THE STARRY ill-".. WENS IN JULY 



75 



glasses. At the point U, about half- 

 way between the stars V and T, there 

 is a remarkable cluster, called by Her- 

 schel the richest mass of stars in the 

 firmament, but which is so condensed 

 that in a small telescope it appears on- 

 ly as a filmy point of light. This clus- 

 ter is on the western borders of a re- 

 gion so remarkably starless that Her- 

 schel supposed that the stars of this 

 region were in some way drawn aside 

 to form the cluster. In i860 this dark 

 space was lit up for a short time by 

 the blazing out here of a temporary 

 star. At the point X a far easier clus- 

 ter will be found, very easily visible 

 in a pair of opera glasses, and even to 

 the naked eye. It first appears as a 

 small bright patch in the edge of the 

 Milky Way, but is easily seen to be 

 made up of thousands of bright stars 

 crowded closely together. 



There are hundreds of objects of in- 

 terest which will be found during an 

 exploration of the broad path of the 

 Milky Way, from Perseus in the north 

 to Scorpio in the south. Only a very 

 few of the more striking ones can be 

 mentioned here, but the reader who is 

 interested may find many excellent lit- 

 tle guidebooks, not only to the region, 

 but to the entire face of the sky. If he 

 possesses a small telescope, he will find, 

 whatever its size, that there are books 

 especially prepared for his instrument 

 and the possession of at least one such 

 book will very greatly increase his en- 

 joyment of an exploration of the hea- 

 vens. 



The Planets In July. 



Mercury remains too near the sun 

 to be observed during July. 



By far the most brilliant planet of 

 the month is the beautiful Venus, 

 which continues its very rapid motion 

 toward the east, passing through Can- 

 cer and almost the entire length of Leo, 

 and mounting each evening perceptibly 

 higher in the western sky. On July 

 13 it will pass above the bright star, 

 Regulus, but as it will then be separat- 

 ed from this star by a distance equal to 

 three times the apparent diameter of 

 the moon, the star figure so formed 

 will not be so striking as if the ap- 

 proach were closer. 



In the telescope this bright evening 

 star is seen to be but little more than 

 half full ; the dark shading of its sur- 

 face as the boundary line between the 

 planet's day and night is approached 



and the twilight effect due to its dense 

 atmosphere are already becoming very 

 conspicuous. 



Mars is still quite high in the west, 

 but its distance from the earth is so 

 great that it is now an unsatisfactory 

 object in the telescope. On July 1 it 

 is a little way to the east of Regulus, 

 and, like Venus it is continually mov- 

 ing eastward, entering the western 

 borders of Virgo by the end of the 

 month. 



The observer will notice how very 

 rapidly the brilliant Venus is overtak- 

 ing the waning Mars. The brighter 

 world will pass to the east of Mars on 

 August 5 ; at this time the two planets 

 will present the appearance of an in- 

 teresting double star in the western 

 heavens and will form a beautiful fig- 

 ure for observation with a small teles- 

 cope 



Jupiter is a little w r ay due south from 

 the star at A, Figure 1, and is just be- 

 yond the borders of our evening star 

 map. After half past nine o'clock 

 throughout the night, however, it is a 

 conspicuous object in the southern sky. 



Uranus is also beyond the borders of 

 our map, almost in the center of the 

 constellation Capricornus. Saturn 

 and Neptune are both morning stars, 

 and are too near the sun to be well ob- 

 served during this month. 



On July 2 at 7 P.M. the earth is at 

 its greatest distance from the sun ; it 

 is then 3,100,000 miles farther away 

 than when in fanuarv these bodies 



:> 



•. 



Figure 3. A typical spiral nebula. Were 

 this seen edgewise, it would probably present 

 much the appearance shown in Figure 2. 



are nearest t o g e t h e r. On ac- 



count of this varying distance our 

 northern winters are slightly warmer 

 and also shorter than are the winters of 

 the southern hemisphere. It is natural 

 to seek in this fact an explanation of 



