by L. J. Norton and L. L. Scranton .. by E. A. Coulson and E. F. G. Herington. by W. H. Tatton and E. W. Drew. by J. D. Livingston and H. W. Schadler. by G. J. Appleton and P. N. Krishnamoorthy. by A.L. Morton and George Tate. by F.R. Winton and L.E. Bayliss. by Olaf A. Hougen and Kenneth M. Watson ..