Astronomia Britannica exhibiting the doctrine of the sphere, and theory of the planets decimally by trigonometry, and by tables : fitted for the meridian of London ... / by John Newton ...

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Title: Astronomia Britannica exhibiting the doctrine of the sphere, and theory of the planets decimally by trigonometry, and by tables : fitted for the meridian of London ... / by John Newton ...
Author: Newton, John, 1622-1678.
Publication: London :: Printed for the author by R. and W. Leybourn, and are to be sold by Thomas Piercepoint ...,; 1657.
Rights/Permissions: To the extent possible under law, the Text Creation Partnership has waived all copyright and related or neighboring rights to this keyboarded and encoded edition of the work described above, according to the terms of the CC0 1.0 Public Domain Dedication (http://creativecommons.org/publicdomain/zero/1.0/). This waiver does not extend to any page images or other supplementary files associated with this work, which may be protected by copyright or other license restrictions. Please go to http://www.textcreationpartnership.org/ for more information.
Subject terms: Astronomy -- Early works to 1800.; Planetary theory -- Early works to 1800.; Astronomy -- Mathematics -- Early works to 1800.
Cite this Item: "Astronomia Britannica exhibiting the doctrine of the sphere, and theory of the planets decimally by trigonometry, and by tables : fitted for the meridian of London ... / by John Newton ..." In the digital collection Early English Books Online. https://name.umdl.umich.edu/A52255.0001.001. University of Michigan Library Digital Collections. Accessed May 23, 2024.

Pages

CHAP. 26. How to direct the Ascendent, or Significator posited in the Signes Ascending.

THe Horoscope or Ascendent, or a Significator posited in the signes ascending, that is, in the 12, 11, 10, 1, 2, or 3 houses, must be dire∣cted to Promittors, by the oblique Ascensions answering to the ele∣vation of the Pole above the Circle of position of the Significator. The elevation of the Pole above the ascendent is the same with that of the place for which the figure is erected. The Poles elevation above the Circle of position of any other Significator must be found as hath been shewed in 22 Chapter. Then if you deduct the oblique Ascension of your Signifi∣cator, from the oblique Ascension of your Promittor, what remaineth is the arke of direction.

For example. Let the Ascendent of the preceding figure in the 16 Chap∣ter be to be directed to the 26 deg of Taurus. The elevation of the Pole of the Circle is the same with that of the place. viz. 51. 5••.

And therefore the oblique Ascension of 26 deg. of Taurus,: 27. 50
To which add a Circle that substraction may be made: 360
And then the Oblique Ascension is: 387. 50
The Oblique Ascension of the Ascendent substract: 162. 82
There rests for the ark of Direction: 224. 68

Page 47

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Another Example.

Let us suppose a Significator to be posited in the signes Ascending but not upon the Cuspe of the Ascendent, in this case though the Arke of Direction must be found out by the Oblique Ascensions as be∣fore; yet the elevation of the Pole above the Circle of position must be first found, because it is not given, as in the last Example.

In the Diagram of the 23 Chapter, let the distance of the Significator from the meridian be 44. 07. The declination thereof North above the Earth H O 14. 85. Hence the Pole L M is 30 degrees. Let this Significa∣tor be posited in 10 degrees of Taurus, the Right Ascension thereof D O 37. 58. His Ascensional difference under the elevation of 30 degrees F O 8. 80. Let the Promittor be in 25 of Gemini, the Right Ascension thereof D S. 84. 55. And the Ascensional difference when this Promittor comes to N. is represented by the letters F V. 14. 47. Now then if you substract the Ascensional Difference of the Significator F O, 8. 80. from the Ascensio∣nal Difference of the Promittor F V. 14. 47. There will remaine O V 5. 67. we call it the Aequation of the Arke of Direction, which be∣ing added to the Right Ascension of the Significator D O. 37. 58. There aggregate is the arch D V 43. 25. Then if you deduct the arch D V 43. 25 from the Right Ascension of the Promittor, D S. 84. 55. There difference is V S 41. 30. The Ark of Direction sought.

Or thus, the Oblique Ascension of the Promittor is 70. 08. The Oblique Ascension of the Significator is 28. 78. There difference 41. 30, is the Ark•• of direction sought, as before.