References in classic literature ?
The cook appeared, noiseless as a black shadow, collected a mass of backbones and heads, and retreated.
From this high backbone of earth, to the north, across the diminishing, down-falling ranges, we caught a glimpse of a far lake.
In addition to the stiffening afforded his backbone by the conscious ownership of eleven millions, he possessed an enormous certitude.
As you all know, by the looking, never have I sprouted one fin out of my backbone.
No man with half the backbone of a man would take it out of the harmless creatures.
At three in the morning the backbone of the hurricane broke.
To keep up the circulation, I ran around the island a dozen times or so, and clambered across its rocky backbone as many times more-- all of which was of greater service to me, as I afterward discovered, than merely to warm me up.
There lay a vast territory, and in that territory were the hugest deposits in the world of iron and coal--the backbone of industrial civilization.
 A certain firmness -- mostly you're [sic] backbone.
So is the backbone of his horse,' quoth the prince.
The Appeal paid union wages; and, in fact, was the backbone of the town, giving employment to hundreds of men and women.
Peter Winn, Senior, scanning the heavens with powerful glasses, saw the monoplane leap into view and grow large over the rugged backbone of Angel Island.