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. XXII. To find the true time of the Suns rising and setting, with the length of the day and night for any day of the Moneth assigned.

ALthough I could prescribe several Rules for the re∣solution of this Question, yet I shall for your greater facility) make choyce of that which I suppose to be most familiar and easie, as by the Examples follow∣ing will appear.

Enter the following Table with the 5, 10, 15, 20, 25 or 30 day of your Month, finding your dayes (aforesaid) on the top, and moneths on the margent, and in the com∣mon

Angle, you will find (by inspection) the exact time of the Suns rising the said dayes, and by the Rule of Proportion for any other intermediate day.

A Table shewing the exact time of the Suns rising every fifth day, exactly calculated for the Latitude of 56. degrees, 20. min.

Names of the Months	The dayes of each Moneth.
	5 day	10 day	15 day	20 day	25 day	30 day
Ianuary	8 21	8 12	8 3	7 53	7 42	7 29
February	7 18	7 6	6 55	6 43	6 31
March	6 12	6 0	5 48	5 36	5 24	5 10
April	4 58	4 48	4 36	4 26	4 15	4 5
May	3 55	3 47	3 39	3 32	3 26	3 21
Iune	3 18	3 17	3 18	3 23	3 23	3 28
Iuly	3 35	3 42	3 50	3 59	4 9	4 19
August	4 32	4 42	4 54	5 5	5 17	5 28
September	5 42	5 54	6 3	6 17	6 29	6 41
October	6 52	7 4	7 16	7 27	7 38	7 49
November	8 1	8 11	8 20	8 27	8 34	8 39
December.	8 42	8 43	8 42	8 40	8 36	8 31
	Time of the Suns rising in hours and min.

Example, I desire to know the exact time of the Suns rising the 15 day of April; I look in the Table for the 15 day, and descends the saids Column, untill I come against the Month given, viz. April, and I find 4. 36. viz. 4 hours, 36. min. past the Suns rises the saids day. In like manner, the 15 day of May the Sun rises 39. min. past 3. in the morning: The 15 of June, 18 min. past 3 in the morning; The 15 of July, 50. min. past 3. in the morning, &c.

But if you would know the time of the Suns rising for any other intermediate day, take the difference, and

work by the Golden Rule, and you shall find the propor∣tiall part to be added.

Example, I desire to know what time the Sun rises the 23 of August; I look into the Table, and I find that the Sun rises the 20 day, at 5 min. past 5. and the 25 day, 17 min. past 5. the difference is 12 min. Then I say— if 5 dayes gives 12 min. What will 3. dayes give? Ans. 7. min. which added to 5 h. 5 min. (the time of the Suns rising the 20 day) the aggregate is 5 h. 12 min. for the exact time of the Suns rising the 23 of August, as was required.

If you desire to know the time of the Suns setting, substract the time of the Suns rising from 12 hours, and the remainder will be the time of his setting.

Example, I desire to know the time of the Suns set∣ting the 15 day of July; I find that he rises that day at

	h.	m.
3 hours 50 min. which known—from	12	00
I substract the time of Sun rising (the 15 of July)	3	50
Rests the exact time of Sun seting the 15 of July	8	10

Lastly, Having thus found the time of the Suns set∣ting, if you double the same, you have the whole length of the day, whose complement to 24 hours, is the length of the night, as in the Example preceeding.

	h.	m.
The Suns semidiurnal arch, or time of's seting	8.	10
which doubled, gives the length of the day	16.	20
Whose Complement to	24.	00
Is the noctural arch, or length of the night	7.	40

This is so plain, that he which understands it not, his ignorance out-weighs his wit, as much as a Milston out-weighs a Feather, and consequently incapable of Subli∣mer Arts and Sciences.