bj Direction, Place, at .ii
- R$
17 The sine of latitudemultiplied by twelve, ant; aivided by the sine of co-latitudegives the equinoctial shadow. What is (Hig. 11), }B( B : : C८: %e the value of the guommon 1 ।। ite being substituted in the rule for the gnormon itself 17 The difference of the latitude of the place of obser vation and the sms meridual zonitli-distance in degrees (fakta /), if their directom le to haneor tlcir sum, 18, J/ {lgir direction le different, is the sun's declination it ih: sine of thi५ latter le multiplied by Jattius and divided by the $int of greatc<f deaPaimthe ult, converted to are, will be the qu'+ longitude, if le ik in the quadramite commencing with Arties 18. If in that commencing with Calee subtract from a half. circle; it in that womending with Tibra, add a half-circle; if in that commencing it ('apricorm, subtract from a circle : the re. sult, in each case, a lie true (thu) longitudle of the Bun at mid-day 20. 'Fo this 1 the quR tion of the apix (qid phala) be vepeatedly applied, with a contrary sign, the Sun's aucan longitude will be found hus passag teach» ho when he lateude of hu observey is known, the sun's declamation, and his true and incan longitados, may be found by observin thus zonth-distance at noon, "he sevol parts of Bhe process are all of them the converse of processes proviously given, and require no explur To ind the sun 's declnation from his tmeridian z€uth-distance and the latitude (reckoned as south, by v. 1), the ule given above, in verses 15 and ]B, is inverted; the true longitu {s found from the declination by he inversion of the method taught in ii. १३, account being baken cof {he quadrant in which the sun may be cording to the principle of ii. 30 : and finally, the can may be derived frod the true longitude by a n¢thorl of sucop8sive approximation, apply pg, a varse the equation of the cente, १५ calculated by 1, 89. tt a hardly neces8ay to remark Zhn¢ %his is a very rough process for
- itainin४itlb Sun's longitude, and could givo, especially in the hands
inu, observers, results only distantly approaching to accuracy. The sun of the latitude of the place of observation { the sun's deolination, if their direction 13 the same, or, in the ary:ase,heir, difference, ई