favorable circumstances, a very interesting planet for
opera-glass observations. The crescent phase can be seen with a powerful
glass near inferior conjunction, and, even when the form of the planet
can not be discerned, its exceeding brilliancy makes it an attractive
object. The flood of light which Venus pours forth, and which is so
dazzling that it baffles the best telescopes, to a greater or less
extent, in any effort to descry the features of that resplendent disk,
is evidently reflected from a cloud-burdened atmosphere. While these
clouds render the planet surprisingly lustrous to our eyes, they must,
of course, keep the globe beneath them most of the time in shadow. It is
a source of keen regret that the surface of Venus can not be seen as
clearly as that of Mars, for, _a priori_, there is rather more reason to
regard Venus as possibly an inhabited world than any other of the
Earth's sister planets, not excepting Mars. Still, even if we could
plainly make out the presence of oceans and continents on Venus, that
fact would hardly be any better indication of the possibility of life
there than is furnished by the phenomena of its atmosphere. It is an
interesting reflection that in admiring the brilliancy of this splendid
planet the light that produces so striking an effect upon our eyes has
but a few minutes before traversed the atmosphere of a distant world,
which, like our own air, may furnish the breath of life to millions of
intelligent creatures, and vibrate with the music of tongues speaking
languages as expressive as those of the earth.
Mars, being both more distant and smaller than Venus, does not present
so splendid a scene, and yet when it is at or near opposition it is a
superb object even for an opera-glass, its deep reddish-yellow color
presenting a fine contrast to that of most of the stars. It can often be
seen in conjunction with, or near to, the moon and stars, and the beauty
of these phenomena is in some cases greatly enhanced by the use of a
glass. To find Mars (and the same remark applies to the other planets),
take its right ascension and declination for the required date from the
Nautical Almanac, and then mark its place upon a planisphere or any good
star-map. This planet is at the present time (1888) slowly drawing
nearer to the earth at each opposition, and in 1892 it will be closer to
us than at any time since 1877, when its two minute satellites were
discovered. It will consequently grow brighter every year until then.
How splendidly it shines when at its nearest approach to the earth may
be inferred from the fact that in 1719 it was so brilliant as actually
to cause a panic. This was doubtless owing to its peculiar redness. I
well remember the almost startling appearance which the planet presented
in the autumn of 1877. Mars is especially interesting because of the
apparently growing belief that it may be an inhabited world, and because
of certain curious markings on its surface that can only be seen under
favorable conditions. The recent completion of the great Lick telescope
and other large glasses, and the approach of the planet to a favorable
opposition, give reason to hope that within the next few years a great
deal of light will be cast upon some of the enigmatical features of
Mars's surface.
[Illustration: JUPITER AND HIS MOONS. (SEEN WITH A FIELD-GLASS; SEVEN
DIAMETERS.)]
Jupiter, although much more distant than Mars, is ordinarily a far more
conspicuous phenomenon in the sky on account of his vast bulk. His
interest to observers with an opera-glass depends mainly upon his four
moons, which, as they circle about him, present a miniature of the solar
system. With a strong opera-glass one or two of Jupiter's little family
of moons may occasionally be caught sight of as excessively minute dots
of light half-hidden in the glare of the planet. If you succeed under
favorable circumstances in seeing one of these moons with your glass,
you will be all the more astonished to learn that there are several
apparently well-authenticated instances of one of the moons of Jupiter
having been seen with the naked eye.
With a field-glass, however, you will have no difficulty in seeing all
of the moons when they are properly situated. If you miss one or more of
them, you may know that it is either between you and the planet, or
behind the planet, or buried in the planet's shadow, or else so close to
the planet as to be concealed by its radiance.
It will be best for the observer to take out of the Nautical Almanac the
"configurations of Jupiter's satellites" for the evenings on which he
intends to make his observations, recollecting that the position of the
whole system, as there given, is reversed, or presented as seen with an
astronomical telescope, which inverts objects looked at, as an
opera-glass does not. In order to bring the satellites into the
positions in which he will see them, our observer has only to turn the
page in the Nautical Almanac showing their configurations upside down.
