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THE GUIDE TO NATURE 



we will be justified in believing from 

 the mathematical investigation of such 

 a swarm that their ultimate destiny is 

 to become, each of them, a sun sur- 



Figure 3. — The orbit in space of the new comet. 



rounded by smaller worlds. Either 

 hypothesis is a most interesting and 

 attractive one. 



The Star Cluster In Canes Venatici. 



At the point M, on a line from the 

 star A, (Figure i) to Arcturus, at H, 

 but somewhat nearer to H, there is a 

 remarkable cluster of thousands of 

 closely packed stars, no less than one- 

 tenth of which are suns which are con 

 tinuously varying in brightness. This 

 is a very curious and thus far wholly 

 unexplained fact. Evidently there is 

 here some unknown cause which acts 

 through this great cloud simultaneous- 

 ly on all of these suns, or else the many 

 stars vary because their origin and 

 past history have been substantially 

 the same. We do not even know the 

 cause of the striking variations ob- 

 served in many of the isolated bright 

 stars of the sky, nor is it certain 

 whether all of the clusters are a part 

 of our Milky Way cluster or not. A 

 further study of these wonderful ob- 

 jects will doubtless in the future throw 

 much light on these and many other 

 most interesting questions. 



the sun's rays. On the evening of 

 April 3 it passes to the east of Mars 

 and both planets may possibly be seen 

 for a few days before and after this 

 time, forming a beautiful figure in the 

 morning dawn. They must be looked 

 for very near the ground, a little to the 

 south of the east point for about one 

 and one-half hours before sunrise. 

 Mercury passes to the east of the sun 

 and becomes an evening star on May I. 



Venus is still brilliant in the morning 

 sky, rising about two hours before sun- 

 rise. Since February 6, however, it 

 has been steadily drawing nearer the 

 sun and it is therefore neither so bright 

 nor in so favorable a position for ob- 

 servation as it has been during the 

 past few weeks. 



Mars also remains close to the sun 

 in the morning sky. It may be de- 

 tected rising almost due east about one 

 and one-half hours before sunrise. The 

 planet is moving northward among the 

 stars; it crosses the celestial equator 

 on April 19, and at this time it will rise 

 exactly at the east point of the horizon. 



Jupiter is too near the sun to be 

 satisfactorily observed, but its distance 

 is continually increasing, and by April 

 30 it may be found very low in the 

 southeast for about two hours before 

 snnrse. 



Saturn, the only bright planet in our 

 evening skies, is still in excellent po- 

 sition for observation. It is moving 

 slowly northeastward, almost on the 

 boundary line between Taurus and 

 Gemini. The rings are now very wide- 

 ly opened out and it will be found 

 a beautiful object for study with a 

 small telescope. 



The Planets In April. 



Mercury, which reached its greatest 

 distance west of the sun on March 20, 

 draws steadily nearer this body 

 throughout the month, and after the 

 first few days of April is wholly lost in 



The New Comet. 



During the early days of March a 

 rather bright comet could be seen in 

 the early morning sky, but this body 

 has since been rapidly receding both 

 from the sun and from the earth and 

 it is now a difficult object in any tele- 

 scope. This comet fell toward the sun 

 from the region of the stars along the 

 path AP, (Figure 3), reaching its near- 

 est distance from the sun, at the point 

 P, on last August 2. At this time it 

 was one hundred and thirty-nine mill- 

 ions of miles from the sun, one and one- 



