118 NEW YORK STATE MUSEUM 



tissue. As the primeval temperature fell, the acid atmosphere 

 would react on the lava-like crust and where the temperature fell 

 below the boiling point of the acids which composed the atmos- 

 phere, the water of the globe would be highly charged with salts 

 resulting from the chemical action. With the continued fall of 

 temperature the chlorine and sulphur would be gradually removed 

 from the atmosphere until the composition of the latter became 

 similar to that of the present day, though containing more car- 

 bonic acid gas. 



This chapter in the earth's history has been so well translated 

 by the aid of chemical science that there is no reason to question 

 its accuracy, but we do not know in detail the history of the mas- 

 sive rocks and gneisses which are now the oldest formations 

 known. It also is probable that a long period of time elapsed be- 

 tween the formation of the primeval ocean and the dawn of life 

 therein. Science has not yet taught us how to measure the length 

 of this period or how to recognize the details of earth-building 

 which occurred in it. 



Present Condition of the Earth's Interior 



It has been found by observations taken in deep mines and 

 wells that in going toward the center of the earth, the tempera- 

 ture increases approximately at the ratio of 1 degree Fahrenheit 

 to 51 feet of depth.* At this rate, a temperature would prevail 

 at the depth of 50 miles at which all known substances would 

 be fused. On this basis rests the theory of a molten interior, 

 which is corroborated by various volcanic phenomena. All 

 through the historic period and through long geologic ages 

 before, volcanoes have poured out from subterranean sources 

 vast quantities of molten rock. Physicists who have inves- 

 tigated this matter claim that if the interior of the earth 

 were fluid, the crust would yield to the attraction of the 

 moon and that the phenomena of tides would occur within the 

 earth itself. It also appears that the great pressure on the in- 

 ternal mass must keep it in a condition of solidity. In this con- 

 nection it is pointed out that volcanic phenomena occur along 



* The extreme ratios are 1-^-40 and 1 ■— 80. 



