O1IAP. XI.] CAUSING MAXIMUM STRAINS. 167 



Reaction at right support : 



---4--1 

 I PJ' 





2d. Uniformly distributed load extending to a distance /S 

 from left support. Load per unit of length =j?. 



r - P a F- 4- 1 

 " 2rcl/i L 2 4?J 



For two dua spans we have only to make n 1 in the 

 above equations. For a uniform load over whole span j3 = I. 



From the above formulae we can find the reactions for any 

 case, and then proceed as indicated above. 



1O9. By means of the graphical method, as we have now 

 seen, we are enabled to solve completely the problem of the 

 continuous girder, and that too without the aid of analytical 

 formulae, tables, or tedious computation. The method can also 

 be applied to continuous girders of variable cross-section, or of 

 uniform strength. We shall not, however, proceed further 

 with the development of the method in this direction. The 

 preceding will, we think, be found to contain all that is practi- 

 cally serviceable. For the application of the method to girders 

 of variable cross-section, we refer the reader to Winkler " Der 

 Bruckenbau? Wien, 1873 where will be found a thorough 

 presentation of the subject, both analytically and graphically, 

 to which we are greatly indebted in the preparation of the 

 preceding pages. Plates 17, 19 and 20, are, with but few alter- 

 ations, reproduced from that work. 



* These formulae are demonstrated in Van Nostrand's Eng. May., July 

 1875. 



