DEPARTMENT OE TERRESTRIAE MAGNETISM. 20/ 



obtained during the various cruises of both the Galilee and the Carnegie, 

 including all sea work by the Department through April 26, 191 1, will also 

 be completed and ready for the printer at the same time. Considerable at- 

 tention has been given to the further discussion of differences between 

 magnetic standards and the possible establishment of international magnetic 

 standards; the results of all intercomparisons obtained by the Department 

 through March 191 1 have been published in the June and September issues 

 of the journal "Terrestrial Magnetism and Atmospheric Electricity." De- 

 scriptions of the two new types of magnetometers designed and constructed 

 by the Department and of the improved deflector for sea work have been 

 prepared and published in the same journal. The Director has also continued 

 his series of papers in the same periodical on "The physical theory of the 

 earth's magnetic and electric phenomena." 



The constants and corrections to the provisional International Magnetic 

 Standards of the Department have been determined or redetermined for 8 

 magnetometers and 6 dip circles. These standardizations have been made 

 by the method of simultaneous comparisons with the standard instruments. 

 The reductions of the field observations have been kept up to date. General 

 and specific instructions for the prosecution of field and ocean work have 

 been prepared as necessary. 



The compilation of past magnetic work, the indexing of current literature, 

 and abstracting of publications of a special interest have been continued. 

 Requisitions for data and information have been numerous and varied and 

 responses have been made in such detail as has been possible. 



SHOP WORK. 



Theodolite-magnetometers 16, 17, and 18 have been completed during the 

 years ; these are of the light, portable type. Four universal magnetometers 

 of the 191 o type (No. 14) are well under way. Some progress has also been 

 made with the design of a compact and portable earth-inductor-magnetometer. 

 The improved type of deflector used on board the Galilee and the Carnegie 

 was completed and forwarded to the Carnegie at Cape Town, April 1911. 

 The construction of accessory instruments and the overhauling and repairing 

 of field outfits have been carried out as necessary. 



PERSONNEI*. 



The personnel of the ofiice force during the year has been as follows: 

 L. A. Bauer, Director; J. A. Fleming, magnetician in charge of ofiice and 

 shop; H. W. Fisk, magnetician; J. P. Ault, magnetician; H. M. W. Ed- 

 monds, magnetic observer from January i to February 14, 191 1 ; C. C. Craft, 

 magnetic observer during part of May and June 191 1 ; H. F. Johnston, mag- 

 netic observer to January 30, 191 1 ; J. H. Millsaps, bookkeeper and stenog- 

 rapher; Emma L. Beehler, stenographer; A. Widmer, chief mechanician; 

 E. Skonberg, mechanician; B. Brauner, messenger to September 15, 191 1. 



