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STAR CHARTS FOR SEPTEMBER.

With September, the midnight sky begins to assume a greater interest. The meridian line is marked out for us in the south with very considerable precision by the first two of four stars which make up a pretty regular

square, generally known

as the Square of Pegasus. Three only

of the four stars are in the

constellation

Pegasus

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one side of him and the Eagle on the other have not yet begun to set, but farther north Bootes has begun to disappear, Arcturus having already gone, and farther south but a few of his fainter stars marks the remains of Sagittarius. We are, however, gaining more than we lose. The head of Orion has

[graphic]

already risen
in the east.

Above it
Taurus is

se.n and

to the north-east being a Andromeda. The
horse is supposed to be inverted, and the arch
of its neck is clearly marked out by three bright
stars. Some fainter stars higher up in the sky,
stretching to the tip of the Swan's wing,
indicate the position of the fore-
legs of the Horse as it flies at

racing speed across the

sky. Below Pegasus

are the brightest stars

of Aquarius, the

Water Bearer,

from whose inverted pitcher a stream of

the Pleiades are completely visible, and farther to the north Castor is rising, though his brother Pollux still remains hidden. In the south-east a new constellation is fully risen

Cetus, the Whale: its principal stars forming an inverted Y, or perhaps giving rather the idea of a lounge chair with the back in clined greatly.

[graphic]

The star where the branches of the Y fork is worthy of particular note; it

faint stars wavers down to Fomalhaut, the star in the mouth of the Southern Fish low down due south. The meridian in the north is marked out sufficiently clearly by the two Pointer stars of the Plough. For the rest, the head of Ophiuchus alone remains above the horizon in the Hercules and the Northern Crown on the

west.

is Mira, the first star recognised to be variable, and which in eleven months passed through a series of changes up to a brightness sometimes of the second order of magnitude. The planets Jupiter and Saturn are still visible low down in the south-west; Saturn just setting.

STAR CHARTS FOR OCTOBER.

The constellations now before us are those of Andromeda, standing by the side of his which set forth the old Greek myth of Perseus Queen, occupies the space between Cygnus and and Andromeda. Right overhead

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is the W of Cassiopeia, the Lady in her Chair, as the con

stellation is sometimes

known. Queen of the Ethiopians,

the legend nairates that she

offended the

Nereids by

in her

beauty.

W

the Pole. The chief stars of Andromeda are the fourth star of the square already alluded to, three stars in a short vertical row near it, and two, out of five bright stars, which reproduce on a

larger and more brilliant scale, and just

E

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below it, the W of Cassiopeia. These stars are
The other members of
B and y Andromedæ.
this larger W are the most southerly 8 Trian-
guli, the principal star of an inconspicuous little
constellation, and a and B Persei.
a Persei is readily picked out
as the brightest star in
the richest part of a

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which

links Cassiopeia to Capella. β Persei, otherwise known

the

Head of
Medusa

called

W

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up eagerly for his prey. He was not destined to obtain his wish, for Perseus, riding on the winged horse Pegasus, came by at the critical moment, and turning the monster into stone by the exhibition of the Head of Medusa, delivered Andromeda and won her for his wife. The chief actors in this legend are all represented in the heavens, Cepheus, the King of Ethiopia and father

by the Arabs, Algol, that is, the Demon-star, is usually the equal of a in brightness, but in a little less than three days it undergoes a very regular change. descending from the 2nd magnitude to the 4th. This change is due to a partial eclipse by a close, dark and therefore invisible companion. The planet Jupiter can be seen just setting in the south-west during the first few days of the month.

STAR CHARTS FOR NOVEMBER.

