SQUARING THE CIRCLE 19 



the giant must make. He will not succeed, unless his 

 microscopes be much better for his size than ours are for 

 ours." 



It would of course be impossible for any human mind to 

 grasp the range of such an illustration as that just given. 

 At the same time these illustrations do serve in some 

 measure to give us an impression, if not an idea, of the 

 vastness on the one hand and the minuteness on the other 

 of the measurements with which we are dealing. I there- 

 fore offer no apology for giving another example of the 

 nearness to absolute accuracy with which the circle has 

 been "squared." 



It is common knowledge that light travels with a ve- 

 locity of about 185,000 miles per second. In other words, 

 light would go completely round the earth in a little more 

 than one-eighth of a second, or, as Herschel puts it, in less 

 time than it would take a swift runner to make a single 

 stride. Taking this distance of 185,000 miles per second 

 as our unit of measurement, let us apply it as follows : 



It is generally believed that our solar system is but an 

 individual unit in a stellar system which may include hun- 

 dreds of thousands of suns like our own, with all their 

 attendant planets and moons. This stellar system again 

 may be to some higher system what our solar system is to 

 our own stellar system, and there may be several such 

 gradations of systems, all going to form one complete whole 

 which, for want of a better name, I shall call a universe. 

 Now' this universe, complete in itself, may be finite and 

 separated from all other systems of a similar kind by an 

 empty space, across which even gravitation cannot exert its 

 influence. Let us suppose that the imaginary boundary of 

 this great universe is a perfect circle, the extent of which 



