[Illustration: Plate 28a.--Arrangement of an iron fence built on a low wall.] FOOTNOTES: [Footnote 1: This chapter reprinted from _Infantry Journal_.] CHAPTER VI REVETMENTS A _revetment_ is a covering or facing placed upon an earth slope to enable it to stand at an inclination greater than it would naturally assume. Some revetments also increase the tenacity of slopes and diminish the injury by fire. The upper parts of revetments that may be struck by projectiles which penetrate the cover of earth must not be made of materials of large units which will splinter when struck. The upper part of the revetments is technically known as _crowning_. SANDBAGS Sandbags are made of coarse canvas or burlap. They are 33 inches long and 14 inches wide. They are filled loosely with earth or sand about 1/2 cubic foot to a bag. Having been placed in position they are pounded down with a shovel to a rectangular form when they will fill a space about 20 by 13 by 5 inches. The sandbag revetment is constructed by laying alternate rows of headers and stretchers, breaking joints. The tied ends of the headers and seams of the stretchers are put into the parapet. Men working in pairs lay the bags and set them firmly in place with a spade or mallet. The advantages are: 1. The portability of the empty bags. Only 62 pounds per one hundred bags. 2. They may be filled with any kind of soil. 3. They are rapidly filled and easily placed in position. 4. They are invaluable in making repairs. 5. They will not splinter. The only disadvantage is that they are not durable. The cloth soon goes to decay and the filling material crumbles away. Plate 29 shows the appearance of a sandbag revetment as seen from the front and from the end. [Illustration: Plate 29.--Sandbag revetment.] A squad of six men with two shovels and one pick should fill 150 bags in an hour. One man uses the pick, two shovel the dirt into the bag, one holds the bag open and two men tie the bags. Having the filled bags ready to hand ten men will lay 75 square feet of revetment in an hour. Four men lay the bags and flatten them out while six carry them. BRUSH Brush is used in many forms for revetting. Almost any kind will serve the purpose. For weaving, it must be live and is most pliable when not in leaf. It should not be more than 1 inch in diameter at the butt. When cut it should be assorted in sizes for the different class of revetments. Poles 2-1/2 inches in diameter are cut for the supports. FASCINES A _fascine_ is a cylindrical bundle of brushwood tightly bound. The usual length is 18 feet, the diameter 9 inches, and the weight normally about 140 pounds. Lengths of 6 and 9 feet, which are sometimes used, are most conveniently obtained by sawing a standard fascine into two or three pieces. [Illustration: Plate 29a.--Fascine.]