Proper harness and harnessing are of the first importance in driving horses, and no one should attempt to handle the reins, and especially those attached to spirited horses, without more or less intimate knowledge of the different parts of harness equipment, how these should be put on and fit, and even what should be done in repairing or replacing them in cases of emergency, when they are broken, and when other parts cannot be substituted. The necessity for this knowledge is sometimes made most unpleasantly evident, as when a careless groom or hostler prepares the way for an accident by improperly har nessing or putting-to a nervous or high-mettled horse, and the driver is not cognisant of the risk he incurs.
It is needless to state that for safety and efficiency, as well as durability, harness should be of good material and well made; while for comfort and convenience it should be as simple and light as may be compatible with strength and other requirements.
The chief parts of harness for single draught, whether light or heavy, fast or slow, are: for the body, collar and traces; pad or saddle, with tugs, to support the shafts; crupper to keep the pad in its place; breeching to assist in backing the carriage or prevent its running on to the horse in descending a hill; and if the horse be inclined to kick, a kicking strap.
In double harness the breeching is often dispensed with. For the head there is the bridle, which is composed of the headstall and bit or bits, to which are attached the reins, sometimes the bearing-rein, and the curb-chain.
The collar is a very important part of the harness, and is that which is usually put on first in the operation of harnessing. It consists of two portions, leather and metal; the first is the collar proper, composed mainly of leather stuffed with hair, straw, or some other appropriate material, and fitting around the neck, close to the shoulders; the other is the hames of metal, one lying on each side of the collar, both being joined by links at the bottom, with rings or terrets towards their upper part for the reins to pass through, and towards the middle an eye, or some other contrivance, for the attachment of the trace.
On the fitting of the collar and point of attachment of the traces the comfort of the horse and his efficiency in draught greatly depend; these points, therefore, should receive close attention. A collar too small presses upon the windpipe and causes distress to the horse, especially if the draught be heavy, and particularly if it be up-hill draught; while a collar too large interferes with the movement of the shoulders, has not a proper bearing, and has, consequently, a great tendency to bruise or chafe the shoulders. Speaking of heavy draught-horse collars, Reynolds remarks: "The collar, intended as it is to supply a cushion for the reception of shocks, and afford relief to pressure under heavy and continual draught, cannot well be too bulky nor too accurately adjusted. Great suffering is entailed, and horses are prone to become vicious and shy workers by being worked in collars too small, or unadapted to special conformation of shoulder, or rendered uncomfortable and irritating by wear or the accumulation of filth. Under severe up-hill draught, the collar will sometimes choke the horse by pressure upon the lower part of the windpipe. This accident usually happens to horses that have long sloping shoulders and fine withers; it may be prevented, or at least the liability may be diminished, by having the collar "piped " - that is, hollowed out at its lower end where it may come into opposition with the windpipe, as that tube enters the chest. It is prudent to work horses prone to choke by the collar in chains rather than shaft-gears."
The collar should so fit that, when the horse is pulling, the weight of the load should be distributed over the front of the shoulders, at their junction with the neck, leaving the windpipe entirely free, instead of bearing only on certain points, or playing injuriously up and down. The collar should be made to fit the neck and shoulders, for as these differ more or less in nearly every horse, so there can be no universally-fitting collar. And when fitting it, the horse should be put into draught at a good pace, as the shape of the neck and shoulders is then different to what it is when the horse is not in motion - so much so, indeed, that a collar which appears to fit well when the animal is standing still will often be found much too short when drawing at a trot.
The lining of the collar should be of some soft, smooth, non-absorbent substance; possibly the best is leather. This should be kept clean and free from dirt and the products of perspiration.
The collar is usually pushed over the head, the wider part uppermost, and turned on the narrowest portion of the neck. This manoeuvre many horses have a decided objection to, and especially when they have been frightened by it in their youth, or the coachman or groom are rough and violent. With such horses, a collar opening at the top is the best, and indeed for all horses it is the most easily put on, as the head is then not at all interfered with.
The point of attachment of the traces to the hames is also of some moment, as if too high or too low the horse draws at a disadvantage. Collar-makers who understand their business, understand the conformation of horses' necks and shoulders, and know where to attach the traces to the hames. Where they do not, even when the collar fits, if the traces are attached too low they will draw the collar away from the upper part of the shoulders. When this is found to be the case, the obvious remedy is to shift the point of 'draft' until an even bearing is obtained. Ignorant people adopt two remedies, one of which partly conceals, while the other aggravates instead of curing the error. The first is to curve the upper part of the collar backwards; this, if not carried to excess is harmless. The other is to lead a strap back from near the top of the collar to the trace buckle, which practically converts the front end of the trace into a fork whose points are attached to the hames, opposite to the two movable ends of the shoulder-blades; so that, in fact, the play of this bone is effectually checked at both ends alternately. The trace should be attached as nearly as possible opposite to the immovable part of the shoulder-blade: that is, to the centre of the bone, which is about an inch higher than the hame-rings or hooks of the majority of wholesale-made collars.