The Earth's three Emeloxjes. 109 



currents in the ocean and in great rivers, but it is forever 

 moving vertically. In some portions of the earth 20 inches of 

 water are evaporated every year, and in other portions 120 

 inches, and the envelope of water, varying from 20 to 120 inches 

 in thickness, is lifted into the heavens and descends again as 

 rain every year. 



There is a third envelope of the earth, which is in the same 

 manner in motion : Modern geography is no longer engaged 

 simply in the study of the position of geographical localities, no 

 longer engaged solely in measuring the depths of the 'seas and 

 the heights of the mountains, no longer engaged in simply de- 

 lineating the currents of the seas and the winds Avhich blow 

 about the earth, but modern geographic science has come to 

 study the origin of the land areas and the reason why the rivers 

 run Avhere they do and why the waters circulate as they do, 

 and it is especially throwing vast light in modern times, in the 

 last decade or two, on the origin of land forms ; it is classify- 

 ing vallej^s, it is classifying plateaus, it is classifying mountains 

 and hills and explaining their origin, it is classifying islands. 

 This study of physiography, this new branch of the study of 

 geography, is being cultivated in many lands, and it has dis- 

 covered that there is an envelope of rock moving horizontally 

 with the waters as the rivers wash the hills and valleys and 

 mountains, and moving vertically by upheaval from beneath 

 and by the pouring out of volcanic lavas from below ; so that 

 the three movable envelopes of the earth, the air, the water 

 and the geologic formations of the rocky envelope, are forever in 

 motion, and the laws of these motions are being studied. It is 

 thus that a new theme is being introduced into the study of our 

 schools; and the reason that geographj^ is in this Conference 

 allied with education is that these new facts, new laws, new 

 principles of this systematic knowledge in relation to the earth, 

 are to be introduced into our schools ; and it forms a theme of 

 Avonderful interest. 



Colonel Francis W. Parker, principal of the Cook County 

 Normal School, read a paper entitled " The Relation of Geog- 

 raphy to History." It is printed on later pages. 



Captain Magnus Andersen, of the ship VlJcing, delivered an 

 address on " Norway and the Vikings." This address also Avill 

 be found on later pages. 



At 1 p m the session Avas adjourned ft>r tAvo hours. 



