The first Figure represents the Triangle or Trigon of Signs, made of Brass or any other solid Matter of a bigness at pleasure. The Construction of this is thus: First draw the Line *ab*, representing the Axis of the World, and *ac* perpendicular thereto, representing the Radius of the Equinoctial, and about the Point a describe the circular Arc *dce* at pleasure. This being done, reckon 23\(\frac{1}{2}\) Deg. both ways from the Point *c* upon the said Arc, for the Sun’s greatest Declination, and draw the two Lines, *ad*, *ae*, for the Summer and Winter Tropicks; likewise draw the Line *de*, which will be bisected by the Radius of the Equinoctial in the Point *o*, about which, as a Center, draw a Circle, whose Circumference passes thro’ the Points *d* and *e* of the Tropicks, and divide the Circumference thereof in 12 equal Parts, beginning from the Point *d*. Then thro’ each Point of Division equally distant from *d* and *e*, draw occult Lines parallel to the Radius of the Equinoctial Circle. These Lines will intersect the Arc *dc* in the Points thro’ which and the Center *a* Lines being drawn, these Lines will represent the beginnings of the Signs of the Zodiack, at 30 Deg. distance from each other,

But to divide the Signs into every 10th or 5th Degree, you must divide the Circumference of the Circle into 36 or 72 equal Parts. After this, we denote the Characters of the Signs upon each Line, as appears *per* Figure. And when the Trigon is divided into every 10th or 5th Degree, we place the Letter of the Month to the first 10 Degrees of each Sign agreeing therewith.

But the Trigon of Signs may be readier made by the means of a Table of the Sun’s Declination; for having drawn the two Lines *ab* and *ac* at right Angles, lay the Center of a Protractor on the Point *a*, with its Limb towards the Point *c*; and keeping it fixed thus, count 23\(\frac{1}{2}\) Deg. on both sides the Radius *ac*, for the Tropicks of ♋︎ and ♑︎, 20 Deg. 12 Min. for the beginnings of the Signs ♌︎, ♊︎, ♐︎ and ♒︎, and 11 Deg. 30 Min for ♉︎, ♍︎, ♏︎. and ♓︎. And in this manner we divide the Spaces for each Sign into every 10th or 5th Deg. by means of the following Table of the Sun’s Declination. *Note*, The Equinoctial Points of ♈︎ and ♎︎ are placed at the end of the Radius of the Equinoctial *ac*.

Degrees of the Ecliptick | Signs | Signs | Signs | Degrees of the Ecliptick | |||
---|---|---|---|---|---|---|---|

♈︎ | ♎︎ | ♉︎ | ♏︎ | ♊︎ | ♐︎ | ||

D. | M. | D. | M. | D. | M. | ||

1 | 0 | 24 | 11 | 51 | 20 | 25 | 29 |

2 | 0 | 48 | 12 | 12 | 20 | 36 | 28 |

3 | 1 | 12 | 12 | 32 | 20 | 48 | 27 |

4 | 1 | 36 | 12 | 53 | 21 | 0 | 26 |

5 | 2 | 0 | 13 | 13 | 21 | 11 | 25 |

6 | 2 | 23 | 13 | 33 | 21 | 21 | 24 |

7 | 2 | 47 | 13 | 53 | 21 | 32 | 23 |

8 | 3 | 11 | 14 | 12 | 21 | 42 | 22 |

9 | 3 | 35 | 14 | 32 | 21 | 51 | 21 |

10 | 3 | 58 | 14 | 51 | 22 | 00 | 20 |

11 | 4 | 22 | 15 | 9 | 22 | 8 | 19 |

12 | 4 | 45 | 15 | 28 | 22 | 17 | 18 |

13 | 5 | 9 | 15 | 47 | 22 | 24 | 17 |

14 | 5 | 32 | 16 | 5 | 22 | 32 | 16 |

15 | 5 | 55 | 16 | 22 | 22 | 39 | 15 |

16 | 6 | 19 | 16 | 40 | 22 | 46 | 14 |

17 | 6 | 42 | 16 | 57 | 22 | 52 | 13 |

18 | 7 | 5 | 17 | 14 | 22 | 57 | 12 |

19 | 7 | 28 | 17 | 30 | 23 | 2 | 11 |

20 | 7 | 50 | 17 | 47 | 23 | 7 | 10 |

21 | 8 | 13 | 18 | 3 | 23 | 11 | 9 |

22 | 8 | 35 | 18 | 16 | 23 | 15 | 8 |

23 | 8 | 58 | 18 | 34 | 23 | 18 | 7 |

24 | 9 | 20 | 18 | 49 | 23 | 21 | 6 |

25 | 9 | 42 | 19 | 3 | 23 | 24 | 5 |

26 | 10 | 4 | 19 | 18 | 23 | 26 | 4 |

27 | 10 | 26 | 19 | 32 | 23 | 27 | 3 |

28 | 10 | 47 | 19 | 46 | 23 | 28 | 2 |

29 | 11 | 9 | 19 | 59 | 23 | 29 | 1 |

30 | 11 | 30 | 20 | 12 | 23 | 30 | 0 |

♓︎ | ♍︎ | ♒︎ | ♌︎ | ♑︎ | ♋︎ |

By this Table we may know the Sun’s Declination and Distance from the Equinoctial Points each Day at Noon, in every Degree of the Signs of the Zodiack, the greatest Declination being 23 Deg. 30 Min. tho’ at present it is but about 23 Deg. 29 Min. but a Minute difference is of no consequence in the Use of Dials. The Degrees of the first Column to the Left-hand, are for the Signs set down upon the Top of the Table, and the Degrees in the last Column numbered upwards, are for the Signs set at the Bottom of the Table.