It's the _man_ refuses, not the poor horse.

Don't you know the ancient proverb 'Faint heart ne'er took fair jump'....?
What's the good of coming here if your heart's the size of your eye-ball instead of being the size of your fist?
_Refuse ?_ Put him over it, man.

_Put_ him over--SIT BACK and lift him, and _put_ him over.

I'll give you a thousand pounds if he refuses _me_...." Then the day when poor bullied, baited, nervous Muggins had reached his limit and come to the end of his tether--or thought he had.
Bumped, banged, bucketed, thrown, sore from head to foot, raw-kneed, laughed at, lashed by the Rough-Riding Sergeant-Major's cruel tongue, blind and sick with dust and pain and rage, he had at last turned his horse inward from his place in the ride to the centre of the School, and dismounted.
How quaintly the tyrant's jaw had dropped in sheer astonishment, and how his face had purpled with rage when he realized that his eyes had not deceived him and that the worm had literally turned--without orders.
Indian, African, and Egyptian service, disappointment, and a bad wife had left Rough-Riding Sergeant-Major Blount with a dangerous temper.
Poor silly Muggins.

He had been Juggins indeed on that occasion, and, as the "ride" halted of its own accord in awed amazement, Dam had longed to tell him so and beg him to return to his place ere worse befell....
"I've 'ad enough, you bull-'eaded brute," shouted poor Muggins, leaving his horse and advancing menacingly upon his (incalculably) superior officer, "an' fer two damns I'd break yer b---- jaw, I would.
You ..." Even as the Rough-Riding Corporal and two other men were dragging the struggling, raving recruit to the door, _en route_ for the Guard-room, entered the great remote, dread Riding-Master himself.
"What's this ?" inquired Hon.