OBSERVATIONS OF ABSOLUTE HORIZONTAL INTENSITY, 1847. 
351 
DEFLECTING Bar. UNIFILAR. BIFILAR. 
Git. Declino-||_. Unifilar oa aa 
Mean Distance | n. | Zem- Circle Scale || meter, ||Civcle Reading|| Deflection. || Reading} Ther- 
Time. =r. Pole.| PT?" || Reading. _| Reading. Reduced. Cor- | mome- 
ture. rected. ter. 
d. h. || Feet. bi s M 4 Se. Div. || Se. Div. - c) Ls C “i wy Se. Diy. 2 
SEPTEMBER 13—14, 1847. 
23 50 Ef E | 56-6 || 260 30 42 56-41) 8-00 || 260 48 20 536-5 50-2 
22 53 0-85 W | 53-2 | 213 17 5 44-27 |} 12-17 || 213 7 25 23 46 15 535-4 50-2 
23 46 w{ E | 56-3 | 260 30 42 45-12]! 8-57 || 260 25 10 535-1 50-2 
22 56 W | 53-4 || 213 17 5 40-65 || 10-75 || 213 1 5 536-4 50-2 
23 33 Bf E | 55-8 || 247 46 18 44-55 || 8-85 || 247 39 27 535-6 50-2 
23 6 1-10 W | 54-1 || 226 11 32 46-52] 11-07 || 226 7 9 10 44 40 534-0 50-2 
23 37 w{ E |55-9 || 247 46 18 40-37 | 8-55 || 247 31 13 534-5 50-2 
23 2 W | 53-8 | 226 11 32 45-37 || 11-05 || 226 4 51 533-6 50-2 | 
23 26 E | E | 55-3 || 240 46 30 45-85 || 9-92 || 240 41 32 | 534-1 50-2 
23 13 1-55 W | 54-6 | 233 6 43 45-96 ||.10-55 || 233 1 34 3 49 36 534-1 50-2 
23 23 w{ E | 55-0 | 240 46 30 44:76) 9-87 || 240 39 23 534-4 50-2 
23 16 W | 54-6 || 233 6 43 45-67 || 10-62 || 233 0 55 || 533-9 50-2 
23 55 | Magnet away. 236 56 7 | 44-74] 7-15 || 236 50 47 
9:0941498 
9-0945213 
9-0948615 
The observations, June 23, 1846 and Jan. 2, 1847, were made with a unifilar magnetometer, by Mr Jones of London, belonging to 
Professor ForBES. The observations, May 31, June 15, Sept. 11, and Sept. 14, 1847, were made with a theodolite magnetometer, by 
Mr Jones, belonging to Sir THoMAs BRISBANE. 
The following magnets were used in these observations :— 
June 23, 1846. 
Jan. 2, 1847. 
May 31, 1847. 
June 15, 1847. 
Sept. 11, 1847. 
Sept. 14, 1847. 
Suspended. Solid, 
2:5 inch. 
3:0 inch. 
Bate Idem. 
Collimator, 3:0 inch. 
Hollow (with mirror), 3:0 inch B. 6. 
em. 
Defiector. 
Solid, 3°65 inch. F. 
Idem. F. 
Collimator, 3°65 inch. 
Idem. 
Idem. 
Collimator marked 4, 
M. 
B. 
The magnets used on the first two days belong to Professor FORBES’ instrument ; those used afterwards belong to Sir THomas BRIs- 
BANE’S instrument, with the exception of the collimator deflector marked 4, used Sept. 14, 1847, which belongs to an instrument made 
by Mr Jones for Professor BAcHE of New York. 
An abstract of the observations for the times of vibrations of the different deflectors is given on the following page, and the final 
results will be found in the Addendum to the Introduction. 
