114 FROM NEBULA TO NEBULA 



rigidity, the universe it controls is at once fraught with 

 kaleidoscopic changes of infinite range, yet withal peren- 

 nially maintained in order. So must it ever continue, as 

 ever it has continued. 



If astronomy is to qualify to take a rightful place 

 among the so-called natural sciences, its devotees must 

 outgrow the ancient habit of viewing the firmament 

 through metaphysical glasses. The doctrine of conser- 

 vation of moment of momentum is quite as much a philo- 

 sophical abstraction as the Ptolemaic one that planets re- 

 volve in exact circles ; the dogma of the persistency of 

 planetary motions, as miraculistic as the parable of the 

 loaves and fishes; the .self -projection of celestial bodies, 

 as frankly contra-natural as Joshua's halting of the sun. 

 Thanks to Copernicus, Kepler, Galileo, and Newton, as- 

 tronomy has, indeed, escaped out of the umbra of medi- 

 evalism, but it is still whelmed in the penumbra that sees 

 only a fraction of the full truth. Astronomers of to-day, 

 unlike the ancient sages, no longer worship the inanimate 

 sun, moon and planets as so many gods and goddesses; 

 nor did Pope Pius on the last apparition of Halley's com- 

 et, in 1910, follow the superstitious example of his prede- 

 cessor, Pope Calixtus III, who, on the occasion of its ap- 

 pearance in 1456, ordered the bells in all the churches to 

 be rung and prayers to be said by everyone for the pur- 

 pose of exorcising the comet, which he and all his genera- 

 tion believed to be an evil spirit. In this connection it 

 may be illuminating to modern readers to scan the fol- 

 lowing passages from the pen of Sir David Brewster 

 (Memoirs of Newton, v. II, pp. 81 and 313), as giving an 

 insight into the extent of Newton 's own teleological views, 

 and particularly as showing that he was not oblivious to 

 the unbridged gaps in his cosmological theories: 



To make such a system with all its motions, required a cause 

 which understood and compared together the quantities of mat- 

 ter in the several bodies of sun and planets, and the gravitating 

 powers resulting from thence; the several distances of the primary 

 planets from the sun and of the secondary ones from Saturn, 

 Jupiter and the earth, and the velocities with which those planets 

 could revolve about those quantities of matter in those central 

 bodies ; and to compare and adjust all these things together in so 



