50 We Never See the Stars. 



order to be seen at all, is 108 times as big as our earth j* its 

 diameter is 35,000 miles, that of the earth being 7912 miles. 



Under ordinary circumstances we do not, without magnify- 

 ing them, see the real discs of the great planets, otherwise we 

 should need no telescope to teach us that Yenus goes through 

 phases like the nioon.f When Yenus is favourably situated 

 she is a highly lustrous body, that looks the same shape as 

 Jupiter, but if the telescope be directed to both, one shows a 

 round face, and the other may appear as a thin crescent of 

 most glorious light. Although the planets are too far off to 

 exhibit real discs to the naked eye, still their being so near in 

 proportion to their size is one reason why they shine with a 

 steadier light, and do not twinkle like the stars. Humboldt 

 and others thought that when light, from one portion of their 

 discs, was for a moment intercepted and then permitted to 

 pass through the air, they did not nicker like stars, because 

 light from other portions of their discs filled up the vacancy 

 that was occasioned, and kept their lustre steadily in view. 

 This cannot be the entire reason of stellar scintillation, as some 

 stars do it much more than others j but whatever action such 

 discs may have, it must lessen, and finally vanish as their 

 distance is increased ; and we must not forget that Neptune, 

 the remotest known member of our system, although 

 2,864,000,000 miles from the sun, is near him, and near us, 

 when compared with the nearest of the stars. 



Spectrum analysis bids fair to teach us what the stars are 

 made of, and we may learn more and more of their wondrous 

 ways. Still we may never behold their faces, nor our descendants 

 after us, to the end of time. We place, however, no limits to 

 the future possibilities of science, but the present generation 

 of men, and their long posterity after them, may be compelled to 

 wait for immortal vision before they will really see the stars. 



* The dimensions and distance of Neptune, and other planets, will have to be 

 revised, to meet the present views of the size and distance of the sun, but this will 

 make no difference in tho argument. 



t This remark is generally true. Had it been otherwise it would not have 

 been necessary to wait for Galileo with his telescope, in order to learn the fact that 

 Venus exhibits phases like the moon. Mr. Webb, in his excellent work, Celestial 

 Object* for Common Telescopes, snys, speaking of Venus when near the 

 earth and exhibiting a sharp and thin form : — "This crescent has been seen even 

 with tho naked eye in the sky of Chili, and with a dark glass in Persia." Difli- 

 cult objects become more visible when the mind knows exactly what the eye ought 

 to see, and tho eye is practised in looking for it. An easy experiment will 

 illustrate this. Let any one not accustomed to it, look for e Lyra?, which to tho 

 naked eye lies close to Vega. The first night of the attempt, tho small star may 

 not be distinguished, afterwards it will become plainer, and if it is looked at fifty 

 <m one hundred times in the course of a month or two, it will seem to have moved 

 further oil', and the observer will wonder why tho separation did not strike him at 

 first. A .similar apparent increase of distance takes place by continued observa- 

 tion of close double Btare through a telescope 



