43S Prece/jlsfor the Applicaiio/i of 



Precepts for the ^application of the New Tablks o/'Vbnus, 

 eovtained in n preceding Part of this Fohwie, illustrated hy 

 an Example. Bj/ the Editor of the Talles. 



The following concise precepts will apply, with very little al- 

 teration, to other planetary tables constructed according to the 

 improved arrangement. 



To find the Heliocentric Longitiide and Latitude. 



1 . From Tab. II. take out the epochs of the mean longitude, 

 perihelion, and node, with the ten argnments of perturbation, 

 and place them in an horizontal line. But if the given year be 

 not found in that Table, take the nearest preceding it *, and add 

 underneath the motions from Tab. I. for so many years as the 

 epoch fialjien tr^syi Tab. II. precedes the given vear. 



2. Under these, write down successively the mean motions 

 for the given month, day, hour, minute, and second, from Ta- 

 bles III. IV. and V. 



3. Add together the numbers in the several columns; rejecting 

 in the longitude, perihelion, and node, 12 sign?, and in the ar- 

 guments of perturbation, 1000, or any multiples thereof respec- 

 tively, if they occur. 



4. From the tabular mean longitude thus found (increased by 

 12 signs if necessary) subtract the longitude perihelion; the 

 remainder will be the mean anomaly, with which enter Tab. VI. 

 (making proportion for the minutes and seconds), and take out 

 the equation of the centre, which set down apart. 



5. With the ten several arguments of perturbation enter Ta- 

 ble VII. and take out the corresponding equations, which write 

 down successively under the quantity found by the last prece|)t, 

 and add the whole together. Then recur to Tab. VI. take from 

 it the secular variation of the elliptic ecjiiation, and apply the 

 same according to its sign to the sum just found : observing that 

 for a period anterior to 1800, the sign of the Table must be 

 changed. 



6. Add the corrected sum of the equations to the mean longi- 

 tude, and from the quantity thus obtained (increased by 12 signs 

 if necessary) subtract the longitude of the node, the remainder 

 is the argument of latitude and of reduction. 



7. With the last-mentioned argument take out from Tab. X. 

 the reduction, which being added to the corrected longitude before 

 found, gives the planet's true heliocentric longitude on the ecliptic 

 reckoned from the mean equinox. 



* Kxcppt 17M(), which, not being a. Julian Bisucrtilc, cannot be used in 

 coniuncdon «ilh Tab. I. 



8. The 



