AT VAN RENSSELAER HARBOR. 



Hourly 

 means. 



Fern Rook Observatory, February 1 and 8, 1854. 



4" 



5 



6 



7 



8 



9 



10 

 11 

 12 

 13 

 14 

 15 

 16 



n 



18 



19 



20 



21 



22 



23 







1 



2 



3 



4 



316d.5 

 319 

 333 

 341 

 35t 

 356 

 369 

 371 

 367 

 386 

 389 

 362 

 333 

 330 

 302 

 271 

 295 

 313 

 297 

 322 

 306 

 335 

 327.5 

 317 

 336 



315-1.7 

 322.5 

 341.9 

 351.4 

 355.3 

 355.0 

 370.4 

 370.8 

 372.8 

 391.2 

 378.6 

 345.4 

 336.2 

 311.7 

 288.6 

 279.7 

 303.9 

 301.6 

 302.9 

 319.9 

 310.7 

 332.9 

 306.7 

 321.5 



332.8 



Fern Rock Observatory, February 10 and 11, 1854. 



4" 



5 



6 



7 



8 



9 

 10 

 11 

 12 

 13 

 14 

 15 

 16 

 17 

 18 

 19 

 20 

 21 

 22 

 23 







1 



2 



3 



4 



293-1.6 

 354.1 

 362.9 

 381.8 

 391.4 

 383.5 

 377.3 

 383.9 

 390.9 

 405.3 

 464.8 

 464.7 

 388.5 

 361.9 

 314.8 

 264.0 

 271.1 

 242.2 

 202.7 

 208.3 

 205.3 

 281.1 

 336.2 

 362.0 



337.2 



Value of a scale division 0'.80. 



Increase of scale readings corresponds to a movement of the north end of the magnet to the east. 



