214 Humboldt's Letters. 



it everywhere, and have measured it ; there will become 

 known, in spite of the bad season, a fine series of obser- 

 vations, which may, as I hope, permit us to draw reliable 

 conclusions. As now developed, forces of polarity, I 

 believe, must be recognised in it. The further deve- 

 lopments will, I hope, enable us to advance beyond 

 superficial conjectures like these. 



The observations of the new planet can be made here 

 so excellently by the heliometer, which is quite invalu- 

 able for this purpose, that their accuracy far surpasses 

 that of the best meridian observations ; of course its 

 greatest usefulness will only be attained when the stars 

 of comparison are equally well determined in their posi- 

 tion. To this determination, then, the power of the 

 meridian observations is directed about the planet itself. 

 Dr. Busch, following my counsel, does not trouble him- 

 self. I have also requested Encke and Schuhmacher to 

 assist in determining the positions of the stars. The 

 former has already received from here a series of excel- 

 lent observations, as a foundation for his calculation of 

 the orbit, and he will soon receive the continuation of 

 them. It is very fortunate that I Jjave arranged my 

 extensive investigations on the exact reduction of 

 observations by my heliometer, and that these are pub- 

 lished in the first volume of my " Astronomische Unter- 

 suchungen." Without them, Wichmann would be unable 

 to reduce them with exactness, as I can do nothing now, 



