Rolling and Smoothing. 153 
tion. When circumstances will permit, the roller 
should be followed by a smoothing harrow, that the 
surface mulch may be restored and the moisture 
stopped before reaching the atmosphere. On clay 
lands the roller must be used with much caution. 
If used immediately after grain is sown and a heavy 
rain follows, there is danger of the soil becoming 
so compact on the surface that the tender shoots 
are unable to get through, and the most direct con- 
nection is established between the soil moisture and 
the air. A good method of treatment for clay is 
to roll before the seed is sown, then harrow and 
Fig. 15. A planker or float. 
make a good seed bed, and then drill in the grain. 
After the plants are well up the roller may be used 
again, which will bring the water to the surface, 
where the growing plants can make use of it before 
it passes off by evaporation. 
Various kinds of plankers or floats may be used 
in the place of the roller to smoothen and compact 
recently tilled lands. A good tool of this kind is 
shown in Fig. 15. “To make this cheap and easily- 
made adjunct to good cultivation, take two hard- 
wood planks, 2x8 inches and 7 feet long, and 
