1813.] at Hackney Wick, 139 



2x +101-93" _ x + 50 . 9 y// Mean of the i s t and 5th wires. 



2x + 10160" = x + 50 . g0 Dhto 2d and 4(hi 



z 

 4- x + 203-53" __ x + 50>g8 Diuo ^ 2dj 3 ^ and 4th> 



4 



3x + 152-00" _ x + 50>c7 Ditto# >2 d, 3d, and 4th. 

 3 x + 152-33" _ x + 50 .j. 8 jjitto lst> 3dj and 5th# 

 5 x + 253-94-" = x + 50>79 DittQ t _ lstj 2dj 3d ^ 4thj and 5th< 



By taking the differences between the time that the star passes 

 the middle wire, and the mean of the times of passing the other 

 wires, the following six corrections are obtained: — 



Subtract 0-57" for the 1st and 5th wires. 

 Subtract 0*40 for the 2d and 4th wires. 

 Subtract 0-48 for the 1st, 2d, 3d, and 4th wires. 

 Subtract 0'27 for the 2d, 3d, and 4th wires. 

 Subtract 0*38 for the 1 st, 3d, and 5th wires. 

 Subtract 0-39 for the 1st, 2d, 3d, 4th, and 5th wires. 



Should the star or sun not be in the equator, these corrections 

 must be multiplied by the natural secant of the object's declina- 

 tion ; or to the logarithm of the equatorial correction add the 

 log. secant of the declination ; the natural number answering to 

 the sum will be the required correction. 



The angles subtended by the spaces between the wires may be 

 found by placing different marks at a given distance from the 

 instrument, and from each other, and then calculating the 

 angles ; or they may be found by observing, with a watch or 

 clock, the seconds and parts of a second the stars, situated in 

 Arion's Belt and Sword, take to pass from wire to wire. 



N.B. Should a star be observed under the Pole, the correction 

 must be added, not subtracted. 



Astronomical Observations. 



July 12, ImmciVion of ir Sagittarius at 12 h 58' 16" Mean Time at Hackney 

 Wick. Certain to a second, and do djmiuution of the star's light took place 

 at the contact. 



