10. Herschel, in the visit which he made to the Cape of Good Hope, for the purpose of erecting to his father the most splendid monument that son ever erected,--the completed survey of the vault of heaven,--had full opportunity of studying a certain pair of remarkable bright spaces of the skies, filled with a cloudy light, which lie near the southern pole; and which, having been unavoidably noticed by the first Antarctic voyagers, are called the _Magellanic Clouds_. When the larger of these two clouds is examined through powerful telescopes, it presents, we are told, a constitution of uncommon complexity: "large patches and tracts of nebulosity in every stage of resolution, from light, irresolvable with eighteen inches of reflecting aperture, up to perfectly separated stars like the Milky Way, and clustering groups sufficiently insulated and condensed to come under the designation of irregular, and in some cases pretty rich clusters. But besides these, there are also nebulæ in abundance, both regular and irregular; globular clusters in every stage of condensation, and objects of a nebulous character quite peculiar, and which have no analogies in any other region of the heavens."[1] He goes on to say, that these nebulæ and clusters are far more crowded in this space than they are in any other, even the most crowded parts, of the nebulous heavens. This _Nubecula Major_, as it is termed, is of a round or oval form, and its diameter is about six degrees, so that it is about twelve times the apparent diameter of the moon. The _Nubecula Minor_ is a smaller patch of the same kind. If we suppose the space occupied by the various objects which the nubecula major includes, to be, in a general way, spherical, its nearest and most remote parts must (as its angular size proves) differ in their distance from us by little more than a tenth part of our distance from its centre. That the two nubeculæ are thus approximately spherical spaces, is in the highest degree probable; not only from the peculiarity of their contents, which suggests the notion of a peculiar group of objects, collected into a limited space; but from the barrenness, as to such objects, of the sky in the neighborhood of these Magellanic Clouds. To suppose (the only other possible supposition) that they are two columns of space, with their ends turned towards us, and their lengths hundreds and thousands of times their breadths, would be too fantastical a proceeding to be tolerated; and would, after all, not explain the facts without further altogether arbitrary assumptions.