[237] 116 



In his commiinication to me, Mr. Goebel states that the end of the 

 eclipse could not be observed quite as well as the beginning, owing to a 

 small twig only observable through the telescope, which came right be- 

 tween the snn and the instrument at the critical moment. Still, he is 

 satisfied that the time of the observation comes within five seconds of the 

 utmost accuracy. Unwilling to assume, myself, any corrections in reference 

 to this accidental error, and considermg the nature and difficulty of the 

 sort of observation, I feel disposed to regard both epochs, of beginning and 

 end, as equally good, and the mean above taken as not far from the trnth. 



1 may remark, with Mr. Walker, that the low power used by Mr. Goe- 

 bel will give a diminished semi diameter, requiring a value for »; of only 

 +0".l47, instead of 4-3'M98. 



2. Mr. Goebel has also observed the occultation of * Sagittarii by the 

 moon on the 5th of June, 1841, at \5h. 40m. 7.945. mean time. No cor- 

 responding observations have been found : the result, therefore, stands 

 uncorrected for the errors of the tables. It gives, according to the reduc- 

 tion by Mr. Walker, longitude of Goebel^s residence 6h. 4tm. 26.96s. 



3. Mr. Goebel has further derived, from observation of 4 emersions and 

 2 immersions of tlie first satellite of Jupiter, a longitude of 6A. Am. 35.52s. 



Combining these three several deductions for a mean result, we have — 



h. m. s. 



Longitude by eclipse of the snn - - - 6 4 23.43 



Longitude by occultation of ff Sagittarii - - 6 4 26.96 



Longitude by satellite of Jupiter "- - - 6 4 35.52 



Mean - - - 6 4 28.64 



Longitu<3e in arc - - 91° 7' 9^6 



I pass, now, to some places where there has been no opportunity of ob- 

 serving occultations or an eclipse, but whose longitude has been determined 

 by lunar distances ; or chronometrieally, by comparison with the preceding 

 stations. 



VI. ST. Peter's — ikbian agency near fort snelling. 



Entrance of the St. Peter's river, called Mdota-niini sotah by the Sioux. 



h. m. s. 



L Longitude, the mean of 10 sets of observations, or 198 

 lunar distances E. and VV. 3 



2. Chronometric longitudes, deduced from the eclipse of 



the sun, observed at Ti-tanka-tanninan lake 



3. Chronometric longitude, deduced from the occultation 



of a Virginis, observed at Red Pipestone Q^uarry - 



4. Chronometric longitude, inferred from St. Louis 



Mean .... 



Longitude in arc - ^ - 



