ON THE MAGNETIC INTENSITY OF THE EARTH. 
TaBueE II. 
19 
Station, Date. 
Madeira............ 1826, May 31............ 
Port Praya ...... 1826, June 22 & 24...... 
St. Catherine...... 1827, Nov. 3 .......c000 
Gorriti ...........,{1826, Oct. 29 & Nov. 6 
Se ots vax backs 1829, Jan. 10 
| Monte Video...... 1827, Dec. 18 
Beare? anise. ca skseces 1828, Oct. 8 ... 
Time of hori- 
zontal vibra- 
tion. 
Observed dip. 
..|576-37| 53 13°5 
584-29) 59 43°8 
598-97 
eee ceceessccess 
..| 555°59) 45 10-0 
anne eer eccccees 1830, June 1 
Sea-bear Bay ...|1829, March 20 
St. Martin’s Covel1827, Jan. 15 & 22...... 
$d ceceseceeenes 1827, March 27 ......... 
Port Famine...... 1828, Jan. 28 .......0.065 
$= derevcceseeeees 1828, May 8 ............ 
ia cesansorces 1828, June 18 & July 20 
hence ce eceeeee 1830, April 26 ......... 
Chiloe ....... .....{1829, Sept. 1 & Dec. 15 
Juan Fernandez .|1830, Feb. 19............ 
Talcuhuano ...... 1829, Dec. 28... 
BER Soteee 1830, May 12............ 
Valparaiso......... 1829, Aug. 4 ..........0. 
Es de swessvevecces 1830, Jan.11 & Feb. 1. 
565-23) 49 52-6 
551-83) 44 49-8 
557:18 
5516 
Coe eeeeeraseces 
at Rio. 
Time asa 
dipping needle 
Intensity, 
Rio | Rio. 
=1°000. | =0°884. 
1556 | 1:377 
1330 |1:177 
1:045 | 0-920 
1:172 j 
1 ot oe 
} 1:065 
1538 | 1-361 
1-691 i 
ie aR 1-498 
1-712 
1-683 FY 5 
1-694 1-505 
1-712 
1-402 | 1321 
1-425 | 1-262 
1-413 A 
i hav 1-250 
1-334 aa 
13 at 1176 
Sabine, 1827.—These observations were made for the pur- 
pose of determining the ratio of the intensity in Paris and 
London, in order to connect and unite in one system, the re- 
sults of the different observers who had made Paris and Lon- 
don respectively the base stations of their series. 
All values of the intensity hitherto determined are relative 
values ; that is to say, each observer has taken some one sta- 
tion as the fundamental one of his series, and has expressed 
the values of the intensity at all his other stations, compara- 
tively with the force at his fundamental station. 
Unless, there- 
fore, two such series have one station common to both, or un- 
less the force at their respective fundamental stations has been 
otherwise compared, they do not form parts of one system, 
and the results of the one series cannot be bro 
_ nexion with those of the other. 
ught into con- 
_ The continental observers in general have taken Paris, either 
_ mediately or immediately, as their fundamental station ; and the 
_ English observers have as generally taken London ; the present 
_ observations were designed, therefore, as a link to connect their 
_ Tespective series into one system. 
Cc 
2 
