THE STARRY HEAVENS IN Tl'LY. 



65 



being originally little nebulous clouds, 

 far out in space, came to feel the gravi- 

 tational pull of our sun and to fall toward 

 that body. Since both the cloud and our 

 sun are rushing through space, the 

 chance of an actual collision occurring 

 is almost infinitely small ; the comet will, 

 in fact, miss the sun but swing around 



then whenever we have a shower of 

 shooting stars it is because our earth 

 ploughs through a great stream of me- 

 teoric particles which were formerly 

 gathered more closely together into the 

 cloud form which we call a comet. 



The further behavior of this new body 

 as it approaches the sun will be watched 



FIGURE 



The path of the faint periodic comet, 1915 b, about the sun. 



that body, and if undisturbed by the pull 

 of any of the planets, will recede into 

 space, never to be seen by us again. 



The present comet will attain its near- 

 est approach to the sun on July i8. The 

 most interesting observation connected 

 with it thus far is the discovery that 

 during Alay its mass disrupted, probably 

 under the tidal and electrical forces of 

 the sun toward which it is falling, and 

 that four masses broke away from the 

 main head and are now receding from 

 this at the rate of about 2,000 miles a 

 day. It is believed that it is from comets 

 which are thus broken up and whose 

 substance is distributed for a great dis- 

 tance along their paths, that no shooting 

 star-streams are formed. If this is so. 



with great interest. It is indeed unfor- 

 tunate that just at this critical time it will 

 not be visible from our northern observa- 

 tories. 



Another most interesting comet w^as 

 re-discovered in April. This body upon 

 its first approach to the sun was dis- 

 turbed in its motion by Jupiter and so 

 forced to follow the closed path shown 

 in Figure 2. It passes completely around 

 this orbit in 5 years 10 months ; its last 

 return was in 1909, and it has appeared 

 altogether six times since its first discov- 

 ery. As the path of this body is so ac- 

 curately known, its apparent position 

 among the stars can be computed for any 

 time with great accuracy. It was search- 

 ed for this year by means of a delicate 



