164 Astronomical and Nautical CoUectiom. 



tain limits. But in an observatory situated in the southern he-" 

 misphere, all the causes, which distort our European observa- 

 tions by small errors which cannot be avoided, and which are 

 with great difficulty discovered ; small irregularities of refrac- 

 tion, for example, small flexures of the telescopes of our instru- 

 ments, and other similar disturbances, would all operate in con- 

 trary directions ; so that, by a comparison of both series of ob- 

 servations, the effects of these common causes of error might be 

 discovered and removed. The Cape of Good Hope is so much 

 the better situated for such an observatory, as it lies under a 

 meridian which passes through the middle of Europe. 



The great comet of last summer I was perhaps able to follow 

 longer than most other astronomers. I saw it last on the 20th 

 October, and on the 12th I obtained a good observation. Per- 

 haps some of your friends would like to have my last observa- 

 tions, I therefore subjoin them. 



Mean Time Bremen. Apparent A. R. App. Decl:N. 



O / '/ O / /' Oil' 



1819. Sept. 17. 8 14 50 133 40 2 50 38 59 



19. 8 3 38 133 50 1 50 46 



24. 9 4 31 134 7 43 51 6 18 



13 36 27 134 8 35 51 6 51 



Oct. 12. 7 52 45 133 20 54 53 52 



Besides General Von Lindener, two or three other observers 

 here have announced that they had been looking at the sun's 

 disc with telescopes on the 26th June 1819, at the time of the 

 comet's transit. Lindener and one other person saw absolutely 

 notiiing on the disc ; the other two maintain that they perceived 

 a faint, confused, and ill defined spot. From these accounts, 

 compared together, it may be inferred, that the nucleus of this 

 comet must have been so transparent as only to occasion a slight 

 obscurity on the part of the surface over which it passed, so 

 inconsiderable as easily to have escaped observation. 



iii. Observations and Elements of the Orbit of the Great Comet of 

 1819. %</ieRev.J. Brinkley, D.D., F.R.S. 

 The remarkable comet, that appeared in July last, was ob- 

 served at the observatory of Trinity College. Dublin, with the 