Of course, since the motions of the satellites, particularly of the
inner ones, are very rapid, their positions are continually changing,
and their configurations are different every night. If the observer has
any doubt about his identification of them, or thinks they may be little
stars, he has only to carefully note their position and then look at
them again the next evening. He may even notice their motion in the
course of a single evening, if he begins early and follows them for
three or four hours. It is impossible to describe the peculiar
attractions of the scene presented by the great planet and his four
little moons on a serene evening to an observer armed with a powerful
glass. Probably much of the impressiveness of the spectacle is owing to
the knowledge that those little points of light, shining now in a row
and now in a cluster, are actually, at every instant, under the
government of their giant neighbor and master, and that as we look upon
them, obediently making their circuits about him, never venturing beyond
a certain distance away, we behold a type of that gravitational mastery
to which our own little planet is subject as it revolves around its
still greater ruler, the sun, to whose control even Jupiter in his turn
must submit.
The beautiful planet Saturn requires for the observation of its rings
magnifying powers far beyond those of the instruments with which our
readers are supposed to be armed. It would be well, however, for the
observer to trace its slow motion among the stars with the aid of the
Nautical Almanac, and he should be able with a good field-glass to see,
under favorable circumstances, the largest of its eight moons, Titan.
This is equal in brilliancy to an 8.5 magnitude star. Its position with
respect to Saturn on any given date can be learned from the Ephemeris.
It may appear somewhat presumptuous to place Uranus, a planet which it
required the telescope and the eye of a Herschel to discover, in a list
of objects for the opera-glass. But it must not be forgotten that Uranus
was seen certainly several, and probably many, times before Herschel's
discovery, being simply mistaken, on account of the slowness of its
motion, for a fixed star. When near opposition, Uranus looks as bright
as a sixth-magnitude star, and can be easily detected with the naked eye
when its position is known. With an opera-glass (and still more readily
with a field-glass) this distant planet can be watched as it moves
deliberately onward in its gigantic orbit. Its passage by neighboring
stars is an exceedingly interesting phenomenon, and it is in this way
that you may recognize the planet.
On the evening of May 29, 1888, I knew, from the co-ordinates given in
the Nautical Almanac, that Uranus was to be found a short distance east
of Mars, which was then only a few degrees from the well-known star
Gamma Virginis. Accordingly, I turned my opera-glass upon Mars, and at
once saw a star in the expected position, which I knew was Uranus. But
there were other small stars in the field, and, supposing I had not been
certain which was Uranus, how could I have recognized it? The answer is
plain: simply by watching for a night or two to see which star moved.
That star would, of course, be Uranus. The accompanying cuts will show
the motions of Mars and Uranus with respect to neighboring stars at that
time, and will serve as an example of the method of distinguishing a
planet from the fixed stars by its change of place. In the first cut we
have the two planets and three neighboring stars as they appeared on May
29th. These stars were best seen with a field-glass, although an
opera-glass readily showed them.
[Illustration: MARS AND URANUS, MAY 29, 1888.]
[Illustration: MARS AND URANUS, JUNE 1, 1888.]
[Illustration: MARS AND URANUS, JUNE 6, 1888.]
On June 1st the relative positions of the planets and stars were as
shown in the second cut. A glance suffices to show that not only Mars
but Uranus also has shifted its position with respect to the three
immovable stars. This change of place alone would have sufficed to
indicate the identity of Uranus. To make sure, the inexperienced
observer had only to continue his observations a few nights longer.
On June 6th Mars and Uranus were in conjunction, and their position, as
well as that of the same set of three stars, is shown in the third cut.
It will be seen that while Mars had changed its place very much more
than Uranus, yet that the latter planet had now moved so far from its
original position on May 29th, that there could be no possibility that
the merest tyro in star-gazing would fail to notice the change. Whenever
the observer sees an object which he suspects to be a planet, he can
satisfy himself of its identity by making a series of little sketches
like the above, showing the position of the suspected object on
successive evenings, with respect to neighboring stars. The same plan
suffices to identify the larger planets, in the case of which no glass
is necessary. The observer can simply make a careful estimate by the
naked eye of the supposed planet's distance and bearing from large stars
near it, and compare them with similar observations made on subsequent
evenings.
