278 



Reports on Special Researches 



Table A. Summary of Results of Direct Com-parisons of Magnetic Observatory Standards. 

 [East declination and inclination of north end of needle below horizon are regarded as positive.) 



No. 



Observatory 



Agincourt 



Alibag 



Antipole 



Batavia 



Cheltenham. . . 

 Christchurch. . . 

 Dehra Dun . . . . 



Falmouth 



Helwan 



Hongkong 



Kew 



Mauritius 



Pilar 



Pola 



Porto Rico . . . . 



Potsdam 



Rio de Janeiro* 



Rome 



Washington . . . , 



Zikawei 



Lukiapang' . . . . 



Date 



1906-12 . . . 

 1911 



1912, Feb.. 

 1911, Nov. 

 1908-13. . . 

 1906-08. . . 

 1909, Oct.. 



1909, Oct.. 

 1908-14. . . 

 1907-11. . . 

 1908-10. . . 

 1911, Aug.. 

 1911-13. . . 



1910, Feb.. 

 1910, Jul. . 



1910, Feb.. 



1913, May. 

 1911-13. .. 

 1907-14. . . 

 1907 



1911, Sep.. 



I. M. S. Observatory 



AD 



+0.3 

 + 1.8 

 +0.5 

 +0.1 

 + 1.1 

 0.0 

 0.0 

 +0.3 

 + 1.1 

 +0.6 

 +0.4 

 -0.3 

 -0.4 

 +0.5 

 +0.2 

 +0.5 

 +0.1 

 -0.1 

 -1.1 

 -1.5 



AH 

 H 



+0.00008 

 -O.OOIOR 

 -0.00214 

 + 0.00122 

 -0.00101 

 +0.00064 

 + 0.00144 

 -0.00049 

 -0.00056 

 +0.00119 

 -0.00008 

 -0.00065 

 -0.00028 

 +0.00039 

 -0.00097 

 +0.00008 

 -0.00029 

 +0.00028 

 0.00000 

 +0.00042 

 +0.00084 



A/ 



+0.8 



-0.1 



+0.6 



+0.2 



+0.7 



-0.9 



+0.4 



-0.8 



+ 1.1 



+0.2 



-1.1 



+0..3* 



+0.3 



+0,6 



+ 1.0 



+0.2 



-0.4 

 0.0 



-0.4 

 0.0 



Grade of Value 



AD 



Aff 

 // 



A/ 



Observatory Instruments 



Magnetometer Inclinnmetor 



'Elliott 98 corrected for // (see p. 216, equation VI); for D, Toronto declinometer is used. 



'Reconstructed Me.verstein unifilar for D; Jones magnetometer No. 1 for H. 



'See footnote, p. 226. 



'This is the correction a.s determined at Washington in 1913 (Table 27 E, p. 264) before the earth inductor was sent to Mauritius. 



'Referred by the United States Coast and Geodetic Survey to the Cheltenham standards (No. 7). 



'New magnetic observatory located at Vassouras, 77 km. northwest of Rio dc Janeiro. 



'Succeeded Zikawei in March 1908. 



Table B. Summnry of Preliminary Results of Indirect Comparisons nf Magnetic Obserratory Standards, 

 (East declination and incUnation of north end of needle below horizon are regarded as positive.] 



'The declination standard at Pavlovsk is a special declinometer. 



Table C. Corrections on I. M. S. of the Magnetic Standards at Kew, Potsdam, and WashiTigton. 

 [East declination and incUnation of north end of needle below horizon are regarded as positive.] 



