Scientific Lectures. 51 



than 300 years' journey by steam at thirty miles an hour ; so 

 that if vou had started with Fernando Cortez, when he began 

 the conquest with Mexico, you would just have got at the sun 

 and had a comfortable residence established of about twenty-five 

 years, going with the velocity of steam all the while. And then to 

 perform the enormous circuit around this great luminary, to fly 

 around as we do every year ! Oh, how fast must we go ! I am not 

 speaking of some fiction of the east, but I am speaking of sober fact, 

 when I say we go eighteen miles every second we live. Yes, while 

 I deliberately say to you, " It moves, yes, it moves," we have gone 

 forty miles. Then the most remote planets are thirty times farther 

 off, and our nearest neighbor among the fixed stars is 7,000 times 

 that. When we come to distances as great as that, we need another 

 unit with which to measm-e them. A mile is srood for nothing in 

 measuring such enormous distances, and, therefore, to illustrate, we 

 must make use of the velocity of light, which I spoke of in the 

 beginning of the lecture. Light travels in a single second 250 times 

 as far as a locomotive would go in a day, and when I tell you that, 

 what I just said is proved. Kow, this being so, remember it, and 

 remember that it would take eight and three-quarter months to travel 

 with the velocity of light from here to the sun, and it does when the 

 sun's light reaches you, and then from our nearest neighbor among 

 the fixed stars, the time occupied at that prodigious rate is three and 

 one quarter years, and other well known stars are thirty, forty, seventy, 

 and more than 100 years distant by the velocity of light, and that 

 the outer parts of the system we see with our bare eye are at least 

 ten times as far off as that. "With the large reflecting telescope, 

 I cannot stop to describe it, of Sir William Herschel, we have 

 gone seventy-five times that again, and that far beyond there seemed 

 to be cloudy looking spots, which might be removed TOO times as far 

 ofl'; there are yet stars like those we see. I have tried to tell you 

 where the fixed stars are. Now, what are they ? Do they shine to 

 us by reflected light? If they shine by reflected light, where, oh, 

 where are the far more enormous bodies that illuminate them, and 

 why don't we see them ? But, what is more, the light of some of 

 them has been measured in a reasonable way, and one of them seems 

 to be as bright as at least 100 suns, or, as some of the results say, 225 

 suns. Therefore, if you will not call them suns, please invent some 

 grander, nobler term by which to describe them. A light exceeding 

 the brightness of the sun is the last figure we can make use of, almost, 



