MOVEMEXTS AXD DEEORMATIOXS OF THE EARTH'S BODY. 563 



quinces, lead to the conclusion that cooling and shrinkage affected the 

 de^p wterior of the ea-th, for the higli central heat must have been con- 

 stantly passmg out toward the surface. Instead, therefore, of the con- 

 traction being concentrated in and limited to the outer 200 miles or so, 

 as under the preceding hypothesis, it was deeply distributed. The 



Pressures in 



Millions of 



Atmospheres. 



3.2 



3.0 



2.8 

 2.6 

 2.4 

 2.2 

 2.0 

 1.8 

 1.6 

 1.4 

 1.2 

 1.0 



o.s 



0.4 



0.2 



0.0 





 Center 



— 



l: 







































- 





b> 









































1 



^ 



X 









































X 



^. 









































^ 







































^^ 









































\ 



1^. 









































\ 



^<- 





































_t'>\l 







































^ 



^ 









































i 



\ 









































^ 



\ 









































^ 



\ 









































\ 



^ 









































s 



N 



^ 



^ 





































Temperatures in 



Dearees C. 



80000 



75000 

 70000 

 65000 

 60000 

 55000 

 50000 

 45000 

 40000 

 35000 

 30000 

 25000 

 20000 

 15000 

 10000 

 5000 

 

 Surface 



1.0 



3959 miles 



Fig. 451. — Diagram illustrating the internal temperatures of the earth u'hen it first 

 became sohd, imder the hypothesis that it solidified from the center outward, and 

 assuming that the f using-point rose directly as the pressure, in accordance T\ith Barus' 

 experiments ^\-ith diabase. The divisions of the base-line represent fractions of the 

 earth's radius. The di^■isious of the vertical lines represent pressures in atmospheres 

 at the left, and temperatures in degrees C. at the right. The lower curve, PC, repre- 

 sents the interior pressures, ranging from one atmosphere at the surface to 3,000,000 

 atmospheres at the center, derived from Laplace's law of density. The upper curve, 

 FC, represents the fusion-points of diabase at the various depths and pressures, and 

 hence the temperatures at which the interior would become solid at the various 

 depths, or, in other words, the initial temperatures of the solid earth. The lower 

 cur^-e is derived from Slichter; the upper is formed by directly plotting the 

 temperatures given by Barus (Am. Jour. Sci., 1893, p. 7). 



contraction "u^thin the outer zone would be less than under the preced- 

 ing view, because the flow of heat from withhi would partially offset 

 the flow outwards, and a correspondmg part of the contraction would 

 be distributed below. 



