276 HISTORY OF FORMAL ASTRONOMY. 



posed declarations of Scripture. Probably a good deal was done for 

 the establishment of those opinions by Thomas Salusbury, who was a 

 warm admirer of Galileo, and published, in 1661, a translation of 

 several of his works bearing upon this subject. The mathematicians 

 of this country, in the seventeenth century, as Napier and Briggs, 

 Horrox and Crabtree, Oughtred and Seth Ward, Wallis and Wren, 

 were probably all decided Copernicans. Kepler dedicates one of his 

 works to Napier, and Ward invented an approximate method of solv- 

 ing Kepler's problem, still known as " the simple elliptical hypothesis." 

 Horrox wrote, and wrote well, in defence of the Copernican opinion, 

 in his Keplerian Astronomy defended and promoted, composed (in 

 Latin) probably about 1635, but not published till 1673, the author 

 having died at the age of twenty-two, and his papers having been 

 lost. But Salusbury's work was calculated for another circle of 

 readers. " The book," he says in the introductory address, " being, 

 for subject and design, intended chiefly for gentlemen, I have been as 

 careless of using a studied pedantry in my style, as careful in con- 

 triving a pleasant and beautiful impression." In order, however, to 

 judge of the advantage under which the Copernican system now 

 came forward, we must consider the additional evidence for it which 

 was brought to light by Galileo's astronomical discoveries. 



Sect. 3. The Heliocentric Theory confirmed by Facts. Galileo's 

 Astronomical Discoveries. 



THE long interval which elapsed between the last great discoveries 

 made by the ancients and the first made by the moderns, had afforded 

 ample time for the development of all the important consequences of 

 the ancient doctrines. But when the human mind had been thor- 

 oughly roused again into activity, this was no longer the course of 

 events. Discoveries crowded on each other ; one wide field of specu- 

 lation was only just opened, when a richer promise tempted the labor- 

 ers away into another quarter. Hence the history of this period con- 

 tains the beginnings of many sciences, but exhibits none fully worked 

 out into a complete or final form. Thus the science of Statics, soon 

 after its revival, was eclipsed and overlaid by that of Dynamics ; and 

 the Copernican system, considered merely with reference to the views 

 of its author, was absorbed in the commanding interest of Physical 

 Astronomy. 



Still, advances were made which had an important bearing on the 



