PREFACE.
WHEN the second volume of my collected papers was published, it was my intention to have entered on some rather elaborate and in part laborious calculations bearing on two of the papers which appear in the present volume. These were however put off from time to time in favour of other matters which claimed my attention; but meanwhile time went on, and I deeply regret to find how long it now is since the second volume appeared. There are other papers which still remain, and I hope, should life and health last, to put these together without delay.
G. G. STOKES.
MALAHIDE, Co. DUBLIN, September, 1901.
OF TECHNOLOG