A stump grinding apparatus having a split cutting wheel includes several replaceable cutter blocks secured to the periphery of the wheel. The present invention also discloses methods of growing X-ray diffractable crystals of polypeptides comprising the active human Aurora 2 kinase catalytic domain. opposite ends of a carcass substantially equidistantly from the centerplane of the drum and substantially radially equidistant from, and substantially concentric about, the rotational axis of the drum. A method for inkjet printing also includes applying a coating solid to a medium to form a layer of the coating solid, in a solid form, having predetermined thickness, and applying ink to the medium. As for the compensation bulk, a LiCAF having a characteristic that *+\u03b1 becomes negative, n being the refractive index, T the temperature and \u03b1 the linear expansion rate, and a ratio of the optical length of the quartz crystal bulk to that of the compensation bulk being approximately set to |*+\u03b1|:3\xd710\u22126.