FORTIFICATIONS Field Works Redans Polygons Military

Description: LEGEND TO THE ILLUSTRATIONS, SEE BELOW Print Specifics: Type of print: Intaglio, steel engraving - Original antique printYear of printing: not indicated in the print - actual: 1844Publisher: Johann Georg HeckCondition: 1 (1. Excellent - 2. Very good - 3. Good - 4. Fair). This print had water stains/brownish spots when I received it (see last two photos). I had the print cleaned and stains removed. Dimensions: 9 x 11.5 inches, (23 x 29 cm) including blank margins (borders) around the image.Paper weight: 3 (1. Thick - 2. Heavier - 3. Medium heavy - 4. Slightly heavier - 5. Thin)Reverse side: Blank Notes: Green color around the print in the photo is a contrasting background on which the print was photographed.Print detail is much sharper than the photo of the print.Photos show the overall view of the print and an enlarged detail. Legend to the illustrations: FIELD FORTIFICATIONS: The object of every fortification is so to surround a spot with obstacles, that a division of troops occupying the same may defend themselves with advantage against superior numbers. If only the passing movements of an army are to be thus supported, the fortifications are but simple. A fundamental principle is, that every point of the work shall be swept by two fires, a direct and a cross or flanking fire, taking the enemy on the side; the distance, therefore, from one flanking point to another must never exceed good musket range, that is, from 300 to 480 feet. Field works are divided into three classes: open works, closed works, and fortified lines. a. Open Works. All works not entirely inclosed by their parapet are said to be open. They are, according to their form, 1, simple redans or tenailles, which consist of the straight lines of fire (faces) meeting each other under a greater or less angle, sometimes broken and furnished with flanks. If it is desired to protect the salient by a cross-fire, the flanks are broken to the front ( fig. 5). The redan bab has the flanks cd, which defend the dead-angle in front of the salient a by a cross-fire. The flanks must never be more than half musket-shot distance from the salient angle, and must stand perpendicularly to the face on which they belong. If the ground is too extended for a simple redan, it is then doubled (fig. 6, gab a g), and here also the flanks bdc can be broken to the front. Such double redans are called swallow-tails, and double swallow-tails when there are three salient and two re-entering angles (fig. 7), in which case the flanks are still broken forward. The salient angles must not be less than 60°, the re-entering not less than 90°. If the extent of the space to be defended or other local circumstances render it requisite, a system of tenailles is employed (fig. 9); the side of the polygon must not, however, exceed 180 feet. When a longer polygon side than this is to be defended, a a (fig. 10), it is broken repeatedly and a bastion constructed upon it. For this purpose the triangle aaa is constructed, from the two new and the old polygon sides, and in the centre c of the new polygon side the perpendicular c b is erected, which for the square is J, for the pentagon J, and for the hexagon, &c, i of the side in length. Through all the points a and b, undetermined lines, a x, are drawn, and a d made equal to s a a, by which the faces of the bastion are given. From d perpendiculars are let fall upon a x, thus obtaining the flanks of the bastion, and if now the extremities of the opposite flanks are united by straight lines, the curtains, we have the complete trace of the bastioned front. Martin2001 Satisfaction Guaranteed Policy! Any item purchased from me may be returned for any (or no) reason for a full refund including all postage. Internet seller since 1998.Five-star service.

Price: 22 USD

Location: Manassas, Virginia

End Time: 2024-05-12T14:32:34.000Z

Shipping Cost: 4.45 USD