THE PLANET JUPITER IN OCT. AND NOV. 1880. 
7 
uprush, or emission, from the planet’s surface ; and that as this 
reaches the outer regions of the atmosphere it is dispersed in the 
direction of the longitude by the effects of the rapid rotatory 
motion of the planet. It is certain that these small spots are 
different in some essential details from the large spot in the 
southern hemisphere, inasmuch as they display a very erratic 
form of appearance and rate of motion, and are probably to be 
accounted for in a totally different manner. On the other 
hand, the minute elliptical spot, south preceding the red spot, 
has, by its constancy of position, sufficiently proved itself to be 
of analogous character. 
We have mentioned light patches and spots as discernible in 
the southern interior border of the great equatorial belt, and 
there is one of these which should be singled out as displaying 
a more prominent aspect than any of the others. It was first 
seen by the writer just before midnight on September 18th, 
when the following reference was entered in his note-book : — 
‘ 1880. September 18th, ll h 50 m , observed Jupiter with 
10-inch reflector, power 150 ; but there were storms and clouds 
which interrupted, though the planet was fairly well defined at 
times. I noticed a bright spot' directly, about half way across 
the disc and just south of the equator. Another bright, ellip- 
tical spot preceded this, and indeed on the equatorial borders of 
the great southern belt the surface was very bright in places, 
giving the impression of more objects of similar kind. The 
chief spot had a pearly whiteness and stood out with con- 
spicuous plainness amongst the mass of detail faintly traceable 
along the planet’s equator.’ 
I took particular care to re-observe this curious appearance 
as often as possible during the ensuing months of October and 
November, and to note, with as much accuracy as eye- estimates 
permitted, the exact times when it crossed the central meridian 
of Jupiter. The following results were thus obtained : — 
Sept. 18 
h m 
. 11 50 ... 
Long. 
85°8 
Nov. 19 
h. m 
. 9 23 ... 
Long. 
339-4 
Oct. 20 
. 11 38 ... 
221-9 
Nov. 20 
. 5 2 ... 
332-a 
Oct. 30 
. 7 28 ... 
137-5 
Nov. 21 
. 10 41 ... 
327-8 
Nov. 2 
. 14 15 ... 
115-6 
Nov. 26 
. 8 44 ... 
289-9 
Nov. 3 
. 9 47 ... 
104-2 
Nov. 27 
. 4 19 ... 
280-2 
Nov. 4 
. 5 25 ... 
96-4 
Nov. 28 
. 9 51 ... 
271-4 
Nov. 8 
. 7 48 ... 
65-4 
Nov. 29 
. 5 27 ... 
262-4 
Nov. 17 
. 8 14 ... 
356-7 
Dec. 3 
. 7 54 ... 
233-4 
Thus in 76 days the spot had apparently traversed 572° *4 of 
Jovian longitude, which is equivalent to 7 0- 5 per day. This is 
with reference to the assumed position of the first meridian, 
