Sun’s mean Motion and Anomaly.

Hours.	Mot. & Ano.
Hours.	°	ʹ	ʺ
ʹ	ʹ	ʺ	ʺʹ
ʺ	ʺ	ʺʹ	ʺʺ
1	0	2	28
2	0	4	56
3	0	7	24
4	0	9	51
5	0	12	19
6	0	14	47
7	0	17	15
8	0	19	43
9	0	22	11
10	0	24	38
11	0	27	6
12	0	29	34
13	0	32	2
14	0	34	30
15	0	36	58
16	0	39	26
17	0	41	53
18	0	44	21
19	0	46	49
20	0	49	17
21	0	51	45
22	0	54	13
23	0	56	40
24	0	59	8
25	1	1	36
26	1	4	4
27	1	6	32
28	1	9	0
29	1	11	28
30	1	13	55
31	1	16	23
32	1	18	51
33	1	21	19
34	1	23	47
35	1	26	15
36	1	28	42
37	1	31	10
38	1	33	38
39	1	36	6
40	1	38	34
41	1	41	2
42	1	43	30
43	1	45	57
44	1	48	25
45	1	50	53
46	1	53	21
47	1	55	49
48	1	58	17
49	2	0	44
50	2	3	12
51	2	5	40
52	2	8	8
53	2	10	36
54	2	13	4
55	2	15	32
56	2	17	59
57	2	20	27
58	2	22	55
59	2	25	23
60	2	27	51

In Leap-years, after February, add one Day and one Day’s motion.

Table XVII. The Sun’s Declination in every Degree of the Ecliptic.

	0		6	1		7	2		8
Signs	♈		♎	♉		♏	♊		♐
	Nor.		Sou.	Nor.		Sou.	Nor.		Sou.
°	°	ʹ	ʺ	°	ʹ	ʺ	°	ʹ	ʺ	°
0	0	0	0	11	29	33	20	11	16	30
1	0	23	54	11	50	35	20	23	49	29
2	0	47	48	12	11	26	20	36	0	28
3	1	11	42	12	32	5	20	47	48	27
4	1	35	34	12	52	31	20	59	13	26
5	1	59	25	13	12	44	21	10	15	25
6	2	23	14	13	32	54	21	20	53	24
7	2	47	1	13	52	32	21	31	7	23
8	3	10	45	14	12	5	21	40	58	22
9	3	34	26	14	31	24	21	50	24	21
10	3	58	4	14	50	28	21	59	25	20
11	4	21	38	15	9	17	22	8	2	19
12	4	45	8	15	27	51	22	16	14	18
13	5	8	34	15	46	9	22	24	0	17
14	5	31	55	16	4	11	22	31	21	16
15	5	55	11	16	21	57	22	38	16	15
16	6	18	21	16	39	26	22	44	45	14
17	6	41	25	16	56	37	22	50	49	13
18	7	4	23	17	13	31	22	56	26	12
19	7	27	15	17	30	7	23	1	36	11
20	7	50	0	17	46	15	23	6	20	10
21	8	12	36	18	2	24	23	10	38	9
22	8	35	5	18	18	3	23	14	29	8
23	8	57	26	18	33	24	23	17	52	7
24	9	19	39	18	48	25	23	20	49	6
25	9	41	43	19	3	5	23	23	19	5
26	10	3	37	19	17	26	23	25	22	4
27	10	25	21	19	31	25	23	26	57	3
28	10	46	56	19	45	3	23	28	5	2
29	11	8	20	19	58	20	23	28	46	1
30	11	29	33	20	11	16	23	29	0	0
Signs	♓		♍	♒		♌	♑		♋
	1		5	10		4	9		3
	Sou.		Nor.	Sou.		Nor.	Sou.		Nor.

If the Sun’s place be taken from the Tables on pag. [114] and [115], his declination may be had thereby, near enough for common use, from this Table, by entering it with the signs at the head and degrees at the left hand; or with the signs at the foot and degrees at the right hand. Thus, March the 5th, the Sun’s place is ♓ 14° 53ʹ (call it 15°, being so near) to which answers 5° 55ʹ 11ʺ of the south declination.

