Abstract: A yttria sintered body is provided which includes yttria as a principal ingredient and 5 to 40 vol. % silicon nitride, and which exhibits enhanced corrosion resistance and mechanical strength.

Abstract: Hitch for securing a racing sulky to a harness or saddle of a horse. The hitch has an elongated, generally cylindrical body which includes a frustoconical tapered front portion, a generally cylindrical mid-portion and a cylindrical rear portion of slightly smaller diameter than that of the mid-portion so as to form a shoulder. The rear portion is adapted to be inserted into the open end of a tubular shaft, such as a shaft of a racing sulky. When so inserted, the hitch may be permanently secured to the shaft. The mid-portion of the hitch includes cylindrical front and rear end members which adjoin the front portion and the rear portion respectively of the hitch. The mid-portion of the hitch has one or more cutouts which define a longitudinally extending rigid strut and (when there is more than one such cutout) one or more transverse spacer discs, which are spaced from the end members and from each other. A rigid rod extends through the rear portion and the mid-portion of the hitch.