EARTH’S FUTURE 
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EARTH’S FUTURE MIRROR’D ON FACE OF MARS 
By Prof. Georgf H. Hamilton 
Lowell Observatory, Flagstaf, Arizona 
Our knowledge of the Earth in its past, present and future 
states has been acquired through exploration and the interest such 
exploration has invoked in its devotees. At first glance “an ex¬ 
plorer” calls to mind one who travels the Earth’s surface and gives 
us knowledge of its topography; the boundaries of its seas and 
lands, its mountain ranges, valleys and plains, and the faunas and 
the floras found there. Exploration of this kind gives us knowl¬ 
edge of the Earth’s present. 
But what of Earth’s past ? Geology must answer that. 
To explore the Earth’s depths, and to find therein evidence of a 
gradual evolution of its crust, an upbuilding through the ages from 
the time of its first formation in the concrete to the present time, 
has a fascination all its own. ,The means at hand to do this, in 
themselves show an evolution from the primitive and increase the 
certainty that the Universe as a whole is bound by inexorable laws 
of cause and effect — omnia mutantur et nos mutamur in illis. 
The explorer became the geologist. Gazing on a mighty es¬ 
carpment and seeing the various strata thus exposed, with its folds 
and faults plainly in view, forced him to reason out the causes of 
such stratification and the probable time expired in their laying 
down. In general, erosion gives him only a superficial knowledge 
of the crust, but in the case of the Grand Canyon of Arizona 
thousands of feet of the surface have been worn away down to 
the primitive igneous rocks, giving us a history so old that man’s 
mind really fails to grasp it. 
And this is not all; there is evidence of erosion on a vast scale 
down to the present rim of the Canyon. Strata upon strata have 
vanished never to return again. This is known from remnants 
