Pebruart 13, 1920] 



SCIENCE 



153 



effort and freedom of initiatiye are by no 

 means incompatible. Important instrumental 

 improvements of many kinds were effected, 

 sources of error previously unsuspected were 

 brought to light, and means of eliminating 

 them were devised. A by-product of the in- 

 vestigation, of great fundamental interest, was 

 the discovery that the peculiar displacements 

 of certain lines in the spectrum of the electric 

 arc, which are gTeatest near the negative pole, 

 are due to the influence of the electric field. 

 These displacements, previously unsuspected, 

 are sufficient to render such lines wholly mi- 

 suitable for use as standards unless rigorous 

 precautions are observed. The international 

 committee, in the light of the new information 

 thus rendered available, will now have no diffi- 

 culty in completing its task of determining 

 the positions of standard lines with an ac- 

 curacy formerly unattainable. 



The variation of latitude is another subject 

 in which international cooperation has yielded 

 important results. It was found some years 

 ago by astronomical observations that the 

 earth's axis does not maintain a fixed direc- 

 tion iiL space, but moves in such a way as to 

 cause the earth's pole to describe a small but 

 complicated curve around a mean position. 

 The change in the direction of the axis is so 

 slight, however, that the most accurate obser- 

 vations made simultaneously at different 

 points on the earth, are required to reveal it. 

 These were undertaken at several stations 

 widely distributed in longitude, in Italy, 

 Japan, and the United States. A new photo- 

 graphic method has recently been devised 

 which will probably render unnecessary the 

 use of more than two stations in future work. 



An extensive cooperative investigation 

 planned by the Division of Geology and 

 Geography of the National Research Council 

 involves the joint effort of geologists and 

 chemists in the study of sediments and sedi- 

 mentary deposits. This is of great impor- 

 tance in connection with many aspects of geo- 

 logical history, and also because of its bear- 

 ing on economic problems, such as the origin 

 and identification of deposits or accumulations 

 of coal, oil, gas, phosphates, sodiimi nitrate, 

 clay, iron, manganese, etc. 



The essential requirements are sufficient in- 

 formation on (1) modern sediments and 

 deposits and (2) changes in sediments after 

 deposition and the causes of such changes. 



In the study of sediments now in process 

 of formation it is important to learn the 

 mechanical state and shapes of particles of 

 different sizes, their mineralogical and chem- 

 ical composition, the arrangement of the 

 material composing the deposit, the source of 

 the material, the transporting agencies, and 

 the cause of precipitation. Modern deposits 

 must be studied in the scores of forms in 

 which they are laid down : in deserts and arid 

 regions and in humid climates, in the beds of 

 great lakes, in the track of glaciers, and in 

 marine beds off the coast, in deltas and bays, 

 or on submarine plateaus, in lagoons, and on 

 reefs in subtropical and tropical waters. 



In much of this work chemical investiga- 

 tions are essential, especially on the composi- 

 tion of the waters flowing into the ocean, 

 yielding data on the chemical degradation of 

 the continent and the amount of soluble mate- 

 rial discharged into the sea. 



In undertaking this extensive investigation, 

 which would include the studies just cited and 

 others on ancient deposits, the following pro- 

 cedure is proposed: (1) To make a more com- 

 plete survey than has yet been made of the 

 investigations that are at present under way 

 in the United States and Canada. (2) To pre- 

 pare, in the light of present geological knowl- 

 edge, a program for the investigations needed 

 to supply an adequate basis for interpreting 

 sediments. As knowledge advances, the pro- 

 gram will have to be modifled. (3) To can- 

 vass the field for existing agencies that are 

 suitable in prosecuting such investigations. 

 (4) To assign problems to those institutions 

 or individuals prepared properly to prosecute 

 researches of the kind needed. (5) To pro- 

 vide additional ag-encies for the study of prob- 

 lems of sedimentation and thereby make 

 possible investigations for which there are 

 either no provisions or only inadequate pro- 

 visions at present. 



It is easy to see how an investigator 

 choosing to deal with some aspect of this 

 large general problem would be assisted by in- 



