1 9 1 
Changes that happen to the fixed Stars. 
All observations upon star^ of any considerable magnitude 
have been made with the naked eye. I was unwilling to in- 
troduce the fallacies, or at least the difficulties that occur in 
the use of a telescope, owing to various causes that need not 
be mentioned, where I could possibly do without it. In num- 
berless instances, however, the telescope has been recurred to, 
notwithstanding the stars under examination were not so small 
but that I saw r them very well with the naked eye ; for in 
very fine nights, and in high situations, all the stars of the 
sixth, and most of the seventh magnitude, are sufficiently 
visible. But when small stars were situated very near each 
ether, or very near brighter ones, it became necessary to re- 
move the objection arising from the light of one star either 
overpowering or blending with that of the other. 
Care has been taken in observations with the naked eye not 
to fix upon a star as-a standard which has another close to it; 
for the united light of the two stars would certainly cause de- 
ceptions. And stars that stand in this predicament of course 
have been referred to others with the assistance of a telescope. 
The largest stars, and in general all such as had no conve- 
nient stars in the same constellation to be compared with 
them, have their lustre ascertained by such as I could find in 
the neighbouring part of the heavens. 
Whenever I use the expression of magnitude, which though 
not of so nice and critical distinction as would be required for 
the purpose of my catalogue, is still a very useful one for ge- 
neral purposes, I have endeavoured to conform my mental 
standard to the notation of Flamsteed. 
The most remarkable expressions of brightness which are 
contradictory to Flamsteed's magnitudes, are pointed out in 
