Page:Popular Science Monthly Volume 29.djvu/82

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THE POPULAR SCIENCE MONTHLY.

with the naked eye is very small. All stars discernible by the keenest of human sight, without the aid of a telescope, have long been noted down on charts, and their position in the vaulted dome exactly determined.

Should one count up all the stars in those parts of the heavens that become visible to us in the course of a year, even this sum would notFig. 1. by far approach seven thousand. However, if one resorts to a telescope, matters grow to be quite different; more and more stars then become visible, the number depending on the strength of the instrument in use. Fig. 1 represents a certain portion of the heavens as seen by the unaided eye. One discerns two brighter stars and several smaller ones. Fig. 2 shows this same spot, but as seen through a powerful telescope. This picture has not merely been drawn from fancy. Each point, even the smallest, was, after close observation, entered with the utmost care on a large chart, of which this illustration

Fig. 2.

is a copy, but reduced in size. And each single one of these stars is a mighty body, in its sphere a shining sun, equaling ours in grandeur and splendor. From the beginning, each of these suns has traveled its prescribed round, and has filled its place in the vast universe. Such charts of the stars are leaves from the great volume of