544 



SCIENTIFIC RECREATIONS. 



Fig. 609. Oi ion. 



ORION, as we have said, can be viewed from either hemisphere, and so 



can some others; but those marked with 

 an asterisk in the foregoing list are not 

 visible in the latitude of London. 



Orion is a very brilliant constellation, 

 and contains two fine stars of the first ma^;- 



o 



nitude, and some of the second. The 

 former are Betelgeux and Rigel. Bellatrix 

 is the third in order. The " belt " is formed 

 of three bright stars, and the sword is visible 

 as five stars just below. Canis Major 

 possesses Sirius, a very fine star (the dog 

 star). Canis Minor has two of the first and 

 second magnitude, and Hydra has one of 

 the first. The Southern Cross is a beautiful 



constellation, invisible in our latitude, but familiar to sailors in the Southern 



Seas. 



THE STARS' DISTANCE AND MAGNITUDE. 



When we gaze up into the sky at night, we see the stars twinkling far 

 away, and we may remark here that this twinkling of the 

 stars is due to the atmosphere and the changes in its 

 power of refraction, and of course the star's light changes 

 its direction. But if we ascend in a balloon into very 

 high and rarefied strata of -the air, we will find the twink- 

 ling less. We have given the number of the stars accord- 

 ing to Flamstead, but the larger the telescope the greater 

 will be the number of stars we shall see, numbers again 



even for our perfected instruments. 



But we can gain some idea of the mag- 

 nitude of the stars when we consider the dis- 

 tance to arrive at, which is a most difficult task, 

 for figures seem scarcely long enough to count 

 the millions of miles, and no instrument can de- 

 tect the parallax. Even supposing the parallax 

 to be a very small fraction of a degree we should 

 get a result equalling trillions of miles. No. 6 1 

 in Cygni was at one time continually observed 

 by Professor Bessel, and he found that its distance 

 and it is the nearest star is sixty-two and a 

 half trillions of miles. 



Let us consider what this means, Light 

 comes to us from the sun (91,000,000 of 

 minutes, and travels at the rate of something 

 a second. But even at that astounding rate 



Fig. 610. Polaris. 



being too far 



Fiir. 6 1 1. The Southern Cros= 



miles) in about 

 like 186,000 miles 



eight 



in 



