48 Statement of a Plan for 



zone of 30° of declination, there is another, viz. the perfecting 

 of the charts by the eye, which is so laborious and requires so 

 much time, that a single individual can make but little pro- 

 gress in it. This may, however, be removed by the co-opera- 

 tion of several ; and the active zeal now prevalent among 

 astronomers allows us to indulge in the hope that many will 

 assist in promoting so great and useful an undertaking. 



It is therefore the wish of the Academy of Sciences to unite 

 for this object the friends of astronomy ; and to procure for 

 them every possible facility. It invites all astronomers to as- 

 sist in filling up the 24- sheets of a complete celestial atlas, for 

 which the foundation has already been laid; viz.: from —15° 

 to +15° of declination and the 24 hours of right ascension: 

 laying down at the same time the following rules to be ob- 

 served in the execution. 



1 °. The net work, or scale, to consist of squares for the de- 

 grees of declination and right ascension : each degree mea- 

 suring 5§ Parisian lines (or 0*51 English inch). It should ex- 

 tend from 4 minutes of time before the beginning of an hour, 

 to 4 minutes of time after its termination ; and thus contain 

 510 squares. 



2°. In this net work are to be marked the stars observed at. 

 Palermo, Paris, and Konigsberg, reduced to the beginning of 

 the year 1800*. 



3°. The largest of them should be marked after the manner 

 of the pattern sheet attached to the present plan : those stars 

 which are visible only through a telescope, by larger and 

 smaller black rings ; and those visible by the naked eye, with 

 the addition of raysf. 



4°. If a star has been observed but once, the same should 

 be marked by a short faint line projecting from one side of it; 

 if twice, or more frequently, by two such lines, ohe on each 

 side of it %. For stars visible to the naked eye, this kind of 

 designation would lead to indistinctness, and is in fact need- 

 less, since they are all described in Piazzi's catalogue ; and 

 therefore show, by their rays, that they have already been 

 observed. 



5°. The sheets in this state must be compared with the 

 heavens : and all the stars, within the limits proposed for the 



* [The stars observed at Palermo are given in Piazzi's catalogue: those 

 observed at Paris, are given in the Histoire Celeste: and those observed at 

 Konigsberg, are given in M. Bessel's Observations. — Sec] 



f [These marks are similar to those adopted by M. Harding in his charts. 

 The exact mode of delineating the different magnitudes may be seen in the 

 pattern sheet. — Sec] 



J [For specimens of this mode of distinguishing the different stars, see 

 the pattern sheet, alluded to in the note in preceding page. — Sec] 



intended 



