NEW WAYS OF MEASURING THE 

 SUN'S DISTANCE. 



IT is 'strange that the problem of determining the sun's dis- 

 tance, which for many ages was regarded as altogether 

 insoluble, and which even during later years had seemed 

 fairly solvable in but one or two ways, should be found, 

 on closer investigation, to admit of many methods of solu- 

 tion. If astronomers should only be as fortunate hereafter 

 in dealing with the problem of determining the distances of 

 the stars, as they have been with the question of the sun's 

 distance, we may hope for knowledge respecting the structure 

 of the universe such as even the Herschels despaired of our 

 ever gaining. Yet this problem of determining star-distances 

 does not seem more intractable, now, than the problem of 

 measuring the sun's distance appeared only two centuries 

 ago. If we rightly view the many methods devised for deal- 

 ing with the easier task, we must admit that the more difficult 

 which, by the way, is in reality infinitely the more inte- 

 resting cannot be regarded as so utterly hopeless as, with 

 our present methods and appliances, it appears to be. True, 

 we know only the distances of two or three stars, approxi- 

 mately, and have means of forming a vague opinion about the 

 distances of only a dozen others, or thereabouts, while at 

 distances now immeasurable lie six thousand stars visible to 

 the eye, and twenty millions within range of the telescope. 

 Yet, in Galileo's time, men might have argued similarly 

 against all hope of measuring the proportions of the solar 



