The English academy, or, A brief introduction to the seven liberal arts grammar, arithmetick, geometrie, musick, astronomie, rhetorick & logic : to which is added the necessary arts and mysteries of navigation, dyaling, surveying, mensuration, gauging & fortification, practically laid down in all their material points and particulars, highly approved to be known by the ingenious, and as such are desirous to profit, or render themselves accomplished : chiefly intended for the instruction of young scholars, who are acquainted with no other than their native language, but may also be very useful to other persons that have made some progress in the studies of the said arts / by John Newton.

CHAP. I. Of the General Subject of Astronomie.

AStronomy, is an Art, by which we are Taught the Measure and Moti∣on of the heavenly Orbs and Stars that are in them.

2. The Heavenly Orbs are either 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, without Stars, as the Primum Mobile, or 〈 in non-Latin alphabet 〉〈 in non-Latin alphabet 〉, such as have Stars in them, as the eight inferiour Orbs.

3. The Stars are either fixed or movea∣ble: The fixed Stars are those which always keep the same distance from one another; but the moveable Stars, otherwise called

Planets, are such as do not always keep the same distance.

4. All the Stars, as well fixed as moveable have a double motion; the one occasioned by the Primum Mobile, from East to West, the other natural or proper to themselves, by which they move from West, to East.

5. According to this double motion of the Stars, this Art of Astronomy is divided in∣to two Parts; the first sheweth the motion of the Primum Mobile, and how the several Heavenly Orbs are by that carried round the World, from East to West, which is called the Diurnal motion of the Stars.

The second part of Astronomy, sheweth the Periodical motion of the Stars, in which the inferiour Orbs, according to their own proper and natural motion, do move from West to East.

6. For the better understanding of these several motions, the Primum Mobile, or tenth Orb, is usually represented by a Sphere or Globe, with such lines drawn about it as the Stars in their motions are supposed to make, or may help to discover unto us, the quantity of their motions, and shew the time of their Risings and Settings, and such like.

7. This Sphere or Globe, is a round bo∣dy, containing one Superficies, in the mid∣dle whereof there is a Point, from whence all Right Lines drawn to the Superficies are equal.

8. In the Sphere or Globe, there are ten imaginary Lines or Circles, of which six are great, and four are small.

9. The great Circles are these which di∣vide the Sphere or Globe into two equal Hemispheres, and such are the Horizon, Ae∣quinoctial, Zodiack and the two Colures; the two first of which are called external and mu∣table, the other internal and immutable.

10. The Lesser Circles, are those which divide the Sphere or Globe, into two une∣qual Hemispheres, whereof one is more, and the other less than the half of the Sphere or Globe; such are the two Tropicks of Can∣cer and Capricorn, and the Artick and An∣tartick Circles, all which are represented in Fig. 9.

11. The Horizon, which is also called the Finitor, is a Circle, which divideth the visible part of the Heavens from the not vi∣sible; that is, the lower Hemisphere from the upper, as the line AB; one of whose Poles is in the Point directly over our heads, and is called the Zenith, the other Diame∣trically opposite, called the Nadir, and no∣ted with the Letters Z. N.

12. The Horizon, is either Sensible or Ra∣tional.

13. That is called the Sensible Horizon, which bounds our sight, and seemeth to di∣vide the Heavens into two equal Hemis∣pheres.

14. And that is called the Rational or In∣telligable Horizon, which doth indeed bisect the Heavens; and this is Right, when it passeth through the Poles of the World; or Oblique, when one of the Poles is some∣what elevated, and the other depressed; or Parallel, when one Pole is in the Verti∣cal Point or Zenith, for then the Horizon is Parallel to the Aequator; it otherwise makes therewith either Right or Oblique Angles.

15. Hence there is a threefold position of Sphere. 1. A Right, where the Horizon is Right; that is, where the Aequator pas∣seth through the Zenith and Nadir, 2. Ob∣lique, when the Horizon is Oblique; that is, when one Pole is somewhat elevated and the other depressed. 3. Parallel, when one of the Poles of the world is in the Zenith.

16. In a Right Sphere, all the Stars do Rise and Set, but in an Oblique Sphere, some are hid from our sight, and some are always above the Horizon.

17. The Meridian is a great Circle pe∣culiar and proper to every place, and drawn through the Vertical point and the Poles of the World, to which when the Sun comes in his Diurnal motion, in the Day-time he mak∣eth the Mid-day, and in the Night time, he maketh Midnight. There may be as many Meridians as there are Vertical points, but upon the Globe they are usually drawn thro' every tenth or fifteenth Degree of the Ae∣quator.