. St. Nicholas [serial] . s forming the upper part of thetriangles, as they hold much of the weight ofthe middle of the bridge, would tend to spreadat their bases; so they should be set into thefloor-timbers a little, or, if the bridge is asmall one, should be held with very strongspikes. The upright—the one post connect-ing the apex of the triangle with the center ofthe floor-timber—may even be a board—a one-foot-wide board, nailed very strongly. H it isa round timber, it must be cut in a little where the ends of this long crosspiece, braces arenailed to the tops of the triangles to keep them
. St. Nicholas [serial] . s forming the upper part of thetriangles, as they hold much of the weight ofthe middle of the bridge, would tend to spreadat their bases; so they should be set into thefloor-timbers a little, or, if the bridge is asmall one, should be held with very strongspikes. The upright—the one post connect-ing the apex of the triangle with the center ofthe floor-timber—may even be a board—a one-foot-wide board, nailed very strongly. H it isa round timber, it must be cut in a little where the ends of this long crosspiece, braces arenailed to the tops of the triangles to keep themfrom leaning to one side or the other, as theymight easily do if not strongly braced. You now have a series of crosspieces run-ning from floor-timber to floor-timber for thelength of the bridge. On these lay two twelve-inch boards, side by side, and your bridge isdone and needs only to be put in position. THE TWO-POST BRIDGE Thls bridge is something like the one-post, ex-cept that it can be made longer. Using three-. A LIGHTLY JLiDE TWO-POST BRIDOE, SHOWING CONSTRUCTION PLAN it meets the apex and where it meets thefloor-timber, so that, when spiked, it can get avery firm hold. In constructing this bridge, let the two sides,as you make them, lie flat on the ground, beingsure to have them of exactly the same stand them up, and place them parallel atthe required width apart that the bridge is tobe. Such a foot-bridge should be about threefeet wide. While the sides are held upright,crosspieces are nailed from one floor-timber tothe other, every two feet. The crosspiece thatcomes alongside of the posts connecting theapexes of the triangles with the floor should belong enough to extend out on either side of thebridge at least half the height of the is, if we have a triangle 5 feet high, anda bridge 3 feet wide, then the center floor-pieceshould have 3 feet for the width of the bridge,and extend out 2J/2 feet on each side. From inch and larger stuff it ca
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Keywords: ., bookcentury1800, bookdecade1870, bookidstnicholasserial4721dodg
