50 Extra OBSERVATIONS OF MAGNETOMETERS, 1841. 
Aveust 20. SEPTEMBER 25. SEPTEMBER 25. 1 
Gtting = PILAR | BALANCE} Gottingen -,_| BIFILAR | BALANCE Gottingen 2 ,.| BIFILAR |BALANCE 
in tone. of apa rine Cor- Mean Time of genes Cor- Cor- Mean Time of eee Cor- Cor- 
Observation. a rected. | rected. Observation. s rected. | rected. Observation. rected. | rected. | 
aohm Ss. 4 Sc. Div. | Mic. Div. | ad. hh. m5 £ Sc. Div. | Mie. Div.] do h. ms. ‘ Se, Div. | Mie. Div. | 
20 22 40 O| 135-28 | 531-0 25 4 46 30 909 $25 5 53 30 655-2 } 
45 0O| 135-82 695 48 30 764-7 55 O| 147-23 
50 O}| 136-02 | 531-5 50 O| 141-87 56 30 666 
55 0) 136-30 691 51 30 1032 58 30 702-9 
23 0 O| 136-97 | 533-8 Hae ao { 812-0 6 O O|} 164-14 
Se Olwagnka 691 30 |: 822-6 1 30 619 
10 O| 137-83 | 532-5 55 829-0 3 30 783-5 
15 O} 138-10 693 55 O| 121-40 5 0O| 188-98 
20 0} 138-30 56 30 910 6 30 823 
58 Al) 849-7 8 30 794-9 
= 30 854-6 10 O} 190-50. 
SEPTEMBER 25. 55 { 861-0 11 30 1007 
5 0 O} 130-45 ta (30 760-3 
95 1 57 30} 916 1 30 802 15 O| 141-12 
2 0 O} 153-14 3. 3 \ 875-1 16 30 689 
2 30 664-3 30 |. 861-1 18 5 834-2 
4 4 42/( 155-82 55 843-6 30 824-8 
5 0} 161-38 5 0} 135-42 55 809-8 
5 18|( 165-54 6 30 823 19 42) ( 194-20 
6 30 1070 8 30 779-7 20 0} 213-43 
10 0| 129-78 9 42 |( 142.20 20 18|| 221-56 
11 30 975 10 O} 152-54 21 30 781 
13 30 804-8 10 18 | 154-80 23 30 592-6 
15 0O| 124-62 11 30 898 25 0} 205-27 
16 30 686 13 30 757-0 26 30 1000 
18 5 ( 784-6 15 0} 142-73 28 30 620-3 
30 |, 799-5 16 30 1005 30 0} 182-91 
55 802-7 18 30 690-5 31 30 655 
20 O| 161-94 20 0} 138-30 33 30 660-7 
21 30 882 21 30 907 35 0) 199-70 
23) 5 { 863-0 23 30 705-7 36 30 682 
30 |: 864-3 25 O| 149-36 38 30 637-0 
55 || 889-0 26 30 907 40 0| 204-40 
24 42 heeeroe 28 30 676-9 41 30 841 
25 Of} 183-33 30 0} 139-52 43 5 { 693-0 
25 18|| 179-95 31 30 $94 30 |. 680-7 
26 30 1045 33. 30 690-2 55 || 667-4 
28 5 863-2 34 42)( 139-05 45 0| 189-03 
30 841-9 35 0\< 130-32 46 30 943 
55 827-9 35 18|{ 121-07 48 milf 604-1 
30 0O| 128-98 36 30 847 30 615-5 
31 30 965 38 30 793-2 55 || 620-2 
33 an 752-8 39 42 { 180-65 50 O| 182-25 
30 757-7 40 0) 184-00 51 30 878 
551 767-4 40 18|| 158-90 53 5)/ 643-3 
35 0} 161-58 41 30 827 30 649-4 
36 30 927 43 30 795-0 55 \ 659-6 
38 30 776-6 45 0} 171-42 55 0| 178-90 
40 0O| 131-47 46 30 695 56 30 763 
41 30 940 48 30 620-07 58 5 { 622-8 
43 30 731-3 50 0} 131-60 30 617-8 
45 0O| 136-37 if 51 30 838 55 | 606-0 
, Aug. 204 22> 1841. Observations made during a thunder-storm. 225 50™. Very heavy rain. 23h 15™, Clearing off. 23%, Thermometer 
Bifilar, 60°-4; Balance, 61°-0. The times of the Bifilar and Balance observations are 2™ 308 after those in the first column. 
From the above it would not appear that the mean directions of the magnets were affected by the thunder-storm; the vibrations of t} 
Declination magnet were occasionally very considerable, and this appeared particularly the case when the fall of rain was unusually heavy ; 
thus, at 22% 50™, when the rain was exceedingly violent, the arc of vibration amounted to about 17’, while at 22 45™, when the fall was con 
paratively slight, the are of vibration did not exceed 3’. EB. R. 
Sept. 254 4" 1841, When the scale of the Bifilar Magnetometer went or was going out of the field of the reading telescope, Mr Russé 
turned the torsion circle so as to bring the scale into the field again ; the following were the readings of the torsion circle at the times annexed + 
2h 2m 30%, 114°, usual position; 4" Om, 108°; 5% 20m, 110°; 54 25m, 111°; 54 40m, 109°; 54 50m, 111°; 6 25m, 112°, The reading of ty 
Bifilar seale was estimated at the following times, the scale being in sight, but beyond the vertical wire of the reading telescope ; 2% 2™ 3( 
5% 18™ 30%, 6h 23m 30%. At 5% 48m 30s the scale was out of sight, so that the reading must have been less than is here noted. 
The observations of the Bifilar Magnetometer are reduced to the torsion circle reading 114°. See Introduction. 
Sept. 254 1841, Bifilar Thermometer, 25, 627-0; 45, 651; 5», 65°°0; 6b, 64°°9; 7%, 642. 
Balance Thermometer, 2%, 60°2; 4%, 63°2; 5%, 63°2; 6h, 63°2; 7», 632. 
