THE APPARENT POSITION OF THE 



\CAL LIGHT. 



137 



the latitude of the boundaries of the " Stronger Light" 

 should be omitted, as not determinable from the sketch 



at the elongation 60° 

 Under the date of 



July 15, 1854, the last result for the latitude of the boundaries of the "Stronger 



Under the date of Aug. 17, 1854, column 



Light" at 60° should also be omitted 



.. 



t" the last result, 18, should be 13 



The required data for the morning observations of Jones at the elongation 



60° were obtained ft 



his 



k by the method previously employed; 1 but the 



longitude of the sun was 



ferred to a date one day 



than that 



giv 



Jones, who employs civil time, so that the same longitude might be retained f< 



all observations belonging 



to the same night, whether made early or late. 



Tl 



precaution, however, is of no practical importance, and might have been neglected 

 without noticeably affecting the results, since a single degree is a relatively small 

 quantity in the data here collected, and given below in Table I., the In ulings of 

 which have the same meaning as those corresponding to them in Table X., already 

 mentioned. An additional column in the present table gives the excess of absorp- 

 tion at the southern over that at the northern boundary, computed in terms of 



means of an auxiliary chart and the tables given in my 



indicated by Italic 



stellar magnitude by 

 former communication 

 figures. 



As previously, negative quantities are 



TABLE I. 



Morning Observations by Jones: Stronger Li g Jit : Elongation 60°. 



No. of 

 Chart. 



Date. 

 1853. 



June 

 July 



July- 



Sept. 

 Sept. 



106 

 108 

 110 

 112 



July 16 113 

 July 18 115 



116 

 132 

 143 



159 







Lat of 





Lat. 





Bound. 



Diff. 



of 



t. 







Absorp- 



Obs. 







tion. 







N. 



o 



s. 



O ! 





o 



O 





26.2 



38 



4 



6 



0.29 



35.2 



62 



7 



6 



0.22 



35.2 



57 



13 



9 



0.51 



35.2 



59 



10 



7 



0.40 



35.4 



53 



10 



9 



0.87 





68 



5 



3 



0.09 



35.4 



54 



10 



5 



0.45 



33.7 



56 



9 



8 



0.73 





71 



11 



6 



0.21 



32.1 



72 



7 







0.07 



21.5 



103 



5 



10 



0.06 



23.0 



114 



6 



9 



0.05 



23.0 



111 



8 



8 



0.13 





124 



10 



8 



0.04 



23.0 



117 



10 



7 



0.07 





125 



6 



7 



0.04 



Xo. of 



Date. 

 1863. 



Sept. 12 

 Sept. 14 



Sept. 15 



Sept. 30 

 62 Oct. 1 



64 Oct. 3 



Oct. 4 



Long. 



of 



Sun. 



i 



186 



23.0 



23.0 



22.4 



22,4 





162 



Lat . of 

 Bound. 



DifT. 

 Absorp- 

 tion. 



0.05 

 0.01 

 0.18 



0.05 



0.02 

 0.02 

 0.0'J 



• '.00 

 ti.03 



0.03 



".02 

 0.01 

 0.00 



0.00 



0.00 

 0.01 





VOL. XI 



1 Proc. Am. Acad. XIX. 171. 



18 



