Mr. herschei/s Account of a Comet. 493 
in the fame ratio. Moreover, the comet being magnified much 
beyond what its light would admit of, appeared hazy and ill- 
defined with thefe great powers, while the ftars preferved that, 
iuftre and diftindnefs which from many thoufand obfervations 
1 Knew they would retain. The fequel has fhewn that my 
lurmifes-were well founded, this proving to-be the Comet we 
have lately obferved. 
I have reduced all my obfervations upon this Comet to the 
following tables. The firft contains the meafures of the gra- 
dual increafe of the Comet’s diameter. The micrometers I 
ufecl, when every circumflance is favourable, will meafure ex- 
tremely fmall angles, fuchas do not exceed a few feconds, true 
£0 6, 8, or 10 thirds at moll; and in the worfi fituations true 
£0 20 or 30 thirds : I have therefore given the meafures of the 
Comet’s diameter in feconds and thirds. And the parts of my 
micrometer being: thus reduced, I have alfo given all. the reft of' 
the meafures in the fame manner;, though in. large difiances, 
iuch as one, two, or three minutes, fo great an exadnefs, for: 
feyeral reafons, is not pretended to. 
TABZS 
