The art of fortification, or architecture militaire as vvell offensiue as defensiue, compiled & set forth, by Samuell Marolois revievved, augmented and corrected by Albert Girard mathematician: & translated out of French into English by Henry Hexam

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Title: The art of fortification, or architecture militaire as vvell offensiue as defensiue, compiled & set forth, by Samuell Marolois revievved, augmented and corrected by Albert Girard mathematician: & translated out of French into English by Henry Hexam
Author: Marolois, Samuel.
Publication: Printed at Amsterdam :: For M. Iohn Iohnson,; Anno 1631.
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: Fortification -- Early works to 1800.
Cite this Item: "The art of fortification, or architecture militaire as vvell offensiue as defensiue, compiled & set forth, by Samuell Marolois revievved, augmented and corrected by Albert Girard mathematician: & translated out of French into English by Henry Hexam." In the digital collection Early English Books Online. https://name.umdl.umich.edu/A07035.0001.001. University of Michigan Library Digital Collections. Accessed May 2, 2024.

Pages

The 28. Figure.

In this present Decagone, a Fortresse with ten angles or Bulwarks, let the angle flanked be 87 degrees, the Gorge in the flanke in reason sesquitertia, the defences 50 and 60 rod, it is required how many the other parts thereof will make?

THe reason sesquitertia is, as 4 to 3, for AB to BC, then the imaginall angle BAC wilbe 36 degrees, 52 minutes, 12 seconds. Moreouer, the angle ADC being 43 ½ then CDF wilbe 28 ½, which is an angle of the triangle GDR, and which may be knowne, seing that DG is 50 rod, therefore GR 23, 858, or its equall KH, and for as much as DH is 60, then DK wilbe knowne, and also DR withall, and so ye shall finde RK for the second flanke: likewise the triangle DEA wilbe knowne, then ED and DR will make knowne ER, or AG, & consequently ye shall haue the triangle ACG for the angle A was found aboue, and the angle G is 28 ½ degrees, then the face wilbe 26, 11334, and hauing found out DF, ye shall finde EF, or the gorge 15, 197: Also FK for the curtaine 32, 10821; DP 78, 00619.