THE SUN.--That spots upon the sun may be seen with no greater optical
aid than that of an opera-glass is perhaps well known to many of my
readers, for during the past ten years public attention has been drawn
to sun-spots in an especial manner, on account of their supposed
connection with meteorology, and in that time there have been many spots
upon the solar disk which could not only be seen with an opera-glass,
but even with the unassisted eye. At present (1888) we are near a
minimum period of sun-spots, and the number to be seen even with a
telescope is comparatively very small, yet only a few days before this
page was written there was a spot on the sun large enough to be
conspicuous with the aid of a field-glass. During the time of a
spot-maximum the sun is occasionally a wonderful object, no matter how
small the power of the instrument used in viewing it may be. Strings of
spots of every variety of shape sometimes extend completely across the
disk. Our illustration shows the appearance of the sun, as drawn by the
author on the 1st of September, 1883. Every one of the spots and
spot-groups there represented could be seen with a good field-glass, and
nearly all of them with an opera-glass.
[Illustration: THE SUN, SEPTEMBER 1, 1883.]
As in all such cases, our interest in the phenomena increases in
proportion to our understanding of their significance and their true
scale of magnitude. In glancing from side to side of the sun's disk, the
eye ranges over a distance of more than 860,000 miles--not a mere ideal
distance, or an expanse of empty space, but a distance filled by an
actual and, so to speak, tangible body, whose diameter is of that
stupendous magnitude. One sees at a glance, then, the enormous scale on
which these spots are formed. The earth placed beside them would be but
a speck, and yet they are mere pits in the surface of the sun, filled
perhaps with partially cooled metallic vapors, which have been cast up
from the interior, and are settling back again. It is worth anybody's
while to get a glimpse at a sun-spot if he can, for, although he may see
it merely as a black dot on the shining disk, yet it represents the play
of physical forces whose might and power are there exercised on a scale
really beyond human comprehension. The imagination of Milton or Dante
would have beheld the mouth of hell yawning in a sun-spot.
In order to view the sun it is, of course, necessary to contrive some
protection for the eyes. This may be constructed by taking two strips of
glass four or five inches long and an inch wide, and smoking one of them
until you can without discomfort look at the sun through it. Then place
the two strips together, with the smoked surface inside--taking care to
separate them slightly by pieces of cardboard placed between the
ends--and fasten the edges together with strips of paper gummed on.
Then, by means of a rubber band, fasten the dark glass thus prepared
over the eye-end of your opera-glass in such a way that both of the
lenses are completely covered by it. It will require a little practice
to enable you to get the sun into the field of view and keep it there,
and for this purpose you should assume a posture--sitting, if
possible--which will enable you to hold the glass very steady. Then
point the glass nearly in the direction of the sun, and move it slowly
about until the disk comes in sight. It is best to carefully focus your
instrument on some distant object before trying to look at the sun with
it.
As there is some danger of the shade-glass being cracked by the heat,
especially if the object-glasses of the instrument are pretty large, it
would be well to get the strips of glass for the shade large enough to
cover the object-end of the instrument instead of the eye-end. At a
little expense an optician will furnish you with strips of glass of
complementary tints, which, when fastened together, give a very pleasing
view of the sun without discoloring the disk. Dark red with dark blue or
green answer very well; but the color must be very deep. The same
arrangement, of course, will serve for viewing an eclipse of the sun.
A word, finally, about the messenger which brings to us all the
knowledge we possess of the contents and marvels of space--light.
Without the all-pervading luminiferous ether, narrow indeed would be our
acquaintance with the physical creation. This is a sympathetic bond by
which we may conceive that intelligent creatures throughout the universe
are united. Light tells us of the existence of suns and systems so
remote that the mind shrinks from the attempt to conceive their
distance; and light bears back again to them a similar message in the
feeble glimmering of our own sun. And can any one believe that there are
no eyes out yonder to receive, and no intelligence to interpret that
message?
Sir Humphry Davy has beautifully expressed a similar thought in one of
his philosophical romances:
In Jupiter you would see creatures similar to those in Saturn, but
with different powers of locomotion; in Mars and Venus you would find
races of created forms more analogous to those belonging to the Earth;
but in every part of the planetary system you would find one character
peculiar to all intelligent natures, a sense of receiving impressions
from light by various organs of vision, and toward this result you can
not but perceive that all the arrangements and motions of the
planetary bodies, their satellites and atmospheres, are subservient.
The spiritual natures, therefore, that pass from system to system in
progression toward power and knowledge preserve at least this one
invariable character, and their intellectual life may be said to
depend more or less upon the influence of light.[G]
[G] See "Consolations in Travel, or, the Last Days of a
Philosopher"; Dialogue I.