Table XVIII. Lunations from 1 to 100000.

Lunat.	Days.	H.	M.	S.
1	Contain 29	12	44	3
2	59	1	28	6
3	88	14	12	9
4	118	2	56	13
5	147	15	40	16
6	177	4	24	19
7	206	17	8	22
8	236	5	52	25
9	265	18	36	28
10	295	7	20	31
20	590	14	41	3
30	885	22	1	34
40	1181	5	22	6
50	1476	12	42	37
60	1771	20	3	9
70	2067	3	23	40
80	2362	10	44	12
90	2657	18	4	43
100	2953	1	25	15
200	5906	2	50	30
300	8859	4	15	45
400	11812	5	41	0
500	14765	7	6	15
600	17718	8	31	30
700	20671	9	56	45
800	23624	11	22	0
900	26577	12	47	15
1000	29530	14	12	30
2000	59061	4	25	0
3000	88591	18	37	30
4000	118122	8	50	0
5000	147652	23	2	30
6000	177183	13	15	0
7000	206714	3	27	30
8000	236244	17	40	0
9000	265775	7	52	30
10000	295305	22	5
20000	590611	20	10
30000	885917	18	15
40000	1181223	16	20
50000	1476529	14	25
60000	1771835	12	30
70000	2067141	10	35
80000	2362447	8	40
90000	2657753	6	45
100000	2953059	4	50

By comparing this Table with the Table on page 113, it is easy to find how many Lunations are contained in any given number of Sidereal, Julian, and Solar years, from 1 to 8000.

CHAP. XX.
Of the fixed Stars.

Why the fixed Stars appear bigger when viewed by the bare eye than when seen through a telescope.

391. The Stars are said to be fixed, because they have been generally observed to keep at the same distance from each other: their apparent diurnal revolutions being caused solely by the Earth’s turning on its Axis. They appear of a sensible magnitude to the bare eye, because the retina is affected not only by the rays of light which are emitted directly from them, but by many thousands more, which falling upon our eye-lids, and upon the aerial particles about us, are reflected into our eyes so strongly as to excite vibrations not only in those points of the retina where the real images of the Stars are formed, but also in other points at some distance round about. This makes us imagine the Stars to be much bigger than they would appear, if we saw them only by the few rays which come directly from them, so as to enter our eyes without being intermixed with others. Any one may be sensible of this, by looking at a Star of the first Magnitude through a long narrow tube; which, though it takes in as much of the sky as would hold a thousand such Stars, yet scarce renders that one visible.

A proof that they shine by their own light.

The more a telescope magnifies, the less is the aperture through which the Star is seen; and consequently the fewer rays it admits into the eye. Now since the Stars appear less in a telescope which magnifies 200 times than they do to the bare eye, insomuch that they seem to be only indivisible points, it proves at once both that the Stars are at immense distances from us, and that they shine by their own proper light. If they shone by borrowed light they would be as invisible without telescopes as the Satellites of Jupiter are: for these Satellites appear bigger when viewed with a good telescope than the largest fixed Stars do.

Their number much less than is generally imagined.

392. The number of Stars discoverable, in either Hemisphere, by the naked eye, is not above a thousand. This at first may appear incredible, because they seem to be without number: But the deception arises from our looking confusedly upon them, without reducing them into any order. For look but stedfastly upon a pretty large portion of the sky, and count the number of Stars in it, you will be surprised to find them so few. Or, if one considers how seldom the Moon meets with any Stars in her way, although there are as many about her Path as in other parts of the Heavens (the Milky way excepted) he will soon be convinced that the Stars are much thinner sown than he was aware of. The British catalogue, which, besides the Stars visible to the bare eye, includes a great number which cannot be seen without the assistance of a telescope, contains no more than 3000, in both Hemispheres.

The absurdity of supposing the Stars were made only to enlighten our nights.

