350 SEE— THE EULER-LAPLACE THEOREM. [Apni 24. 



outlined in his nebular hypothesis of 1796. He thus misled the 

 scientific world for more than a century, till the capture theory, 

 involving formation in the distance with subsequent approach to 

 their central masses, under the secular action of a resisting medium, 

 was developed by the present writer in 1908-10. 



It is equally well known that Laplace always held the comets 

 to be foreign to our system — another misleading doctrine in cos- 

 mogony, finally overthrown in 1910 by the independent researches 

 of Stromgren of Copenhagen, and the present writer, who showed 

 that the comets are surviving residues of the ancient nebula which 

 formed our solar system. 



In my "Researches," Vol. II., pp. 138-139, I have drawn atten- 

 tion to two letters from Euler to the Royal Society, pointing out, as 

 early as 1749, that the earth was once beyond the present orbit of 

 Saturn. He does not there discuss the secular decrease of the 

 eccentricity of the planetary orbits ; yet as he had grounds for hold- 

 ing to a secular approach to the central masses, he was the first 

 writer to outline sound views in cosmogony. 



Under the circumstances it appears appropriate that the theorem 

 on the secular decrease of the eccentricities of the orbits of bodies 

 moving in resisting media, should be known by the name of the 

 Euler-Laplace theorem. This recognizes the correct historical de- 

 velopment, as now made out ; and probably will always hold a 

 fundamental place in the science of celestial evolution. 



Mare Island, California^ 

 April 6, 19x5. 



