[This discussion applies to the four preceding papers by Mr. G. B. NICHOLS,Mr. W. KAYE PARRY,Mr. W. R. MAGUIRE,and Mr. P. F. COMBER,which were discussed conjointly.]

[This discussion applies to the four preceding papers by Mr. G. B. NICHOLS,Mr. W. KAYE PARRY,Mr. W. R. MAGUIRE,and Mr. P. F. COMBER,which were discussed conjointly.]