Light is a result, and an expression, of the energy of cosmical life.
The universe lives while light exists. But when the throbbing energies
of all the suns are exhausted, and space is filled with universal gloom,
the light of intelligence must vanish too.
One can not read the wonderful messages of light--one can not study the
sun, the moon, and the stars in any manner--without perceiving that the
physical universe is enormously greater than he had thought, and that
the creation, of which the Earth is an infinitesimal part, is almost
infinitely more magnificent in actual magnitude than the imaginary
domain which men of old times pictured as the dwelling-place of the
all-controlling gods; without feeling that he has risen to a higher
plane, and that his intellectual life has taken a nobler aim and a
broader scope.
INDEX.
Achernar, 94.
Albireo ([beta] Cygni), 55.
Alcor, 27.
Alcyone, 102.
Maedler's "Central Sun," 104.
Aldebaran, 22, 89, 91, 94, 95, 98.
Algenib ([alpha] Persei), 84, 85.
Algol, the Demon-Star, 83.
probable cause of variation of, 85.
Al-Mamoun, the Caliph, observation of a temporary star, 35.
Almaach ([gamma] Andromedae), 79, 82.
Alphard, 16.
Alpha Andromedae, 79.
Agnarii (Sadalmelik), 67.
Arietis (Hamal), 74.
Capricorni (Giedi), 65.
Ceti (Menkar), 70.
Draconis, formerly the pole-star, 102.
Librae, 52.
Ophiuchi (Ras Alhague), 42.
Orionis (Betelgeuse), 91, 98, 106.
Pegasi (Markab), 70.
Ursae Majoris, 28.
Alpheratz ([alpha] Andromedae), 79.
Alps, the lunar, 135.
Altai Mountains, 135.
Altair, 55.
Andromedae, map of, 76.
mythology of, 75.
Antares, 32, 33, 98.
Antinous, 55.
Apennines, the lunar, 135.
Apollonius, regarded the moon as a mirror, 119.
Aquarius, map of, 64.
mythology of, 67.
Aquila, map of, 56.
mythology of, 55.
Aratus, description of the Manger, 15.
the "Diosemia" of, 15.
the Phenomena of, 20.
story of Virgo, 51.
description of the "Royal Family," 78.
description of Cetus, 70.
Arcturus, 10, 24, 26, 49, 56.
Argo, map of, 110.
mythology of, 115.
Aries, map of, 71.
mythology of, 75.
Ariosto, story of a trip to the moon, 136.
Aristarchus, the shining mountain, 125.
Aselli, 15.
Asterope, 103.
Atlas, 102.
Auriga, map of, 23.
mythology of, 23.
star swarms in, 22.
Autumn, map of the Stars of, 62.
Bartschius invents Monoceros, 117.
Bay of Dew, 129.
Bay of Rainbows, 129.
Bear's head, stars forming the, 28.
Bellatrix, 90, 107.
Belt, Orion's, 90, 107.
Berenice's Hair, the constellation of, 24.
picture of, 53.
Bessel, studies of Sirius and Procyon, 20.
letter about "dark stars," 114.
Beta Andromedae (Mirach), 79.
Arietis (Sheratan), 75.
Capricorni (Dabih), 65.
Cassiopeia, 74.
Beta Corvi, 25.
Cygni (Albireo), 55.
Librae, 52.
Leonis (Denebola), 12.
Lyrae, 50.
Pegasi, 70.
Scorpionis, 34.
Ursae Minoris (Kochab), 27.
Betelgeuse ([alpha] Orionis), 91, 98, 106.
Bethlehem, the so-called Star of, 87.
Biela's comet, it breaks up, 82.
Biela meteors, radiant point of the, 82.
Booetes, map of, 50.
mythology of, 53.
Calisto, another name of Ursa Major, 29.
Cancer, map of, 18.
mythology of, 15.
Canes Venatici, 54.
Canis Major, map of, 110.
mythology of, 115.
Canis Minor, map of, 18.
mythology of, 21.
Canopus, 114.
Capella, 9, 22, 49, 89, 91.
Cape Heraclides, 129.
Laplace, 129.
Capricornus, map of, 64.
mythology of, 67.
Cassiopeia, map of, 76.
mythology of, 75.
