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PREFACE, 



This volume was designed, primarily, as a workijig manual for the 

 tidal computers of the U. S. Coast and Geodetic Survey, and the aim 

 has been to produce a convenient work of reference on the subject 

 of the harmonic analysis and prediction of the tides. 



It is based largely upon the works of Sir William Thomson, Prof. 

 George H. Darwin, and Dr. Rollin A. Harris. The tidal components 

 scheduled in this volume are those which have been in general use in 

 the harmonic prediction of the tides for many years, and they are 

 sometmies called the Darwinian components. It may be added that 

 Dr. A. T. Doodson, of the Tidal Institute, University of Liverpool, in 

 a recent development of the tide-producing force by a method differ- 

 ing somewhat from that used by Professor Darwin, has obtained a 

 new schedule of components which include some elements which were 

 not contained in the Darwinian schedule. Although the additional 

 components are generally of small theoretical magnitude, it is possible 

 that some may be found by further investigation to be of sufficient 

 importance to be taken into account in the analysis and prediction, 

 of the tides. 



The volume includes a collection of tables used in the anatysis and 

 prediction of the tides, these tables being prepared with the aim of 

 facilitating the work of the computer. At the end of the volume 

 there is given a table of the principal tidal harmonic constants for 

 many stations throughout the world, thus providing the data required 

 for the harmonic prediction of the tides at these stations. A table 

 of this kind is, of course, subject to growth and revision, and it is 

 hoped that the present compilation may serve as a basis for future 

 publications in which the entire maritime world is more comprehen- 

 sivel}^ represented. 



