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.

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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 April 26, 2025.

Pages

PROBL. 1.

How to adde one sign to another on the Line of Natural Sines.

TO adde one sine to another, is to aug∣ment the line of one sine by the line of the other sine to be added to it. Ex. gr. To adde the sine 15 to the sine 20, I take the distance from the beginning of the line of sines unto 15, and setting one point of the Compasses in 20, upon the same line, turn the other toward 90, which I finde touch in 37. So that in this case (for we regard not the Arithmetical, but proportional aggre∣gate) 15 added to 20, upon the line of na∣tural sines, is the sine 37 upon that line, and from the beginning of the line to 37 is the distance I am to take for the summe of 20 and 15 sines.