Castor, 17.
Catharina, 135.
Caucasus Mountains, 135.
Celaeno, 103.
Central Gulf, 129.
"Central Sun," Maedler's ideas about a, 104.
Cepheus, map of, 58, 76.
Cetus, map of, 71.
mythology of, 70.
Chi Ceti, 73.
Clavius, 124, 132, 133.
Coal-Sack, 57.
Comet, Biela's, 82.
Comet, Halley's, the Crab Nebula mistaken for, 97.
Constellations, origin of, 6, 42, 61.
along the Milky-Way, 116.
the zodiacal, 16.
Constellations, St. Paul's knowledge of, 19.
Copernicus, 136.
Corvus, map of, 26.
mythology of, 25.
"Crimson Star," 110.
Crisian Sea, 127.
Cynosura, a name of Ursa Minor, 29.
Cygnus, map of, 56.
Cyrillus, 135.
Dabih ([beta] Capricorni), 65.
Dark Stars, Bessel's suggestion about, 114.
Davy, Humphry, on life in other worlds, 147.
Delta Canis Majoris, 112.
Cephei, 88.
Tauri, 99.
Deltoton, 75.
Denebola ([beta] Leonis), 12, 14, 24.
Dipper, the Great, 10, 27.
Dog-Days, origin of the, 111.
Dog-Star, 111.
Dolphin, map of the, 56.
mythology of the, 55.
Draco, map of, 58.
mythology of, 57.
El Nath, 22, 97.
Epsilon Leonis, 12.
Lyrae, 49.
Tauri, 99.
Virginis, 51.
Equinox, autumnal, 52.
vernal, 74.
Eridanus, map of, 93.
Eta Aquilae, 55.
Field-glass, 6.
Field of the Nebulae, 51.
Flammarion, on [alpha] Capricorni, 65.
Flood traditions connected with the Pleiades, 101, 102.
Focus, importance of a sharp, 11.
Fomalhaut, 63.
Fontenelle, "Plurality of Worlds," 60.
Galileo, his telescope an opera-glass, 4.
his description of Praesepe, 15.
his description of the moon, 118.
power of his telescope, 119.
Gamma Andromedae, 79, 82.
Leonis, 11.
Pegasi, 70.
Tauri, 99.
Virginis, 51.
"Garnet Star" (Mu Cephei), 88.
Gemini, map of, 18.
mythology of, 19.
Genesis, a celestial, 68.
Giedi ([alpha] Capricorni), 65.
Glass, use of smoked or colored, 130, 146.
Goldschmidt sees a nebula in the Pleiades, 104.
Gomelza, 20.
Gore, estimate of the stars in 13 M, 45.
"Grape-Gatherer" ([epsilon] Virginis), 51.
Grensted, Rev. Mr., suggestion about lunar rays, 132.
Grimaldi, 130.
Halley's comet and Crab Nebula, 97.
Hamal ([alpha] Arietis), 74.
Haemus Mountains, 128.
Henry, Paul and Prosper, photographs of the Pleiades, 105.
Hercules, map of, 44.
mythology of, 45.
motion of solar system toward, 43.
Herschel, William, discovers Uranus, 19.
computation of stars in 13 M, 45.
advice about seeing star-colors, 88.
thinks he sees lunar volcano, 125.
John, description of 8 M, 34.
suggestion about [alpha] Capricorni, 65.
Holden, Prof., on the Milky-Way, 40.
structure of Ring Nebula, 105.
Hooke, discovers first telescopic double star, 75.
Hyades, 89, 95, 98, 99.
Hydra, map of part of, 26.
mythology of, 16.
Hydra's Heart (Alphard), 16.
Humboldt Sea, 130.
Jeaurat, chart of the Pleiades, 104.
Job's coffin, 55.
Jupiter, 141.
satellites of, 142.
Kappa Argus, 116.
Tauri, 100.
Kepler observes the star of 1604, 42.
Kingsley, story of Andromeda, 77.
"King's lucky star," 67.
Kochab (Beta Ursae Minoris), 27.
Lake of Death, 129.
of Dreams, 129.
Land of Drought, 130.
of Hoar Frost, 130.
Leo, map of, 12.
mythology of, 13.
sickle-shaped figure in, 9, 14.
Lepus, map of, 93.
