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. V. To find how long the Effects of an Eclipse conti∣nues, and when they begin and end.

QƲot horas durat Eclipsis Solaris tot annorum duratoris, effectus praenunciat: Quot horas durat Lunaris ut mensem. How many hours the Sun is Eclipsed, so ma∣ny years will the effects continue, but if it be a Lunar Eclipse, so many Months.

Now to find the time when the effects of some Eclipse begins and ends, observe if the Eclipse falls in the Eastern Horizon, the effects thereof will manifest themselves, about the next four Months following the Eclipse, and will more strongly operate in the first third part of its whole Duration — But if it fall in the Mid-heaven, the Events thereof will begin to appear in the 4th Mo∣neth next following, but most apparent will the effects be in the middle most third part of its whole Duration. — But if it happen in the West part of the Horizon, the effects shall not begin untill about the last four Mo∣neths, and its greatest Operation will be in the last third part of its whole Duration.

Therefore we are to observe at the midle of the Eclipse, how far the Luminary eclipsed is distant from the rising, and how long it continueth above the Hori∣zon: which known, reduce them into minuts (for faci∣lity of Operation) and then say by the Golden Rule — if the time of the whole continuance of the Luminary eclipsed above the Horizon, give 365 dayes (or a whole year) What shall the time of the rising give? Multiply and Divide, and the Quotient will yeeld your desire.

As for example, in the Eclipse of the Moon that is to happen the 27 of July 1664. (in the Meridian of the Ho∣nourable and Famous City of Glasgow) at a 11 hours, 12 min. 12 seconds. The Moons Nocturnal Arch is 8 hours, 30 min. reduced into minuts is 510.

The Sun sets (in the Latitude of 56 deg.) at 45 min. past 7. which in this case may serve for the time of the Moons rising: so that the distance of the Moon at the greatest Obscuration, is 3 hours, 37 min. which re∣duced (as aforesaid) into minuts, is 217.

Now 365 (the dayes in a Common Year) multiplied by 217. the product 79205. divided by 510. the Quotient is 155. 31—102. Or you may perform the Operation with more facility and greater expedition by the Loga∣rithmes, which was first invented by the thrice noble and Illistruous Lord, viz. John Lord Nepper, Barron of Marchi∣ston, &c. in Scotland, whose Name and Fame will never Terminate, until the general Dissolution.

The Operations, by his Lagarithmes, is this,

	Logarith.
Length of the night, 8 h. 30 m. or 510 m.	2, 707570
The Common Year hath 365 dayes.	2, 562293
Distance of the greatest obscuration, 3 h. 37 m. or 217 m.	2, 336459
	4, 898752
Dayes or the Effects begin. 155.	2, 161182

And so many dayes it will be, before the Effects begin to operate, and therefore from the day of the Eclipse, (viz. the 27 of July, 1664.) I number 155 dayes, and it points out the 29. of December following, on which day the Eclipse begins to Operate. And because the Dura∣tion of the saids Eclipse is 4 h. 1 m. 8 s. (according to my Doctrine of Eclipses) therefore the Effects will last 4 Months, from the 29 of December 1664. as aforesaid.

Moreover, Ptolomy saith, that how many hours the Sun is distant from the Horoscope (or ascendant, all's one) at the time of his Eclipse, so many years will it be ere the Effects begin to Operate: so that if the Eclipse be in or near the West Angle, it may be 12 whole years, be∣fore the Effects take place: But I rather consent to Ori∣ganus, who saith, they Inchoate at the very day of the Eclipse. Consentem namque est Eclipses statim operari, & effectus suos aliquasque extendere. Orig. par. 3. cap. 2. de effectibus.

Thus having shown you how to find the time of the be∣ginning and ending of the Effects of the Eclipses and time of continuance, I come next to shew in what Kingdoms and Countreys the Effects will principally manifest themselves.