THE NOBILITY OF KNOWLEDGE, 619 



The occasion of this outburst of fanaticism was the approaching 

 publication of a work in which he had dared to question the received 

 opinions of theologians and schoolmen, in regard to cosmogony. He 

 had, forsooth, denied that the visible firmament was a solid azure- 

 colored shell, to which the sun and planets were fastened, and through 

 whose opened doors the rain descended. He had proved that the sun 

 was the centre of the system, around which the earth and planets 

 revolved, and, with his clear scientific vision, he had been able to 

 gain glimpses, at least, of the grand conceptions of modern astron- 

 omy : For this man was Nicolas Copernicus, and the expected book 

 was his great work — " De Orbium Coelestium Revolutionibus " — des- 

 tined to form the broad basis of astronomical science* The work was 

 printing at Nuremberg, and the last proofs had been returned ; but 

 reports had come that a similar outburst of fanaticism was raging at 

 that place, that a mob had burnt the manuscript on the public square, 

 and had threatened to break the press should the printing proceed. 

 But, thanks to God ! the old man was not to die before the hour of 

 triumph came. While still conscious, a horse, covered with foam, gal- 

 lops to the door of his humble dwelling, and an armed messenger 

 enters the chamber, who, breathless with haste, places in the hands of 

 the dying man a volume still wet from the press. He has only strength 

 to return a smile of recognition, and murmur the last words : 



" Nunc dimittis servum tuum, Domine." 



Grand close of a noble life ! The seed has been sown — what could we 

 desire more? 



Again the centuries roll on — not one, but three ; while the seed 

 grows to a great tree, which overshadows the nations. Great minds 

 have never been wanting to cherish and prune it, like Tycho Brahe 

 and Kepler, Galileo and Newton, Laplace and Lagrange ; and 

 although at times some, while lingering in the deep shade of the 

 foliage, may have lost sight of the summit, the noble tree has ever 

 pointed upward to direct aspiration and encourage hope. 



On the evening of the 24th of September, 1846, in the Observatory 

 of Berlin, a trained astronomical observer was carefully measuring 

 the position of a faint star in the constellation Capricorn. Only the 

 day before, he had received from Le Yerrier a letter announcing the 

 result of that remarkable investigation which has made the name of 

 this distinguished French astronomer so justly celebrated. By the 

 studies of the great men who succeeded Copernicus, his system had 

 become so perfected as to enable the astronomer to predict, with un- 

 erring certainty, the paths of the planets through the heavens. But 

 there was one failing case. 



The planet Uranus, then supposed to be the outer planet of the 

 solar system, wandered from the path which theory assigned to it ; 

 and although the deviations were but small, yet any discrepancy be- 



