8.2$ Mr. Pigott’s Obfervathns 
At its greatefl brightnefs 44 ± hours. 
In decreafing - - 62 ± hours. 
At its lead brightnefs 30 ± hours. 
In increafing - - 36 ± hours. 
All thefe changes, which hitherto feem to be regular and con- 
ffant, are performed in 7 days 4 hours 38 — minutes; this Ifhall 
ifile its period, and hereafter will fhew how it is determined 
with fuch exadnefs. 
The flats to which q Antinoi was compared are in order 
thus : $ Aquilae third magnitude, /3 Aquilae and 9 Serpentis 
fourth magnitudes, ; Antinoi fourth or fifth magnitude, and p, 
Aquilae a bright fifth. I find, by feveral years obfervation, 
that 0 Aquilae retains the fame brightnefs. t Antinoi, which 
lias been examined with particular attention by Mr. Goqd- 
ricke and myfelf, is fufpeded by us both to be fubjed to a 
fmall variation, but not fufficiently apparent, fo as to affed 
materially thefe companions, and polfibly it may be only the 
effed of fome optical illufion ; for I have frequently remarked, 
that both in the twilight and moon-light, or when the air is in 
the lead hazy, there is a greater difference between the bright- 
nefs of many of the liars, than in a dark night and clear Iky. 
In the following journal of obfervations of rj Antinoi, the 
Greek letters / 3 , S 9 p 9 belong to Aquila, and ;, v, to Antinous ; 
fecondly, the magnitudes marked in column the third are by 
ebimation, and can be of no further ufe than merely to give, 
at firfl fight, an idea of the bar’s brightnefs ; and laftly, the 
lines diftinguilhed by inverted commas, are extrads from Mr. 
Goodricke’s journal, whofe friendly abidance I have often ex- 
perienced, and was the more welcome on this occafion^ becaufe 
repeated attention and great exadnefs were requifite. 
.e Dates, 
