MAKYI.AXD WEATHER SERVICE 325 



In the vicinity of Hagerstown there is an area of former swamp 

 or bog land too wet for ordinary crops, but of such a loose and 

 easily tilled character that some crops would do well in it if only 

 the right one could he found. A consideration of the region in 

 which some of the great celery farms are located showed the owner 

 thai this soil was suited to this crop, and the test of a trial crop was 

 made, since which celery has been a staple crop on that farm. 



In considering the relative fertility of different soils, it is difficult 

 to make statements of a positive character concerning the influence 

 of small variations in the composition or texture of the soils men- 

 tioned, or present in a given area; for the differences in the farm 

 practice of two neighboring farmers upon the same soil, are often 

 such as to produce as great difference in the year's returns as is 

 found between two at a greater distance from each other and on soils 

 differing materially in respect to the rock from which they have 

 been derived. Where the soils differ in the way mentioned in con- 

 nection with serpentine, and limestone, or certain shales and 

 gneisses, the differences of the. individual methods cannot make good 

 the absolute lack in the one case of the necessary elements to make 

 a soil, and provide food for the possible plant growth, or in the 

 other case, to so alter the texture as to make the soil produced by 

 weathering of the shale of a character more useful to plant activ- 

 ities and more retentive of moisture, except in a very slight degree. 

 Thus any statement as to relative fertility of the several sections of 

 the State are necessarily general averages, and serve to indicate 

 the general tendencies of the section, rather than the positive re- 

 sults of individuals. 



Trees and Soils. — In the slow processes of Nature, the gradual 

 weathering of shale into soil was fast enough to furnish support to 

 an extensive and valuable natural crop, the forest growth. But 

 with the substitution of human haste for deliberate Nature, there 

 comes a great change. The trees are removed, the steel plow loosens 

 and overturns the soil, corn is planted in the raw earth, and then 

 the rains come. The humus that had been accumulating for decades 

 by the gradual contributions from the trees, is now below the sur- 

 face, buried by the plow. Only raw soil is exposed to the rain, and 



