Comparisons of Magnetic Standards, 1905-14 



233 



NO. lO.-FALMOUTH OBSERVATORY. ENGLAND. 



The comparisons at the Falmouth Observatory were obtained at the time of the visit of 

 the Carnegie to Fahnouth in October 1909. The station occupied was the brick pier in the 

 small hut used by the Observatory for the absolute observations. The mark for the declina- 

 tion observations was the same one used by the Observatorj^ and is a stone set up on the 

 hillside opposite; its azimuth, as determined by the Observatory is 4 40'.7 W. of S. At 

 certain times the bisecting of the stone must be made with some uncertainty, which fact 

 may account for the range in the tabulated declination-differences, C. I. W. Falmouth. 



It was not possible at the time for Superintendent E. Kitto to observe simultaneously 

 with the Carnegie observer, Mr. E. Kidson. Accordingly the "Falmouth" values are those 

 derived from the magnetograph as based on Mr. Kitto's absolute observations made on 

 October 6, 25 and 30, and Mr. Baker's on October 14, 1909; they are the final values as 

 supplied in June 1913. Mr. Kidson observed with C. I. W. magnetometers Nos. 2 and 4, 

 and with Dover dip circle No. 201 (needles Nos. 1 and 2). The Observatory instruments 

 were: EUiott magnetometer No. 66 and dip circle No. 86, needles 1 and 2. 



T.A^LE 10 A. Results of Comparisons at the Falmouth Observatory, 1909. 



Local mean time 



Date 



1909 

 Oct. 22 

 22 

 22 

 23 

 23 

 23 

 29 

 29 



From To 



h m 

 10 07 



12 12 



13 31 



10 02 



11 48 



13 07 

 11 01 



14 24 



h m 

 10 16 



12 21 



13 40 



10 11 



11 57 



13 16 

 11 10 



14 33 



Value obtained 



C. I. W. 



Falmouth 



C. I.W.- 

 Falmouth 



Weight 





-17 46.1 

 50.1 

 49.8 

 52.2 

 52.5 

 57.71 

 47.7 

 50.9 



Declination 



o / 



17 46.4 

 49.7 

 50.6 

 51.5 

 51.7 

 56.0' 

 49.4 

 51.5 



Weighted mean value of (C. I. W. Falmouth) . . 



Horizontal Intensity 



Oct. 



7 

 18741 

 758 

 758 

 776 

 734 

 7071 

 768 

 762 



7 

 18757 

 759 

 766 

 768 

 746 

 736' 

 768 

 766 



Weighted mean value of (C. I. W. Falmouth) . . 



Inclination 



7 

 -16 



- 1 



- 8 

 + 8 

 -12 

 -29' 







- 4 



1.0 

 1.0 

 1.0 

 1.0 

 1.0 

 0.5 

 1.0 

 1.0 



1.0 

 1.0 

 1.0 

 1.0 

 1.0 

 0.5 

 1.0 

 1.0 



Remarks 



C. I. W. magnetometer 2 used. 



C. I. W. magnetometer 4 used. 



>C. I. W. magnetometer 2 used. 



>C. I. W. magnetometer 4 used. 



- 6.3-y or -0.00034//. 



Oct. 



+66 31.1 

 32.5 

 35.9' 

 30.4 

 31.3 



+66 33.3 

 34.6 

 37.7' 

 31.0 

 31.4 



Weighted mean value of (C. I. W. Falmouth) . . 



^A slight magnetic disturbance occurred at the time of these observations. 

 Table 10 B. Results of Comparisons between the Observatory Standards at Fahnouth and Kew, 1891 to 1909. 



