March 30, 1871 | 
NATURE 

aperture and power most frequently of 212.* For the 
sake of convenience we may call the dark streaks Je/ts 
and the luminous ones zozes ; and we may divide the disc 
into three portions—the equatorial, the northern, and the 
southern region. 
The equatorial region may be described as a coloured 
girdle surrounding the planet, and consisting of two belts 
with a lighter space included betweenthem. The relative 
proportion of these belts—the edges of the girdle—seems not 
invariable, and should be noted. Especial attention should 
be paid also to the tint of this region, as a diminution of 
intensity is suspected. The centre of the girdle is one of 
the most interesting portions of the disc, containing a num- 
ber of dark markings projecting into it from the S. (upper 
as inverted) border, but not reaching the opposite N. edge, 
and taking the form of the piers of a bridge, or, when more 
fully developed or perfectly seen, of festoons, in which 
lichter yellow elliptical areas are included. For atmo- 
spheric phenomena, as these appear to be, they maintain 
a singular degree of uniformity and persistency, although 
their dimensions seem to vary, on different sides of the 
globe. An examination of earlier drawings, some of them 
in private hands, which I have been permitted to inspect, 
shows that, although at present conspicuous chiefly in the 
equatorial region, they are by no means restricted to that 
portion of the planet’s surface. And here it may be noted 
that for the due comprehension of these details, especial 
attention should be paid to the laws of perspective. The 
Joreshortening, as it is technically termed, of the regions 
approximating to the planet’s limb, has a great influence 
on the apparent form of every marking lying in a meri- 
dional direction, while the ordinary belts are entirely un- 
affected by it. In all probability our familiarity from early 
youth with the common maps of the globe in two hemi- 
spheres may tend to preoccupy us with erroneous im- 
pressions in this respect, the exterior portions of those 
hemispheres being projected on an entirely artificial 
system, which exhibits them as little foreshortened as may 
be, and consequently extremely unlike their natural appear- 
ance on the globe. For any one unacquainted with per- 
spective, it would be worth while to compare the edges of 
such a map with the corresponding portions of a terrestrial 
globe, as regarded from one point of view; or a globe 
being surrounded with a strip of paper bearing a number 
of equidistant markings, it will be mstructive to notice the 
wide change in their aspect as the globe is made to rotate 
on its axis. To this foreshortening, it may be noted, rather 
than to atmospheric obscuration, as has often been alleged, 
we may ascribe the invisibility of many features of the 
planet in the neighbourhood of the limb ; the existence of 
an external hazy envelope may be probable, but the fading 
of the belts at their extremities, which has often been re- 
ferred to in this light, cannot be considered conclusive ; 
for it is remarkable that as telescopes have been improved, 
this alleged fading has been less spoken of. It is not at 
all shown in the finest drawing hitherto published (that by 
De La Rue), in the use of an instrument of the most critical 
defining power ; and with my nine-inch speculum it is so 
doubtful under favourable circumstances that I should not 
have independently noted it. Attention might well be 
given to this point, as if a difference should be found with 
the same eye and telescope in different seasons, it would 
plainly suggest atmospheric variation. j 
The northern region commences with a very luminous 
zone, to my eye the brightest and whitest part of the disc, 
and usually free from interruptions. Next to this comes 
a belt of remarkable intensity and permanency, from the 
edges of which dark but short markings have been, though 
rarely, seen to project. Its colour formed an uniform 
contrast with the equatorial belts during the last season ; 
but I have thought this less striking recently. This great 
belt is commonly divided on the north side by a narrow 
light zone from a small thin companion of uncertain 
* The results have already been given in detail in the Popular Science 
Review, July 1870. 


431 

aspect, and during the present season not invariably 
parallel to its overpowering neighbour ; sometimes, it is a 
mere edging to a streaky cap reaching to the pole, at 
others, a light stripe intervenes. 
Passing now to the other side of the central girdle, we 
find next to its south border a region of some breadth, 
less luminous and much less tranquil than the correspond- 
ing north zone. It is interrupted by a belt of variable 
position and aspect, sometimes very feeble and narrow, at 
others a rival or more to the neighbouring edge of the 
central girdle. Its origin lies so close to this latter belt that 
it almost seems to branch out from it, and last season 
it followed an independent, and, in part, slightly spiral 
track round the greater part of the globe before its 
disappearance ; at present I have not been able to trace 
its whole course, but I see that some remarkable changes 
have taken place. In this zone lay last winter the 
very curious elliptical marking described by Gledhill 
and Mayer, but not, I believe, by others. I never saw it, 
though it must have been repeatedly before my eyes—a 
valuable caution to myself and-other students—for I had 
supposed myself too familiar with every portion of the 
disc to have overlooked so singular a feature. It is pos- 
sible that my failure may have arisen from my having 
omitted to stop off the extreme margin of my speculum, 
which lies quite open in its cell without any rim. I had 
been repeatedly requested to do so by its accomplished 
maker, but from want of leisure and some difficulty in 
the arrangement had neglected it till near the close 
of those observations, when the evident improvement of 
definition made me regret that I had recourse to the ex- 
pedient so late. This precaution, which is requisite with 
all open specula, is in the ordinary mode of mounting 
rendered needless by enclosure in a cell. ; 
South of this changeable region lies a grey belt of un- 
certain form and extent, sometimes divided in two, at others 
partially interrupted by white spots. Between this and the 
south pole another belt is occasionally seen, and I have 
thought the colouring of this and the corresponding 
north area, not identical. The extreme foreshortening 
of these regions, and the nearly vertical position 
of the planet’s axis, must ever prevent us from ob- 
taining much knowledge of a wide tract surrounding 
either pole. The north pole is at present the one more ex- 
posed, not only to our view but to solar influences ; and it 
may be worthy of notice that there is some existing dis- 
similarity in the aspect of the two hemispheres. An 
axial inclination of little more than 3° would indeed cause 
but little variety of season on the earth; but with the 
very dissimilar constitution and condition of Jupiter we 
know not how much may be effected by its influence. 
These suggestions need not be carried into further de- 
tail. We shall however note, for the benefit of those 
who are little accustomed to the object, that the optical 
changes produced by rotation alone are such that we 
must be on our guard against being misled by their ex- 
tent and rapidity. Big: 
. W. WEBB 


NOTES 
We have received the first Report of the Royal Commission on 
Scientific Instruction and the Advancement of Science just as we 
were going to press. We therefore let the Report, which we 
print elsewhere, speak for itself, We observe that it is signed 
by all the Commissioners, and we trust that it is the earnest of 
other, equally if not more important, ones to follow. 
We are informed that the future of the Kew Observatory is 
now being considered by the Kew Committee. We would ask 
whether the occasion is not a fitting one to bring before the 
Royal Commission on the Advancement of Science, which is now 
sitting, the disgraceful state of this country in the matter of such 
