mRACTICAL ARBORICULTURE 



157 



WHY HAVE FORESTS DISAPPEARED IN COLORADO AND 

 OTHER SEMI-ARID STATES? 



Neither science nor physics, as construed by modern philosophy, explains 

 the contrary conditions existing in the Orient to-day with that of B. C. 1000, 

 or even A. D. 100. No more do they interpret the causes of America's arid 

 belt or its encroachment upon the fertile country. 



Meteorology details the thermal changes of the atmosphere and their in- 

 fluences upon air currents, moisture and precipitation, but meteorology does 

 not explain why a country which once produced such massive trees should 

 now be so barren, or why a province that once had abundant rains should be 

 so arid. 



Mathematics has no data upon which to predict a theorem and is thus 

 unable to enlighten us when this change occurred. 



Geology makes mention of fossils and petrifactions which are found in 

 various parts of the earth, and in different geological periods. It presumes 



: 

 . 



IN PETRIFIED FORESTS 



that indefinite ages have elapsed since certain changes occurred, but geology 

 does not explain why these trees once thrived in a region which will produce 

 them no more. 







Botany gives the distribution of plants upon the globe, relates with minute- 

 ness those plants which exist in an arid climate, yet botany has never at- 

 tempted to explain why the sequoia grows upon the highest Sierras and 

 nowhere else in the world, while undoubtedly it did thrive in the Rocky 

 Mountains in former times. 



There is no rule of science which can satisfactorily account for the 

 change which has taken place in climate since these trees grew. Nor yet 

 how long since the change occurred. 



Speculation fails to elucidate the problem and only tells us that the 

 Sierra Nevada Mountains squeeze the moisture out of the passing clouds 

 before they reach the desert. Was it always so? Was this natural law in 

 force when the mighty cedars and sequoias were growing in the Rocky Moun- 

 tains? 1 



