COMPARISONS OF MAGNETIC STANDARDS, 1915-21 



475 



Table B. Summary of Results of Indirect Comparisons of Magnetic Observatory Standards} 

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



Volu 



10B 

 10A 



28 



24A 

 24 



26 



25 



Approximate 



Observatory 



De Bilt. 



Falmouth 8 



Greenwich 



Irkutsk 



Katherinenburg 



Kew s I 



Meanook 



Pare St. Maur. . 



Pavlov.sk 

 Pola .... 



Potsdam ( 



Rude Skov. . . . 

 Tiflis (Karsani) 



Upsala . . 

 Valencia 



Val Joyeux. 



-13 



-13 



-17 

 -16 

 + 2 

 + 11 

 -17 

 -16 

 +28 . 129 

 -15 .197 



185 



185 



188 

 185 

 199 



176 

 184 

 185 



+ 1 



- 9 



-10 



- 9 

 -10 

 + 3 



-11 

 -20 



-14 



-14 



.166 

 .222 



.189 

 .188 

 .174 

 . 2.34 



11.4 

 .179 



.197 

 .198 



+67 



+67 



+66 

 +67 



+70 

 +71 

 +67 

 +67 

 +7.1 

 +65 



+ 71 



+60 



+66 

 +66 

 +69 

 +56 



Date 



1910, June. 



1913, July.. 



1913,Jun,Jul 

 1913, June. 

 190.8, July.. 

 1908, June 

 1898, Sep . . 

 1913, June. 

 1917, Sep 

 1898, Aug . 



1908-1910.. 



1902, July.. 



1902, June . 

 1913, July.. 

 190S, Sep. . 

 1907, Dec. 



+71 1908, Sep.. 

 +68 1913, June. 



+65 

 +65 



1910, June. 

 1913, July.. 



I. M. S. Observatory 



AD 



+0.5 

 -1.4 



+0.4 

 +0.5 

 -0.5 

 -0.9 



0.0 

 -1.2 



-0.6 



0.0 

 -1.6(?) 

 +0.2 



+ 1.3 

 +0 7 

 -11 



H 



-0 00013 

 -0.00037 



-0.00023 

 +0.00071 

 +0 . 00022 

 +0.00029 

 -0 00008 

 -0.00074 

 +0.00031 

 -0.00021 



M 



-1.0 



/+0.7 

 1+1.2 

 +0.2 

 -0.8 

 -1.3 

 +0.2 

 -1.1 

 -0 



o.o 



- J :; 



-0.3 



}+0.9 



-0.2 

 +0. 

 -0.8 

 +0.1 



-0.5 



+0.6 



0.0 



+2.0 



+4.5 



Grade of 

 value 



,\/i 



A7 



Observatory instruments 



Magnetometer 



Edelrnann 2 



Edelmann 2 



Elliott 66 



Gibson 3< 



Wild-Freiberg. 

 Wild-Freiberg. 



Jones 



Elliott 48 



Brunner 



(large model) 

 Wild-Freiberg< 



/Schneidrr 



Bamberg 7904 



Iwanseharl. . 



Bamberg 1973 

 Wild-Edel- 



mann 



Lamont . .... 

 Dover 139.. . 



>Moureaux. . . 



Chasselon 37' 



Inclinometer 



DC. 



/Weber EI. 

 ISchulze EI. 88. 



Dover DC. 86; 1.2 



EI. 



W-E. EI. 



W-E. EI. 



BarrowDC.33;l,2 

 Dover DC. 200; 1,2 



Brunner DC. 

 EI. 



Wild EI. 



Schulze EI. I 

 W-E. EI. 



W-E. EI. 



DC. 60; 3, 4. 



Dover DC. 118. 

 /EI. 61. 

 \Brunner DC. 



Brunner DC. 



1 For previous values see Res. Dep. Ten-. Mag., Vol. II, page 278. 



2 The declinations are observed with a special declinometer. 

 See foot-note 4 of Table 2IA. 



'Special declinometer for declination. 

 'See also No. 10 of Table A. 



6 See page 473. 



7 Probably same as magnetometer designated "Moureaux" for the 1910 results. 



2. The accumulated data show that the provisional international magnetic stand- 

 ards adopted for the work of the Carnegie Institution of Washington are absolute to a 

 precision well within the magnitude of the unavoidable errors of observation and of 

 determination of constants for the various types of instruments used. 



3. The absolute precision obtainable with carefully designed magnetometers and 

 inductors, provided instruments are carefully used and comparisons are made with 

 reliable standards at least every two or three years, is of the order 0'.2 in declination 

 and inclination and of the order 0.00015// in horizontal intensity. 



Throughout this work the author has had the privilege of the advice, interest, and 

 suggestion of the Director of the Department, Dr. Louis A. Bauer, as well as that of 

 all of his colleagues, including among others particularly Messrs. Harlan W. Fisk, 

 William J. Peters, and J. P. Ault. 



