474 



Special Reports 



whence, since from his work we have zero correction for earth inductor No. 61 on I. M.S., 

 I. M. S.- Val Joyeux dip circle= +2'.0. 



Thus there appears to have been some change in the dip circle at Val Joyeux in 1902, 

 1910, and 1913. 



GENERAL SUMMARY AND CONCLUSIONS. 



1. Tables A and B give general summaries of the results obtained both through direct 

 comparisons by the Carnegie Institution of Washington at the observatory concerned 

 and through indirect comparisons resulting from comparisons of other magnetic organi- 

 zations. 



Table A. Summary of Results of Direct Comparisons of Magnetic Observatory Standards, 1905-1921. 

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



Volume 



II 

 No. 



IV 



No. 



Observatory 



Approximate 



Date 



I. M. S. Observatory 



H 



M 



Grade of 

 value 



Mi 



Al 



Observatory instruments 



Magnetometer 



Inclinometer 



Agincourt 1 . . . 



Alibag 



Antipolo 



Batavia 



Cheltenham. . 



Christchurch . 



Ottawa 5 



Dehra Dun . . 

 Eskdalemuir . 

 Falmouth 6 . . . 



Greenwich . . . 



Helwan 



Hongkong. . . 

 Honolulu .... 



Kew 



Mauritius. . . . 

 Loanda 



Lukiapang 10 . . 



Pilar 



Pola 



Porto Rico s . . 

 Potsdam 



Rio de Janeiro 



Rome 12 



Samoa 



Stonyhurst. . . 



Tananarive . . 

 Watheroo"... 

 Washington. . 

 Zikawei 



+ 1 



+ 1 



+ 1 



- 6 



+ 17 



-13 



+ 3 

 -18 

 -IS 



-15 



- 2 

 



+10 



-15 



- 9 

 -15 



+ 9 



- 9 

 _ o 



- 9 

 -10 



- 8 

 + 10 

 -17 



- 8 



- 4 



- 5 



- 3 



c.g.s. 



.160 



.368 

 .3S2 

 .367 

 .196 



224 



.150 



.332 

 .167 

 .1SS 



.185 



.300 

 .372 

 .289 



,1S4 



.233 

 .249 



.332 



.255 



.222 

 288 



.188 



. 216 



.238 

 .353 

 .173 

 .221 

 .249 

 .190 

 .331 



+75 



+24 

 + 16 

 -31 

 +71 



-68 



+76 



+44 

 +70 

 +67 



+67 



+41 

 +31 

 +39 



+67 



-53 

 -37 



+46 



-26 



+60 

 +50 

 +66 



-15 



+57 

 -29 

 +69 

 -53 

 -64 

 +71 

 +46 



(1906-1915. 

 \1916-1921. 



1911 



1912, Feb.. 



1911. Nov.. 



1908-1918. 



1906-1920. 



1915 



1915 



1909. Oct. . 

 1915, Sep.. 



1909, Oct. . 



1915-1919. 



190S-1918. 



Pins 19 15 

 1915-1921. 



1908-1919 



1911. Aug.. 

 1920, Mar.. 



1907-1917. 



1911, Aug.. 

 1913-1917. 



1910, Feb.. 

 1910, Jul... 

 1910, Feb.. 



1913-1919. 



1911-1913. 

 1905-1921. 

 1915, Sep.. 

 1920, Nov.. 

 1920, Sep.. 

 1907-1921. 

 1907 



-1.3 



0.0 

 +0.3 

 + 1.8 

 +0 



0.0 



+0.4 



+ 1.5 

 -0.3 



0.0 

 -0.8 



0.0 



-1.3 



+0.5 



+0.9 



0.0 



+0.3 



+0.4 

 +2.2 



-1.3 



+0.4 

 -0.6 

 -0.4 

 +0.5 

 +0.2 

 +0.5 

 , 0.0 

 -0.3 

 -3.0 

 0.0 

 +5.4 

 +0.1 

 -0.1 

 -1.1 



+0.00039 

 0.00000 

 -0.0010S 

 -0.00214 

 +0.00122 

 -0. 00006 ' 



+0. 00073 j 



-0 



+0 

 +0 

 -0 

 -0 







-0 

 +0. 

