5 8 SOME OF THE MARKINGS ON JUPITER. 



the lower regions of the atmosphere, possibly the result of some 

 volcanic action. 



" The principal markings are called belts or bands, because 

 they surround almost continuously the body of the planet. Thus 

 these belts and bands are conveniently mapped out for purposes 

 of observation and study on the surface. (See diagram.) The 

 one covering the region of the equator is called the equatorial 

 band, and is characterised by a number of white flocculent spots 

 of various tints, chiefly of a yellowish hue, the yellowness being 

 far more dense at some seasons, which is the case at the present 

 date. 



There is a thin dark line very near the equator, which is 

 occasionally broken up into parts, and sometimes very difficult of 

 detection owing to its faintness. It is called the equatorial belt. 

 On the equatorial band there are frequently seen strange lines, 

 when definition is good, stretching quite across the space, and 

 generally at an angle to the axis of the planet. They are con- 

 ventionally called wisps. They vary in width and density, and 

 are always weired-looking objects." Bordering the equatorial 

 region there are two much denser belts. The upper one on 

 the diagram is called the South Equatorial belt, and the lower 

 one the North Equatorial belt. (It will be remembered that all 

 astronomical telescopes invert and reverse the object viewed.) 

 The southern of the great belts is always, more or less, in 

 activity, and perhaps the most interesting of any portion of the 

 planet. 



It is generally duplex, i.e., divided into two distinct portions, 

 though in some parts those two portions are united. It is, on 

 the whole, the most active part of the Jovian surface. It is very 

 disturbed at the present time, there being many dark and light 

 spots of various dimensions and intensity on both portions of 

 this belt. There is a curious bay or depression on the south 

 edge of the southern portion, and in this bay, though not 

 attached to it, there lies the wonderful red spot, which has 

 excited so much attention for several years past. The following, 

 that is the eastern end of the bay, is often very dark, and 



