152 
MAJOR SABINE ON TERRESTRIAL MAGNETISM. 
Santa Cruz 
. Y - 
1-284 ; 
Z = 
1 - 270 ; 
Mean = 
1-277 
Bahia 
— 
0-879-; 
== 
0-877; 
= 
0-878 
Cape of Good Hope . . 
— 
1-032 ; 
— 
1-030; 
= 
1-031 
Swan River ..... 
• H 
^ 1-647 ; 
„ 1-643; 
— 
1*665 ; 
1-661 ; 
} = 
1-654 
Point Swan 
. = 
1-341 ; 
= 
1-306; 
= 
1-324 
Port Usborne .... 
= 
1-337; 
1-343 ; 
= 
1-340 
Port George IV. . . . 
. = 
1-329; 
= 
1-339; 
= 
1-334 
Hobart Town .... 
1-830; 
= 
1-830 
Sydney 
f 1-694 ; 
l 1-693; 
} = 
1-693 
Three Hummock Island . 
— 
1-788; 
= 
1-799; 
= 
1-793 
Dunheved 
= 
1-657; 
1-671 ; 
= 
1-664 
Paramatta ..... 
1-681 ; 
~ 
1-697; 
= 
1-689 
K. 
These observations were made with a needle belonging to myself, which Sir John 
Franklin took out with him to Van Diemen’s Land, on his proceeding to assume the 
government of that island. It was one of those which Mr. David Douglas had em- 
ployed in magnetic observations in North America and the Sandwich Islands, and 
had preserved its magnetism unchanged for several years antecedent to Sir John 
Franklin’s departure. The following account of its times of vibration at Hobart 
Town shows that its magnetism was equally steady after its arrival there, and affords 
presumptive evidence that it had been so in the interval. This presumption is cor- 
roborated by the remarkable agreement of the intensities obtained with it at the Cape 
of Good Hope and Hobart Town, with those of Captain FitzRoy in 1836 at the same 
places. The account is copied from a memorandum in my possession received from 
Sir John Franklin. A second needle which accompanied it proved too unsteady in 
its magnetism to yield any useful results. 
“ Rates of Major Sabine’s intensity needle six inches long, suspended by a fine 
thread of unspun silk. 
“ Dublin, July 20th, 1836 : Provost’s Garden, Trinity College, dip 70° 59'-5 : therm. 
59°'3 : 10 vibrations in 57’88 seconds. Observer, Major Sabine. 
“ Cape of Good Hope, November 1836 : observatory, dip. 52° 3-8' : 10 vibrations in 
50T82 seconds : therm. 74°. Observer, Lieut. Thomas Burnett, R.N. 
“ Hobart Town, January 24th, 1837: in the Garden at Government House ; 10 
vibrations in 49‘88 seconds : therm 64°. Observer, Lieut. Thomas Burnett, R.N. 
“Hobart Town, May 4th, 1838: in cottage-garden, ten feet from west window: 
10 vibrations in 50-970 seconds: therm. 53°. Observer, Captain Charles Drink- 
water Bethune, R.N. 
