on's cultivator is shown at f.
Wilkie's horse-hoe and drill-harrow g (Scotland, 1820) has a central fixed share and adjustable side shares, which are expanded or contracted according to the state of the crop or the width of the balk.
Following the shares is a frame with harrow-teeth.
Either the share or the harrow-teeth may be removed, and the remainder used separately.
The depth is adjusted by the caster-wheel in front.
h shows another form, somewhat modified.
In Fig. 1545, a is Colman's cultivator, and that below it is known as a skim-cultivator, with a long, curved, flat share, whose depth is regulated by a crank and screw.
Fig. 1546 shows one American form of cultivator, in which the plows are managed by levers in driving and riding, and by the handles when walking behind the machine.
The plow-beams are gimbaljointed to standards depending from the axle, and have vertical and lateral movement by two handlevers.
Fig. 1547 shows a f