Neglecting therefore his companion

The Milky Way still passes through the brighter. zenith, but now runs from south-east to north- and proceeding farther on the curve which

west. The zenith itself lies in Perseus,

not far from the centre of its rich

cluster. Algol marks the

meridian, which also

passes some 10° lower

down through the constellation

Aries, the Ram; and the bright

est star

of Cetus,

these five bright stars have clearly marked out, we are led inevitably-at about the same distance beyond Procyon that Procyon is from Pollux to the

[graphic]

prince of stars

-Siriuswhich has not long risen in

the

W

E

somewhat lower in the sky, is also now close to its culmination. The principal stars of Aries have passed the meridian an hour or more, and consist of three fairly bright stars in a very flat triangle. Looking again up to

Cassiopeia, now slightly be

low the zenith towards the

north-west, and follow

ing the main stream of

Perseus to Capella,

we find ourselves

on the prime

vertical, that is, the east and west line.

south-east. Across the base of the grand arch which these six stars make, flows the Milky Way. Under the span of the arch lies the premier constellation Orion. Sirius, Procyon, and Betelgeux form a nearly equilateral triangle, Betelgeux being the star in the shoulder of Orion. A line from Sirius upward through the other shoulder (Bellatrix) of the giant brings us to Aldebar a n, the eye of Bull. Following.

[graphic]

Dropping downwards towards the east point we next find Menkalinan, the second star of Fol. Auriga, lower still Castor and Pollux. lowing around the sweep which these four stars give us, we are brought a little further south and east to a third pair, a and B of Canis Minor. Of these a-Procyon-is by far the

the line still farther, we come to the Pleiades, now almost at their culmination. Amongst so many bright constellations coming up in the east and south it is easy to pass over those sinking out of view. The little groups Delphinus and Equuleus are just sinking in the west, and what is left of Aquarius sprawls along the horizon from the west to the south-west point.

STAR CHARTS FOR DECEMBER.

The south meridian is now at its most brilliant a and 8 marking out the heads of the two Twins epoch. Orion is culminating, Rigel, its brightest very distinctly, whilst a row of fairly bright stars star in the Giant's knee, being within a few minutes of transit. Aldebaran, the

brightest star of the

Bull, has passed but

half

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indicates their feet almost as pre

cisely, Far down in the south below Sirius himself we find a rich cluster of bright stars, the other members of the constellation Canis Major,

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which, though not well seen in these

E

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B Tauri with Bellatrix (y Orionis). Capella,
besides the indications of its place which have
been already given, may easily be recognised by
the proximity to it of three fairly bright stars,
arranged in a neat right-angled
triangle. The other principal
stars of the constellation

can easily be recog

nised. If we take

B (Menkalinan) as

the headpiece

of a cross,

Capella

the extre mity of

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In the east Leo has already risen, whilst the western horizon is occupied by Cetus, Pisces, and Pegasus, all three of which have commenced to set. In the north-west the out

stretched wings of the Swan brood along the horizon line, the head and neck being

already below it. Farther to the north, Vega grazes the horizon,

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the Dra

gon's

one arm, we find very symmetrically placed for the extremity of the other, and, which has just transited, for the foot; the cross, however, is inclined at a considerable angle to the meridian. Similarly the Twins, which are rapidly coming up, are inclined at about the same angle,

The

head almost touches the ground at the north point, and of Hercules only the knee appears. Plough is driving his furrow vertically upwards in the north-east, with the head and hand of Boötes just visible behind the handle, and the Hunting Dogs, whom he is cheering on, below it.

In the year 1902 there will be three Eclipses of the Sun and two of the Moon.

April 8.-A Partial Eclipse of the Sun.

Invisible throughout the British Isles. This Eclipse is visible only in the high latitudes of the North Pacific Ocean, where at the greatest phase about one-sixteenth of the Sun's diameter is obscured.

April 22.-A Total Eclipse of the

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WHAT IS AN ECLIPSE? Astronomically, the word "Eclipse" is applied to the darkening, real or apparent, of heavenly body, especially of the Sun or Moon, though some of the satellites of other planets besides the earth are also "eclipsed from time to time. An Eclipse of the Moon is caused by its passage through the Shadow of the Earth; an Eclipse of the Sun by the interposition of the Moon between the Sun and ECLIPSE, the observer, or what comes to the same thing, by the passage of the Moon's Shadow over the observer.

