TREE-I'ORM OUT OF ITS UNIT. 25 



lightning's flash. It is Man in combination who has done 

 these things. The present state of perfection to which 

 art and science have been carried is the necessary re- 

 sult of the labors, of our fathers who have preceded us. 

 The steam engine and electric telegraph are not the pro- 

 duct of the present, but of all ages. They are the work 

 of countless human generations; of beings frail and 

 perishable as summer leaves swept by autumnal winds 

 from the trees of the forest. It is thus that the noble 

 tree of science grows — ntjt the deadly Upas, dissemina- 

 ting everywhere poison and death, but the " Tree of Life," 

 whose "leaves are for the healing of the nations." 



We may also learn from the tree an impressive lesson 

 of our own frailty. Where are the leaves which built up 

 this massive and majestic tree, which carries in the inte- 

 rior of its stem the monumental history of its life, the im- 

 pression left by centuries of seasons ? And where are the 

 workmen who felled the forest and drained the swamps of 

 Pennsylvania, built her cities and railroads, and spread 

 over her hills and valleys so many scenes of rural industry, 

 peace, and progress ? This is the work of former generar- 

 tions, who have passed away like summer leaves from the 

 tree which they were engaged in constructing. "We now 

 supply their places, and carry on their labors. "We profit 

 by the industry and experience of those human genera- 

 tions which have preceded us. Each industrious man 

 works not only for himself, but for posterity. "We contri- 

 bute a little during the active periods of our life, to the ad- 

 vancement of the science and the civilization of society, 

 and then we pass away and are seen no more here, for- 

 ever. " "We all do fade as a leaf." 



