92 * MASSACHUSETTS AGEICULTUEE. 



timbers of existing railroads requires the expenditure of $30,- 

 000,000 annually. More than $100,000,000 worth of sawed 

 timber is consumed yearly, while for fuel $75,000,000 worth 

 is burned every year, without mentioning the vast quantities 

 used for various other purposes. While this enormous de- 

 mand is constantly increasing our supply is decreasing, and it 

 needs not the eye of the prophet to behold in the near future 

 an exhausted supply and a denuded country, unless the people 

 arouse themselves for the protection of this most important crop. 



Trees were not made merely to furnish us fuel and timber, 

 fruit and shade, but for the influences they have upon the soil, 

 crops and climate. There is in the study of vegetable physi- 

 ology a broad field for investigation, through the intricate 

 labyrinths of which the diligent student of science may wander, 

 ever finding something new to excite his thirst for knowledge. 

 From the lowest shrub to the giant Sequoia^ there are influ- 

 ences at work upon the soil beneath and the air above us, the 

 silent workings of which we seldom notice. One of the hard- 

 est things for our people to learn is the climatic value of trees, 

 yet history and science teach us that they are most intimately 

 connected with the climate of all countries. The influence 

 which the forests exert on the humidity of the earth and air, 

 on temperature and precipitation is immense. Spread out 

 between the sky and earth, they prevent the rays of the sun 

 from reaching the ground and evaporating too rapidly the 

 water which falls. The humus ^ or vegetable mould formed 

 by the forests, is capable of absorbing almost twice its own 

 weight of water; thus they act as a sponge, and retaining a 

 large part of the rainfall, allow it to pass off gradually into 

 the brooks and rivers which water the surrounding country. 

 It is also observed by eminent investigators, that a greater 

 amount of rain falls in wooded than in cleared districts ; as the 

 lightning-rod abstracts the electric fluid from the stormy sky, 

 so the forest attracts to itself the rain from the clouds. They 

 also insure the permanence and regularity of natural springs 

 and the water-courses fed by them. 



Now let us notice the changes produced by the destruction 

 of the forest. Evaporation increases with great rapidity ; 

 the soil is no longer a sponge but a dust-heap, and the rain 

 which falls hurries over it, carrying vast quantities of earthy 



