THE PROOF OF THE EARTH'S MOTION 289 



could he detect any shift of position which he could regard as 

 certainly due to stellar parallax. His discovery of the cause 

 of aberration was announced in 1729. They did him due 

 honour, and made him Astronomer Royal. There, by the 

 minute precision and wide range of his observations, he laid the 

 foundations from which in after centuries the theory of the 

 universe will be builded, and of which some beginnings have 

 been made in our own time. He was the founder of modern 

 stellar astronomy ; but it was not until a century after him 

 that the invention of the heliometer made possible the dis- 

 covery which had been the real quest of his quiet, fruitful life. 



Meantime there were problems of nearer import to dwellers 

 within our little solar world. 



