RIDING-SCHOOL—is a convenient receptacle, with every accommodation for riding in the winter season, and where the young of both sexes are taught to ride by proper masters. Of these there are many in the Metropolis of much celebrity; among the most eminent are CAPTAIN CARTER'S, near Grosvernor Square; MR. COWLING'S, Moorfields; MR. JONES'S, Royal Circus; MR. ASTLEY'S Amphitheatre, Westminster Bridge; MR. HALL'S, Piccadilly; and MR. DAVIS'S, in Edgware Road; at most of which horses are completely broke and bitted for purposes of every denomination. RIG.—A horse is so called upon whom the operation of CASTRATION has been ill performed; by leaving one of the TESTES, or so much of the EPIDIDYMIS, behind, as enables him to become exceedingly teazing and troublesome to mares, either in the field or stable. There have been instances of COLTS having been cut by ignorant and illiterate operators, who, by letting one of the testes recede during the process, it has remained, and the horse then retains the power of propagating; many such having been known to get FOALS. RING-BONE—is an ossified enlargement upon the pastern, originating in a ligamentary twist, and consequent protrusion, at the junction of the pastern with the coronary-bone; it forms a callous substance soon after the injury, and ossifies in a very short time. Some horses do moderate work without much seeming inconvenience; others become lame, and frequently continue so, in opposition to every endeavour at alleviation or cure. A ring-bone seldom submits to either the strongest REPELLENTS, SOLVENTS, or BLISTERING. The best method to avoid disappointment in waiting the effect of either, is to FIRE the part in the form of _a star_, so soon as the protrusion (or prominence) is at first perceived. ROAN.—A horse is called a roan in colour, when his coat seems to be formed of the mixed combination of sorrel and white hairs in nearly an equal proportion. Horses of this description are, in general, of no great attraction, although they may prove equal in execution with others of every colour: the prevalence of opinion, however, is, that they are weaker in constitution, less likely to work, and more subject to disease.