308 
OBSERVATIONS ON THE MAGNETIC DIP, 
; Longitude 
; August 4, 1843, 
82. Near Cleveland, Ohio, at Professor Kirtland’s, Latitude 
Total intensity, 
: Duration Calculated] 
Dip. No.of | Epoch of commencing | of 500 |Tempe-| duration Square of the | Horizontal| Total intensity, |that at Cincin= 
|Needle. Vibrations. Vibrations.| rature. at 60°. Preceding, intensity. | Hor. being 1000, |nati being 1000. 
73° 08’ 5 3h.52m.048.4 P| 1442, 80° |1439.74|2072851.2676)880.74 
6 4 30 O1 2 |14386.8 1434,68/2058306.'7024/879.60 
Mean,|880.17 3033.54 | 1016.34 
Near the lake, in a woodland. Substratum, the “ black shale.’ 
As the intensity at Copper Harbour is evidently high, compared with that which 
shows itself at the other localities along the south shore of the lake, it is proper, perhaps, 
to make a group of all the others, excluding those of the harbour, as from one to five, 
inclusive, in the following table. 
SUMMARY, BY 
GROUPING. 
“Tide of | We | ‘i Total Intensity.| Total Intensity. 
the Group. Names of Places. Latitude. | Longitude, Dip. LOCKE. SABINE 
Sg 1. Sault St. Marie, 46° 31’ | 84° 32’ |77°30'15”) 1036.65 | 
Eq |2. Encampment, 46 44 |87 43 |76 5819; 1034.10 : 
#8 |3. Mouth of Eagle River, | 47 27 | 88 23 |77 54380| 1036.72 
“a (4. Mouth of Ontonagon, | 46 52 |89 31 |77 1310] 1039.23 
= |5. Lapointe, 46 47 |90 58 |76 5600] 1044.50 
| 
Mean of the above, 46°62'12"/88"08'36" 77°18'27"| 1038.24 1882.64 
as 6. Houghton’s River, 47 28 88 Ol |77 2045) 1026.62 
g= |7. Magnet Inlet, (7) 47 29 |88 01 |78 4520} 1065.23 
22 (8. 500 ft.E.of Mag.Inlet,(8)| 47 29 | 88 01 /78 83730] 1059.31 
o& |9- Isthmus, 47 29 | 88 00 /|78 2800] 1055.50 
£8 |10. United States Agency, | 47 29 | 88 0110/77 1330 | 1086.58 
| Mean of the above, 47°28'48" 88°00" 78°05'01”| 1058.65 1919.65 
11. Isle Royale, 48 06 |88 47 |78 0736) 1052.60 1908.08 
Mean of all the above obser-| j.01 erg 'ao01 ni sanlmm od dinar | ‘ ; | 
. vations on Lake Superior, 47°15'32 es 10'43”'77°44'00"| 1048.82 | 1901.82 | 
The following table exhibits the total intensity of several of the most important places, 
expressed, both in the values referred to Cincinnati, and in those used by Colonel Sabine. 
tp ae 
‘hwes pA ss es ia ss Total Intensity. Total Intensity. , 
Stations. Latitude. Longitude, Dip. Cincinnati 1000. SABINE. Observer. | Year. 
QGasmar, South America, - - - = 9°38’ S. |'78°85 5°00'S. 551.40 1000.00 |Humboldt/1802 
New York, - - - ~~ - + + (4043 N./7401  |72 41 N.| 994.30. | 4803.00 |Locke {1841 
Peppiensti, «~ °° " = #578 39 06 84 22 70 27 00 | 1000.06 1813.30 6 184] 
Williamstown, Kentucky,- - - - [8836 (8422 700407 | 993.25 1801.06 m 1840 
St. Louis, Missouri, - ~ - * 7 38 36 90 15 69 31 26 997.35 1808.35 “ 1839 
Davenport, Iowa, - - + $4 -y-(4h 80 90 35 715500} 1012.91 1836.71 “ 1839 
Mean of five stations on the South Shore,|46 52 12 |88 08 36 |77 18 27 | 1038.24 1882.64 “ 1843 
Five stations on Copper Harbour, L,S.,|47 28 48 |88 00 50/78 0501 | 1058.65 | 1919.65 “ 1843 
Isle Royale, - - - - - 48 06 88 47 78 07 36 | 1052.60 1908.08 + 1843 
Mean of all the stations on Lake Superior 47 1532 '88 10 43 I77 4400 | 1048.82 1901.82 “ 1843 
