LXVi. J. I. HAYCROFT. 



girder would be the heavier of the two when properly designed 

 instead of, as stated, 50 per cent, lighter. 



The raison d'etre of Professor Vierendeel's bridge has entirely 

 escaped Mr. Bowman's notice. As shown by the author, the 

 Professor's object was to prove the superiority of his design as 

 regards correctness of ascertained stresses over rivetted lattice 

 girders in ordinary practice. This, the Author considers, he has 

 effectively done. Professor Vierendeel's truss does not compete 

 with ordinary plate girders, which are rarely constructed of 100 

 feet span, but with lattice girders of that and greater spans. 

 Had Mr. Bowman designed a rivetted lattice truss of same span 

 as the Professor's, and been able to demonstrate its superiority 

 in weight saved, under equal loadings and same range of stress, 

 he would have accomplished something. As it is, he has done 

 nothing beyond showing how unstable a truss may be designed. 



