664 GAUSS’S OBSERVATIONS OF THE 
proportionably less weight than the inclinations of 1842, which 
rest respectively on thirty-two, sixty-four, and forty positions. 
33. 
All the inclinations hitherto given still require a small common 
correction, on account of the influence exerted at the place of ob- 
servation by the magnets in the Astronomical and Magnetical 
Observatories: 5-15 must be deducted from the results through- 
out to free them from this effect. (Compare Resultate, vol. v. 
page 33.) 
The absolute degree of confidence due to the determinations 
of inclination still remains dependent on the correctness of the 
assumption, that the instrument itself contains no particles which 
can act magnetically on the needle. There are no grounds for 
such an apprehension in the case of the instrument which I have 
employed ; some observations which I made with a loaded needle 
in the manner mentioned in Article 18, always gave discrepan- 
cies of a few minutes only, which are quite naturally explained, 
partly by the unavoidable errors of observation, and partly from 
the actual anomalies of the inclination itself. The sufficiently 
satisfactory agreement of the values found in Article 11 for the 
quantity there designated by « is also opposed to the existence 
of such disturbances. It is true that such tests are not suited 
to the detection of very small influences, and I must therefore re- 
serve a further test by more searching means. 
34. 
In conclusion I subjoin my own results, together with some 
earlier determinations by other observers. 
1805."Dec..-—-- .. 5 69° 29! 
1826. Sept. . . . 68-29 ag | Humboldt. 
1837. July 1... 67 47 0 
kai ikeatabs io cuir pied sof Forbes. 
1841. Oct. 8 cour Gfie425a$ 
1842. June 21 sw Gf 309689 
The two first of these results are taken from the additions to 
the thirteenth volume of the Voyage aux Régions Equinowiales, 
p- 152; the first was made with an Inclinatorium of Lenoir’s ; 
the second with an instrument of Gambey’s: the latter rests 
on two needles, of which the separate results are given as 
68° 30! 7" and 68° 28’ 15", with which the above mean does not 
