NUMBER, DISTANCE, AND MAGNITUDE OF STARS. 159 



putation gives at 100,000,000, a number from which, if our globe and system were stricken 

 they would no more be missed than a unit taken from 



" the autumnal leaves that strew the brooks 



In Vallambrosa." 



There are several parts of the firmament in which stars appear to the naked eye closely 

 packed together, and others which present a general indivisible luminosity to the unas- 

 sisted vision. The chief of these are the Pleiades, Hyades, the Milky Way, and Presepe. 

 The latter is a region faintly gleaming in the sombre districts of Cancer, which may be 

 easily found by running a line through Castor and Pollux and continuing it to the south- 

 east about three times the distance between those stars. The ancients were acquainted 

 with Presepe, a speck of light which they supposed to be the general effect of three stars, 

 as it is not resolvable into component parts by the unaided gaze ; but Galileo with his 

 imperfect means discovered it to be a congress of thirty-six. The Hyades appear to 

 consist of five stars, but between thirty and forty are readily discernible under a moderate 

 instrumental power. The Pleiades also yield a similar result, their optical number, six 

 or seven, being largely multiplied by the application of a telescope. The constituents of 

 the group are thus stated in modern catalogues : 



Keppler - 32 stars. Hook - - 78 



De la Hire - - 64 Rheita - 118 



But the cluster easily resolves into about forty constituents. Of the Milky Way the 

 Roman poet wrote, as the path leading to great Jupiter's abode, whose "groundwork is of 

 stars." Milton, likewise, speaks of that " broad and ample road, whose dust is gold, and 

 pavement stars." These poetical conceptions become verities when an instrument suf- 

 ficiently powerful is directed to the zone in question. It is found to be composed of stars 

 which assume the appearance of a tortuous consecutive girdle of light, owing to their 

 grouping and distance. Some idea may be formed of their profuseness from the fact that 

 Herschel was led to the conclusion, when examining this wonderful region, that in some 

 parts of it no less than fifty thousand were included within a zone two degrees in breadth, 

 which passed under his review in a single hour's observation. Yet this is but a specimen 

 of countless combinations which are discoverable in the concavity of the heavens, so 

 remote from us as to escape the observation of the eye, yet recognised by its aided vision, 

 forming clusters of various shapes, as rich in stars as the zone which we can analyse 

 proves to be. 



That luminous celestial highway which the Greeks called the Galaxy, and the Romans 

 the Via Lactea, from its whiteness, is more or less visible at all seasons of the year ; but 

 in northern latitudes it is seen to. the best advantage in the interval between the close of 

 July and the beginning of November. It varies in breadth from four to eighteen 

 degrees, and also in brightness, being most resplendent in the southern hemisphere, about 

 the constellations Argo Navis, Robur Carolinum, and the Cross. " The general aspect," 

 says Sir John Herschel, " of the southern circumpolar region, including in that expres- 

 sion 60 or 70, is in a high degree rich and magnificent, owing to the superior brilliancy 

 and larger development of the Milky Way ; which from the constellation of Orion to that 

 of Antinous, is in a blaze of light, strangely interrupted, however, with vacant and almost 

 starless patches, especially in Scorpio near a Centauri and the Cross ; while to the north 

 it fades away pale and dim, and is in comparison hardly traceable." This vast zone is a 

 sensible annulus in the heavens, and most probably really of that shape. It passes from 

 the head of Cepheus about 30 from the North Pole, through Cassiopeia, nearly covering 

 Perseus, over part of Auriga, and crossing the ecliptic between the feet of Gemini and the 

 horns of Taurus, proceeds over the equinoctial into the southern hemisphere to within 20 



