24. ALTERNATE FREEZING AND THAWING. 
lengths of twelve feet, in the shape of the letter A. 
He finds they are quite as effective as tiles, and 
more easily placed in the drain. He put some 
down in 1848, and they are at present perfectly 
sound. My practice is to under-drain during the 
summer, then fal: plow and sub-soil, leaving the 
land in ridges during the winter. In the spring, 
when the ground is dry enough to work, surface 
plow, running the lifting sub-soil plow in the bot- 
tom of the furrow. ‘This latter operation, with the 
effects on the soil of the alternate freezing and 
thawing during the winter months, leaves the soil 
in fine mechanical condition. The land is then 
made ready for a root crop, usually potatoes, which 
are planted in the ordinary way, the rows wide 
enough apart to admit of horse implements. Before 
planting, I apply to the surface broadcast five or six 
hundred pounds of super-phosphate to the acre, and 
harrow it in, and put wood-ashes into the drill at 
the time of planting. The surface should be kept 
loose and free from weeds, by frequent disturbance 
of the surface soil with the horse-hoe. 
When the crop is harvested, the land will be in 
excellent condition for setting out trees, which may 
be done in the fall or the following spring, as cir- 
cumstances may dictate. 
Persons desirous of knowing more about under- 
