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SCIENCE 



[N. S. Vol. XLIII, No. 1115 



basic triangulation whenever a biological survey 

 of any kind has been undertaken in a region in 

 Tphieh the Coast Survey has operated, which of 

 course means anywhere on the coast of the United 

 States. On the other hand, the hydrographic and 

 topographic results of this biological work have 

 always been made available to the survey. 



On both the Atlantic and Pacific coasts a con- 

 siderable part of the offshore soundings found on 

 the charts was determined by the steamers FisJi- 

 Hawh and Albatross in pursuance of their fishery 

 investigations, and some of the inshore data of 

 certain of the earlier charts came from reconnois- 

 sances by the Albatross. While much of the latter 

 has been superseded by more accurate work as the 

 Coast Survey was able to extend its operations, it 

 served a good purpose for some years. Later 

 there came into the command of these two vessels 

 naval ofiicers Who had been trained in the survey, 

 with resulting improvement in the character and 

 accuracy of the fishery surveys, not only those 

 under their immediate direction, but throughout 

 the service. I can not let this opportunity pass 

 without paying humble tribute to the distinguished 

 labors in behalf of oceanic physics and biology 

 performed by men like Z. L. Tanner and J. F. 

 Moser, who, while retaining their naval status, 

 commanded fishery vessels, and collected invaluable 

 material for the Coast Survey. 



The gathering of hydrographic and other data 

 for use of the Coast and Geodetic Survey by the 

 steamer Albatross has been particularly extensive 

 in the Pacific Ocean and along the west coast of 

 America. 



Work Done by the United States Coast and Geo- 

 detic Survey in the Field of Terrestrial Mag- 

 netism: Dr. L. a. Bauer. 



From the earliest days of the establishment of 

 the Coast Survey, magnetic observations for the 

 prime use of the surveyor and of the mariner were 

 considered a legitimate and useful part of its 

 work. In the ' ' Plan for the Reorganization of 

 the Survey of the Coast," as adopted in 1843, ex- 

 plicit provision was made for the making of ' ' All 

 such magnetic observations as circumstances and 

 the state of the annual appropriations may allow. ' ' 

 Since then Congress, by annual appropriations, 

 has continuously and increasingly recognized the 

 importance of this feature of the work of the 

 survey, so that in 1899 an enlarged appropriation 

 made it possible to carry out a magnetic survey of 

 the whole United iStates on a systematic basis, and 

 with an expedition theretofore not possible. 



When the first chart of the lines of equal mag- 

 netic declination, known to the surveyor and the 

 mariner as the lines of equal variation of the 

 compass, was issued by the Coast Survey in 1855, 

 the number of available stations at which magnetic 

 observations had been made amounted to about 

 150, and these were distributed very irregularly 

 and covered but a limited region of our country. 

 At the close of 1915 the number of these stations 

 was 5,000, the stations now being distributed 

 fairly uniformly over the United iStates. Besides, 

 a vast amount of magnetic data has been compiled 

 from other sources and the survey has also made 

 magnetic observations at some 500 stations in our 

 outlying possessions. The average distance apart 

 of the places at which accurate magnetic observa- 

 tions have now been made in the United States is 

 about 25 miles. Meridian lines for the use of sur- 

 veyors have been established at many county seats 

 throughout the country, magnetic data at sea have 

 been accumulated on cruises of the Coast Survey 

 vessels, and five magnetic observatories, where the 

 countless fluctuations of the earth's magnetism 

 are being continuously recorded, are at present in 

 operation under the direction of the survey. 



The contributions of the Coast and Geodetic 

 Survey to the advancement of our knowledge in 

 terrestrial magnetism, in fulfilment of both prac- 

 tical and scientific demands, have been unexcelled 

 by any other national organization. Because of 

 its extensive compilations of data relating to the 

 change of the compass direction from time to time, 

 the Coast and Geodetic Survey is able to furnish 

 promptly information of priceless value in the 

 adjudication of disputed land boundaries, the 

 bearings of which were referred to the compass di- 

 rection when originally laid out, 100 to 150 years 

 or more ago. 



The changes in the compass direction reach very 

 appreciable amounts with the lapse of time. The 

 compass even changes its direction between morning 

 and afternoon by an amount appreciable in accurate 

 land surveying. During a so-called magnetic 

 storm, the compass direction may change suddenly 

 by a degree or more. All such fluctuations are re- 

 corded at the magnetic observatories of the sur- 

 vey, and the information is published promptly, 

 and made readily accessible to all interested. 



The assumption frequently made by surveyors 

 that the compass has changed its direction regu- 

 larly at the rate of 3 minutes per year or 1 degree 

 in 20 years, is not borne out by the data of the 

 survey. At the present time, for example, in the 

 New England states the north end of the com- 



