The semicircle on a sector in two books. Containing the description of a general and portable instrument; whereby most problems (reducible to instrumental practice) in astronomy, trigonometry, arithmetick, geometry, geography, topography, navigation, dyalling, &c. are speedily and exactly resolved. By J. T.

About this Item

Title
The semicircle on a sector in two books. Containing the description of a general and portable instrument; whereby most problems (reducible to instrumental practice) in astronomy, trigonometry, arithmetick, geometry, geography, topography, navigation, dyalling, &c. are speedily and exactly resolved. By J. T.
Author
Taylor, John, 1666 or 7-1687.
Publication
London :: printed for William Tompson, bookseller at Harborough in Leicestershire,
1667.
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Subject terms
Mathematics -- Early works to 1800.
Navigation -- Early works to 1800.
Dialing -- Early works to 1800.
Link to this Item
http://name.umdl.umich.edu/A64223.0001.001
Cite this Item
"The semicircle on a sector in two books. Containing the description of a general and portable instrument; whereby most problems (reducible to instrumental practice) in astronomy, trigonometry, arithmetick, geometry, geography, topography, navigation, dyalling, &c. are speedily and exactly resolved. By J. T." In the digital collection Early English Books Online. https://name.umdl.umich.edu/A64223.0001.001. University of Michigan Library Digital Collections. Accessed May 8, 2025.

Pages

Page 31

PROBL. 8.

To finde the Suns Azimuth in any latitude in Northern Declination.

Proport. 1. As the sine of the latitude to the sine of declination, so is the radius to the sine of altitude at East, or West. By Probl. 2. substract this from the present altitude, then,

Proport. 2. As the cosine of the latitude is to that residue, so is the radius to a fourth sine. Again,

Proport. 3. As the cosine of the altitude is to that fourth sine, so is the radius to the sine of the Azimuth from East or West.

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