TERRESTRIAL MAGNETIC INTENSITY. 



33 



66. Besides this there are two coincidences, with results by other observers 

 with different instruments, proving similar accuracy, although I was in both 

 cases unaware of the independent data, until my own observations had been 

 made and calculated. 



The dip at Brussels in the end of March 1837, was determined by 



M. QUETELET, 68 28.8 



By needle A. 2. on the 10th May 1837, ......... 68 28.5 



Difference, 0.3 



o / 



The dip at Berlin, 20th June 1837, was determined byM. ENCKE, 68 4.9 

 By needle A. 2. on the 12th July 1837, 68 5.5 



Difference, 0.6 



These were the only direct comparisons which 1 have had an opportunity of making. 



67. The following table contains a notice of the particular stations at which 

 the observations were made, their geographical positions, and the Total Intensities 

 deduced from mean results. 



TABLE IV. 



