The Arabian Nights Entertainments, vol 4

e. But when he found that the horse still rose with the same swiftness, his alarm was great. He turned the peg several times, one way and the other, but all in vain. It was then he grew sensible of his fault, in not having learnt the necessary precautions to guide the horse before he mounted. He immediately apprehended the great danger he was in, but that apprehension did not deprive him of his reason. He examined the horse's head and neck with attention, and perceived behind the right ear another peg, smaller than the other. He turned that peg, and presently perceived that he descended in the same oblique manner as he had mounted, but not so swiftly.

Night had overshadowed that part of the earth over which the prince was when he found out and turned the small peg; and as the horse descended, he by degrees lost sight of the sun, till it grew quite dark; insomuch that, instead of choosing what place he would go to, he was forced to let the bridle lie upon the horse's neck, and wait patiently till he ali