The remaining five papers, numbers 5, 9, 12, 13 and 28 deal with cer- 
tain mathematical questions which arise in hydrodynamical analysis. 
Finally the editor’s thanks are due to Professor Lunde of Trondheim 
for his kind advice on one difficult question, and also to Dr. T. Francis 
Ogilvie and to Dr. J. N. Newman, both of the David Taylor Model Basin, 
for their kindness in verifying some of the references to American papers. 
Flat 103 
6, Charterhouse Square 
LONDON E.C.1 
C. WIGLEY 
11th March, 1963 
