New Comet. 393 



JSTote on Olservaiions which should be attended to for the Pur- 

 pose of determining the Siins Parallax. 



1. There will be an oppoytion of Mais in December 1817- 

 This planet will be for some time on the parallel of the 118th 



star of Tanrus, whose mean position on the Ist January 1818 

 will be A\ 79 31' 9"-4. Dec. 24° :)9' 32"'3. From the 19th 

 November the difference of declination between the planet and 

 ihe star will be only eight minutes ; and that of their right ascen- 

 sion in time only a few minntes. It will be no difficult matter, 

 therefore, to measure their difference of dechnation several times 

 each night, which, compared with observations of the same taken 

 in Europe, will give the parallax of Mars. 



N.B. It must be remarked, that the star is double; but as 

 the distance between the two stars is small, it will be best to refer 

 the interval which separates them to the planet. 



2. The same by the inferior conjunction of Venus on the 26th 

 December 1818. ■ r^ 



On the 24th November Venus will be in conjunction with a- Ca- 

 pricorni, and their differeiice of latitude will be only 5 minntes. 



On the 1 9th December the planet vv^ill be on the parallel of 

 T Sagittarii. 



And on the 21st December on that of <r Sagittarii. 



But as it is not likely that these stars can be easily seen in the 

 daytime, within so small a distance from the sun, it will be better 

 to'compare the pla\>et with Antares A\ 16'^ IS", and Dec. 26^' S. 

 on tlie parallel of which s'tar it will be 2Sth November. 



if these phaMjomena could be observed in India, and at the 

 Cape of Good Hope, the parallax of Venus might be obtained 

 with great precision. The absolute error of the instrument 

 would be immaterial, provided the planet were always referred to 

 the star. 



NEW COMKT. 



Midivolda, April 13.— Yesterday evening, about fifteen mi- 

 nutes past ten o'clock, a comet was seen in the west, but on 

 account of the dark clouds v.-as not visible above three minutes. 

 Its light so mucii outshone the stars, that it was not easy to de- 

 termine precisely in what constellation it appeared. It was in or 

 near Gemini. 



The al)ove notice in the foreign journals having led to a very 

 diligent scrutiny of the heavens by the astronomers of this coun- 

 try, the followi'ng are the reports' of the only successful observa- 

 tions which we believe have as yet been made in England. 



To the Editor,— Sir, the appearance of a teles(;opic comet 

 having been announced in some of the continental journals, I 

 carefully watched for it, with a telescope of the niagniiyuig 



power 