393. As we have incomparably more light from the Moon than from all the Stars together, it were the greatest absurdity to imagine that the Stars were made for no other purpose than to cast a faint light upon the Earth: especially since many more require the assistance of a good telescope to find them out, than are visible without that Instrument. Our Sun is surrounded by a system of Planets and Comets; all which would be invisible from the nearest fixed Star. And from what we already know of the immense distance of the Stars, the nearest may be computed at 32,000,000,000,000 of miles from us which is more than a cannon bullet would fly in 7,000,000 of years. Hence ’tis easy to prove, that the Sun seen from such a distance, would appear no bigger than a Star of the first magnitude. From all this it is highly probable that each Star is a Sun to a system of worlds moving round it though unseen by us; especially, as the doctrine of a plurality of worlds is rational, and greatly manifests the Power, Wisdom, and Goodness of the great Creator.

Their different Magnitudes.

394. The Stars, on account of their apparently various magnitudes, have been distributed into several classes or orders. Those which appear largest are called Stars of the first magnitude; the next to them in lustre, Stars of the second magnitude, and so on to the sixth, which are the smallest that are visible to the bare eye. This distribution having been made long before the invention of telescopes, the Stars which cannot be seen without the assistance of these instruments are distinguished by the name of Telescopic Stars.

And division into Constellations.

395. The antients divided the starry Sphere into particular Constellations, or Systems of Stars, according as they lay near one another, so as to occupy those spaces which the figures of different sorts of animals or things would take up, if they were there delineated. And those Stars which could not be brought into any particular Constellation were called unformed Stars.

The use of this division.

396. This division of the Stars into different Constellations or Asterisms, serves to distinguish them from one another, so that any particular Star may be readily found in the Heavens by means of a Celestial Globe; on which the Constellations are so delineated as to put the most remarkable Stars into such parts of the figures as are most easily distinguished. The number of the antient Constellations is 48, and upon our present Globes about 70. On Senex’s Globes are inserted Bayer’s Letters; the first in the Greek Alphabet being put to the biggest Star in each Constellation, the second to the next, and so on: by which means, every Star is as easily found as if a name were given to it. Thus, if the Star γ in the Constellation of the Ram be mentioned, every Astronomer knows as well what Star is meant as if it were pointed out to him in the Heavens.

The Zodiac.

397. There is also a division of the Heavens into three parts. 1. The Zodiac, (ζωδιακὸς) from ζώδιον Zodion an Animal, because most of the Constellations in it, which are twelve in number, are the figures of Animals: as Aries the Ram, Taurus the Bull, Gemini the Twins, Cancer the Crab, Leo the Lion, Virgo the Virgin, Libra the Balance, Scorpio the Scorpion, Sagittarius the Archer, Capricornus the Goat, Aquarius the Water-bearer, and Pisces the Fishes. The Zodiac goes quite round the Heavens: it is about 16 degrees broad, so that it takes in the Orbits of all the Planets, and likewise the Orbit of the Moon. Along the middle of this Zone or Belt is the Ecliptic, or Circle which the Earth describes annually as seen from the Sun; and which the Sun appears to describe as seen from the Earth. 2. All that Region of the Heavens, which is on the north side of the Zodiac, containing 21 Constellations. And 3. that on the south side, containing 15.

The manner of dividing it by the antients.

398. The antients divided the Zodiac into the above 12 Constellations or Signs in the following manner. They took a vessel with a small hole in the bottom, and having filled it with water, suffered the same to distil drop by drop into another Vessel set beneath to receive it; beginning at the moment when some Star rose, and continuing until it rose the next following night. The water fallen down into the receiver they divided into twelve equal parts; and having two other small vessels in readiness, each of them fit to contain one part, they again poured all the water into the upper vessel, and strictly observing the rising of some Star in the Zodiac, they at the same time suffered the water to drop into one of the small vessels; and as soon as it was full, they shifted it and set an empty one in it’s place. By this means, when each vessel was full, they observed what Star of the Zodiac rose; and though not possible in one night, yet in many, they observed the rising of twelve Stars, by which they divided the Zodiac into twelve parts.

399. The names of the Constellations, and the number of Stars observed in each of them by different Astronomers, are as follows.