Lick telescope, views of Milky-Way, 40.
views of Ring Nebula, 105.
Light, the messenger of the universe, 147.
in a star-cluster, 45.
Libra, description and mythology of, 52.
Life, does it exist beyond the earth? 37, 48, 137, 139, 140, 147.
Locke, Richard Adams, author of the "Moon Hoax," 125.
Lyra, map of, 44.
mythology of, 45.
Maedler, on the "Central Sun," 104.
Maginus, 124.
Maia, 103, 105.
Man in the Moon, 121.
Manger (Praesepe), 15.
Marine glass, 6.
Markab ([alpha] Pegasi), 70.
Marsh of Mists, 129.
of Putrefaction, 129.
of Sleep, 127.
Mars, 140.
Medusa, the head of, 83.
Menelaus, 128.
Menkalina, 22.
Menkar ([alpha] Ceti), 70.
Mercury, 139.
Merope, 102, 103.
Mesarthim, 75.
Meteors, radiant point of November, 11.
radiant point of Biela, 82.
Micromegas, the story of, 115.
Milk-Dipper, 34.
Milky-Way, 17, 34, 39, 40, 43, 57, 81, 86, 116.
Mira ([omicron] Ceti), 71.
probable cause of its variations, 72.
Milton, account of Libra, 52.
Mirach ([beta] Andromedae), 79.
Mizar, 27.
Moon, mountains of the, 120.
shadows on the, 120.
map of the, 123.
list of mountains, "seas," etc., 123.
inhabitableness of the, 136.
the other side of the, 138.
"Moon Hoax," 125, 128.
Monoceros, map of, 110.
Mu Argus, 116.
Scorpionis, 36.
Nebulae (and Star-Clusters):
4 M, 34.
6 M, 37.
7 M, 37.
8 M, 38.
13 M, 45.
24 M, 38.
25 M, 39.
30 M, 66.
34 M, 86.
35 M, 18.
37 M, 23.
38 M, 23.
41 M, 112.
46 M, 116.
50 M, 117.
80 M, 35.
93 M, 116.
2^7, 117.
33^7, 23.
38^8, 116.
Andromeda, Great Nebula in, 79, 80.
Aquarius, Nebula in, 68.
Crab Nebula, 97, 98.
Field of the Nebulae, 51.
Horseshoe Nebula, 39.
Orion, Great Nebula in, 107.
Perseus, Great Cluster in, 86.
Pleiades, nebulae in the, 104.
Ring Nebula in Lyra, 50.
Nebular hypothesis, 68.
Neison, description of sunrise on Clavius, 133.
Newton, 134.
"Nile-Star," 111.
Northern Cross, 54, 55.
Northern Crown, map of the, 44.
Northern Fish, 73, 79.
Nu Andromedae, 79, 82.
Aquarii, a pointer to a nebula, 68.
Canis Majoris, 112.
Draconis, 58.
Scorpionis, 34.
Ocean of Storms, 130.
Omicron Ceti (Mira), 71, 72.
Cygni, 57.
Omicron two Eridani, a flying-star, 95.
Opera-glass, views of the stars with, 3.
how to choose a good, 4.
magnifying power of, 4.
defects of, 5.
Ophiuchus and Serpens, map of, 41.
mythology of, 41.
Orion, map of, 93.
mythology of, 109.
great array of stars around, 90.
riches of, 106.
spectacle of the rising of, 89.
Orpheus, fancies about the moon, 119.
Pegasus, map of, 64.
mythology of, 69.
Perseus, map of, 76.
mythology of, 75.
great cluster in, 86.
Phantom, another name of Hercules, 45.
Photography, astronomical, 3, 105.
Pi Argus, 116.
Five Orionis, 109.
Pegasi, 70.
Pisces, map of, 71.
mythology of, 74.
Piscis Australis, 67.
Plato, 135.
Pleiades, 10, 22, 89, 95.
names of the, 100.
mythology of, 100.
and the Flood, 101, 102.
and the Great Pyramid, 101.
picture of the, 103.
common motion of the, 104.
Pleione, 102, 103.
Pole-star, 10, 26.
Pollux, 17.
Praesepe (the Manger), 15.
Prime Meridian, 74.
Proclus, 127.
Procyon, 9, 20.
Pyramid of Cheops and the Pleiades, 101.
Pyrenees Mountains, 128.
