Ouranoskopia, or, The contemplation of the heavens, in a perpetual speculum, or general prognostication for ever wherein is succinctly demonstrated the names and natures of the signs, planets and aspects, terms of art, order of the spheres, the colours, magnitudes, motions, solid proportions and distances of the seven planets from the earth ... / by Iames Corss ...

CHAP. XXIII. To find the Golden-Numbers, Epacts, and age of the Moon for any year of God assign'd.

1. TO find the Golden-Number, add 1. to the number of years given, the aggregate divide by 19. the remainder is the Golden Number, required.

2. To find the Epact, multiply the Golden Number (so found as aforesaid) by 11, the Product divide by 30. the remainder is the Epact, required.

Example, Anno Christi, 1698. I demand the Golden Number and Epact for the saids year?

To 1698. I add 1. the aggregate 1699. I divide by 19. rests (by the quotient) 8. for the Golden Number, which multiplyed by a 11. the Product is 88. this di∣vided by 30. the remainder (besides the quotient) is 28. and so much is the Epact of the saids year 1698. as was required.

3. To know the age of the Moon at all times: Find first the Epact for that year, and unto it add the number of the dayes of the Month, and the Moneths from March (counting March for one) and the aggregate (if it be less then 30.) is the age of the Moon, required.

Example, I demand the age of the Moon the 20 day of September 1664. first I find the Epact for that year (either by the former Rule, or by the Table following) to be 12. to which I add 20. (the day of the Moneth assign'd) the sum is 32. to which I add the number of Moneths from March, (calling March one, April two, May three, &c.) which is 7. the aggregate is 39. from which I deduct 29. rests 19. for the age of the Moon the 20 of September 1664. as was required.— The operation.

The day of the given Moneth	20 dayes
The number of months from March	7 dayes
The Epact of the year assign'd	12 dayes
Aggregate	39 dayes
The Common Lunar revolution. subst.	29 dayes
Rests the age of the Moon, required	19 dayes

But because every one cannot Multiply and Divide, that thereby they might find the Golden Numbers and Epacts, and consequently the Age of the Moon: I have therefore composed the following Table, which (by In∣spection only) will shew you all the Golden Numbers, Epacts, Sudayes Letters, and Whitsundayes for 51 years to come, beginning Anno 1662. ending Anno 1713.

Years of Christ	Gol. num.	Epact.	Sun. lett.	Whitsun∣day.
1662	10	20	e	May 18
1663	11	1	d	June 7
1664	12	12	cb	May 29
1665	13	23	a	May 14
1666	14	4	g	June 3
1667	15	15	f	May 26
1668	10	26	ed	May 10
1669	17	7	c	May 30
1670	18	18	b	May 22
1671	19	29	a	June 11
1672	1	11	gf	May 26
1673	2	22	e	May 18
1674	3	3	d	June 7
1675	4	14	c	May 23
1676	5	25	ba	May 14
1677	6	6	g	June 3
1678	7	17	f	May 19
1679	8	28	e	June 8
1680	9	9	dc	May 30
1681	10	20	b	May 22
1682	11	1	a	June 4
1683	12	12	g	May 27
1684	13	23	fe	May 18
1685	14	4	d	June 7
1686	15	15	c	May 23
1687	16	26	b	May 15
1688	17	7	ag	June 3
1689	18	18	f	May 19
1690	19	24	e	June 8
1691	1	11	d	May 31
1692	2	22	cb	May 15
1693	3	3	a	June 4
1694	4	14	g	May 27
1695	5	25	f	May 12
1696	6	6	ed	May 31
1697	7	17	c	May 23
1698	8	28	b	June 12
1699	9	9	a	May 28
1700	10	20	gf	May 19
1701	11	1	e	June 8
1702	12	12	d	May 24
1703	13	23	c	May 16
1704	14	4	ba	June 4
1705	15	15	g	May 27
1706	16	26	f	May 12
1707	17	7	e	June 1
1708	18	18	dc	May 23
1709	19	29	b••	June 12
1710	1	11	a	May 28
1711	2	22	g	May 20
1712	3	3	fe	June 8
1713	4	14	d	May 24

The use of this Table is this, find the year of God in the Table, and over against it, you have (1) the Golden Number: (2.) The Epact: (3.) The Sunday Letter: And (4.) the Month and Day when Whitsunday falls: I shall Illustrate it by an Example or two.

Suppose the year of Christ given were 1665. against 1665. In the Table I find (1.) 13 for the Golden Num∣ber: (2.) 23 for the Epact: (3.) A, for the Sunday Letter: And (4.) May the 14 for Whitsunday. — In like manner, if the years assigned were 1698. the Golden Number is 8. the Epast is 28. the Sunday Letter B. and Whitsunday falls that year on the 12 of June, &c. More Examples were superfluous.

Here note, that where you find two Dominical Let∣ters, it signifieth that year is Leap-year, and therefore you are to take the first of them for January and Februa∣ry, and the second Letter for all the year after.