AN
EPITOME of ASTRONOMY,
WITH
_THE NEW DISCOVERIES_:
INCLUDING AN ACCOUNT OF THE
Eídouraníon,
OR
TRANSPARENT ORRERY;
(INVENTED BY A. WALKER)
AS LECTURED UPON BY HIS SON,
_W. WALKER_.
STARS TEACH AS WELL AS SHINE! YOUNG.
OS HOMINI SUBLIME DEDIT; CŒLUMQUE TUERI
JUSSIT, ET ERECTOS AD SIDERA TOLLERE VULTUS.
OVID MET. 1. 85.
THE FOURTEENTH EDITION.
Ipswich;
PRINTED FOR THE AUTHOR,
BY BURRELL AND BRANSBY;
AND SOLD BY J. ROBSON AND W. CLARKE, BOND-STREET;
AND G. KEARSLEY, FLEET-STREET, LONDON.
1800.
AN
_EPITOME of ASTRONOMY_;
AS ILLUSTRATED BY THE
Eídouraníon,
OR
TRANSPARENT ORRERY.
This elaborate Machine is 20 feet diameter: it stands vertical before
the spectators; and its globes are so large, that they are distinctly
seen in the most distant part of a Theatre. Every Planet and Satellite
seems suspended in space, without any support; performing its annual
and diurnal revolutions without any apparent cause. It is certainly the
nearest approach to the magnificent simplicity of nature, and to its just
proportions, as to magnitude and motion, of any Orrery yet made: and
besides being a most brilliant and beautiful spectacle, conveys to the
mind the most sublime instruction: rendering astronomical truths so plain
and intelligible, that even those who have not so much as thought upon
the subject, may acquire clear ideas of the laws, motions, appearances,
eclipses, transits, influences, &c. of the planetary system.
Scene 1.
_THE SUN AND EARTH_:
With the Zodiacal Constellations.
As information is the primary object of this lecture, it is thought more
useful to exhibit PARTS of the solar system, separately, before a grand
display was made of the whole. This scene therefore, opens with only the
Sun and the Earth. The Sun seems suspended in the middle of the system,
and by spots on his face, is seen to turn round on his axis in 25¼ days;
light issues from his orb in all directions; in the blaze of which is
suspended the Earth, turning on its axis to produce day and night, and
revolving round the Sun to produce the seasons: its axis inclines 23½
degrees from a perpendicular to the plane of its orbit; and by that axis
keeping parallel to itself during this annual journey, the northern and
southern hemispheres are alternately addressed to the Sun; shewing, when
it is summer in one, it is winter in the other, and _vice versâ_. This
scene so naturally exhibits the cause of day, night, twilight, summer
and winter, spring and autumn, long and short days, &c. that a bare
inspection of the Machine is sufficient to convey the clearest idea of
these phænomena.
* * * * *
The Earth in this scene ought to be unshackled with meridians or
parallels of latitude:—to be a free and independent ball, with land and
water represented as they would appear to a distant spectator looking at
the real Earth. But as globes are seldom seen without these appendages, a
globe of two feet in diameter, equipped with meridians and parallels of
latitude (being requisite for illustration) will perform a diurnal and
annual motion round the Sun, and explain the above phænomena on so large
a scale, that their effects on the smallest island may be seen from the
most distant part of the theatre.
This scene is surrounded by transparent paintings of the twelve signs of
the Zodiac, shewing how the Sun, or rather the Earth, enters and passes
thro’ Aries, Taurus, Gemini, Cancer, &c.
* * * * *
Auxiliary scenes accompany this, to shew the principles of planetary
motion; the formation of the constellations and their allegorical
history; the oblate, yet nearly globular figure of the Earth; how ships
and mountains appear at sea; with ships moving round a large globe of six
feet diameter, &c. proving that the Earth can contain inhabitants on all
sides, &c.