MAGNETICAL OBSERVATIONS. 



19 



1856. August 27. A. M. 



Theodolite and declinometer. 



CIHCLE TO THE RIGHT. 



Chronometer. 



4'' 32'" 



Mark A 

 4 35 

 Mark A 



Scale 



71. G 

 71 7 

 71.7 



71.7 

 71.7 

 71.7 



Mean. 



98° 45'.3 



358 15.0 



98 45.3 



35S 18.7 

 Mean 



Bearing of A. 



N. 79° 29'.7 E. 



79 33.4 



N. 79 31.6 E. 



Magnetical azimuth of mark A, N. 79° 32'.8 E. 



Horizontal intensity. Experiments of vibration. 



1856. August 26, P. M. Vibrating magnet D 3. 



No. 





 10 

 20 

 80 



40 



50 



100 



Chronometer. 



lO'' 47"" 32 ^8 

 47 59.0 



48 

 48 

 49 

 49 

 51 



25.0 

 51.0 

 17.0 

 43.5 

 54.5 



No. 



300 

 310 

 320 

 330 

 340 

 350 

 200 



Chronometer. 



IP 



10 



0° 



1 

 1 

 1 



2 

 2 



56 



39 ^0 

 5.2 

 31.4 

 58.0 

 24.0 

 50.5 

 17.0 



Time of 300 vibrations 



13" 



6^2 

 6.2 

 6.4 



7.0 

 7.0 

 7.0 



13 6.63 



Extreme scale readings. 





 100 

 200 

 300 

 350 



10.0 

 14.0 

 16.0 



18.0 

 20.0 



50.0 

 46.0 

 44.0 

 42.0 

 40.0 



Temperature 76° F. 

 Time of 1 vibration 2^6221. 



1856. August 26, A. M. 



Vibrating magnet D 3. 



No. 





 10 

 20 

 30 

 40 

 50 

 100 



Chronometer. 



11" 



4" 59 \0 

 5 25.0 

 51.0 

 18.0 

 44 

 10.0 

 20.8 



No. 



Chronometer. 



300 

 310 

 320 

 330 

 340 

 350 

 200 



11'' 



IS" 



18 



18 



19 



19 



20 



13 



5^0 

 32.0 

 57.2 

 23.8 

 60 

 16.0 

 43.0 



Time of 300 vibrations. 



IS-" 6^0 

 7.0 

 6.2 

 6.8 

 8.0 

 6.0 



13 6.17 



Extreme scale readings. 





 100 

 200 

 350 



14.0 

 16.0 

 19.0 

 22.0 



46.0 

 44.0 

 41.0 

 38.0 



Temperature 76° F. 

 Time of 1 vibration 2^.6206. 



