22 



OBSERVATIONS ON 



Dip. 





Epoch of 

 commeDcing 

 vibration, 

 hrs. min. sec. 



Duration 

 of 500 

 ■vibra- 

 tions. 



P.2 



Calculated 



duration 



at 60°. 



Square of the 

 preceding. 



Horizon- 

 tal inten- 

 sity. 



Total in- 

 tensity : 

 hor. being 

 1000. 



Total inten- 

 sity : that ai 

 Cincinnati 

 = 1000. 



185. Eagle River, a few rods eastward of the last, and on tlie high bank over the adit, being 

 near the burying-ground. 



77° 39' 00" 



4 



5 35 00 



1359.12 62 



1358.95 18467451025 670.77 



3136.1 



1048.1 



186. Eagle River Mine, on a hill about three-quarters of a mile west of the works, as by the 

 previous latitude and longitude. — July 1, 1847. 



77° 56' 04" 



4 

 5 

 6 



7 49 00.0 



8 20 08.6 

 8 44 03.6 



1370.72 

 1668.80 

 1662.40 



71.5 

 74.0 

 74.0 



1669.70 

 1667.16 

 1660.74 



18760780900 660.29 



27794224656 656.50 



27580633476 653.68 



Mean 656.82 



8141.9 



1050.1 



187. Cliflf Mine.— Lat. 47° 24' N. Long. 88° 26' W. July 1, 1847. 



77° 46' 20" 



4 



4 30 00 P 



1380.33 



53 



1381.00 



19067610000 

 1857776900 



649.67 

 666.80 



3068.1 

 8111.4 



1025.4 

 1039.8 



77 87 37 



4 



5 56 00 



1363.60 



70 



1362.72 



188. Copper Falls.— Lat. 47° 27' N. Long. 88° 12' 30" W. July 2, 1847. 



78° 20' 00" 



4 



3 32 01.2 



1538.36 



69 



1537.44 



19146256900 



647.00 3125.5 



1044.6 



78 16 29 



4 



3 01 04.0 



1372.8 



76 



1871.31 



18804636700 



658.75 3241.6 



1083.2 



189. Baite du Gris (^Encampment).— LsX. 47° 24' N. Long. 88° 06' W. July 9, 1847. 



77° 06' 30" 



5 



8 19 25 A 



1620.39 



69 



1619.37 



26223591969 



695.00 



3115.1 



1041.1 



190. Sibley's Mine {Lac La Belle).— L&t 47° 24' N. Long. 88° 08' W. July 8, 1847. 



76° 13' 26" 



5 



12 46 04 



1557.36 



77 



1555.51 



24195802500 



754.1 



3167.1 



1058.5 



EEMARKS. 



186. Eagle River Mine. — Geology : feldspathic greenstone. 



187. Cliff Mine. — Range 32, township 58, section 36; United States surveys. Locality : inside of 

 the mine. Geology : the instruments were placed on the immense mass of native copper which laid ex- 

 posed in the gallery. 



Second locality : outside of the mine, and over the vein on the highest point of the ridge. Geology : 

 trappean. 



188. Copper Falls. — Range 31 W., township 58 N., section 11. Geology: over the vein of metallic 

 copper. 



Second locality : in a wood one-fifth of a mile below the falls. 



189. Baite du Gris (Encampment). — Range 29, township 58, section 34 ; United States surveys. 

 Geology : sandstone, very near to the trap. 



190. Sibley's Mine (Lac La Belle). — Range 29, township 58, section 32; United States surveys 

 Geology : sienite, with sulphuret of copper. 



