. The Encyclopaedia Britannica; ... A dictionary of arts, sciences and general literature. the force in magnitude as well as iodirection. The siaes of the polygon may be arranged in any order,provided care is taken so to draw them that in passing round thepolygon in one direction this direction may for each eide corres-pond to the direction of the force which it represents. This polygon of forces may, by a slight extension of the abovedefinition, be called the reciprocal figure of the external forces, ifthe sides are arranged in tlie same order as that of the joints oawhich they act, so that i
. The Encyclopaedia Britannica; ... A dictionary of arts, sciences and general literature. the force in magnitude as well as iodirection. The siaes of the polygon may be arranged in any order,provided care is taken so to draw them that in passing round thepolygon in one direction this direction may for each eide corres-pond to the direction of the force which it represents. This polygon of forces may, by a slight extension of the abovedefinition, be called the reciprocal figure of the external forces, ifthe sides are arranged in tlie same order as that of the joints oawhich they act, so that if the joints and forces be numbered 1, 2, 3,4, &c., passing round the outside of the frame in one direction, andreturning at last to joint 1, then in the polygon the side represent-ing the force 2 will be next the side representing the force 1, andwill be followed by the side representing the force 3, and so polygon falls under the definition of a reciprocal figure givenby Clerk Maxwell, if we consider the frame as a point in equiUbiiumunder the external forces. Fig. z ±zFig. 66a. Fig. 666. Fig. 66(i. Fig. 66 shows a frame supported at the two end joints, and loadedat each top joint. The loads and the supporting forces areindicated by arrows. Fig. 66a shows the reciprocal figure orpolygon for the external forces on the assumption that the reactionsare slightly inclined. The lines in fig. 66o, lettered in the usualmanner, correspond to the forces indicated by arrows in fig. 65, andlettered according to Mr Bows method. When all the forces arevertical, as will be the case in girders, the polygon of externalforces will be reduced to two straight lines, fig. 666, superirnposedand divided so that the length AX represents the load AX, thelength AB the load AB, the length YX the reaction YX, and soforth. The line XZ consists of a series of lengths, as XA,AB DZ, representing the loads taken in their order. In sub-sequent diagrams the two reaction lines will, for the sak
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectencyclo, bookyear1902
