7° Dr. Herschel’s Discovery of four additional 
with some rays or inequalities, when high powers are used, 
and the object to be viewed is very minute. It seems, how- 
ever, from the observations of March i6‘, 1789, and Feb. 2 6 y 
1792, that the cause of deception, in this case, must be looked 
for elsewhere. It has often happened, that the situation of the 
eye-glass, being on one side of the tube, which brings the ob- 
server close to the mouth of it, has occasioned a visible defect 
in the view of a very minute object, when proper care has not 
been taken to keep out of the way ; especially when the wind 
is in such a quarter as to come from the observer across the 
telescope. The direction of a current of air alone may also 
affect vision. Without, however, entering further into the dis- 
cussion of a subject that must be attended with uncertainty, I 
will only add, that the observation of the 26th seems to be very 
decisive against the existence of a ring. When the surmises 
arose at first, I thought it proper to suppose, that a ring might 
be in such a situation as to render it almost invisible ; and that, 
consequently, observations should not be given up, till a suffi- 
cient time had elapsed to obtain a better view of such a sup- 
posed ring, by a removal of the planet from its node. This 
has now sufficiently been obtained in the course of ten years ; 
for, let the node of the ring have been in any situation what- 
soever, provided it kept to the same, we must by this time 
have had a pretty good view of the ring itself. Placing there- 
fore great confidence on the observation of March 5, 1792, 
supported by my late views of the planet, I venture to affirm, 
that it has no ring in the least resembling that, or rather those, 
of Saturn. 
The flattening of the poles of the planet seems to be suffi- 
ciently ascertained by many observations. The 7-feet, the 
