438 



Special Reports 



Table 10B. Results of Horizontal-Intensity Comparisons at the Kew Observatory, 1915. 



Series 



Date 



1915 

 Aug. 9 

 9 



10 

 10 



11 



12 

 12 

 12 



Local mean time 1 



From 



ft m 

 9 50 



11 31 



10 30 



12 57 



11 51 



9 53 

 11 17 

 14 00 



To 



ft m 



11 24 



12 49 



12 12 

 14 22 



13 43 



11 09 



12 28 

 15 17 



Hor. int. obtained 



I. M. S. 



18427 

 32 



25 

 38 



38 



25 

 33 



48 



Kew 



I. M. S.- 

 Kew 



7 

 18441' 



45= 



31 

 50' 



47 



34> 

 41* 



56* 



Mean . 



II 



18442 

 44 



29 

 35 



18450' 

 52' 



36* 

 43* 



Mean 



Weighted mean value of (I. M. S. Kew). 



7 



-14 

 -13 



- 9 



Remarks 



C. I. W. magnetometer No. 26 at 

 O m ; Kew Jones magnetometer at 

 A',. 



C. I. W. magnetometer No. 26 at 

 Om\ Kew values from magneto- 

 gram. 



C. I. W. magnetometer No. 26 at 

 iV; Kew value from magneto- 

 gram. 



C. I. W. magnetometer No. 26 at 

 N m ; Kew Jones magnetometer at 

 0. 



9.9< = 9.4y (weight, 2) 



C. I. W. magnetometer No. 26 at 

 JV; Kew Jones magnetometer at 

 O. 



C. I. W. magnetometer No. 26 at 

 O m ; Kew Jones magnetometer at 



- 7.8< = 7.37 (weight, 1) 



.2 7 i = 8. 7 7 or 0.00047// when 

 corrected for final values Kew 

 distribution coefficients. 



i Times given apply to C. I. W. observations. 



* These values result fiom observations not strictly simultaneous with the C. I. W. observations but reduced to the 

 times of the C. I. W. observations by reference to the magnetograms. 



' These values are scaled from the magnetograms which were standardized by the observations of August 9 and 12 

 with Jones unifilar magnetometer. 



< The Kew values are rounded off to the nearest y in application of correction for revised values of distribution co- 

 efficients for 1915; Dr. Chree states that the values for (I. M. S. Kew) become 0.57 less when correction is made on this 

 account. 



to final values of distribution coefficient and moment of inertia for No. 40 as determined 

 by the Coast and Geodetic Survey, give, after applying correction of 07 to Kew 

 results to correct for new value of inertia (see p. 436) : 



(a) Kew C. & G. S. No. 40 = + 7 7 at Kew = +0.00038//. 



Fifteen and one-half sets of comparisons during February, March, and November 1915 

 gave, according to data supplied by Director E. Lester Jones of the Coast and Geodetic 

 Survey: 



(b) Cheltenham C. & G. S. No. 40 = +0.00001//. 

 From (a) and (b) we have : 



(c) Cheltenham Kew = -0.00037//. 

 Since from page 407 



(d) I. M. S. Cheltenham = -0.00006//, 

 we have 



(e) I. M. S. Kew = -0.00043//, 



which is in substantial agreement with the value directly determined at Kew by Series 

 I and II of 1915, viz, -0.00047//. 



Series 111, 1919. 



This series was obtained by Observer F. Brown during April 1 to 4, 1919, prior to 

 his departure for field work in Africa. Because of the scant time at his disposal and 

 because of other demands upon the time of the Observatory staff complete intercom- 



