T I M 



lion for the hour so deduced by Tab. VI. -~ equation of time at prec. noon. 



This last rule also gives the time of a star's passage over the meridian 

 in mean solar time, the star's R. A. being substituted for sid. time. 



Ex. Given mean solar time 57*. Wm. 17,4s., Nov. 8, 1827 j to find the 

 corresponding sidereal time, 



d. m. x. 

 5 19 17,4 

 Equation of time -f. 16 6,9 



5 35 24,3 

 55,1 



By Tab. VII. 



5 36 19,4 



5 36 19,4 

 R. A. Sun. N. Aim. 14 51 25,8 



55,09 



Sid. Time ~~~~~~.~ 20 27 45,2 



When the longitude is different from that of Greenwich, a propor- 

 tional correction must be made for the difference. 



If the Naut Aim. is not at hand, sidereal time may be found very 

 nearly by the following Table, merely adding the sun's mean R. A. in 

 the table to the time of day where you are. ( Woodhouse.) 

 Sun's mean R. A. 



Ex. Given as before j to find the 



sidereal time. 



h. m. .r. 

 Nov. 6th 15 



2d 7 53 



Given time . 



Sid. time 20 2-7 10,4 



Or more accurately by adding the 

 acceleration 55,1 s, as found in the 

 last example, to the given time, we 

 should have sid. time 20. 28. 5,5. 



317 



