450 



Special Reports 



Table 14B. Results of Horizontal-Intensity Comparisons at the Rio de Janeiro (Vassouras) Observatory, 1915 and 1919. 



Series 



Date 



1915 

 Mar. 27 

 27 

 27 

 28 

 29 

 29 

 30 

 30 



Local mean time 1 



From To 



h m 



9 59 



14 06 



16 18 



7 57 



8 13 

 14 01 



8 49 

 14 09 



h m 

 11 47 



15 21 

 17 22 



8 42 

 10 33 



16 37 

 10 45 

 16 15 



Hor. int. obtained' 



I. M. S. 



24603 



562 



604 

 580 

 600 

 567 



Rio de 

 Janeiro 



24669 



652 



Mean value of (I. M. S. Rio de Janeiro). 



II 



1919 

 Sep. 24 

 24 

 24 

 25 

 25 

 25 



24519 

 449 

 381 

 460 

 459 

 418 



24601 

 530 

 480 

 564 

 537 

 497 



Mean value of (I. M. S. Rio de Janeiro) 



Mean value of (I. M. S. Rio de Janeiro) from I and II. 



I. M. S.- 

 Rio de 

 Janeiro 



-66 



-90 



Remarks 



C. I. W. magnetometer No. 19 

 at B; Rio de Janeiro magnetom- 

 eter No. 25 at A. 



C. I. W. magnetometer No. 19 

 at A ; Rio de Janeiro magnetom- 

 eter No. 25 at B. 



78.5-ror -0.0032// 



82 



81 

 99 

 104 



78 



79 



C. I. W. magnetometer No. 16 

 at A ; Rio de Janeiro magnetom- 

 eter No. 25 at B. 



C. I. W. magnetometer No. 16 

 at B; Rio de Janeiro magnetom- 

 eter No 25 at A. 



- 87.2 7 or -0.00355// 



82. St or -0.0034// 



' The times given apply for the C. I. W. observations; the Rio de Janeiro observations were not strictly simultaneous, 

 but the intervals between the mean times for the corresponding sets are not great enough to affect materially the values of 

 (I. M. S. Rio de Janeiro) since the diurnal variation in horizontal intensity is small. 



'All values are referred to station A by the value of station-difference determined from each series; in 1915, A 

 B5.7-,, and in 1919, A=B-6.6y. 



Table 14C. Results of Inclination Comparisons at the Rio de Janeiro {Vassouras) Observatory, 1915 and 1919. 



1 All values are referred to station A; in 1915, .4=B-0'.8, and in 1919, A=Cl'.9. 



'' The Rio de Janeiro values given are deduced from magnetograms of horizontal intensity and of vortical intensity, 

 using for inclination base-lino the value determined from the six sets of inclination observations made on September 26 and 

 27 with dip circle 221. 



Assembling the results as already published in Volume 11 and as given above, 

 we have: 



(14) I. M. S.-Rio de Janeiro (Cooke magnetometer No. 20) = +0'.5 (1913). 

 (14a) I. M. S.-Rio de Janeiro (Cooke magnetometer No. 20) = -0.00029f/ (1913). 



" See Res. Dep. Terr. Mag., Vol. II, pp. 253-254. 