Ras Alhague ([alpha] Ophiuchi), 42.
Rays of the Moon, 131.
Regulus, 9, 11.
Revolution of the heavens, 7, 30.
Rho Ophiuchi, 33.
Rigel, 91, 94, 98, 108.
Ring Nebula, 50.
"Royal Family," 63, 75.
Rutherford, photograph of the moon, 122.
Sadalmelik ([alpha] Aquarii), 67.
Sagitta, map of, 56.
Sagittarius, map of, 34.
mythology of, 34.
Saiph, 90.
Saturn, 142.
Scorpio, map of, 34.
mythology of, 32.
pair of stars in sting of, 37.
Schickhard, 130.
Sea of Clouds, 130.
Sea of Cold, 129.
Sea of Fertility, 127.
Sea of Humors, 130.
Sea of Nectar, 128.
Sea of Serenity, 128.
Sea of Showers, 129.
Sea of Tranquillity, 127.
Sea of Vapors, 129.
Secchi, Father, types of the stars, 106.
description of a star-swarm, 39.
Seiss, Rev. Dr., on Canis Minor, 21.
description of Auriga, 23.
Sheratan ([beta] Arietis), 75.
Sidus Ludovicianum, 27.
Sirius, 9, 22, 91.
color of, 111.
size and distance of, 112.
the companion of, 21, 114.
its light compared with the sun's, 46.
Sigma Tauri, 99.
Sixty-one Cygni, 56.
Smyth, Admiral, on Capricorn, 67.
description of Aldebaran, 98.
description of 35 M, 18.
Solstice, summer, 16, 19.
winter, 38.
Sobieski's Shield, 39.
Solar system, voyaging of, in space, 43.
Southern Cross, 91, 116.
South Sea, 130.
Spectroscopic analysis, 3, 98.
Spica, 10, 24, 26, 51.
Spring, map of the stars of, 8.
Square of Pegasus, 69.
St. Paul, acquainted with the constellations, 19.
Star-Clusters (see Nebulae, etc.).
Star-Cluster, light in a, 45.
Summer, map of the stars of, 31.
Sun, opera-glass observations of the, 145.
the, a variable star, 72.
Sword of Orion, 107.
Taurus, map of, 93.
mythology of, 102.
the "Golden Horns" of, 96.
Poniatowskii, 42.
Tau Aquarii, 68.
Taygeta, 103.
Temporary stars:
134 B. C. the first on record, 35.
393 A. D., 35.
827, 35.
1203, 35.
1572, Tycho's star, 87.
1578, 36.
1604, 36, 42.
1860, 35, 81.
1885, 80.
Temple, discovers a nebula in the Pleiades, 104.
Tennyson, describes the Pleiades, 105.
Theophilus, 135.
Theta Orionis, 107.
Serpentis, 43.
Tauri, 99.
Tobias Mayer, sees the planet Neptune, 69.
Triangles, map of the, 71.
mythology of, 75.
Twenty-two Canis Majoris, 112.
Scorpii, 33.
Tycho Brahe, invents Antinous, 55.
places Hamal in Aries, 75.
studies the star of 1572, 87.
Tycho, 122, 131.
Upsilon Tauri, 100.
Uranus, discovery of, 19.
how to find, 142.
Ursa Major, map of, 27.
mythology of, 28.
stars in the feet of, 28.
Ursa Minor, map of, 27.
mythology of, 28.
Vega, 49.
Venus, mistaken for artificial light, 2.
opera-glass observation of, 139.
Virgil, description of Taurus, 96.
Virgo, map of, 50.
mythology of, 51.
Vision, seeing with averted, 13.
Voltaire, story of "Micromegas," 115.
Vulpecula, map of, 56.
Webb, Rev. T. W., on telescopes, 5.
on 35 M, 18.
Western Fish, 73.
Winter, brilliancy of the heavens in, 91.
map of the stars of, 92.
Woman in the Moon, 121.
Zeta Corvi, 25.
Cassiopeia, 86.
Leonis, 11.
Lyrae, 50.
Scorpionis, 36.
Tauri, a pointer to the Crab Nebula, 97.
Zi Argus, 116.
Zodiac, 16.
Zodiac, divided among the Twelve Apostles, 86.
of Dendera, 14.
Zoellner, estimate of Sirius's light, 46.
THE END.