It is not found, however, that (barring contagious diseases) where their owners are good judges of condition, coach-horses are much subject to disease. After a hot summer, coach-horses are most liable to derangement; and the month of October is the worst in the year for them, in consequence of it being their moulting season. Coach-horses, indeed, are certain to sweat three days out of four, which keeps their blood pure, and renders almost unnecessary medicine, of which, in general, they have but a small portion--perhaps less than they should have. It is a mistake, however, that fleshy horses cannot go fast in harness; they are more powerful in draught than thin ones; and, having only themselves to carry, flesh does not injure their legs, as in riding. In a fast coach, then, a horse ought not to work more than four days without rest, as he becomes leg-weary, and wears out the sooner; and he becomes also too highly excited. A horse a mile, reckoning only one side of the ground, is about the proportion. Thus we may suppose that ten horses work the coach up and down a ten-mile stage, which gives eight at work, and two at rest. Every horse, then, rests the fourth day. In slow, heavy work, however, coach-horses will do their ground every day, barring accidents or illness. In slow work, the average duration of coaching stock may be from six to seven years, provided they are at first fresh, and firm on their legs. In fast work, their time may be from three to four years, or scarcely perhaps so much. Coach proprietors on a large scale should have a break for their young horses, previous to going into regular work. The practice of putting a young horse unaccustomed to harness into a coach laden with passengers is most reprehensible; and when injury is sustained by it, it should be visited by the severest penalties the law can inflict. HARNESS. In the manufacture of harness we have arrived at a degree of perfection, to which the invention of the patent shining leather has mainly contributed. A handsome horse well harnessed is a noble sight; yet in no country, except England, is the art of putting a horse into harness at all understood. If, however, our road horses were put to their coaches in the loose awkward fashion of the continental people, we could not travel at the rate we do. It is the command given over the coach-horse that enables us to do it.