PREFACE 
This volume was designed primarily as a working manual for use 
in the United States Coast and Geodetic Survey and describes the 
procedure used in this office for the harmonic analysis and prediction 
of tides and tidal currents. It is based largely upon the works of 
Sir William Thomson, Prof. George H. Darwin, and Dr. Rollin A. 
Harris. In recent years there also has been considerable work done 
on this subject by Dr. A. T. Doodson, of the Tidal Institute of the 
University of Liverpool. 
The first edition of the present work was published in 1924. In 
this revised edition there has been a rearrangement of the material in 
the first part of the volume to bring out more clearly the development 
of the tidal forces. Tables of astronomical data and other tables to 
facilitate the computations have been retained with a few revisions 
and additions and there has been added a list of symbols used in 
the work. 
The collection of tidal harmonic constants for the world that 
appeared in the earlier edition has been omitted altogether because 
the work of maintaining such a list has now been taken over by the 
International Hydrographic Bureau at Monaco. These constants 
are now published in International Hydrographic Bureau Special 
Publication No. 26, which consists of a collection of loose sheets which 
permit the addition of new constants as they become available. 
Special acknowledgment is due Walter B. Zerbe, associate mathe- 
matician of the Division of Tides and Currents, who reviewed the 
manuscript of this edition and offered many valuable suggestions. 
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