486 MR JOHN ALLAN BROUN ON THE BIFILAR MAGNETOMETER, 
By water experiments in 
1843, g = 0-000260 
1849, g = 0:000234 
The latter value should be preferred, having been made with more care, though 
it is a question whether the temperature coefficient is constant. We have then, 
adopting the value of g = 0:000234, 
[q] = 0°804 g. 
37. November 1843 to December 1845, 4 = 0:000087. 
TABLE XV.—SuMS OF DIFFHRENCES OF BIFILAR MBANS. Toronto, 1844-45. 






Month. ZAt. ZAR. q Month, ZAt. | ZAR. q 
. : Bera. eReatnehlh ues rey on, Se. div... aqaull 
1843. Nov. 57°12 83:03 1:45 | 1844, Dec. 49:01 54°35 #11 
Dec. 47-59 64°48 1:35 | 1845. Jan. 71:29 98°70 1:38 
1844. Jan. 83:19 86:37 1:04 Feb. 63°68 63°40 1:00 
Feb. 54:19 78°87 1:46 March 48:18 53°38 1 | 
March 60°59 20°28 0°33 Apvil 54°34 84:04 1°55 
April 66°64 67:50 1-01 May 82°21 | Ta Toy 1:43 
May 59°30 97°93 1°65 June 56°78 68:90 1-20 
June 43°27 64:93 1:50 July 59°37 61:05 1:03 
July 41-38 | 47-25 | 1-14 Aug. | 41-74 | 67-68 | 1-62 
Aug. 40°38 57°70 1-42 Sept. 43:84 | 81-41 1:86 
Sept. 39°28 75°82 1:93 Oct. 58:94 84:00 1-43] 
Oct. 58°73 85°84 1:46 Nov. 48-52 58°16 1:20 
Nov. 51:14 | 136-78 2°67 Dec. 67°15 69°61 1:04 
The final results are, 
873°62 : : 
1844. g= 6705 = 1-350 se, div.; probable error = 0°10 sc. div, 
,__ 907:90 : 
1845. q= 696-04 = 1:304 ” 39 = 0:06 9 
1929-03 
26 months q= 1447-80 => 1 33 33 ” = 0 05 ” 
Therefore, 
[g]= 0-000116 
By water experiments, last determination, 
i= 0-000234 
and: 

