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.
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: 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 June 6, 2025.

Pages

PROBL. 13.

The declination and Azimuth given to find the altitude of the Sun or any Star.

Take the declination from the Scale of al∣titudes; set one point of your Compasses in the Azimuth given, then in North declina∣nation turn the other point toward the head, in South toward the end; and thereto laying the thread, on the limb you have the altitude, numbring from 60/0 on the moveable piece toward the end. Ex. gr. At 7 deg. North declination, and 48 deg. Azimuth from South, the altitude is 35 deg. but at 7 deg. declination South, and 50 deg. Azimuth the altitude is onely 18 deg. 30 min.