CHAP, xm.] 



ANALYTICAL FOKMUL.E. 



215 



Let us take the first case. For load on A B, we have from 



780 

 our triangle or formulas the moment at B = w Z 2 . At D, 



56 780 56 



11644 

 For load on C D, we have at once from triangle the moment 



D- 616 



~~ 11644^ 



Finally, for load on F G, we have for moment at F, from 

 627 



11644 



theref ore at D 209 X 



45 



11644 



w P. 



All these moments at D are positive ; we have therefore, for 



the first case of loading, the total moment at D = -f 



717 



w 



If we make I = 80 ft. and w = 2 tons, we find the moment 

 at D = 788, and dividing by 10 we obtain 78.8 tons as the 

 strain in A a, Fig. 88, corresponding with our tabulation, Art. 

 127. 



Table for all the Moments. 



All the moments may be found from a simple table similar 

 to the following, which will be found perhaps preferable to the 

 triangle of Art. 138. 



TABLE FOK MOMENTS. UNIFORM LOAD IN SINGLE SPAN. 



Support counted from Left. Denominator A . 



