ECL 
I C L 
sklcrably larger than her disc. There may 
however be total eclipses within a small dis- 
tance of the nodes; but their duration is the 
less as they are farther from it, till they be- 
come only partial ones, and at last none at 
all. 4. The moon, even in the middle of an 
eclipse, has usually a faint appearance of 
light, resembling tarnished copper, which 
Gassendus, Ricciolus, Kepler, & c. attribute 
t o the light of the sun, refracted by the earth’s 
atmosphere, and so transmitted thither. 
I Lastly. She grows sensibly paler and dim- 
mer, before entering into the real shadow, 
owing to a penumbra which surrounds that 
shadow to some distance. 
ECLIPTA, a genus of the class and order 
syngenesia polygamia superflua. The recept. 
is chaffy; down none; corollets of the disk 
four-cleft. There are five species, herba- 
ceous plants of the East and West Indies. 
ECLIPTIC, in astronomy, a great circle 
of the sphere, supposed to be drawn through 
the middle of the zodiac, making an angle 
with the equinoctial of about 23° 30', which 
is the sun’s greatest declination ; or, more 
strictly speaking, it is that path or way among 
the fixed stars that the earth appears to de- 
scribe to an eye placed in the sun. See As- 
tronomy. 
The ecliptic approaching nearer and nearer 
to a parallelism with the equator, at the rate 
of half a second in a year nearly, or from 50" 
to 55" in 100 years, as is deduced from an- 
tient and modern observations compared to- 
gether; and as the mean obliquity of the 
ecliptic was 23° 28", about the end of the year 
1788, or beginning of 1789, by adding half 
a second for each preceding year, or sub- 
tracting the same for each following year, 
the mean obliquity will be found nearly for 
any year either before or since that period. 
The quantity however of this change is va- 
riously stated by different authors, from 50" 
to 60" or 70" for each century or 100 years. 
Hipparchus, almost 2000 years since, ob- 
served the obliquity of the ecliptic, and found 
it about 23° 51'; and all succeeding astrono- 
mers, to the present time, having observed 
the same, have found it always less and less, 
being now rather under 23° 28'; a difference 
of about 23' in 1950 years; which gives a me- 
dium of 70" in 100 years. There is great 
reason however to think that the diminution 
is variable. fc 
This diminution of the obliquity of the 
' ecliptic to the equator, according to Mr. 
Long, and some others, is chiefly owing to 
the unequal attraction of the sun and moon 
on the protuberant matter about the earth’s 
equator. For if it is considered, say they, 
that the earth is not a perfect sphere, but an 
oblate spheroid, having its axis shorter than 
its equatorial diameter; and that the sun and 
moon are constantly acting obliquely upon 
the greater quantity of matter about the 
equator, drawing it in a manner towards a 
nearer and nearer coincidence with the 
ecliptic; it will not appear strange that these 
actions should gradually diminish the angle 
between the planes of these two circles. Nor 
is it less probable that the mutual attractions 
of all the planets should have a tendency to 
bring their orbits to a coincidence ; though 
this change is too small to become sensible in 
many ages. 
It is now, however well known, that tins 
change in the obliquity of the ecliptic is 
ECL 
wholly owing to the actions' of the planets 
upon the earth, and especially the planets 
Venus and Jupiter. According to La Grange, 
who proceeds upon theory, the annual change 
of obliquity is variable, 'and lias its limits; 
about 2000 years ago, he thinks it was after 
the rate of about 38" in 100 years; that it is 
now, and will be for 400 years to come 56" 
per century ; but 20ti0 years hence 49" per 
century. According to Cassini, who com- 
putes from observations of the obliquity be- 
tween the years 1739 and 1778, the annual 
change at present is 60" or 1° in 100 years. 
But according to La Lande, the diminution 
is at the rate of 88" per century; while Dr 
Maskelyne makes it only 50" in the same 
time. 
Beside the regular diminution of the obli- 
quity of the ecliptic, at the rate of near 50 
seconds in a century, or half a second a year, 
which arises from a' change of the ecliptic it- 
self, it is subject to two periodial inequalities, 
the one produced by the unequal force of the 
sun in causing the precession of the equi- 
noxes, and the other depending on the nu- 
tation of the earth’s axis. See the Explana- 
tion and Use of Dr. Maskelyne’s Tables and 
Observations, pa. vi, where we are shewn 
how to calculate tiiose inequalities, and where 
he shews that, from his own observations, the 
mean obliquity of the ecliptic to the begin- 
ning of the year 1769, was 23° 28' 9" -7. 
To find the obliquity of the ecliptic, or the 
greatest declination of the sun ; about the 
time of the summer solstice, observe very 
carefully the sun’s zenith distance for se- 
veral days together, then the difference 
between this distance and the latitude of the 
place, will be the obliquity sought, when the 
sun and equator are both on one side of the 
place of observation; but their sum will be 
the obliquity when they are on different sides 
of it. Or it may be found by observing the 
meridian altitude or zenith distance, of the 
sun’s centre, on the days of tha summer and 
winter solstice ; then the difference of the 
two will be the distance between the tropics, 
the halt of which will be the obliquity sought. 
