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POPULAR SCIENCE REVIEW. 
question our doubts are not altogether dispelled. Extreme 
acuteness of vision will, in individual instances, lead to success 
of abnormal character, and certainly in Mr. Ward’s case the 
remarkable accordances in the observed and calculated positions 
appear to be conclusive evidence that he was not mistaken. 
It will be readily inferred that the great distance, and con- 
sequent feebleness, of Uranus must render any markings upon 
the disc of the planet beyond the reach of our best telescopes ; 
and indeed this appears to have been a matter of common 
experience. Though the surface has been often scanned for 
traces of spots, we seldom find mention that any have been 
distinguished. Consequently the period of rotation has yet to 
be determined. It is true that an approximate value was 
assigned by Mr. T. H. Buffham from observations with a 9-inch 
reflector in 1870 and 1872, but the materials on which the com- 
putation was based were slender and necessarily somewhat un- 
certain, so that his period of about twelve hours stands greatly 
in need of confirmation. The bright spots and zones seen on 
the disk in the years mentioned appear to have entirely eluded 
other observers, though they are probably phenomena of per- 
manent character and within reach of instruments of moderate 
size. Mr. Buffham * thus describes them : — 
‘ 1870, Jan. 25, ll h to 12 h in clear and tolerably steady air ; 
power 132 showed that the disk was not uniform. With powers 
202 and 320, two round bright spots were perceived, not quite 
crossing the centre but a little nearer to the eastern side of the 
planet, the position angle of a line passing through their centres 
being about 20° and 200, — ellipticity of Uranus seemed obvious, 
the major axis lying parallel to the line of the spots. 
4 Jan. 27, 10 h to 10J h ; some fog, and definition not good, 
but the appearance of the spots was almost exactly the same as 
on the 25th.’ 
On March 19 glimpses were obtained of a light streak and 
two spots. On April 1, 4, 6, and 8, a luminous zone was seen 
on the disk, and in February and March, 1872, when observations 
were resumed, certain regions were noted brighter than others, 
and underwent changes indicating the rotation of the planet in 
a similar direction to that derived from the results obtained in 
1870. Mr. Buffham points out that if this is admitted, then 
the plane of the planet’s equator is not coincident with the 
plane of the orbits of the satellites. Nor need we be surprised 
at this departure from the general rule, where such an anomalous 
inclination exists. In singular confirmation of this is Mr. Las- 
sell’s observation of 1862, Jan. 29, where he says, “ I received 
an impression which I am unable to render certain of an equa- 
torial dark belt, and of an ellipticity of form.” ’ 
* Monthly Notices It. A. S., January, 1873. 