 -0 

 f-0. 

 -0. 



l-o. 



-0 



00253 

 00106 

 00144 

 00097 

 00049 

 00058 

 00119 

 00049 

 00109 

 00003 

 00008 

 00046 

 00109 



I llll Hi.. 



1+0. 

 1+0 



-o 

 -o 

 +o. 



+0. 

 +0 

 -0 

 -0 



+o. 



+0 

 +0 

 -0 



+o. 

 o 



+0 



fll* ll'.S 



00175 

 00101 



133 



00039 



00003' 



00008 



00029 



0034 



00025 



00012 



00010 



0037 



00015 



00000 



00042 



-0.1 



o.o 

 -o.i 



+0.6 

 +0.2 

 +0.8 

 -1.1 

 -0.1 

 +0.6 

 -0.2 

 +0.4 

 -0.1 

 -0.8 



-0.7 



+ 12 

 -0.8 

 +0.1 



-0.8 



+0.3 

 +4.6 

 -0.4 

 0.0 

 +0.3 

 -0.1 

 +0.6 

 +1.0" 

 +0.2 

 -0.7 

 -0.7 

 -0.4 

 +0.7 

 -1.4 

 +4.5 

 0.0 

 0.0 

 -0.4 



6 



Elliott 98' 



Elliott 9S' 



Cooke 7 



Elliott 28 



Mey., Jones I 3 

 Wild 26 



f Kew 1 



Tesdorpf 1977. 



Cooke 15 



Elliott 17 



Elliott 60 



Elliott 66 



Gibson 3 7 



Elliott 87 



Elliott 55 



Cooke 36 



Jones 



Elliott 24 



Elliott 200.... 



Elliott 49 



Dover 138 



Dover 175. . 

 Bamberg 7904 



Cooke 31 



Wansrhaff. . . . 



Cooke 20 



Cooke 25 



Dover 122 



Tesdorpf 2025. 



Jones 



Brunner 

 C.I.W. 7 



C.I.W. 3 



Elliott 49 



EI. 89. 

 EI. 89'. 

 DC. 160. 

 DC. 7; 2. 

 EI. 47. 

 Wild EI. 26. 

 DC. 147; 1,2, 3. 

 EI. 109. 

 DC. 145; 1, 2. 

 EI. 1911. 

 EI. 30. 

 EI. 103. 

 DC. 86; 1, 2. 



EI. 



DC. 193; 3, 8. 

 DC. 71; 3. 4. 7, 8. 

 EI. 4. 



DC. 33; 1, 2. 



EI. 4. 



DC. 115; 1. 



DC. 33; 14. 



EI. 42. 



DC. 216; EI. 3. 



EI. 3. 



Wild EI. 



EI. 1. 



EI. (Schulze 1). 



DC. 8075; 1, 2. 



DC. 221; 1, 2, 2<Kt. 



DC. 51; 1, 2, 5, 6. 



EI. 2. 



DC. 159; 1, 2. 



DC. 



EI. 2 (C.I.W.) 



EI. 48. 



DC. 33: 14. 



' Beginning with January 1916 published results for Agincourt are reduced to I. M. S. and to the horizontal-intensity 

 on. (See page 400.) 

 Elliott 08 corrected for H (see Vol. II, page 216, equation VI); for D, Toronto declinometer is used. 

 ' Reconstructed Meyerstein unifilar for D; Jones magnetometer 1 for H. 

 ' Standard in H since 1913 is 0.001// less than that previously used (see page 407). 

 'Through observations made at Washington, Agincourt, and Ottawa. 



,p Brick pier of absolute observatory later reported to have been found magnetic by Mr. h. F. Richardson (see British 

 Meteorological and Magnetic Year Book for 1913, part IV, section 2. page SO). 

 ' Declinometer used for D. 



8 Refencd by the United States Coast and Geodetic Survey to the Cheltenham standards. 

 "This is correction as determined at Washington in 1913 (see vol. II, page 2111'. 

 '"Succeeded Zikawei in March 1908, 

 11 See foot-note 3, page 407. 



'Values given supersede those- published in Volume II, pages 254 to 256 (see page 451). 

 "Referred by the Department of Terrestrial Magnetism to I. M.S. 



