632 KANSAS CITY REVIEW OF SCIENCE. 



Jovian meridian directly north of the following end of red spot. As it requires 

 more than one hour for the Jovian rotation to carry the major axis of spot across 

 the central meridian, and all changes of relative position must take place be- 

 tween my micrometer threads, I had a very rare opportunity to compare changes, 

 however slight. Not twenty minutes had passed till I could see, independently 

 of the threads, that the white spot had a rapid motion relatively to the red spot. 

 It was so marked and proceeded so uniformly with the time that I resolved to 

 measure it minutely. My observation of the transit closed at 8h. lom. and then 

 I estimated by the eye that the bright nucleus had gained on the following end 

 of the red spot, in one hour, three-eighths of the interval between my threads. 

 The mean of a number of careful measures proved it to be three hundred and 

 sixty-one one-thousandths of the interval, or 4.33" of the Jovian disc. 



Now the question comes up, was this a motion of translation ? If so, we 

 shall have to believe that a motion can take place in the Jovian atmosphere at 

 the rate of nearly seven thousand miles per hour. As this seems scarcely credi- 

 ble, I prefer to think that this angular displacement is the index of a progressing 

 transmission of light through a lower stratum of atmosphere, or else a part of an 

 auroral display. I am the more inclined to consider the phenomenon as the 

 result of a progressive transmission of light from the body of the planet through 

 changing media, since the size and consistency of the nucleus changed consider- 

 ably during the hour. I decline, however, to speculate on the subject, and give 

 the fact and measure for what it may be worth. 



Within the last few years many of these bright spots have been observed. 

 That they seem to have a rapid motion has been shown over and over again. 

 Some of them have been followed entirely around the planet. 



I will add, that for the last two years the color of the equatorial belts has 

 remained gray or brown ; for some time previously they had borne a ruddy hue. 

 Occasionally the margins of the main belts have been tinged with red, and some- 

 times with a very fine blue. Within the last two years two very marked changes 

 have occurred: i. There are now three distinct broad equatorial belts in place 

 of two. 2. A very conspicuous belt now stretches entirely across the Southern 

 Hemisphere of the planet, and in apparent contact with the red spot. Its north- 

 ern margin, on the finest nights, is almost blue. It has been forming for months 

 past, but has taken its distinct outline within the last six months. It is now a 

 prominent feature of the great disc immediately south of red spot. It would be 

 highly instructive could all these successive changes be presented to the eye by 

 such drawings as would show not only the correct shape and outline through 

 successive weeks, but also discharges in consistency, continuity and color. 



Morrison Observatory, January 6, 1882. 



Note. — On January 22d at yh. 30m., an entirely new belt was observed in 

 the Equatorial Zone of Jupiter, situated between the middle and southern equa- 

 torial belts. It was continuous and very fine and sharp. I have never before 

 seen a belt in this position, though I have carefully examined the planet many 



