Page:Popular Science Monthly Volume 58.djvu/324

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POPULAR SCIENCE MONTHLY.

it is advisable to consider the distribution of the lucid stars as a whole.

Dr. Gould finds that the stars brighter than the fourth magnitude are arranged more symmetrically relatively to the bright stars we have just described than to the galactic circle. This and other facts suggested to him the existence of a small cluster within which our sun is eccentrically situated and which is itself not far from the middle plane of the galaxy. This cluster appears to be of a flattened shape and to consist of somewhat more than 400 stars of magnitudes ranging from

Fig. 4. Northern Hemisphere.

the first to the seventh. Since Gould wrote, the extreme inequality in the intrinsic brightness of the stars has been brought to light and seems to weaken the basis of his conclusion on this particular point.

A very thorough study of the subject, but without considering the galaxy, has also been made by Schiaparelli. The work is based on the photometric measures of Pickering and the Uranometria Argentina of Gould. One of its valuable features is a series of planispheres, showing in a visible form the star density in every region of the heavens for stars of various magnitudes. We reproduce in a condensed form two of