Moon's

Moons

SUN

THE HARVEST MOON. When does the Harvest Moon occur? is a question frequently asked. The Full Moon which happens on or nearest to LUNAR the Autumnal Equinox (about Sept. 23rd)

is called the Harvest Moon because it rises from night to night after the full, more nearly after sunset than any other Full Moon in the year, and is therefore favourable for evening work in carrying late crops. The succeeding Moon is called the Hunters' Moon. In 1902 the Harvest Moon is full on Sept. 17.

EARTH

It will be seen, however, from the diagram that since the apparent angular diameters of the Sun and Moon are very nearly the same, it is only when the spectator is on, or very close to, the line joining the centres of those two bodies that a Total Eclipse of the Sun can take place; and, indeed, even if he be on that central line, should the Moon be in the more distant portion of her orbit, her apparent diameter may be less than that of the Sun, so that even in a Central Eclipse a small view of the Sun is still visible. This constitutes what is known as an Annular Eclipse, but there is not one of the Eclipses visible in 1902 of this character. But even when the Eclipse is total on the central line, an observer far from that line will only see a portion of the Sun hidden, as the lines of the diagram clearly indicate.

In an Eclipse of the Moon the Eclipse is due to a real cutting off of light from the Moon. A Lunar Eclipse, if total for any place, must usually be total for every place from which the Moon can be seen. Lunar Eclipses are not, however, by any means always total. One Partial Eclipse occurs in May, 1902.

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The axis of the Earth's Shadow is always directed a point exactly opposite to the Sun. Did the Moon move accurately in the plane of the ecliptic she would be eclipsed at every Full Moon, but since her plane is inclined at about 5° to that of the ecliptic, she will pass into the Shadow and suffer Eclipse only, if, at the time of the Full Moon, she is near one of the nodes of her orbit. As this seldom happens, we find that there cannot be more than three Lunar Eclipses in the year (and this only if the Full Moon is at a node early in January), and there may be none. Usually, however, we have two Lunar Eclipses in the year, Total only if the Moon passes fairly near to the centre of the earth's shadow.

ECLIPSE.

BRITISH OBSERVATORIES.

GREENWICH, lat. 51° 28′ 38'1" N. Opened 1675, under the direction of Flamstead, Astronomer Royal. The chief centre for observations on astronomy and navigation.

CAMBRIDGE, lon. oh om 22'75 E.; lat. 52° 12' 51'6" N. Founded by the University in 1824. OXFORD Radcliffe, Íon. oh 5m 26s W.; lat. 51° 45' 35'4" N. Erected about 1772.

OXFORD UNIVERSITY, lat. 51° 45′ 34'2" N. Celebrated for its 124-in. equatorial refractor.

LIVERPOOL. Established 1838--transferred to Birkenhead in 1867. Lon. oh 12m 17'35 W.; lat. 53° 24' 4'8" N.

KEW, lon. oh 1m 15'18 W.: lat. 51° 28' 6" N. This is the chief meteorological observatory of United Kingdom.

DURHAM, lon. ob 6m 19'75 W.; lat. 54° 46' 6'2 N. Founded 1841. Is under the direction of the University Professor of Mathematics.

EDINBURGH-Carlton Hill, lon. oh 12m 44 28W, lat. 55° 55′ 28'0" N. Elected in 1818. A time gun is fired thence daily.

GLASGOW lon. o 17m 10'55 W.; lat. 55° 52′ 42'8" N. Open ed in 1840. On the north side of the city near Gartnavel.

DUBLIN, lon. oh 25m 21°18 W.; lat. 53°23′13′′ N. Opened in 1785. Is under direction of Irisa Astronomer Royal.

ARMAGH, lon. ob 26m 354 W.; lat. 54° 21' 2'7 N. Founded in 1701, and enlarged n 1327. CORK-Queen's College lat. + 51° 55' 30". Erected in 1878.

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