200 WARREN UPHAM; M.A., F.G.S.A., ON THE NEBULAR AND 



Planetesimal Hypothesis " ; but only a very brief abstract or 

 note of this address was published.* 



From the oral statements in this and other unpublished 

 addresses, Professor Herman L. Fairchild, Secretary of the 

 Geological Society of America, presented on January 1st, 1904, 

 at the sixteenth annual meeting of that society, an able 

 discussion of the geologic bearings of the new hypothesis.! 



The recent detailed publication of it, in Year Book No. 3 of 

 the Carnegie Institution, from which I have so largely quoted, has 

 no diagrams or other graphic illustrations ; but such desirable 

 aids for the more definite development of the subject, with 

 ample treatment of its relations to geology, are intended to be 

 published soon, in the second volume of a geological text-book 

 by Professors T. C. Chamberlin and E. I). Salisbury, whose 

 first volume of this work was issued early last year.! 



Chamberlin has contributed greatly to the establishment of 

 an acceptable nebular theory, consistent with the known 

 relations of the planets, their satellites, and the sun, by his 

 derivation of the solar system from a spiral nebula, and by his 

 indicating the probable mode of origin of such nebulae, which 

 abound by tens of thousands throughout the starry heavens, as 

 discovered by the most powerful telescopes. 



Both the meteoritic hypothesis of Lockyer and the 

 planetesimal hypothesis of Chamberlin seem to me probably 

 true in their regarding the nebulous matter from which planets 

 and suns are made as having become mostly solid, though finely 

 divided, and as very cold, being in almost absolutely cold and 

 immensely extended space, previous to the condensation and 

 segregation which formed it into worlds and stars. 



During the accumulation of the planets and their satellites, 

 much or perhaps nearly all of the nebulous matter forming 

 them had remained, until thus gathered as great bodies, 

 apparently in solid and cold molecules or in small masses 

 brought together by their gravitative attraction, as seems 

 reliably evidenced by the rings of Saturn and by the many 

 little asteroids. 



* Bulletin Geol. Soc. America, vol. xiv, p. 548, March, 1904 ; and Am. 

 Geologist, vol. xxxii, p. 14, July, 1903. 



t " Geology under the Planetesimal Hypothesis of Earth-Origin," 

 Bulletin Geol. Soc. America, vol. xv, pp. 243-266, published June 23, 

 1904 ; and Am. Geologist, vol. xxxiii, pp. 94-116, Feb., 1904. 



X Geology. In two volumes. Vol. I. Geologic Processes and their 

 Kesults, New York, Henry Holt and Co., 1904, pp. xix, 654. 



