200 THE POPULAR SCIENCE MONTHLY. 



less than 3'. The star Beta (/3) is remarkably variable in brightness. 

 You may watch these variations, which run through a regular period 

 of about 12 days, 21f hours, for yourself. The star will be at its 

 minimum of brightness on June 7th and 20th ; July 3d, 15th, and 

 28th ; August 10th and 23d. Between Beta and Gamma (y) lies the 

 beautiful Ring nebula, but it is hopelessly beyond the reach of the 

 optical means we are employing. 



Let us turn next to the stars in the west. In consulting the ac- 

 companying map of Virgo and Bootes, the observer is supposed to 

 face the southwest, at the hours and dates mentioned above as those 

 to which the circular map corresponds. He will then see the bright 

 star Spica in Virgo not far above the horizon, while Arcturus will be 

 half-way up the sky, and the Northern Crown will be near the zenith. 

 The planet Jupiter will be close to Spica, and will completely out- 

 shine it. In fact, during the whole summer, this fine star will be to a 

 considerable extent robbed of its brilliance by the proximity of the 

 great planet. The reader may find it convenient to mark the place of 

 Jupiter on the map just to the left of Spica. 



The constellation Virgo is an interesting one in mythological story. 

 Aratus tells us that the Virgin's home was once on earth, where she 

 bore the name of Justice and in the golden age all men obeyed her. 

 In the silver age her visits to men became less frequent, " no longer 

 finding the spirits of former days " ; and, finally, when the brazen age 

 came with the clangor of war : 



"Justice, loathing that race of men, 

 Winged her flight to heaven ; and fixed 



Her station in that region 

 Where still by night is seen 

 The Virgin goddess near to bright Bootes." 



The chief star of Virgo, Spica, is remarkable for its pure white light. 

 To my eye there is no conspicuous star in the sky equal to it in this 

 respect, and it gains in beauty when viewed with a glass. With the 

 aid of the map the reader will find the celebrated binary star Gamma 

 (y) Virginis, although he will not be able to separate its components 

 without a telescope. It is a curious fact that the star Epsilon (c) in 

 Virgo has for many ages been known as the Grape-Gatherer. It has 

 borne this name in Greek, in Latin, in Persian, and in Arabic, the 

 origin of the appellation undoubtedly being that it was observed to rise 

 just before the sun in the season of the vintage. It will be observed 

 that the stars e, 8, y, -q, and (3, mark two sides of a quadrilateral figure 

 of which the opposite corner is indicated by Denebola in the tail of 

 Leo. AVithin this quadrilateral lies the marvelous Field of the Nebu- 

 la?, a region where with adequate optical power one may find hundreds 

 of these strange objects thronging together, a very storehouse of the 

 germs of suns and worlds. Unfortunately, these nebulae are far be- 



