THE 



POPULAR SCIENCE 

 MONTHLY. 



MAY, 1879. 



THE ORIGIN OF WORLDS. 



Br Professor DANIEL VAUGHAN. 



IT is from the order of succession in Nature, and not from the ever- 

 lasting endurance of her works, that we may reasonably expect 

 the reign of perpetual activity in her wide domains. In the animal and 

 the vegetable kingdoms the ravages of decay and death are eternally 

 repaired by the birth of new representatives of life ; and the loss which 

 our continents undergo by occasional submergence is compensated by 

 the appearance of new lands above the waters. Even those stupen- 

 dous catastrophes involving planetary fate do not make an irreparable 

 loss in the vast array of celestial objects. The matter saved from such 

 mighty wrecks will again be available for useful ends ; the forces which 

 seem destroyed in the terrific convulsions only assume other forms to 

 participate in new movements and operations, and even the space-per- 

 vading medium, while dooming the present worlds to an end in the dis- 

 tant future, yet contributes much to bring others into being, and to 

 perpetuate the events and the wonders of our universe. A clew to 

 the manner in which such important purposes are achieved is to be 

 found on tracing the fate of planets or of satellites introduced into orbits 

 of the smallest size possible ; and these inquiries can be conducted with 

 the aid of mathematical principles which are almost wholly unavailable 

 in pursuing the details of the nebular hypothesis. 



In treating on the equilibrium figure of the earth supposed to be a 

 homogeneous fluid, Laplace has been much embarrassed on finding that, 

 if the rotation were so rapid as to reduce the length of the day to two 

 hours and twenty-five minutes, stability would cease to be possible, 

 though the equatorial gravity would be only partially neutralized by 

 centrifugal force. In solving analogous problems respecting the form 

 of satellites confined to very small orbits and distorted from a spherical 

 vol. xv. 1 



