284 CARNEGIE INSTITUTION OF WASHINGTON. 



ment's expedition at Lakin, Kansas, during the solar eclipse of June 

 8, 1918, summarized on pages 307 and 308 of the 1919 report, have been 

 confirmed by the observations of the Department's expedition at 

 Sobral, Brazil, during the solar eclipse of May 29, 1919. (For a fuller 

 account, see pp. 319-320.) 



Assistance in the investigational work was rendered by Messrs. 

 A. Sterling, W. F. Wallis, and G. R. Wait. 



STANDARDIZATION AND INSTRUMENT WORK. 



The investigations and work under this head have been conducted 

 in the Magnetic Survey Division, in charge of Mr. J. A. Fleming, to 

 whose report on pages 301-305 reference may be made for details. 

 Mr. Fleming's report relates the progress made in the construction 

 and improvements of various instruments and apparatus required for 

 the experimental and observational work of the Department. 



The success achieved in the construction and use of magnetic instru- 

 ments of the Department's design has resulted in a demand for similar 

 instruments by foreign institutions to such an extent as to make it 

 unfortunately impossible under present conditions to respond to all 

 the requests received. 



Further attention has been attracted, by various institutions at 

 home and abroad, to the methods developed by the Department in the 

 making of non-magnetic castings. 



Assistance in the investigational work was rendered Mr. Fleming by 

 Magnetic] ans H. W. Fisk and W. F. WalHs and Instrument-makers 

 C. Huff, G. H. Jung, W. F. Steiner, and J. G. Lorz. 



MISCELLANEOUS ACTIVITIES. 



Atmospheric refraction. — A joint investigation was made by the 

 Director and Mr. Peters concerning the bearing of certain geophysical 

 observations made during the solar eclipse of May 29, 1919, by the 

 Department's expeditions at Sobral, Brazil, and Cape Palmas, Liberia, 

 and by the Brazilian expedition at Sobral, upon the deflections of light 

 observed by the British expeditions. Mr. Peters confined his special 

 attention to the computation of differential terrestrial refraction as 

 dependent upon zenith-distance of star and meteorological conditions. 

 In this connection it was found that certain formulae in Chauvenet's 

 "Spherical and Practical Astronomy" required amplification (see 

 p. 299). 



The dip-of-horizon measures made on the present cruise (VI) of 

 the Carnegie were tabulated and adjusted, under Mr. Peters's direction, 

 and the summary of results from 1907 to 1920 was brought up to April 

 1920. (For further account, see pp. 299-300.) 



Assistance was rendered by Drs. Slocum and Hedrick, as well as by 

 Computers Duvall and Ennis. 



