on the periodical Star in Collo Ceti. 341 
that we ffiould obferve fome apparent diameter or other 
of the fun thus removed from us; and this is what I here 
have called the apparent diameter. This muft be owing 
to fome optical deception, de la lande explains it 
thus: “ Si l’on'voit dans les lunettes une lumiere eparfe 
“ qui environne les etoiles, qui les amplifie et les fait 
<( paroitre come fi elles avoient 5 a 6" de diametre, on 
doit attribuer cette apparence a la vivacite de leur lu- 
“ miere, a Fair environnant et illumine, a l’aberration des 
“ verres, a l’impreffion trop vive qui fe fait fur la retine.” 
061 . 19, 1779, The periodical liar preceded a very 
obfcure telefcopic liar at the diftance of 1 ' 45". 16. This 
meafure was extremely difficult to take, the fmall ftar 
being fo obfcure as hardly to bear the field of view to be 
fufficiently enlightened: both alfo having nearly the 
fame declination, they therefore pafs the parallel hairs of 
the micrometer almoft at rectangles. However, I Ihould 
fuppofe, the meafure muft be true to 3 or 4". 
I meafured the diftance once more, with a better light 
and more fatisfadtion to myfelf, and found it i' 5o".47, 
1 2 o’ clock, The periodical ftar is now about the me- 
ridian, and brighter than a arietis. 
06 t. 30, 1779, 9 o’clock, The periodical ftar is ftili- 
increafed, and vifibly larger than a arietis, though not in 
the meridian at prefent. 
Z z 2 — o’clock, 
