AT TWENTY-ONE STATIONS IN EUROPE. 99 



The difference in the dip at Brientz, as shown by the two needles, (No. 1 

 and No. 2,) is very considerable, and, from the separate observed quantities, 

 the results by No. 2 would, appear more worthy of confidence than that by 

 No. 1. 



The two horizontal needles, oscillated by Professor Forbes, on the Faulhorn, 

 gave 1.071 and 1.060, mean 1.065 for the horizontal intensity compared with 

 Paris, and the needle oscillated at the lower station, Meyringen, for compari- 

 son, 1.075. My results, both at the upper and lower stations, exceed these, be- 

 ing 1.082 and 1.078. The difference of the horizontal intensities at the upper 

 and lower stations appears equally from my series and that of Professor Forbes 

 to have been very small ; less, in fact, than the differences between two needles 

 at the same station. 



I am not aware that Professor Forbes determined the dip at his two corre- 

 sponding stations. Using the mean dip for Brientz, the total intensity at the 

 lower station appears very nearly the same with that at the upper; using the 

 dip given by needle No. 1, it would, of course, be less; and using that shown 

 by needle No. 2, it would exceed the total intensity at the upper station by 

 only .0046. 



The details given in the preceding pages appear to me essential, in order to 

 a just conclusion as to the character of the results, and for reference in regard 

 to the localities and circumstances of the observations. The comparisons of 

 my conclusions with those of others, as far as I am acquainted with them, will 

 probably be found convenient, and, in some cases, had a specific object in 

 reference to these observations themselves. The results being thus unavoid- 

 ably scattered, I have thought it best, in conclusion, to present them in a, sin- 

 gle table, divested of particulars. 



