114 Hijiory tj Ajlronoviy for the Year iSoi. 



Bouvard followed with affidultv, and the orbit of which 

 will be very well determined, though it appeared only ten 

 davs. 



Thulis has fcnt me fcven obfervations, from the I2th to 

 the 2i(l of July, deduced only from the azimuths and alti- 

 tudes, without having been able to conipare them with ftars ; 

 but we were more fortunate at Paris, and Mechain had fuf- 

 ficient data to calculate the elements in the following manner 

 by a lirft (ketch: 



T ,• • r. r Perihelion - 6' 17° 



Inclmation - 25 ( j^j^^^,^^.^ _ ^ 



Node - o^b|,, .>- . a ^ ,. u 



Ll'allage Augult 7, 15 hours. 



This fmall comet, found ahnoft at the fiime time bv four 

 perlons, proves that it is not difficult to difcover comets. 

 Three or four have been feen in the courfe of a year; and 

 if a few amateurs would employ thcmfelves in fearching for 

 them, it is probable that the number would rapidly increafe. 

 This is ftill a defideratum in aftronomy ; it is humiliating 

 for us, that we do not know whether it is by thoufands or 

 tens of thoufands that comets ought to be counted, and whe- 

 ther they return, or lofc themfelves in the immenfity of the 

 univerfe. 



Nothing is necelTary but a common telefcope to fearch for 

 and find comets, and to point out their fituation to aflrono- 

 mcrs. 1 fuppofe that the obferver is provided with a wooden 

 quadrant of two feet radius, which any carpenter can make, 

 and that a meridian has been traced out with a large circle 

 on the floor; that the circle is divided into degrees, and that 

 the inftrument is directed towards the place where the comet 

 is. Both the altitude and diflance from the meridian will be 

 thus found for the time of obfervation. Nothing more will 

 be necefTary to enable allronomers to find a comet which 

 may have been announced. To find comets, it is not necef- 

 fary, therefore, to know the ftars. But there are a hundred 

 nebula' which have iome refemblance to fmall comets. Thole 

 who wifli to diftinguifli them muft have recourie to the Ce- 

 leftial Atlas *, where they are all marked. This ftudy will 

 neither be long nor difhcult. The Atlas of Berlin is much 

 more complete: we fhall give an account of it hereafter. 



The night-telefcope employed by Meflier, and with which 

 he has already found twenty comets, is two feet in length, 

 and has an aperture of 2, inches: it has three eye-glaife;?. 

 The firfl; ne.xt the eye has a focus of 3' inches, and 10 lines 

 of aperture; the feeond 9, and the third 9- inches. There 

 arc 10 lines between the two, and 5 inches between the pre- 

 • A Paris, chez Lamarche, rue du Foin- 



4 ceding 



