- of the Magnetic Poles of the Earth... 119 
wee 
the mean of 21 observations made within a few days. If we 
calculate from them the situation of the point of convergence,’ 
the following will be the result: t 
Situation of the Peint of Convergence, "7 
Distance from | Longitude West 
the Pole. =| from London. 
° / ° U 
19 44 99 53 
19 42 99 54 
19 32 101 24 
19 23 105 20 
19 33 
As the result of the 4th observation deviates considerably 
from the others, and having moreover reason to believe that 
1 have noted it wrong, we will omit it entirely*. As, more- 
over, from the reasons given above, we must consider the 7th 
observation the most accurate, I thought that I ought only to 
rely on the mean obtained from the determinations 2—7 and 
1—7, by which we obtain the following for the determination 
of the point of convergence in 1769: 
Distance from the pole ...... = 19° 43! 
Longitude W. of London .... = 99 53} 
E. of Greenwich... =259 58 
If in the North we follow the coast of Norway, the declina- 
tion decreases, and at last entirely disappears in the White 
Sea. Thus Bohr found it in the year.1818, in Bergen = 24° 
18’ W.; Lieut. Christie, in Vadsée in Varangerfiorden, the 
28th of June of the same year, = 7° 55'.. Inthe year 1770, in 
the vicinity of Spitzbergen, Captain Phipps found.the decli- 
* “The observation No.4. is given by Lambert (Astron. Jahrb. 1779, 
p. 148) as follows: Variation 24° 0! W. Long. 292° 11’, Lat. 56° 33!, The 
point of convergence is calculated after this. On the other hand, you will find 
in my extracts from the Philosophical Transactions for 1775, the latitude 
= 56° 53!, and the declination = 28° 0! W., which would remove the re- 
sult still further. As I have not the above work at hand, I cannot make 
out where the error lies.””—On the Magnetism of the Earth, p. 90, note. 
According to the Philosophical Transactions for 1775, p. 135, Lambert is cor- 
rect : Hutchins, however, adds: “ These experiments were made in conjunc- 
tion with Capt. Richards, in the cabin of the Prince Rupert, whilst she lay 
among the ice. ‘The ship frequently varied the position of her head a point 
of the compass ; but by replacing the instrument as often as we found occa- 
sion, I have the greatest reason to think these observations (which took up 
nearly three hours) are pretty accurate.” Under all these circumstances, 
we may be justified in entirely overlooking this observation.—K. 
nation 
