-RECENT CHANGES IN THE SURFACE OF JUPITER. 65 
marki and some of these were subject to frequent changes ; in 
addition to these markings my measures included some fainter 
belts in the temperate zones and the polar ca 
to have disappeared, and the remaining two seem much altered in 
density, colour, and position, especially the northern one, which 
often seemed of a brilliant red. 
I selected a time for the measures when the great red spot 
was visible, so that its latitude might be thereby fixed. I was 
not a little surprised, when I came to compare these measures 
with others taken in 1876, to find that the one set might be sub- 
stituted for the other without much error; I then compared other 
measures that I had taken, with similar results, and looked to see 
if I could find older measures. So far I have only succeeded in 
years, and seem to have been very carefully made. They referred 
to the two extremes of each faint belt, which were no doubt the 
best marked features, and I find that they agree with my 
thus ap 
Seventy years, thefour best marked belts of Jupiter were found in the 
Same latitudes, and it is hence a fair inference that they are 
always there. During the four years over which my own work 
has extended, several fainter belts in the temperate zones and the 
Polar caps have remained in the same positions. 
Comparing the made June 2, 1876, and November 2, 
1880, photographed copies of which are attached, no one would at 
first sight think te 
