MARCH 19, 1921 THURAS: PROBLEM OF PHYSICAL OCEANOGRAPHY 135 



developed several new methods of investigation. They have been 

 especially interested in the waters of the Gulf Stream, on account of 

 its effect on their climate, and would be very glad to cooperate with 

 us in a careful study of this Stream. 



Development of instruments. — In order to obtain a clearer and more 

 complete understanding of the dynamics of ocean circulation, an 

 effort has been made in recent years to develop recording instruments. 

 Hans Pettersson of Goteborg, Sweden, has built a photographic re- 

 cording current meter which will give a continuous record of current 

 velocity and direction for a period of two weeks. By the use of special 

 anchors and buoys the instrument can be firmly anchored at any 

 depth up to several hundred meters. Dr. R. A. Daly of Harvard 

 University has recently had constructed a thermograph which will 

 give a continuous record of temperature for a week or more; this in- 

 strument can be used at great depths in the ocean. The U. S. Coast 

 Guard in conjunction with the Bureau of Standards has designed and 

 constructed a recording salinity apparatus and a recording thermom- 

 eter which will give continuous records of temperature, salinity and 

 density of the sea water taken from intake pipes below the surface 

 by a moving vessel. As all of these instruments have been developed 

 independently, it might be possible by cooperation and further re- 

 search to develop a single instrument which would give all of these 

 physical properties at each oceanographic station. 



Oceanographic laboratory. — A physical oceanographic laboratory 

 should be established where instruments could be tested and improved 

 and research carried on. This laboratory should be located in Wash- 

 ington, preferably at the Bureau of Standards, where there are facili- 

 ties for handling and developing work in scientific instruments. 



SUMMARY 



The physical oceanographic observations collected in our Atlantic 

 waters indicate that that stage in development has been reached which 

 calls for more thorough plans of work extending over a long period 

 of time. These investigations can be accomplished most successfully 

 by international cooperation, development of physical oceanographic 

 instruments, and establishment of a permanent oceanographic labora- 

 torv. 