Table of the obliquity of the ecliptic at dif- 
ferent periods . 
Authors’ Names. 
Years be- 
fore Christ 
Obliquity. 
Pytheas 
324 
0 
23 
49 
// 
23 
Eratosthenes andH ipchus 
230 & 140 
23 
51 
20 
aft. Christ. 
Ptolemy 
140 
23 
48 
45 
Almahmon 
832 
23 
35 
Albategnius 
880 
23 
35 
Thebat 
911 
23 
33 
30 
Abul Wasi and Hamed 
999 
23 
35 
Persian tables in Chry- 
spcocea 
1004 
23 
35 
Albatrunius - 
1007 
23 
35 
Arzachel 
1104 
23 
33 
30 
Almaeon 
1140 
23 
33 
30 
Choja Nassir Oddin 
1290 
23 
30 
Prophatius the Jew 
1300 
23 
32 
Ebn Shattir - 
1363 
23 
31 
Purbach and Regiomon- 
tanus 
1460 
23 
30 
Ulugh Beigh 
1463 
23 
30 
17 
Walther 
1476 
23 
30 
Ditto corrected by re- 
fraction, &c. 
— — - 
23 
29 
8 
4E2 
I C L 
Authors’ Names 
Years af- 
ter Christ. 
587 
Obliquity. 
Werner 
1510 
0 
23 
/ 
28 
// 
30 
Copernicus - 
1525 
23 
28 
24 
Egnatio Danti 
1570 
23 
29 
Prince of Hesse 
1570 
23 
31 
Rothman and Byrge 
1570 
23 
30 
20 
Tycho Brahe 
1584 
23 
31 
30 
Ditto corrected 
— 
23 
29 
Wright 
Kepler 
1594 
23 
30 
1627 
23 
30 
30 
Gassendus 
1630 
23 
31 
Ricciolus 
1646 
23 
30 
20 
Ditto corrected 
1655 
23 
29 
Hevelius 
1653 
23 
30 
20 
Ditto corrected 
1661 
23 
28 
52 
Cassini 
1655 
23 
29 
15 
Montons corrected, &c. 
1660 
23 
29 
3 
Richer corrected - 
1672 
23 
28 
52 
De la Hire - 
1686 
23 
29 
Ditto corrected 
. 
23 
29 
28 
Flainstead 
1690 
23 
29 
Bianchini 
1703 
23 
28 
25 
Roemer 
1706 
23 
28 
41 
Louville 
1715 
23 
28 
24 
Godin - 
1730 
23 
28 
.20 
Bradley 
1750 
23 
28 
18 
Mayer 
1756 
23 
28 
16 
Maskelyne - 
1769 
23 
28 
10 
Hornsby 
1772 
23 
28 
8 
As to the obliquity of the ecliptic, or the 
angle which its plane makes with that of the 
equinoctial, it is found to vary. 
Ecliptic, in geography, a great circle on 
the terrestrial globe, not ‘only answering to, 
but falling within the plane of the celestial 
ecliptic. See Globe. 
ECLOGUE, in poetry, a kind of 
pastoral composition, or a small elegant 
poem, in a natural simple style. See Poe- 
try. 
ECPHORA, in architecture commonly 
the distance between the extremity of a mem- 
ber or moulding, and the naked part of the 
column, or any other part it projects from. 
EC STATIC I, in Grecian antiquity, a sort 
of diviners, who were cast into trances or ec- 
stacies, in which they lay like dead men, or 
persons asleep, deprived of all sense or mo- 
tion, but after some .time, returning to them- 
selves, they gave strange relations of what 
they had seen and heard. 
EC1IIESIS, in church-history, a confes- 
sion of faith, in the form of an edict, publish- 
ed in the year 639, by the emperor Heraclius, 
with a view to pacify the troubles occasioned 
by the Eutychian heresy in the eastern 
church. The same prince revoked it, on 
being informed that pope Severinus had con- 
demned it, as favouring the monothelites ; 
declaring at the same time that Sergius, pa- 
triarch of Constantinople, was the author 
of it. 
EC1 HLIPSIS, among Latin gramma- 
rians, a figure of prosody, whereby the m at 
the end ot a word, when the following word 
begins with a vowel, is elided, or cut off, to- 
gether with the vowel preceding it, for the 
sake of the measure of the verse ; thus they 
read mult’ ille, for multum ille. 
r lhe reason of an ecthlipsis, which in Latin 
verse ought always to take place when the 
immediately following word begins with a 
vowel, is to prevent the harshness of an hia- 
tus, or concourse of vowels* 
