32 THE SIDE HEAL UNIVERSE. 



Not only have the relative distances of various portions of 

 this grand cluster been proximately determined, but the spaces 

 beyond have been sounded. The process by which these re- 

 sults have been accomplished, may be easily brought within 

 the reader's comprehension by the following illustrations: 

 Suppose any given object is removed from a point of observa- 

 tion to a distance at which it is barely discernible by the 

 naked eye. Now, a telescope which has the power of pene- 

 trating space to ten times the distance that can be reached 

 with the naked eye, would show that same object, with the 

 same degree of distinctness, ten times as far off. Take, then, 

 a telescope of twenty degrees of space-penetrating power, and 

 remove the object twenty times its first distance, and it will 

 still be seen with equal distinctness and apparent nearness. 

 And so also of still larger telescopes and correspondingly 

 farther distances. 



Now, when we gaze into the heavens on a clear night, with 

 the naked eye, we observe, in any given portion of the Milky 

 Way a distinct number of stars, the faintest of which are 

 barely discernible. If the astronomer, then, takes a telescope 

 of ten powers, as compared with the unassisted eye, and sur- 

 veys the same field, all the stars before observed will appear 

 with increased brilliancy, besides which many more will be 

 visible, the remotest and faintest of which may be presumed 

 to be ten times as far off as the farthest ones which previously 

 appeared. He then takes a still larger telescope, and still 

 more objects appear, the remotest of which may, in like man- 

 ner, be presumed to be situated in a relative depth of space 

 proportioned to the increased degree of telescopic power. So 

 correspondingly of a larger, and still larger, instrument, until 

 one is obtained which reveals no more stars, but only shows 

 those in the same field of view, in increased brightness. The 



