MOUNTAIN TREES 



Did you ever stop to think of the 

 forces at work in the trunk and leaves 

 of one of these forest monarchs: what 

 energies are required to pump the sap to 

 the pinnacles of the high crowns, what 

 chemical agencies are ever at work in 

 the manufacture of food, what marvel- 

 ous adaptations are present for the con- 

 servation of moisture? The internal 

 pressure in cells of trees is so intense as 

 to seem almost incredible. Weiler, when 

 experimenting with Scotch fir, found 

 that in the young wood cells the pres- 

 sure was 240 pounds to the square inch. 

 Dixon found in the cells of certain 

 leaves a pressure of from 150 to 450 

 pounds to the square inch. As said by 

 G. Scott Elliot, "no locomotive engine 

 has cylinders strong enough to resist 

 such internal pressure as this." 



Plants have satisfactorily solved a 

 problem in support the solution of 

 which engineers have never found. A 

 chimney 50 feet high must have a diam- 

 eter at base of at least three feet, but a 



35 



