AND THE INTENSITY OF MAGNETICAL FORCE. 289 
to the Red River, with the descent of the Red River to Lake Winnipeg,—and a trans- 
verse or east and west line, through the spot, or not very distant from it, where the 
highest intensity should be found in the north and south line, would appear extremely 
desirable; the east and west line to be pursued in both directions until the intensity 
of the force should be decidedly decreasing. 
“Believe me, my dear Sir, with much respect, very sincerely yours, 
“EDWARD SABINE.” 
J. SERIES, 1838, OHIO. 
Cincinnati, Latitude 89° 06’; Longitude 84° 22’, W.; March 20, 1838. 
‘Total intensity, 
that at Cincin- 
nati being 1000, 
| Duration Calculated 
Dip. No. of |Epoch ofcommencing) of 500 |Tempe-| duration Square of the 
Needle. Vibrations, bcntee rature.| at 60° preceding. 
Horizontal Total intensity, 
intensity. Hor, being 1000. 
70°28'08"| 1 |2h.03mm.05s.6 P 1544.00 89°00/1538.63/2367382,2769| 1000 | 
2 1513.76)2291469.3376| 1000 
3 1235.60/1525225,0000) 1000 | 
Mean, 1000 | 2991.1 1000. 
Remarks.—Needle No. 1. The mean time or duration for five hundred vibrations at 
the temperature of 60° deduced from ten series, of five hundred vibrations each, made 
March 10, is equal to 1540.20. 
Needle No. 2. The mean time or duration of five hundred vibrations, at the tempe- 
rature of 60°, deduced from five series, of five hundred vibrations each, made March 
10 to 11, is equal to 1513.76. 
Needle No. 3. The duration of five hundred vibrations at the temperature of 60°, 
deduced from ten series, of five hundred vibrations each, made January 17 to 20, equal to 
1235.60. 
Locality. Longworth’s garden. Substratum, diluvial loam and gravel based on the 
horizontally stratified blue limestone of the silurian formation. 
Dayton, Latitude 39° 44’, N.; Longitude 84° 17’, W.; March 26, 1838. 
1°22/42”) 1 |3h.00m.00s.6 P\1572.80]73°00] 1570.35 
1 |2 55 04 O* (1578. [85 380/1573.27 
Mean,|1571.81) 2470555,24 | 958.25 
2 |6 30 04 5A1544.40|53 00)1546.00 
2 |8 24 OL 6 {1548.00/60 '75)1548.00 
Mean,|1547.00} 2393209.00 | 957.20 
8 |? 14 04 4 |1260.00155 6 |1260.32 
3 19 18 O1 2 |1262.00)67 5 |1261.45 
Mean,|1260.88] 1589868.81 | 959.20 
* March 27. Mean,| 958.20 | 3001.0 1003.2 
Geology. Alluvium underlaid by horizontally stratified blue limestone. 
Springfield, Ohio, Latitude 39° 54’; Longitude 83° 51’; March 29, 1838. 
71°27'23" 1 |9h.58m.02s.4 A|1580.00,67° 50 1578.58)249 1914.81.64) 950.02 
Sot 17. UO 1557.80.71 00,1554.72 2417154.2784) 948.00 
8 11233 02 0 11268.0072 00 1267.72)1607113.9984| 949.04 
Mean, 
Substratum, cliff limestone in horizontal strata. Place, } mile north of the village. 
949.02 | 2984.3 997.8 
