322 A METHOD OF CALCULATING 



6. Add the fecant of B, the fine of A, and the cofine 

 of the latitude of the place, together; the fum (rejecting 

 twice radius) is the fine of the altitude of the nonagefi- 

 mal degree. 



7. Add the tangent of the latitude to the tangent of 

 the obliquity of the ecliptic ; the fum is the fine of an 

 angle, which call X. 



8. When the right afcenfion of the meridian is 



360—X& 90 1 £ r g 1 X & 90 i « 1 r B 

 90&180+X I - J * I 90&180— X M UJ 180— B 

 |i 180+X&270 fz 1 - [180— X&270 fa N1 180+B 



« L 270&360— x J = L ° J 270 & x J = J L 3 6o— b J 2 



_c 



of the nonagefimal degree. 



9. Add the moon's latitude to 90 when it is of a con- 

 trary name to the latitude of the place; but fubtra6t it 

 from 90 when it is of the fame name; the fum or re- 

 mainder is the moon's polar diftance. Alfo take the 

 difference between the moon's longitude and the longi- 

 tude of the nonagefimal degree, which difference call 

 P : alfo let half the fum of the moon's polar diftance 

 and altitude of the nonagefimal degree be called Q, 

 and half their difference R. 



10. Add the fecant of Q, the cofine of R, and the 

 cotangent of half P, together; the fum is the tangent of 

 an arc m : alfo add the cofecant of Q, the fine of R, 

 and the cotangent of half P together; the fum is the 



tangent of an arc n. 



11. If 



