May 12, 1916] 



SCIENCE 



673 



namieal, or world wave theory, fitted and ex- 

 plained the simple tides, and thus became the 

 basis of all tidal work and theories. Later the 

 tides in the Pacific and Indian oceans were stud- 

 ied and were found to differ greatly from those 

 of Europe, in fact, the tides of the North Atlantic 

 are exceptional in their simplicity. Yet as each 

 new complication was found, it was explained 

 away, as a modification of the general grand 

 wave, due to some local condition. The theory that 

 the tides are a world phenomenon has the sup- 

 port of the world's greatest mathematicians and 

 all the prestige their names can lend. 



Certain investigation of the Coast and Geo- 

 detic Survey would indicate that this theory may 

 not be the correct explanation of the oceanic tides. 

 During the century of its existence this body of 

 skiUful observers and able investigators has col- 

 lected and discussed an enormous amount of tidal 

 data in both the Atlantic and the Pacific oceans. 

 As these observations were collected and brought 

 together, discrepancies were found; the tides of 

 one port could not be fitted into and made to har- 

 monize with the tides of another place. A few 

 such discrepancies could be explained as modifica- 

 tions of the general tidal wave, but as observa- 

 tions were increased in number, discrepancies mul- 

 tiplied, and to fit all conditions, the general tidal 

 wave would have to writhe and squirm, and change 

 its form and character from place to place until 

 it lost all semblance of a single imiform progres- 

 sive wave. Gradually there has been evolved the 

 feeling that the tides are not a world phenomenon, 

 but are strictly local in character and in being; 

 that the tides of the Atlantic Ocean are due to the 

 oscillations in the waters of the Atlantic, inde- 

 pendent of what has or may happen in the waters 

 of the Pacific. 



This idea of the tides as purely local phenom- 

 ena, as opposed to the theory of a grand earth- 

 wide wave, has been elaborated and developed by 

 the Coast and Geodetic Survey into a thoroughly 

 consistent theory. And this explanation of the 

 tides stands out as the great scientific contribu- 

 tion of the Coast and Geodetic Survey to the theo- 

 ries of oceanic tides. 



The Contribution of the United States Coast and 



Geodetic Survey to Physical Geography: Dr. 



Douglas Wilson Johnson. 



Every division of physical geography is in- 

 debted to the XJ. S. Coast and Geodetic Survey for 

 the invaluable contributions which it has made 

 during the past hundred years of its existence. 



Considering the general earth relations, we owe 



to the services of this organization much of our 

 knowledge concerning the size and form of the 

 globe. Among the Coast and Geodetic Survey's 

 contributions along this Une are its longitude de- 

 terminations, international cooperative work in 

 the determination of the variation of latitude, 

 and the gravity and azimuth observations made in 

 connection with extensive triangulation work. 

 Terrestrial magnetism has received a special 

 study along this Une, and has added largely to our 

 stock of information on this important phenome- 

 non of the earth. 



The physical hydrography of the ocean has been 

 enriched by the detailed study of the form and 

 composition of the bottom through the regular 

 hydrographic operations of the survey and special 

 oceanographic cruises which they have made. Our 

 knowledge of the Gulf Stream and other currents 

 of the ocean and its tributaries comes largely 

 from the researches of the survey. Its work along 

 tidal lines and regarding tidal currents has been 

 truly monumental, and among its many impor- 

 tant contributions along this line may be men- 

 tioned the exposition of the equilibrium theory of 

 tides, and its development. 



In the study of land forms, the detailed charts 

 of coastal features revised by frequent resurveys 

 gives a complete record of the changes in coastal 

 topography, and by throwing considerable light 

 on the laws of wave and current action have 

 proven to be of incalculable value. 



Even the physical geography of the atmos- 

 phere is indebted to the survey, for Ferrel's 

 meteorological researches and other studies of the 

 winds and related phenomena are among the im- 

 portant contributions of the survey along those 

 lines. 



At the banquet, on April 6, in addition 

 to the address of the president of the 

 United States, printed above, the following 

 addresses were made : 



The Minister of Switzerland said in part: 

 It may surprise some of you that the only for- 

 eigner who has the privilege to say a few words 

 on this festive occasion is the Swiss minister. 

 Needless to state that there is no foundation 

 whatsoever for the facetious suggestion that pro- 

 found political reasons governed the choice of the 

 representative of the only country which has no 

 coasts, no harbors and no navy, to assist in this 

 Jubilee Celebration of the United States Coast 

 Survey. 



