CULTIVATOR  ,' also called SCUFFLER, SCARIFIER Or GRUBBER, an agricultural

implement employed in breaking up land or in stirring it after ploughing . The first all-iron cultivator, known as 'Finlayson's grubber, was a large harrow with curved teeth carried on wheels, and was brought out about 1820 . It was designed to meet the need for some implement of intermediate character between the plough and harrow, which should stir the soil deeply and expeditiously without reversing it, and bring the weeds unbroken to the surface . The chief modern improvement has been the imparting of vibratory movement and hence greater stirring capacity to the tines, either by making them of spring steel or by fitting springs to the point of attachment of the tine to the framework of the machine . In its modern form the implement consists of a framework fitted with rows of curved stems or tines, which may be raised clear of the ground or lowered into work by means of a lever, and differs from the harrow in that it is provided with two wheels, which prevent the tines from embedding themselves too deeply in the soil . The stems may be fitted either with chisel-points or with broad shares, according as it is required to merely stir the soil or to bring up weeds and clean the surface . In the disk cultivator revolving disks take the place of tines . The implement is usually provided with a seat for the driver and is drawn by horses, but steam power is also commonly applied to it, the speed of the operation in that case increasing its effectiveness . The method is the same as that of steam-ploughing (see PLOUGH) .