Farther, it is of Importance to remark, that you ought at no time, neither in the extended, supple or equal Trot, to confine your Horse in the Hand in Expectation of raising him, and fixing his Head in a proper Place; if his Apuy be full in the Hand, and the Action of his Trot should be check'd and restrain'd by the Power of his Bridle, his Bars would very soon grow callous, and his Mouth be harden'd and dead; if, on the contrary, he has a fine and sensible Mouth, this very Restraint would offend and make him uneasy. You must endeavour then, as has already been said, to give him by degrees, and insensibly, a true and just Apuy, to place his Head, and form his Mouth, by Stops and Half-stops; by sometimes moderating and restraining him with a gentle and light Hand, and yielding it to him immediately again; and by sometimes letting him trot without feeling the Bridle at all.
There is a Difference between Horses who are heavy in the Hand, and such as endeavour to force it. The first Sort lean and throw all their Weight upon the Hand, either as they happen to be weak, or too heavy and clumsy in their Fore-parts, or from having their Mouths too fleshy and gross, and consequently dull and insensible. The second pull against the Hand, because their Bars are lean, hard, and generally round; and the first may be brought to go equal, and upon their Haunches, by means of the Trot and slow Gallop; and the other may be made light and active by Art, and by settling them well in their Trot, which will also give them Strength and Vigour. Horses of the first sort are generally sluggish, the other kind are for the most part impatient and disobedient, and upon that very account more dangerous and incorrigible.
The only Proof, or rather the most certain Sign of your Horse's trotting well, is, that when he is in his Trot, and you begin to press him a little, he offers to Gallop.
After having trotted your Horse sufficiently upon a strait Line, or directly forward, work him upon large Circles; but before you put him to this, walk him gently round the Circle, that he may comprehend and know the Ground he is to go over.—This being done, work him in the Trot; a Horse that is loaded before, and heavily made, will find more Pains and Difficulty in uniting his Strength, in order to be able to turn, than in going strait forward.—The Action of turning trys the Strength of his Reins, and employs his Memory and Attention, therefore let one Part of your Lessons be to trot them strait forward; finish them in the same Manner, observing that the Intervals between the Stops (which you should make very often) be long, or short, as you judge necessary: I say you should make frequent Stops, for they often serve as a Correction to Horses that abandon themselves, force the Hand, or bear too much upon it in their Trot.
There are some Horses who are supple in their Shoulders, but which nevertheless abandon themselves; this Fault is occasion'd by the Rider's having often held his Bridle-hand too tight and strict in working them upon large Circles: To remedy this, trot them upon one Line or Tread, and very large; stop them often, keeping back your Body and outward Leg, in order to make them bend and play their Haunches.
The principal Effects then of the Trot, are to make a Horse light and active, and to give him a just Apuy. In reality, in this Action he is always supported on one Side by one of his Fore-legs, and on the other by one of his Hind-legs: Now the fore and hind Parts being equally supported cross-wise, the Rider can't fail to supple and loosen his Limbs, and fix his Head; but if the Trot disposes and prepares the Spirits and Motions of a sinewy and active Horse for the justest Lessons, if it calls out and unfolds the Powers and Strength of the Animal, which before were buried and shut up, if I may use the Expression, in the Stiffness of his Joints and Limbs; if this first Exercise to which you put your Horse, is the Foundation of all the different Airs and Manages, it ought to be given in Proportion to the Strength and Vigour of the Horse.
To judge of this you must go farther than mere outward Appearances. A Horse may be but weak in the Loins, and yet execute any Air, and accompany it with Vigour, as long as his Strength is united and intire; but if he becomes disunited, by having been work'd beyond his Ability in the Trot, he will then falter in his Air, and perform it without Vigour and Grace.
There are also some Horses, who are very strong in the Loins, but who are weak in their Limbs; these are apt to retain themselves, they bend and sink in their Trot, and go as if they were afraid of hurting their Shoulders, their Legs or Feet. This Irresolution proceeds only from a natural Sense they have of their Weakness.—This kind of Horses should not be too much exercised in the Trot, nor have sharp Correction; their Shoulders, Legs, or Hocks would be weaken'd and injur'd; so that learning in a little Time to hang back, and abandon themselves on the Apuy, they would never be able to furnish any Air with Vigour and Justness.
Let every Lesson then be weigh'd; the only Method by which Success can be insured, is the Discretion you shall use, in giving them in proportion to the Strength of the Horse, and from your Sagacity in deciding upon what Air or Manage is most proper for him; to which you must be directed by observing which seems most suited to his Inclination and Capacity.
I finish this Chapter by describing the Manner of trotting a Colt, who has never been back'd. Put a plain Snaffle in his Mouth, fit a Caveson to his Nose, to the Ring of which you will tie a Longe of a reasonable Length; let a Groom hold this Longe, who having got at some Distance from the Colt, must stand still in the Middle of the Circle, which the Horse will make; let another follow him with a long Whip or Chambriere in his Hand.—The Colt being alarm'd, will be forced to go forward, and to turn within the Length of the Cord.—The Groom must hold it tight in his Hand, by this means he will draw in or towards the Center the Head of the Colt, and his Croupe will consequently be out of the Circle.—In working a young Horse after this Manner, don't press or hurry him, let him walk first, afterwards put him to the Trot; if you neglect this Method his Legs will be embarras'd, he will lean on one Side, and be more upon one Haunch than the other; the inner Fore-foot will strike against the outward, and the Pain which this will occasion, will drive him to seek some Means of Defence, and make him disobedient.