The 20. Plate & 94. Figure.
IF it be needefull to fortifie a right Curtaine, vvhereof the angles of the Bul∣warks are right, ye must doe as followeth. Let there be taken 70 rod, wanting 6 seconds (that is 69. 64. rod) and putt vpon the said curtaine A, E, as many times as the said curtaine will beare it, as appeareth here by the points A, B, C, D, E, from vvhich points shall rise the privie perpendi∣culars A F, B G, C H, D I, & F K the Capitals of 28, 97. rod, and on each side of the said points A, B, C, D, E, shalbe placed 16, 97. rod, as from A, to L. and at M, raysing the perpendiculars L, N, and M, O, 12 rod, the flanks 6, 11: then the lines NF, and FO, being drawne, vvhich vvill make the faces of the Bulwarks, ye shall haue that which is necessarie for the description of such a Bulwarke, where∣of the face is 24, rod, the flanke 12. the line of defense fichant 60, 37, and the line of the gorge L, A, 16. 97, rod. The moate maye be made broader, seing that the an∣gle of the Tenaille Z hindreth, that the angle of the flanke T, cannot discover the angle flanked F: but if the expence vvere not too much (which hapneth vvhen one makes the moate very deepe) one might to that end cut the part X, Y, Z, and so this inconveniencie vvould be remedied. For I finde that such Bulwarks are farre better, then those that are made vpon an angle; because the gorge is very large; the flank, the face, and the curtaine of a competent measure, and according to our former rules, to wit, the line of Defense fichant is 60 rod, or thereabouts, the Curtaine 36, the flank 12, the face 24, and the gorge wel nigh 17, rod, which is much better, and larger, then in the Bulwarks, that are made vpon some angle. So that such Bulwarks ought to be preferred before the others, were it not for some other reason, which makes one change his minde, as for to haue more place, or otherwise. Novv touching the distance of Bulwarks, or a Polygone interiour mentioned of 70 rod vvanting 6 seconds, these 6 seconds are of noe great moment: neverthelesse one must obserue the dimention as neere as possible maye be: Otherwise one might say, that the face being 24, the curtaine 36, the flank 12, rod, and the angle flanked right, that then the Capitall wilbe wel nigh 29, the gorge 17, the defense flanking 41. the line of the Poligone interiour, or exteriour 70. rod, the formed-flanked is 35 degrees, and 16 minutes.