NOTES. 



477 



Name of Period in 

 Star. Years. 



Herculis 30' 216 



n Corona? 42* J 



Cancri 58-910 



| Ursa; Majoris .. .. 58-262 

 Leonis . . . N . . 82 533 



p Ophiuchi 73-862 



3062 in Dorpat Catalogue 94- 765 



gBootis 117-140 



SCygni 178-700 



y Virginia 182-120 



Castor 252-660 



r Coronae 736-880 



yVirginis 632-270 



Centauri 77-000 



Orbit of y Virginis. 



Perihelion passage .. 1836-40 

 Inclination .. .. 27 36' 



Position of ascending Node 19 7 

 Angle between line of Nodes 



and Apsides . . . . 295 13 

 Eccentricity .. .. 0-8794 

 Period in years . . . . 184 53 



Perihelion 



1831-41 



1807-21 



1853-37 



1817-25 



1849-76 



1806-83 



1837-41 



1779-8^ 



1862-87 



1836-43 



1855-83 



1826*48 



1699 



1851-50 



By whom 

 Computed. 



Madler. 



Madler. 



Madler. 



Savary. 



Villarceaux. 



Encke. 



Madler. 



SirJ.Herschel. 



Hind. 



SirJ.Herschel. 



Sir J. Herschel. 



Hind. 



Hind. 



Jacob. 



Orbit of Herculis. 

 Perihelion passage . . 1830 56 



Inclination 140 39' 



Position of ascending Node 217 14' 

 Angle between line of Nodes 



and Apsides .. .. 266*53 

 Eccentricity .. .. 0-4381 

 Period in years .. .. 37*21 



Computed by J. Fletcher, Esq., 1853. 



NOTE 233, p. 403. The mass is found in the manner explained in the 

 text ; but the method of computing the distance of the star may be made 

 more clear by what follows. Though the orbit of the satellite star is really 

 and apparently elliptical, let it be represented by CDO, fig. 14, for the 

 sake of illustration, the earth being in d. It is clear that, when the star 

 moves through CDO, its light will take longer in coming to the earth from 

 than from C, by the whole time it employs in passing through O C, 

 the breadth of its orbit. When that time is known by observation, reduced 

 to seconds, and multiplied by 190,000, which is the number of miles light 

 darts through in a second, the product will be the breadth of the orbit in 

 miles. From this the dimensions of the ellipse will be obtained by the aid 

 of observation ; the length and position of any diameter as Sp may be found ; 

 and as all the angles of the triangle dSp can be determined by observation, 

 the distance of the star from the earth may be computed. 



NOTE 234, p. 405. The mean results of MM. Argelander, Otto Struve, 

 and Luhndahl for stars in the northern hemisphere and the epoch 1790, 

 places the point to which the sun is tending in 259 5' of right ascension 

 and 55 23' of north polar distance. Mr. Gallaway computed from stars 

 in the southern hemisphere, at the same epoch, the point to have been in 

 260 1' right ascension and 55 37' north polar distance, results nearly 

 identical, though from very diflerent data. 



NOTE 235, p. 414. One of the globular clusters mentioned in the text is 

 represented in fig. 1 , plate 8. The stars are gradually condensed towards 



