TABLES 660-668.— ABUNDANCE OF ELEMENTS 



625 



TABLE 660.— ELEMENTAL ABUNDANCES IN THE UNIVERSE *" 



(Atoms per 10,000 atoms of Si *) 



204 Brown and Harrison, Rev. Mod. Phys., vol. 21, p. 625, 1949. 



* Silicon is 12.3 percent by weight in meteorites. t The hydrogen-helium ratio and the ratio of hydrogen 



and helium to the "oxygen group" elements (C, N, O, Ne, Fe) are those computed by J. Greenstein and reported 

 by M. Harrison, Astrophys. Journ., vol. 108, p. 310, 1940. t See Table 663. § Stellar and meteoritic 



values have been combined by equalizing the calcium abundances. || The letters S, P, Sc, Pe, and M desig- 



nate the sources chosen (solar, planetary nebulae, T-Scorpii, y Pegasi, or meteoritic). 



TABLE 661.— ABUNDANCE OF ELEMENTS IN OUR PLANET GIVEN IN 

 PERCENTAGE BY WEIGHT* 



* This table was selected from several sources including the report by Brown (see footnote 204) and 

 data furnished by Ingerson of the U. S. Geological Survey. t The lithosphere, 10 miles of earth 



crust, makes up 93 percent, the hydrosphere makes up 7 percent, and the atmosphere makes up 0.03 

 percent of the part of the earth considered. Proc. Nat. Acad. Sci., vol. 8, p. 114, 1922. 



SMITHSONIAN PHYSICAL TABLES 



