88 SOME NOTES ON JUPITER DURING HIS OPPOSITION OP 1876. 



his dependents, bound together inseparably as they are by the law 

 of gravitation." 



Whether these influences, as in the case of Jupiter, make them- 

 selves manifest to us by wha,t our telescopes show us to be going 

 on on his disk cannot yet however be placed among astrono- 

 mical facts. It is to obtain evidence on this point that they are 

 so anxious in the Northern hemisphere that Southern observers 

 should fill the gap which, in consequence of the great Southern 

 declination of Jupiter, would otherwise exist in the records on 

 which this theory is to be built. 



Turning our attention now to the minute white spots men- 

 tioned in the circular, let us see what records we can find of their 

 previous appearance, and what connection we can trace between 

 their apparition and the maximum of the solar spots. I think 

 we shall find there are some striking coincidences. 



The first account that I can lay my hand on is one by Cassini, 

 in the " Memoires del' Academic" for 1692, where there is a paper 

 in which he notices great changes and bright spots on Jupiter. 

 I find there was a sun-spot maximum for the year 1693. 



There are some observations of Sir William Herschel of white 

 spots and irregular bands in 1778, 1779, and 1780. He also 

 observes what he calls a similar appearance in 1790. Two very 

 considerable solar and magnetic maxima occurred — the one in 

 1779, and the other in 1789. 



In the year 1848 the Eev. W. E. Dawes perceived some very 

 remarkable white spots in Jupiter, which he likened to the 

 circular craters on the Moon, and on the 27th March of the 

 following year, Mr. Las sell saw them in his 20-feet equatorial 

 reflector. Again, in May of the same year. Professor Schumacker, 

 of Altona, observed four or five of these features on one of the 

 belts, which he thus describes : — " They are white spots, and are 

 all perfectly round, distinct, and bright. . The largest of them is 

 as distinct and well-defined as the disk of a satellite appears in 

 a 9-feet reflector. They are striking phenomena, keeping their 

 relative positions, as they are carried along by Jupiter's rotation, 

 and there are no other similar spots on his disk." A sun-spot 

 maximum occurred just at this time. De La Eue, in 1856, very 

 near a sun-spot minimum, with 13 inches of aperture, makes a 

 drawing showing no traces of white spots, and another drawing 

 made at the same time by Piazzi Smyth, on Tennerifie, agrees 

 almost entirely with his. Lassell again, in 1859, approaching a 

 spot maximum, figures the white markings, and says he " had 

 failed to see these spots for many years, but latterly they had 

 appeared again." In 1861, Sir W. Keith Murray contributed 

 some drawings with a 9-inch refractor showing the spots, and 

 other observers confirmed his observations with telescopes of 

 5 inches and upwards. At the same time the report of the 



