tend to compact the soil more than the other types and are therefore
better adapted to loose soils and to finishing off after the work of
the deep cutting harrows. They are also used for covering seeds.

[Illustration: FIG. 56.--SPIKE-TOOTHED HARROWS.]

[Illustration: FIG. 57.--A COULTER-TOOTHED HARROW.]

[Illustration: FIG. 58.--A PLANK HARROW.]

_Coulter-toothed harrows._ The coulter-toothed harrows (Fig. 57) have
teeth resembling the coulter of a plow twisted or bent into various
shapes. The Acme is a good example of this class of harrow. It cuts,
turns and pulverizes the surface soil somewhat after the manner of the
plow. It prepares a fine mulch and leaves an excellent seed bed. It
is an excellent harrow to finish off with after using a rolling
cutter.

_Chain harrows._ The chain harrow consists of a web of chains linked
together. They have a wonderful power for breaking clods and are
useful for collecting weeds. They shake the dirt from the weeds and
roll them into heaps. Chain harrows tend to compact the soil.

_Brush harrows._ The brush harrow is a primitive form made by
fastening brush to a long pole. Brush harrows are quite useful for
brushing in seed and for pulverizing manure broadcasted on grass
lands.

_Plank harrows._ The plank harrow (see Fig. 58) is made of several
planks fastened together so that each plank overlaps the next one to